Internet Engineering Task Force (IETF)                          M. Sweet
Request for Comments: 8011                                    Apple Inc.
Obsoletes: 2911, 3381, 3382                                  I. McDonald
Category: Standards Track                               High North, Inc.
ISSN: 2070-1721                                             January 2017


         Internet Printing Protocol/1.1: Model and Semantics

Abstract

  The Internet Printing Protocol (IPP) is an application-level protocol
  for distributed printing using Internet tools and technologies.  This
  document describes a simplified model consisting of abstract objects,
  attributes, and operations that is independent of encoding and
  transport.  The model consists of several objects, including Printers
  and Jobs.  Jobs optionally support multiple Documents.

  IPP semantics allow End Users and Operators to query Printer
  capabilities; submit Print Jobs; inquire about the status of Print
  Jobs and Printers; and cancel, hold, and release Print Jobs.  IPP
  semantics also allow Operators to pause and resume Jobs and Printers.

  Security, internationalization, and directory issues are also
  addressed by the model and semantics.  The IPP message encoding and
  transport are described in "Internet Printing Protocol/1.1: Encoding
  and Transport" (RFC 8010).

  This document obsoletes RFCs 2911, 3381, and 3382.

Status of This Memo

  This is an Internet Standards Track document.

  This document is a product of the Internet Engineering Task Force
  (IETF).  It represents the consensus of the IETF community.  It has
  received public review and has been approved for publication by the
  Internet Engineering Steering Group (IESG).  Further information on
  Internet Standards is available in Section 2 of RFC 7841.

  Information about the current status of this document, any errata,
  and how to provide feedback on it may be obtained at
  http://www.rfc-editor.org/info/rfc8011.








Sweet & McDonald             Standards Track                    [Page 1]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


Copyright Notice

  Copyright (c) 2017 IETF Trust and the persons identified as the
  document authors.  All rights reserved.

  This document is subject to BCP 78 and the IETF Trust's Legal
  Provisions Relating to IETF Documents
  (http://trustee.ietf.org/license-info) in effect on the date of
  publication of this document.  Please review these documents
  carefully, as they describe your rights and restrictions with respect
  to this document.  Code Components extracted from this document must
  include Simplified BSD License text as described in Section 4.e of
  the Trust Legal Provisions and are provided without warranty as
  described in the Simplified BSD License.





































Sweet & McDonald             Standards Track                    [Page 2]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


Table of Contents

  1. Introduction ....................................................9
     1.1. Simplified Printing Model .................................12
  2. Conventions Used in This Document ..............................15
     2.1. Requirements Language .....................................15
     2.2. Printing Terminology ......................................15
     2.3. Model Terminology .........................................16
          2.3.1. Administrator ......................................16
          2.3.2. Attributes .........................................16
                 2.3.2.1. Attribute Group Name ......................16
                 2.3.2.2. Attribute Name ............................16
                 2.3.2.3. Attribute Syntax ..........................16
                 2.3.2.4. Attribute Value ...........................17
          2.3.3. End User ...........................................17
          2.3.4. Impression .........................................17
          2.3.5. Input Page .........................................17
          2.3.6. Job Creation Operation .............................17
          2.3.7. Keyword ............................................17
          2.3.8. Media Sheet ........................................18
          2.3.9. Operator ...........................................18
          2.3.10. Set ...............................................18
          2.3.11. Support of Attributes .............................18
          2.3.12. Terminating State .................................21
     2.4. Abbreviations .............................................21
  3. IPP Objects ....................................................22
     3.1. Printer Object ............................................22
     3.2. Job Object ................................................25
     3.3. Object Relationships ......................................25
     3.4. Object Identity ...........................................26
  4. IPP Operations .................................................29
     4.1. Common Semantics ..........................................30
          4.1.1. Required Parameters ................................30
          4.1.2. Operation IDs and Request IDs ......................31
          4.1.3. Attributes .........................................31
          4.1.4. Character Set and Natural Language
                 Operation Attributes ...............................33
                 4.1.4.1. Request Operation Attributes ..............34
                 4.1.4.2. Response Operation Attributes .............38
          4.1.5. Operation Targets ..................................39
          4.1.6. Operation Response Status-Code Values and
                 Status Messages ....................................41
                 4.1.6.1. "status-code" (type2 enum) ................41
                 4.1.6.2. "status-message" (text(255)) ..............42
                 4.1.6.3. "detailed-status-message" (text(MAX)) .....43
                 4.1.6.4. "document-access-error" (text(MAX)) .......43





Sweet & McDonald             Standards Track                    [Page 3]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


          4.1.7. Unsupported Attributes .............................44
          4.1.8. Versions ...........................................45
          4.1.9. Job Creation Operations ............................48
     4.2. Printer Operations ........................................50
          4.2.1. Print-Job Operation ................................51
                 4.2.1.1. Print-Job Request .........................51
                 4.2.1.2. Print-Job Response ........................56
          4.2.2. Print-URI Operation ................................58
          4.2.3. Validate-Job Operation .............................59
          4.2.4. Create-Job Operation ...............................59
          4.2.5. Get-Printer-Attributes Operation ...................60
                 4.2.5.1. Get-Printer-Attributes Request ............61
                 4.2.5.2. Get-Printer-Attributes Response ...........63
          4.2.6. Get-Jobs Operation .................................64
                 4.2.6.1. Get-Jobs Request ..........................65
                 4.2.6.2. Get-Jobs Response .........................66
          4.2.7. Pause-Printer Operation ............................68
                 4.2.7.1. Pause-Printer Request .....................71
                 4.2.7.2. Pause-Printer Response ....................71
          4.2.8. Resume-Printer Operation ...........................72
          4.2.9. Purge-Jobs Operation ...............................73
     4.3. Job Operations ............................................73
          4.3.1. Send-Document Operation ............................74
                 4.3.1.1. Send-Document Request .....................75
                 4.3.1.2. Send-Document Response ....................77
          4.3.2. Send-URI Operation .................................78
          4.3.3. Cancel-Job Operation ...............................78
                 4.3.3.1. Cancel-Job Request ........................80
                 4.3.3.2. Cancel-Job Response .......................81
          4.3.4. Get-Job-Attributes Operation .......................81
                 4.3.4.1. Get-Job-Attributes Request ................82
                 4.3.4.2. Get-Job-Attributes Response ...............83
          4.3.5. Hold-Job Operation .................................84
                 4.3.5.1. Hold-Job Request ..........................86
                 4.3.5.2. Hold-Job Response .........................87
          4.3.6. Release-Job Operation ..............................87
          4.3.7. Restart-Job Operation ..............................89
                 4.3.7.1. Restart-Job Request .......................91
                 4.3.7.2. Restart-Job Response ......................92
  5. Object Attributes ..............................................92
     5.1. Attribute Syntaxes ........................................92
          5.1.1. Out-of-Band Values - 'unknown',
                 'unsupported', and 'no-value' ......................93
          5.1.2. 'text' .............................................93
                 5.1.2.1. 'textWithoutLanguage' .....................94
                 5.1.2.2. 'textWithLanguage' ........................94





Sweet & McDonald             Standards Track                    [Page 4]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


          5.1.3. 'name' .............................................95
                 5.1.3.1. 'nameWithoutLanguage' .....................96
                 5.1.3.2. 'nameWithLanguage' ........................96
                 5.1.3.3. Matching 'name' Attribute Values ..........97
          5.1.4. 'keyword' ..........................................98
          5.1.5. 'enum' .............................................99
          5.1.6. 'uri' .............................................100
          5.1.7. 'uriScheme' .......................................100
          5.1.8. 'charset' .........................................101
          5.1.9. 'naturalLanguage' .................................102
          5.1.10. 'mimeMediaType' ..................................102
                 5.1.10.1. 'application/octet-stream' -
                           Auto-Sensing the Document Format ........103
          5.1.11. 'octetString' ....................................104
          5.1.12. 'boolean' ........................................104
          5.1.13. 'integer' ........................................104
          5.1.14. 'rangeOfInteger' .................................105
          5.1.15. 'dateTime' .......................................105
          5.1.16. 'resolution' .....................................105
          5.1.17. 'collection' .....................................105
          5.1.18. '1setOf X' .......................................106
     5.2. Job Template Attributes ..................................106
          5.2.1. job-priority (integer(1:100)) .....................109
          5.2.2. job-hold-until (type2 keyword | name(MAX)) ........111
          5.2.3. job-sheets (type2 keyword | name(MAX)) ............112
          5.2.4. multiple-document-handling (type2 keyword) ........113
          5.2.5. copies (integer(1:MAX)) ...........................115
          5.2.6. finishings (1setOf type2 enum) ....................115
          5.2.7. page-ranges (1setOf rangeOfInteger(1:MAX)) ........118
          5.2.8. sides (type2 keyword) .............................119
          5.2.9. number-up (integer(1:MAX)) ........................120
          5.2.10. orientation-requested (type2 enum) ...............120
          5.2.11. media (type2 keyword | name(MAX)) ................123
          5.2.12. printer-resolution (resolution) ..................124
          5.2.13. print-quality (type2 enum) .......................124
     5.3. Job Description and Status Attributes ....................124
          5.3.1. job-id (integer(1:MAX)) ...........................126
          5.3.2. job-uri (uri) .....................................126
          5.3.3. job-printer-uri (uri) .............................127
          5.3.4. job-more-info (uri) ...............................127
          5.3.5. job-name (name(MAX)) ..............................127
          5.3.6. job-originating-user-name (name(MAX)) .............128
          5.3.7. job-state (type1 enum) ............................128
                 5.3.7.1. Forwarding Servers .......................132
                 5.3.7.2. Partitioning of Job States ...............132
          5.3.8. job-state-reasons (1setOf type2 keyword) ..........133
          5.3.9. job-state-message (text(MAX)) .....................138
          5.3.10. job-detailed-status-messages (1setOf text(MAX)) ..139



Sweet & McDonald             Standards Track                    [Page 5]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


          5.3.11. job-document-access-errors (1setOf text(MAX)) ....139
          5.3.12. number-of-documents (integer(0:MAX)) .............139
          5.3.13. output-device-assigned (name(127)) ...............139
          5.3.14. Event Time Job Status Attributes .................140
                 5.3.14.1. time-at-creation (integer(MIN:MAX)) .....140
                 5.3.14.2. time-at-processing (integer(MIN:MAX)) ...141
                 5.3.14.3. time-at-completed (integer(MIN:MAX)) ....141
                 5.3.14.4. job-printer-up-time (integer(1:MAX)) ....141
                 5.3.14.5. date-time-at-creation
                           (dateTime|unknown) ......................141
                 5.3.14.6. date-time-at-processing
                           (dateTime|unknown|no-value) .............141
                 5.3.14.7. date-time-at-completed
                           (dateTime|unknown|no-value) .............141
          5.3.15. number-of-intervening-jobs (integer(0:MAX)) ......142
          5.3.16. job-message-from-operator (text(127)) ............142
          5.3.17. Job Size Attributes ..............................142
                 5.3.17.1. job-k-octets (integer(0:MAX)) ...........142
                 5.3.17.2. job-impressions (integer(0:MAX)) ........143
                 5.3.17.3. job-media-sheets (integer(1:MAX)) .......143
          5.3.18. Job Progress Attributes ..........................144
                 5.3.18.1. job-k-octets-processed
                           (integer(0:MAX)) ........................144
                 5.3.18.2. job-impressions-completed
                           (integer(0:MAX)) ........................144
                 5.3.18.3. job-media-sheets-completed
                           (integer(0:MAX)) ........................144
          5.3.19. attributes-charset (charset) .....................144
          5.3.20. attributes-natural-language (naturalLanguage) ....145
     5.4. Printer Description and Status Attributes ................145
          5.4.1. printer-uri-supported (1setOf uri) ................147
          5.4.2. uri-authentication-supported (1setOf type2
                 keyword) ..........................................148
          5.4.3. uri-security-supported (1setOf type2 keyword) .....149
          5.4.4. printer-name (name(127)) ..........................150
          5.4.5. printer-location (text(127)) ......................150
          5.4.6. printer-info (text(127)) ..........................151
          5.4.7. printer-more-info (uri) ...........................151
          5.4.8. printer-driver-installer (uri) ....................151
          5.4.9. printer-make-and-model (text(127)) ................151
          5.4.10. printer-more-info-manufacturer (uri) .............151
          5.4.11. printer-state (type1 enum) .......................152
          5.4.12. printer-state-reasons (1setOf type2 keyword) .....152
          5.4.13. printer-state-message (text(MAX)) ................157
          5.4.14. ipp-versions-supported (1setOf type2 keyword) ....157
          5.4.15. operations-supported (1setOf type2 enum) .........157





Sweet & McDonald             Standards Track                    [Page 6]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


          5.4.16. multiple-document-jobs-supported (boolean) .......159
          5.4.17. charset-configured (charset) .....................159
          5.4.18. charset-supported (1setOf charset) ...............159
          5.4.19. natural-language-configured (naturalLanguage) ....160
          5.4.20. generated-natural-language-supported
                  (1setOf naturalLanguage) .........................160
          5.4.21. document-format-default (mimeMediaType) ..........160
          5.4.22. document-format-supported (1setOf
                  mimeMediaType) ...................................161
          5.4.23. printer-is-accepting-jobs (boolean) ..............161
          5.4.24. queued-job-count (integer(0:MAX)) ................161
          5.4.25. printer-message-from-operator (text(127)) ........161
          5.4.26. color-supported (boolean) ........................161
          5.4.27. reference-uri-schemes-supported (1setOf
                  uriScheme) .......................................162
          5.4.28. pdl-override-supported (type2 keyword) ...........162
          5.4.29. printer-up-time (integer(1:MAX)) .................162
          5.4.30. printer-current-time (dateTime|unknown) ..........163
          5.4.31. multiple-operation-time-out (integer(1:MAX)) .....164
          5.4.32. compression-supported (1setOf type2 keyword) .....164
          5.4.33. job-k-octets-supported (rangeOfInteger(0:MAX)) ...165
          5.4.34. job-impressions-supported
                  (rangeOfInteger(0:MAX)) ..........................165
          5.4.35. job-media-sheets-supported
                  (rangeOfInteger(1:MAX)) ..........................165
          5.4.36. pages-per-minute (integer(0:MAX)) ................165
          5.4.37. pages-per-minute-color (integer(0:MAX)) ..........165
  6. Conformance ...................................................166
     6.1. Client Conformance Requirements ..........................166
     6.2. IPP Object Conformance Requirements ......................168
          6.2.1. Objects ...........................................168
          6.2.2. Operations ........................................168
          6.2.3. IPP Object Attributes .............................170
          6.2.4. Versions ..........................................170
          6.2.5. Extensions ........................................171
          6.2.6. Attribute Syntaxes ................................171
          6.2.7. Security ..........................................172
     6.3. Charset and Natural Language Requirements ................172
  7. IANA Considerations ...........................................173
     7.1. Object Extensions ........................................174
     7.2. Attribute Extensibility ..................................174
     7.3. Keyword Extensibility ....................................175
     7.4. Enum Extensibility .......................................176
     7.5. Attribute Group Extensibility ............................176
     7.6. Out-of-Band Attribute Value Extensibility ................176
     7.7. Attribute Syntax Extensibility ...........................177
     7.8. Operation Extensibility ..................................177
     7.9. Status-Code Extensibility ................................178



Sweet & McDonald             Standards Track                    [Page 7]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  8. Internationalization Considerations ...........................179
  9. Security Considerations .......................................183
     9.1. Security Scenarios .......................................184
          9.1.1. Client and Server in the Same Security Domain .....184
          9.1.2. Client and Server in Different Security Domains ...184
          9.1.3. Print by Reference ................................184
     9.2. URIs in Operation, Job, and Printer Attributes ...........185
     9.3. URIs for Each Authentication Mechanism ...................185
     9.4. Restricted Queries .......................................186
     9.5. Operations Performed by Operators and Administrators .....186
     9.6. Queries on Jobs Submitted Using Non-IPP Protocols ........186
  10. Changes since RFC 2911 .......................................187
  11. References ...................................................188
     11.1. Normative References ....................................188
     11.2. Informative References ..................................194
  Appendix A. Formats for IPP Registration Proposals ...............197
    A.1. Attribute Registration ....................................197
    A.2. type2 'keyword' Attribute Value Registration ..............198
    A.3. type2 'enum' Attribute Value Registration .................198
    A.4. Operation Registration ....................................199
    A.5. Status-Code Registration ..................................199
  Appendix B. Status-Code Values and Suggested Status-Code
              Messages .............................................200
    B.1. Status-Code Values ........................................201
      B.1.1. Informational .........................................201
      B.1.2. Successful Status-Code Values .........................201
        B.1.2.1. successful-ok (0x0000) ............................201
        B.1.2.2. successful-ok-ignored-or-substituted-attributes
                 (0x0001) ..........................................202
        B.1.2.3. successful-ok-conflicting-attributes (0x0002) .....202
      B.1.3. Redirection Status-Code Values ........................202
      B.1.4. Client Error Status-Code Values .......................202
        B.1.4.1. client-error-bad-request (0x0400) .................203
        B.1.4.2. client-error-forbidden (0x0401) ...................203
        B.1.4.3. client-error-not-authenticated (0x0402) ...........203
        B.1.4.4. client-error-not-authorized (0x0403) ..............203
        B.1.4.5. client-error-not-possible (0x0404) ................203
        B.1.4.6. client-error-timeout (0x0405) .....................204
        B.1.4.7. client-error-not-found (0x0406) ...................204
        B.1.4.8. client-error-gone (0x0407) ........................204
        B.1.4.9. client-error-request-entity-too-large (0x0408) ....205
        B.1.4.10. client-error-request-value-too-long (0x0409) .....205
        B.1.4.11. client-error-document-format-not-supported
                  (0x040a) .........................................205
        B.1.4.12. client-error-attributes-or-values-not-supported
                  (0x040b) .........................................206
        B.1.4.13. client-error-uri-scheme-not-supported (0x040c) ...206
        B.1.4.14. client-error-charset-not-supported (0x040d) ......206



Sweet & McDonald             Standards Track                    [Page 8]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


        B.1.4.15. client-error-conflicting-attributes (0x040e) .....207
        B.1.4.16. client-error-compression-not-supported (0x040f) ..207
        B.1.4.17. client-error-compression-error (0x0410) ..........207
        B.1.4.18. client-error-document-format-error (0x0411) ......207
        B.1.4.19. client-error-document-access-error (0x0412) ......207
      B.1.5. Server Error Status-Code Values .......................208
        B.1.5.1. server-error-internal-error (0x0500) ..............208
        B.1.5.2. server-error-operation-not-supported (0x0501) .....208
        B.1.5.3. server-error-service-unavailable (0x0502) .........208
        B.1.5.4. server-error-version-not-supported (0x0503) .......209
        B.1.5.5. server-error-device-error (0x0504) ................209
        B.1.5.6. server-error-temporary-error (0x0505) .............210
        B.1.5.7. server-error-not-accepting-jobs (0x0506) ..........210
        B.1.5.8. server-error-busy (0x0507) ........................210
        B.1.5.9. server-error-job-canceled (0x0508) ................210
        B.1.5.10. server-error-multiple-document-jobs-not-supported
                  (0x0509) .........................................210
    B.2. Status-Code Values for IPP Operations .....................211
  Appendix C. Processing IPP Attributes ............................213
    C.1. Fidelity ..................................................213
    C.2. Page Description Language (PDL) Override ..................215
    C.3. Using Job Template Attributes during Document Processing ..217
  Appendix D. Generic Directory Schema .............................218
  Acknowledgements .................................................221
  Authors' Addresses ...............................................221

1.  Introduction

  The Internet Printing Protocol (IPP) is an application-level protocol
  for distributed printing using Internet tools and technologies.  IPP
  version 1.1 (IPP/1.1) focuses primarily on End User functionality
  with a few administrative operations included.  IPP versions 2.0,
  2.1, and 2.2 provide many new operations and are defined separately.

  This document is just one of a suite of documents that fully define
  IPP.  The full set of IETF IPP documents includes:

     Design Goals for an Internet Printing Protocol [RFC2567]

     Rationale for the Structure of the Model and Protocol for the
     Internet Printing Protocol [RFC2568]

     Internet Printing Protocol/1.1: Model and Semantics (this
     document)

     Internet Printing Protocol/1.1: Encoding and Transport [RFC8010]

     Internet Printing Protocol/1.1: Implementor's Guide [RFC3196]



Sweet & McDonald             Standards Track                    [Page 9]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


     Internet Printing Protocol/1.1: IPP URL Scheme [RFC3510]

     Internet Printing Protocol (IPP) over HTTPS Transport Binding and
     the 'ipps' URI Scheme [RFC7472]

     Internet Printing Protocol (IPP): Requirements for Job, Printer,
     and Device Administrative Operations [RFC3239]

     Internet Printing Protocol (IPP): Job and Printer Set Operations
     [RFC3380]

     Internet Printing Protocol (IPP): Job and Printer Administrative
     Operations [RFC3998]

     Internet Printing Protocol (IPP): Requirements for IPP
     Notifications [RFC3997]

     Internet Printing Protocol (IPP): Event Notifications and
     Subscriptions [RFC3995]

     Internet Printing Protocol (IPP): The 'ippget' Delivery Method for
     Event Notifications [RFC3996]

     Mapping between LPD and IPP Protocols [RFC2569]

  Anyone reading these documents for the first time is strongly
  encouraged to read the IPP documents in the above order.  Additional
  IPP specifications have been published by the IEEE-ISTO Printer
  Working Group's IPP Workgroup [PWG-IPP-WG].  The following standards
  are highly recommended reading:

     PWG Media Standardized Names 2.0 (MSN2) [PWG5101.1]

     IPP Finishings 2.0 (FIN) [PWG5100.1]

     Internet Printing Protocol (IPP): "output-bin" attribute extension
     [PWG5100.2]

     Internet Printing Protocol (IPP): Production Printing Attributes -
     Set 1 [PWG5100.3] (for "media-col" Job Template attribute)

     Standard for The Internet Printing Protocol (IPP): Document Object
     [PWG5100.5]

     Standard for The Internet Printing Protocol (IPP): Page Overrides
     [PWG5100.6]





Sweet & McDonald             Standards Track                   [Page 10]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


     Standard for The Internet Printing Protocol (IPP): Job Extensions
     [PWG5100.7]

     Standard for Internet Printing Protocol (IPP): "-actual"
     attributes [PWG5100.8]

     Internet Printing Protocol (IPP): Printer State Extensions v1.0
     [PWG5100.9]

     Internet Printing Protocol (IPP): Job and Printer Extensions -
     Set 2 (JPS2) [PWG5100.11]

     IPP Version 2.0, 2.1, and 2.2 [PWG5100.12]

     IPP: Job and Printer Extensions - Set 3 (JPS3) [PWG5100.13]

     IPP Everywhere [PWG5100.14]

     IPP FaxOut Service [PWG5100.15]

     IPP Transaction-Based Printing Extensions [PWG5100.16]

     IPP Scan Service (SCAN) [PWG5100.17]

     IPP Shared Infrastructure Extensions (INFRA) [PWG5100.18]

     IPP Implementor's Guide v2.0 (IG) [PWG5100.19]

  This document is organized as follows:

  o  The rest of Section 1 is an introduction to the IPP simplified
     model for distributed printing;

  o  Section 2 defines the terminology and conventions used within this
     document;

  o  Section 3 introduces the object types covered in this document
     with their basic behaviors, attributes, and interactions;

  o  Section 4 defines the core operations for IPP/1.1.  IPP operations
     are synchronous -- each operation has both a request and a
     response;

  o  Section 5 defines the core attributes (and their syntaxes) that
     are used in the model;






Sweet & McDonald             Standards Track                   [Page 11]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  o  Sections 6 and 7 summarize the implementation conformance
     requirements for objects that support the protocol and IANA
     considerations, respectively;

  o  Sections 8 and 9 cover the internationalization and security
     considerations for IPP; and

  o  The appendices provide a reference for status-code values,
     processing of IPP attributes, and the generic directory schema.

1.1.  Simplified Printing Model

  In order to achieve its goal of realizing a workable printing
  protocol for the Internet, the Internet Printing Protocol (IPP) is
  based on a simplified printing model that abstracts the many
  components of real-world printing solutions.  The Internet is a
  distributed computing environment where requesters of print services
  (Clients, applications, Printer drivers, etc.) cooperate and interact
  with print service providers.  This document (sometimes referred to
  here as the "Model and Semantics" document) describes a simple,
  abstract model for IPP even though the underlying configurations can
  be complex "n-tier" client/server systems.  An important simplifying
  step in the IPP Model is to expose only the key objects and
  interfaces required for printing.  The model described in this
  document does not include features, interfaces, and relationships
  that are beyond the scope of IPP/1.1.  IPP/1.1 incorporates many of
  the relevant ideas and lessons learned from other specification and
  development efforts [HTPP] [ISO10175] [LDPA] [P1387.4] [PSIS]
  [RFC1179] [SWP].  IPP is heavily influenced by the printing model
  introduced in the Document Printing Application (DPA) [ISO10175]
  standard.  Although DPA specifies both End User and administrative
  features, IPP/1.1 focuses primarily on End User functionality with a
  few additional OPTIONAL operations for Administrators and Operators.

  The IPP Model encapsulates the important components of distributed
  printing into the following IPP object types:

  o  Printer (Section 3.1)

  o  Job (Section 3.2)

  o  Document (see [PWG5100.5])

  o  Subscription (see [RFC3995])

  Each object type has an associated set of operations (see Section 4)
  and attributes (see Section 5).




Sweet & McDonald             Standards Track                   [Page 12]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  It is important, however, to understand that in real system
  implementations (which lie underneath the abstracted IPP Model),
  there are other components of a print service that are not explicitly
  defined in the IPP Model.  The following figure illustrates where IPP
  fits with respect to these other components.

                               +----------------+
                               |   Application  |
                     o         + . . . . . . .  |
                    \|/        |    Spooler     |
                    / \        + . . . . . . .  |   +---------+
                  End User     | Printer Driver |---|  File   |
        +-----------+ +-----+  +-------+--------+   +----+----+
        |  Browser  | | GUI |          |                 |
        +-----+-----+ +--+--+          |                 |
              |          |             |                 |
              |      +---+-------------+--+              |
  N   D   S   |      |      IPP Client    |--------------+
  O   I   E   |      +---------+----------+
  T   R   C   |                |
  I   E   U   |
  F   C   R   -------------- Transport -------------------
  I   T   I
  C   O   T                    |         --+
  A   R   Y           +--------+--------+  |
  T   Y               |    IPP Server   |  |
  I                   +--------+--------+  |
  O                            |           |
  N                   +-----------------+  | IPP Printer
                      |  Print Service  |  |
                      +-----------------+  |
                               |         --+
                      +-----------------+
                      | Output Device(s)|
                      +-----------------+

                           Figure 1: IPP Model

  An IPP Printer object ("Printer") encapsulates the functions normally
  associated with physical Output Devices along with the spooling,
  scheduling, and multiple device management functions often associated
  with a print server.  Printers are optionally registered as entries
  in a directory where End Users find and select them based on some
  sort of filtered context-based searching mechanism (see Appendix D).
  The directory is used to store relatively static information about
  the Printer, allowing End Users to search for and find Printers that
  match their search criteria -- for example, name, location, context,
  Printer capabilities, etc.  The more dynamic information, such as



Sweet & McDonald             Standards Track                   [Page 13]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  state, currently loaded and ready media, number of Jobs at the
  Printer, errors, warnings, and so forth, is directly associated with
  the Printer itself rather than with the entry in the directory, which
  only references the Printer.

  IPP Clients ("Clients") implement IPP on the Client side and give
  End Users (or programs running on behalf of End Users) the ability to
  query Printers and submit and manage Print Jobs.  An IPP server is
  just that part of the Printer object that implements the server-side
  protocol.  The rest of the Printer object implements (or gateways
  into) the application semantics of the print service itself.
  Printers can be embedded in an Output Device or can be implemented on
  a host on the network that communicates with an Output Device.

  When a Job is submitted to the Printer and the Printer has validated
  the attributes in the submission request, the Printer creates a new
  IPP Job object ("Job").  The End User then interacts with this new
  Job to query its status and monitor the progress of the Job.  An
  End User can also cancel their Print Jobs by using the Job's
  Cancel-Job operation.  An End User can also hold, release, and
  restart their Print Jobs using the Job's OPTIONAL Hold-Job,
  Release-Job, and Restart-Job operations, if implemented.

  A privileged Operator or Administrator of a Printer can cancel, hold,
  release, and restart any user's Job using the REQUIRED Cancel-Job and
  the OPTIONAL Hold-Job, Release-Job, and Restart-Job operations.  In
  addition, a privileged Operator or Administrator of a Printer can
  pause, resume, or purge (Jobs from) a Printer using the OPTIONAL
  Pause-Printer, Resume-Printer, and Purge-Jobs operations, if
  implemented.

  The notification service is defined in "Internet Printing Protocol
  (IPP): Event Notifications and Subscriptions" [RFC3995].  By using
  such a notification service, the End User is able to register for and
  receive Printer-specific and Job-specific events asynchronously.
  Otherwise, an End User can query the status of Printers and can
  follow the progress of Jobs by polling using the
  Get-Printer-Attributes, Get-Jobs, and Get-Job-Attributes operations.













Sweet & McDonald             Standards Track                   [Page 14]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


2.  Conventions Used in This Document

2.1.  Requirements Language

  The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
  "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
  document are to be interpreted as described in [RFC2119].

  The key word "DEPRECATED" in this document refers to an operation,
  attribute, or value that SHOULD NOT be used or supported in new
  implementations.

2.2.  Printing Terminology

  Client: Initiator of outgoing IPP session requests and sender of
  outgoing IPP operation requests (Hypertext Transfer Protocol
  (HTTP/1.1) user agent, as defined in [RFC7230]).

  Document: An object created and managed by a Printer that contains
  description, processing, and status information.  A Document object
  can have attached data and is bound to a single Job [PWG5100.5].

  'ipp' URI: An IPP URI as defined in [RFC3510].

  'ipps' URI: An IPP URI as defined in [RFC7472].

  Job: An object created and managed by a Printer that contains
  description, processing, and status information.  The Job also
  contains zero or more Document objects.

  Logical Device: A print server, software service, or gateway that
  processes Jobs and either forwards or stores the processed Job or
  uses one or more Physical Devices to render output.

  Output Device: A single Logical or Physical Device.

  Physical Device: A hardware implementation of an endpoint device,
  e.g., a marking engine, a fax modem, etc.

  Printer: Listener for incoming IPP session requests and receiver of
  incoming IPP operation requests (HTTP/1.1 server, as defined in
  [RFC7230]) that represents one or more Physical Devices or a Logical
  Device.








Sweet & McDonald             Standards Track                   [Page 15]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


2.3.  Model Terminology

2.3.1.  Administrator

  An End User who is also authorized to manage all aspects of an Output
  Device or Printer, including creating the Printer instances and
  controlling the authorization of other End Users and Operators
  [RFC2567].

2.3.2.  Attributes

  An attribute is an item of information that is associated with an
  instance of an IPP object (Printer, Job, etc.).  An attribute
  consists of an attribute name and one or more attribute values.  Each
  attribute has a specific attribute syntax.  All object attributes are
  defined in Section 5, and all operation attributes are defined in
  Section 4.

  Job Template attributes are described in Section 5.2.  The Client
  optionally supplies Job Template attributes in a Job Creation request
  (operation requests that create Job objects).  The Printer object has
  associated attributes that define supported and default values for
  the Printer.

2.3.2.1.  Attribute Group Name

  Related attributes are grouped into named groups.  The name of the
  group is a keyword.  The group name can be used in place of naming
  all the attributes in the group explicitly.  Attribute groups are
  defined in Section 4.

2.3.2.2.  Attribute Name

  Each attribute is uniquely identified in this document by its
  attribute name.  An attribute name is a keyword.  The keyword
  attribute name is given in the section title in this document that
  describes that attribute.  In running text in this document,
  attribute names are indicated inside double quotation marks (") where
  the quotation marks are not part of the keyword itself.

2.3.2.3.  Attribute Syntax

  Each attribute is defined using an explicit syntax type.  In this
  document, each syntax type is defined as a keyword with specific
  meaning.  The "Encoding and Transport" document [RFC8010] indicates
  the actual "on-the-wire" encoding rules for each syntax type.
  Attribute syntax types are defined in Section 5.1.




Sweet & McDonald             Standards Track                   [Page 16]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


2.3.2.4.  Attribute Value

  Each attribute has one or more values.  Attribute values are
  represented in the syntax type specified for that attribute.  In
  running text in this document, attribute values are indicated inside
  single quotation marks ('), whether their attribute syntax is
  keyword, integer, text, etc. where the quotation marks are not part
  of the value itself.

2.3.3.  End User

  An End User is a person or software process that is authorized to
  perform basic printing functions, including finding/locating a
  Printer, creating a local instance of a Printer, viewing Printer
  status, viewing Printer capabilities, submitting a Print Job, viewing
  Print Job status, and altering the attributes of a Print Job
  [RFC2567].

2.3.4.  Impression

  An Impression is the content imposed upon one side of a Media Sheet
  by a marking engine, independent of the number of times that the
  sheet side passes any marker.  An Impression contains one or more
  Input Pages that are imposed (scaled, translated, and/or rotated)
  during processing of the Document data.

2.3.5.  Input Page

  An Input Page is a page according to the definition of "pages" in the
  language used to express the Document data.

2.3.6.  Job Creation Operation

  A Job Creation operation is any operation that causes the creation of
  a Job object, e.g., the Create-Job, Print-Job, and Print-URI
  operations defined in this document.

2.3.7.  Keyword

  Keywords are used within this document as identifiers of semantic
  entities within the abstract model (see Section 5.1.4).  Attribute
  names, some attribute values, attribute syntaxes, and attribute group
  names are represented as keywords.








Sweet & McDonald             Standards Track                   [Page 17]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


2.3.8.  Media Sheet

  A Media Sheet is a single instance of a medium, whether printing on
  one or both sides of the medium.  Media Sheets also include sections
  of roll media.

2.3.9.  Operator

  An Operator is an End User that also has special rights on the Output
  Device or Printer.  The Operator typically monitors the status of the
  Printer and also manages and controls the Jobs at the Output Device
  [RFC2567].  The Operator is allowed to query and control the Printer,
  Jobs, and Documents based on site policy.

2.3.10.  Set

  A Set is a logical boundary between the delivered Media Sheets of a
  printed Job.  For example, in the case of a ten-page single Document
  with collated pages and a request for 50 copies, each of the 50
  printed copies of the Document constitutes a Set.  If the pages were
  uncollated, then 50 copies of each of the individual pages within the
  Document would represent each Set.  Finishing processes operate on
  Sets.

2.3.11.  Support of Attributes

  By definition, a Printer supports an attribute only if that Printer
  accepts it in a request or responds with the corresponding attribute
  populated with some value(s) in a response to a query for that
  attribute.  A Printer supports an attribute value if the value is one
  of the Printer's "supported values" attributes.  The device behind a
  Printer can exhibit a behavior that corresponds to some IPP
  attribute, but if the Printer, when queried for that attribute,
  doesn't respond with the attribute, then as far as IPP is concerned,
  that implementation does not support that feature.  If the Printer's
  "xxx-supported" attribute is not populated with a particular value
  (even if that value is a legal value for that attribute), then that
  Printer does not support that particular value.

  A conforming implementation supports all REQUIRED attributes.
  However, even for REQUIRED attributes, conformance to IPP does not
  mandate that all implementations support all possible values
  representing all possible Job processing behaviors and features.  For
  example, if a given instance of a Printer supports only certain
  Document formats, then that Printer responds with the
  "document-format-supported" attribute populated with a set of values,
  or possibly only one value, taken from the entire set of possible
  values defined for that attribute.  This limited set of values



Sweet & McDonald             Standards Track                   [Page 18]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  represents the Printer's set of supported Document formats.
  Supporting an attribute and some set of values for that attribute
  enables IPP End Users to be aware of and make use of those features
  associated with that attribute and those values.  If an
  implementation chooses to not support an attribute or some specific
  value, then IPP End Users would have no ability to make use of that
  feature within the context of IPP itself.  However, due to existing
  practice and legacy systems that are not IPP aware, there might be
  some other mechanism outside the scope of IPP to control or request
  the "unsupported" feature (such as embedded instructions within the
  Document data itself).

  For example, consider the following for the "finishings-supported"
  attribute.

  1)  If a Printer is not physically capable of stapling, the
      "finishings-supported" attribute MUST NOT be populated with the
      value of 'staple'.

  2)  A Printer is physically capable of stapling; however, an
      implementation chooses not to support stapling in the IPP
      "finishings" attribute.  In this case, 'staple' MUST NOT be a
      value in the "finishings-supported" Printer Description
      attribute.  Without support for the value 'staple', an IPP
      End User would have no means within the protocol itself to
      request that a Job be stapled.  However, an existing Document
      data formatter might be able to request that the Document be
      stapled directly with an embedded instruction within the Document
      data.  In this case, the IPP implementation does not "support"
      stapling; however, the End User is still able to have some
      control over the stapling of the completed Job.

  3)  A Printer is physically capable of stapling, and an
      implementation chooses to support stapling in the IPP
      "finishings" attribute.  In this case, 'staple' MUST be a value
      in the "finishings-supported" Printer attribute.  Doing so
      enables End Users to be aware of and make use of the stapling
      feature using IPP attributes.

  Even though support for Job Template attributes by a Printer is
  OPTIONAL in IPP/1.1, Printers whose associated device(s) is capable
  of realizing any feature or function that corresponds to an IPP
  attribute and some associated value SHOULD support that IPP attribute
  and value.







Sweet & McDonald             Standards Track                   [Page 19]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  The set of values in any of the supported value attributes is set
  (populated) by some administrative process or automatic sensing
  mechanism that is outside the scope of this document.  For
  administrative policy and control reasons, an Administrator can
  choose to make only a subset of possible values visible to the
  End User.  In this case, the real Output Device behind the IPP
  Printer abstraction can be capable of a certain feature; however, an
  Administrator is specifying that access to that feature not be
  exposed to the End User through IPP.  Also, since a Printer can
  represent a logical print device (not just a Physical Device), the
  actual process for supporting a value is undefined and left up to the
  implementation.  However, if a Printer supports a value, some manual
  human action might be needed to realize the semantic action
  associated with the value, but no End User action is required.

  For example, if one of the values in the "finishings-supported"
  attribute is 'staple', the actual process might be an automatic
  staple action by a Physical Device controlled by some command sent to
  the device.  Or, the actual process of stapling might be a manual
  action by an Operator at an Operator-attended Printer.

  For another example of how supported attributes function, consider an
  Administrator who desires to control all Print Jobs so that no Job
  sheets are printed in order to conserve paper.  To force no Job
  sheets, the Administrator sets the only supported value for the
  "job-sheets-supported" attribute to 'none'.  In this case, if a
  Client requests anything except 'none', the Job Creation request is
  rejected or the "job-sheets" value is ignored (depending on the value
  of "ipp-attribute-fidelity").  To force the use of Job start/end
  sheets on all Jobs, the Administrator does not include the value
  'none' in the "job-sheets-supported" attribute.  In this case, if a
  Client requests 'none', the Job Creation request is rejected or the
  "job-sheets" value is ignored (again depending on the value of
  "ipp-attribute-fidelity").

  Job Template attributes will typically have corresponding
  "xxx-supported" and "xxx-default" Printer Description attributes that
  contain the supported and default values for the attribute.  For
  capabilities that are not associated with a Job, the convention is to
  have an "xxx-supported" Printer Description attribute that lists the
  supported values and an "xxx-configured" Printer Description
  attribute that contains the value being used by the Printer.  For
  example, the "charset-supported" Printer Description attribute
  (Section 5.4.18) lists the supported character sets for the Printer
  while the "charset-configured" Printer Description attribute
  (Section 5.4.17) specifies the character set being used by the
  Printer.




Sweet & McDonald             Standards Track                   [Page 20]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


2.3.12.  Terminating State

  The final state for a Job or other object is called its Terminating
  State.  For example, the 'aborted', 'canceled', and 'completed' Job
  states are Terminating States.

2.4.  Abbreviations

  ABNF: Augmented Backus-Naur Form [RFC5234]

  ASCII: American Standard Code for Information Interchange [RFC20]

  HTTP: Hypertext Transfer Protocol [RFC7230]

  HTTPS: HTTP over TLS [RFC2818]

  IANA: Internet Assigned Numbers Authority

  IEEE: Institute of Electrical and Electronics Engineers

  IESG: Internet Engineering Steering Group

  IPP: Internet Printing Protocol (this document, [RFC8010], and
  [PWG5100.12])

  ISTO: IEEE Industry Standards and Technology Organization

  LPD: Line Printer Daemon Protocol [RFC1179]

  PWG: IEEE-ISTO Printer Working Group

  RFC: Request for Comments

  TCP: Transmission Control Protocol [RFC793]

  TLS: Transport Layer Security [RFC5246]

  URI: Uniform Resource Identifier [RFC3986]

  URL: Uniform Resource Locator [RFC3986]

  UTF-8: Unicode Transformation Format - 8-bit [RFC3629]









Sweet & McDonald             Standards Track                   [Page 21]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


3.  IPP Objects

  This document defines IPP objects of types Printer and Job.  Each
  type of object models relevant aspects of a real-world entity such as
  a real Printer or real Print Job.  Each object type is defined as a
  set of possible attributes that can be supported by instances of that
  object type.  For each object (instance), the actual set of supported
  attributes and values describe a specific implementation.  The
  object's attributes and values describe its state, capabilities,
  realizable features, Job processing functions, and default behaviors
  and characteristics.  For example, the Printer object type is defined
  as a set of attributes that each Printer object potentially supports.
  In the same manner, the Job object type is defined as a set of
  attributes that are potentially supported by each Job object.

  Each attribute included in the set of attributes defining an object
  type is labeled as:

  o  "REQUIRED": each object MUST support the attribute.

  o  "RECOMMENDED": each object SHOULD support the attribute.

  o  "OPTIONAL": each object MAY support the attribute.

  Some definitions of attribute values indicate that an object MUST or
  SHOULD support the value; otherwise, support of the value is
  OPTIONAL.  However, if an implementation supports an attribute, it
  MUST support at least one of the possible values for that attribute.

3.1.  Printer Object

  The major component of the IPP Model is the Printer object.  A
  Printer object implements the server side of the IPP/1.1 protocol.
  Using the protocol, End Users can query the attributes of the Printer
  object and submit Print Jobs to the Printer object.  The actual
  implementation components behind the Printer abstraction can take on
  different forms and different configurations.  However, the model
  abstraction allows the details of the configuration of real
  components to remain opaque to the End User.  Section 4 describes
  each of the Printer operations in detail.











Sweet & McDonald             Standards Track                   [Page 22]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  The capabilities and state of a Printer object are described by its
  attributes.  Printer attributes are divided into two groups:

  o  "job-template" attributes: These attributes describe supported Job
     processing capabilities and defaults for the Printer object (see
     Section 5.2)

  o  "printer-description" attributes: These attributes describe the
     Printer's identification, state, location, references to other
     sources of information about the Printer object, etc. (see
     Section 5.4)

  Since a Printer object is an abstraction of a generic Document Output
  Device and print service provider, a Printer object could be used to
  represent any real or virtual device with semantics consistent with
  the Printer object, such as a fax device, an imager, or even a CD
  writer.

  Some examples of configurations supporting a Printer object include:

  1.  An Output Device with no spooling capabilities

  2.  An Output Device with a built-in spooler

  3.  A print server supporting IPP with one or more associated Output
      Devices

      3a.  The associated Output Devices are or are not capable of
           spooling Jobs

      3b.  The associated Output Devices possibly support IPP

  Figure 2 shows some examples of how Printers can be realized on top
  of various distributed printing configurations.  The embedded case
  below represents configurations 1 and 2 above.  The "hosted Printer"
  and "fan out" items represent configurations 3a and 3b, respectively.

  In this document, the term "Client" refers to a software entity that
  sends IPP operation requests to an IPP Printer and accepts IPP
  operation responses.  A Client MAY be:

  1.  contained within software controlled by an End User, e.g.,
      activated by the "Print" menu item in an application, or

  2.  the print server component that sends IPP requests to either an
      Output Device or another "downstream" print server.





Sweet & McDonald             Standards Track                   [Page 23]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  The term "IPP Printer" is a network entity that accepts IPP operation
  requests and returns IPP operation responses.  As such, an IPP
  Printer object MAY be:

  1.  an (embedded) device component that accepts IPP requests and
      controls the device, or

  2.  a component of a print server that accepts IPP requests (where
      the print server controls one or more networked devices using IPP
      or other protocols).

  Legend:

  ##### indicates a Printer object that is
        either embedded in an Output Device or
        hosted in a server.  The Printer object
        might or might not be capable of queuing/spooling.

  any   indicates any network protocol or direct
        connect, including IPP

  embedded Printer:
                                            Output Device
                                          +---------------+
   O   +--------+                         |  ###########  |
  /|\  | Client |------------IPP------------># Printer #  |
  / \  +--------+                         |  # Object  #  |
                                          |  ###########  |
                                          +---------------+
  hosted Printer:
                                          +---------------+
   O   +--------+        ###########      |               |
  /|\  | Client |--IPP--># Printer #-any->| Output Device |
  / \  +--------+        # Object  #      |               |
                         ###########      +---------------+
                                           +---------------+
  fan out:                                 |               |
                                       +-->| Output Device |
                                   any/    |               |
   O   +--------+      ###########   /     +---------------+
  /|\  | Client |-IPP-># Printer #--*
  / \  +--------+      # Object  #   \     +---------------+
                       ########### any\    |               |
                                       +-->| Output Device |
                                           |               |
                                           +---------------+

                Figure 2: IPP Printer Object Architecture



Sweet & McDonald             Standards Track                   [Page 24]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


3.2.  Job Object

  A Job object is used to model a Print Job.  A Job object contains
  zero or more Documents.  The information required to create a Job
  object is sent in a Job Creation request from the End User via an IPP
  Client to the Printer.  The Printer validates the Job Creation
  request, and if the Printer accepts the request, the Printer creates
  the new Job object.  Section 4 describes each of the Job operations
  in detail.

  The characteristics and state of a Job object are described by its
  attributes.  Job attributes are grouped into two groups as follows:

  o  "job-template" attributes: These attributes can be supplied by the
     Client or End User and include Job processing instructions that
     are intended to override any Printer defaults and/or instructions
     embedded within the Document data (see Section 5.2)

  o  "job-description" attributes: These attributes describe the Job's
     identification, state, size, etc.  The Client supplies some of
     these attributes, and the Printer generates others (see
     Section 5.3)

  An implementation MUST support at least one Document per Job object.
  An implementation MAY support multiple Documents per Job object.  A
  Document is either:

  o  a stream of Document data in a format supported by the Printer
     (typically a Page Description Language -- PDL), or

  o  a reference to such a stream of Document data.

  All Job processing instructions are modeled as Job object attributes.
  These attributes are called "Job Template attributes", and they apply
  equally to all Documents within a Job object.

3.3.  Object Relationships

  IPP objects have relationships that are maintained persistently along
  with the persistent storage of the object attributes.

  A Printer object can represent either one or more physical Output
  Devices or a Logical Device that "processes" Jobs but never actually
  uses a physical Output Device to put marks on paper.  Examples of
  Logical Devices include a web page publisher or a gateway into an
  online Document archive or repository.  A Printer contains zero or
  more Job objects.




Sweet & McDonald             Standards Track                   [Page 25]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  A Job object is contained by exactly one Printer; however, the
  identical Document data associated with a Job could be sent to either
  the same or a different Printer.  In this case, a second Job object
  would be created that would be almost identical to the first Job;
  however, it would have new (different) Job object identifiers (see
  Section 3.4).

  A Job either is empty (before any Documents have been added) or
  contains one or more Documents.  If the contained Document is a
  stream of Document data, that stream can be contained in only one
  Document.  However, there can be identical copies of the stream in
  other Documents in the same or different Jobs.  If the contained
  Document is just a reference to a stream of Document data, other
  Documents (in the same or different Job(s)) contain the same
  reference.

3.4.  Object Identity

  All IPP objects (Printers, Jobs, etc.) are identified by a Uniform
  Resource Identifier (URI) [RFC3986] so that they can be persistently
  and unambiguously referenced.  Since every URL is a specialized form
  of a URI, even though the more generic term "URI" is used throughout
  the rest of this document, its usage is intended to cover the more
  specific notion of "URL" as well.

  An Administrator configures Printers to either support or not support
  authentication and/or message privacy using Transport Layer Security
  (TLS) [RFC5246]; the mechanism for security configuration is outside
  the scope of this document.  In some situations, both types of
  connections (both authenticated and unauthenticated) can be
  established using a single communication channel that has some sort
  of negotiation mechanism.  In other situations, multiple
  communication channels are used, one for each type of security
  configuration.  Section 9 provides a full description of all security
  considerations and configurations.

  If a Printer supports more than one communication channel, some or
  all of those channels might support and/or require different security
  mechanisms.  In such cases, an Administrator could expose the
  simultaneous support for these multiple communication channels as
  multiple URIs for a single Printer where each URI represents one of
  the communication channels to the Printer.  To support this
  flexibility, the IPP Printer object type defines a multi-valued
  identification attribute called the "printer-uri-supported" attribute
  that MUST contain at least one URI.  The "printer-uri-supported"
  attribute has two companion attributes, the "uri-security-supported"
  attribute and the "uri-authentication-supported" attribute.  Both
  have the same cardinality as "printer-uri-supported".  The purpose of



Sweet & McDonald             Standards Track                   [Page 26]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  the "uri-security-supported" attribute is to indicate the security
  mechanisms (if any) used for each URI listed in
  "printer-uri-supported".  The purpose of the
  "uri-authentication-supported" attribute is to indicate the
  authentication mechanisms (if any) used for each URI listed in
  "printer-uri-supported".  These three attributes are fully described
  in Sections 5.4.1, 5.4.2, and 5.4.3.

  When a Job is submitted to the Printer via a Job Creation request,
  the Client supplies only a single Printer URI.  The Client-supplied
  Printer URI MUST be one of the values in the "printer-uri-supported"
  Printer attribute.

  IPP/1.1 does not specify how the Client obtains the Client-supplied
  URI, but it is RECOMMENDED that a Printer be registered as an entry
  in a directory service.  End Users and programs can then interrogate
  the directory, searching for Printers.  Appendix D defines a generic
  schema for Printer object entries in the directory service and
  describes how the entry acts as a bridge to the actual IPP Printer.
  The entry in the directory that represents the IPP Printer includes
  the possibly many URIs for that Printer as values in one of its
  attributes.

  When a Client submits a Job Creation request to the Printer, the
  Printer validates the request and creates a new Job object.  The
  Printer assigns the new Job a numeric identifier that is stored in
  the "job-id" Job attribute and a URI that is stored in the "job-uri"
  Job attribute.  Both the numeric identifier and URI can then be used
  by Clients as the target for subsequent Job operations; the numeric
  identifier is preferred.  The Printer generates the Job numeric
  identifier and URI based on its configured security policy and the
  URI used by the Client in the Job Creation request.

  For example, consider a Printer that supports both a communication
  channel secured by the use of TLS (using HTTP over TLS with an
  "https" schemed URI) and another open communication channel that is
  not secured with TLS (using a simple "http" schemed URI).  If a
  Client submits a Job using the secure URI, the Printer assigns the
  new Job a secure URI as well.  If a Client were to submit a Job using
  the open-channel URI, the Printer might assign the new Job an
  open-channel URI.  Clients SHOULD use the "printer-uri" and "job-id"
  attributes to target a Job to avoid any ambiguity about the security
  of the communication channel.

  In addition, the Printer also populates the Job's "job-printer-uri"
  attribute.  This is a reference back to the Printer that created the
  Job.  If a Client only has access to a Job's "job-uri" identifier,
  the Client can query the Job's "job-printer-uri" attribute in order



Sweet & McDonald             Standards Track                   [Page 27]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  to determine which Printer created the Job.  If the Printer supports
  more than one URI, the Printer picks the one URI supplied by the
  Client when creating the Job to build the value for and to populate
  the Job's "job-printer-uri" attribute.

  In addition to identifiers, IPP objects have names -- "printer-name"
  for Printers and "job-name" for Jobs.  An object name is not
  guaranteed to be unique across all instances of all objects.  A
  Printer's name is chosen and set by an Administrator through some
  mechanism outside the scope of this document.  A Job's name can be
  chosen and supplied by the Client submitting the Job.  If the Client
  does not supply a Job name, the Printer generates a name for the new
  Job.  In all cases, the name only has local meaning.

  To summarize:

  o  Each Printer is identified by one or more URIs.  The Printer's
     "printer-uri-supported" attribute contains the URI(s).

  o  The Printer's "uri-security-supported" attribute identifies the
     communication channel security protocols that have been configured
     for the various Printer URIs (e.g., 'tls' or 'none').

  o  The Printer's "uri-authentication-supported" attribute identifies
     the authentication mechanisms that have been configured for the
     various Printer URIs (e.g., 'digest', 'none', etc.).

  o  Each Job is identified by a numeric identifier, which is a 32-bit
     positive integer.  The Job's "job-id" attribute contains the
     Job ID.  The Job ID is only unique within the context of the
     Printer that created the Job.

  o  Each Job is also identified by a URI.  The Job's "job-uri"
     attribute contains the URI, although its use by Clients is
     DEPRECATED.

  o  Each Job has a "job-printer-uri" attribute, which contains the URI
     of the Printer that was used to create the Job.  This attribute is
     used to determine the Printer that created a Job when given only
     the URI for the Job.  This linkage is necessary to determine the
     languages, charsets, and operations that are supported on that Job
     (the basis for such support comes from the creating Printer).

  o  Each Printer has a name, which is not necessarily unique.  The
     Administrator chooses and sets this name through some mechanism
     outside the scope of this IPP/1.1 document.  The Printer's
     "printer-name" attribute contains the name.




Sweet & McDonald             Standards Track                   [Page 28]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  o  Each Job has a name, which is not necessarily unique.  The Client
     optionally supplies this name in the Job Creation request.  If the
     Client does not supply this name, the Printer generates a name for
     the Job.  The Job's "job-name" attribute contains the name.

4.  IPP Operations

  IPP objects (Printers, Jobs, etc.) support operations.  An operation
  consists of a request and a response.  When a Client communicates
  with a Printer or its Jobs, the Client issues an operation request to
  the Printer URI and object's numeric identifier, if needed.
  Operation requests and responses have parameters that identify the
  operation.  Operations also have attributes that affect the runtime
  characteristics of the operation (the intended target, localization
  information, etc.).  These operation-specific attributes are called
  "operation attributes" (as compared to object attributes such as
  Printer attributes or Job attributes).  Each request carries along
  with it any operation attributes, object attributes, and/or Document
  data required to perform the operation.  Each request requires a
  response from the object.  Each response indicates success or failure
  of the operation with a status-code as a response parameter.  The
  response contains any operation attributes, object attributes, and/or
  status messages generated during the execution of the operation
  request.

  This section describes the semantics of the IPP operations, both
  requests and responses, in terms of the parameters, attributes, and
  other data associated with each operation.

  The Printer operations defined in this document are:

     Print-Job (Section 4.2.1)

     Print-URI (Section 4.2.2)

     Validate-Job (Section 4.2.3)

     Create-Job (Section 4.2.4)

     Get-Printer-Attributes (Section 4.2.5)

     Get-Jobs (Section 4.2.6)

     Pause-Printer (Section 4.2.7)

     Resume-Printer (Section 4.2.8)

     Purge-Jobs (Section 4.2.9)



Sweet & McDonald             Standards Track                   [Page 29]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  The Job operations defined in this document are:

     Send-Document (Section 4.3.1)

     Send-URI (Section 4.3.2)

     Cancel-Job (Section 4.3.3)

     Get-Job-Attributes (Section 4.3.4)

     Hold-Job (Section 4.3.5)

     Release-Job (Section 4.3.6)

     Restart-Job (Section 4.3.7)

  The Send-Document and Send-URI Job operations are used to add
  Documents to an existing Job created using the Create-Job operation.

4.1.  Common Semantics

  All IPP operations require some common parameters and operation
  attributes.  These common elements and their semantic characteristics
  are defined and described in more detail in the following sections.

4.1.1.  Required Parameters

  Every operation request contains the following REQUIRED parameters:

  o  a "version-number",

  o  an "operation-id",

  o  a "request-id", and

  o  the attributes that are REQUIRED for that type of request.

  Every operation response contains the following REQUIRED parameters:

  o  a "version-number",

  o  a "status-code",

  o  the "request-id" that was supplied in the corresponding request,
     and

  o  the attributes that are REQUIRED for that type of response.




Sweet & McDonald             Standards Track                   [Page 30]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  The Encoding and Transport document [RFC8010] defines special rules
  for the encoding of these parameters.  All other operation elements
  are represented using the more generic encoding rules for attributes
  and groups of attributes.

4.1.2.  Operation IDs and Request IDs

  Each IPP operation request includes an identifying "operation-id"
  value.  Valid values are defined in the "operations-supported"
  Printer attribute section (see Section 5.4.15).  The Client specifies
  which operation is being requested by supplying the correct
  "operation-id" value.

  In addition, every invocation of an operation is identified by a
  "request-id" value.  For each request, the Client chooses the
  "request-id", which MUST be an integer (possibly unique, depending on
  Client requirements) in the range from 1 to 2**31 - 1 (inclusive).
  This "request-id" allows Clients to manage multiple outstanding
  requests.  The receiving IPP object (Printer, Job, etc.) copies all
  32 bits of the Client-supplied "request-id" attribute into the
  response so that the Client can match the response with the correct
  outstanding request, even if the "request-id" is out of range.  If
  the request is terminated before the complete "request-id" is
  received, the IPP object rejects the request and returns a response
  with a "request-id" of 0.

  Note: In some cases, the transport protocol underneath IPP might be a
  connection-oriented protocol that would make it impossible for a
  Client to receive responses in any order other than the order in
  which the corresponding requests were sent.  In such cases, the
  "request-id" attribute would not be essential for correct protocol
  operation.  However, in other transport mappings the operation
  responses could come back in any order, in which case the
  "request-id" is essential.

4.1.3.  Attributes

  Operation requests and responses are both composed of groups of
  attributes and/or Document data.  The attribute groups are:

  o  Operation Attributes: These attributes are passed in the operation
     and affect the IPP object's behavior while processing the
     operation request, and they can affect other attributes or groups
     of attributes.  Some operation attributes describe the Document
     data associated with the Print Job and are associated with new Job
     objects; however, most operation attributes do not persist beyond
     the life of the operation.  The description of each operation
     attribute includes conformance statements indicating which



Sweet & McDonald             Standards Track                   [Page 31]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


     operation attributes are REQUIRED and which are OPTIONAL for an
     IPP object to support, as well as which attributes a Client MUST
     supply in a request and an IPP object MUST supply in a response.

  o  Job Template Attributes: These attributes affect the processing of
     a Job.  A Client MAY supply Job Template attributes in a Job
     Creation request, and the receiving object MUST be prepared to
     receive all supported attributes.  The Job object can later be
     queried to find out what Job Template attributes were originally
     requested in the Job Creation request, and such attributes are
     returned in the response as Job object attributes.  The Printer
     object can be queried about its Job Template attributes to find
     out what type of Job processing capabilities are supported and/or
     what the default Job processing behaviors are, though such
     attributes are returned in the response as Printer object
     attributes.  The "ipp-attribute-fidelity" operation attribute
     affects processing of all Client-supplied Job Template attributes
     -- see Section 4.2.1.1 and Appendix C for a full description of
     "ipp-attribute-fidelity" and its relationship to other attributes.

  o  Job Object Attributes: These attributes are returned in response
     to a query operation directed at a Job object.

  o  Printer Object Attributes: These attributes are returned in
     response to a query operation directed at a Printer object.

  o  Unsupported Attributes: In a Job Creation request, the Client
     supplies a set of operation and Job Template attributes.  If any
     of these attributes or their values are unsupported by the Printer
     object, the Printer object SHOULD return the set of unsupported
     attributes in the response.  Section 4.1.7, Section 4.2.1.2, and
     Appendix C give a full description of how Job Template attributes
     supplied by the Client in a Job Creation request are processed by
     the Printer object and how unsupported attributes are returned to
     the Client.  Because of extensibility, any IPP object might
     receive a request that contains new or unknown attributes or
     values for which it has no support.  In such cases, the IPP object
     processes what it can and returns the unsupported attributes in
     the response.  The Unsupported Attributes group is defined for all
     operation responses for returning unsupported attributes that the
     Client supplied in the request.

  Later in this section, each operation is formally defined by
  identifying the allowed and expected groups of attributes for each
  request and response.  The model identifies a specific order for each
  group in each request or response, but the attributes within each
  group can be in any order, unless specified otherwise.




Sweet & McDonald             Standards Track                   [Page 32]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  The attributes within a group MUST be unique; if an attribute with
  the same name occurs more than once, the group is malformed.  Clients
  MUST NOT submit such malformed requests, and Printers MUST NOT return
  such malformed responses.  If such a malformed request is submitted
  to a Printer, the Printer MUST either (1) reject the request with the
  'client-error-bad-request' status-code (RECOMMENDED -- see
  Appendix B.1.4.1) or (2) process the request normally after selecting
  only one of the attribute instances, depending on implementation.
  Which attribute is selected when there are duplicate attributes
  depends on implementation.  The IPP Printer MUST NOT use the values
  from more than one such duplicate attribute instance.

  Each attribute definition includes the attribute's name followed by
  the name of its attribute syntax(es) in parentheses.  In addition,
  each 'integer' attribute can be followed by the allowed range in
  parentheses, (m:n), for values of that attribute.  Each 'text' or
  'name' attribute can be followed by the maximum size in octets in
  parentheses, (size), for values of that attribute.  For more details
  on attribute syntax notation, see the descriptions of these attribute
  syntaxes in Section 5.1.

  Note: Document data included in the operation is not strictly an
  attribute, but it is treated as a special attribute group for
  ordering purposes.  The only operations defined in this document that
  support supplying the Document data within an operation request are
  Print-Job and Send-Document.  There are no operations defined in this
  document whose responses include Document data.

  Some operations are REQUIRED for IPP objects to support; the others
  are OPTIONAL (see Section 6.2.2).  Therefore, before using an
  OPTIONAL operation, a Client SHOULD first use the REQUIRED
  Get-Printer-Attributes operation to query the Printer's
  "operations-supported" attribute in order to determine which OPTIONAL
  operations are actually supported.  The Client SHOULD NOT use an
  OPTIONAL operation that is not supported.  When an IPP object
  receives a request to perform an operation it does not support, it
  MUST return the 'server-error-operation-not-supported' status-code
  (see Appendix B.1.5.2).  An IPP object is non-conformant if it does
  not support a REQUIRED operation.

4.1.4.  Character Set and Natural Language Operation Attributes

  Some Job and Printer attributes have values that are text strings and
  names intended for human understanding rather than machine
  understanding (see the 'text' and 'name' attribute syntax
  descriptions in Section 5.1).  The following sections describe two
  special operation attributes called "attributes-charset" and
  "attributes-natural-language" whose values are used when interpreting



Sweet & McDonald             Standards Track                   [Page 33]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  other attributes using the 'text' and 'name' attribute syntaxes.  For
  Job Creation operations, the IPP Printer implementation also saves
  these two attributes with the new Job object as Job Status
  attributes.

  The "attributes-charset" and "attributes-natural-language" attributes
  MUST be the first two attributes in every IPP request and response,
  as part of the initial Operation Attributes group of the IPP message.
  The "attributes-charset" attribute MUST be the first attribute in the
  group, and the "attributes-natural-language" attribute MUST be the
  second attribute in the group.

  For the sake of brevity in this document, these operation attribute
  descriptions are not repeated with every operation request and
  response but instead have a reference back to this section.

4.1.4.1.  Request Operation Attributes

  The Client MUST supply and the Printer object MUST support the
  following REQUIRED operation attributes in every IPP operation
  request:

  "attributes-charset" (charset):

     This operation attribute identifies the charset (coded character
     set and encoding method) used by any 'text' and 'name' attributes
     that the Client is supplying in this request.  It also identifies
     the charset that the Printer object MUST use (if supported) for
     all 'text' and 'name' attributes and status messages that the
     Printer object returns in the response to this request.  See
     Sections 5.1.2 and 5.1.3 for the definitions of the 'text' and
     'name' attribute syntaxes.

     All Clients and IPP objects MUST support the 'utf-8' charset
     [RFC3629] and MAY support additional charsets, provided that they
     are registered with IANA [RFC2978] [IANA-CS].  If the Printer
     object does not support the Client-supplied charset value, the
     Printer object MUST reject the request, set the
     "attributes-charset" to 'utf-8' in the response, and return the
     'client-error-charset-not-supported' status-code and any 'text' or
     'name' attributes using the 'utf-8' charset.  The Printer MAY
     return any attributes in the Unsupported Attributes group (see
     Sections 4.1.7 and 4.2.1.2).  The Printer object MUST indicate the
     charset(s) supported as the values of the "charset-supported"
     Printer attribute (see Section 5.4.18), so that the Client can
     query to determine which charset(s) is supported.





Sweet & McDonald             Standards Track                   [Page 34]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


     Note to Client implementors: Since IPP objects are only required
     to support the 'utf-8' charset, in order to maximize
     interoperability with multiple IPP object implementations, a
     Client SHOULD supply 'utf-8' in the "attributes-charset" operation
     attribute, even though the Client is only passing and able to
     present a simpler charset, such as US-ASCII [RFC20] or ISO-8859-1
     [ISO8859-1].  Then the Client will have to filter out, perform
     charset conversion on, or replace those characters that are
     returned in the response that it cannot present to its user.  On
     the other hand, if both the Client and the IPP objects also
     support a charset in common besides 'utf-8', the Client can use
     that charset in order to avoid charset conversion or data loss.

     See the 'charset' attribute syntax description in Section 5.1.8
     for the syntax and semantic interpretation of the values of this
     attribute and for example values.

  "attributes-natural-language" (naturalLanguage):

     This operation attribute identifies the natural language [RFC5646]
     used by any 'text' and 'name' attributes that the Client is
     supplying in this request.  This attribute also identifies the
     natural language that the Printer object SHOULD use for all 'text'
     and 'name' attributes and status messages that the Printer object
     returns in the response to this request.  See the
     'naturalLanguage' attribute syntax description in Section 5.1.9
     for the syntax and semantic interpretation of the values of this
     attribute and for example values.

     There are no REQUIRED natural languages required for the Printer
     object to support.  However, the Printer's
     "generated-natural-language-supported" attribute identifies the
     natural languages supported by the Printer object and any
     contained Jobs for all text strings generated by the IPP object.
     A Client MAY query this attribute to determine which natural
     language(s) is supported for generated messages.

     For any of the attributes for which the Printer object generates
     text, i.e., for the "job-state-message", "printer-state-message",
     and status messages (see Section 4.1.6), the Printer object MUST
     be able to generate these text strings in any of its supported
     natural languages.  If the Client requests a natural language that
     is not supported, the Printer object MUST return these generated
     messages in the Printer's configured natural language as specified
     by the Printer's "natural-language-configured" attribute (see
     Section 5.4.19).





Sweet & McDonald             Standards Track                   [Page 35]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


     For other 'text' and 'name' attributes supplied by the Client,
     authentication system, Operator, Administrator, or manufacturer
     (i.e., for "job-originating-user-name", "printer-name" (name),
     "printer-location" (text), "printer-info" (text), and
     "printer-make-and-model" (text)), the Printer object is only
     required to support the configured natural language of the Printer
     identified by the Printer's "natural-language-configured"
     attribute, though support of additional natural languages for
     these attributes is permitted.

     For any 'text' or 'name' attribute in the request that is in a
     different natural language than the value supplied in the
     "attributes-natural-language" operation attribute, the Client MUST
     use the Natural Language Override mechanism (see Sections 5.1.2.2
     and 5.1.3.2) for each such attribute value supplied.  The Client
     MAY use the Natural Language Override mechanism redundantly, i.e.,
     use it even when the value is in the same natural language as the
     value supplied in the "attributes-natural-language" operation
     attribute of the request.

     The IPP object MUST accept any natural language and any Natural
     Language Override, whether the IPP object supports that natural
     language or not (and independent of the value of the
     "ipp-attribute-fidelity" operation attribute).  That is, the IPP
     object accepts all Client-supplied values no matter what the
     values are in the Printer's "generated-natural-language-supported"
     attribute.  That attribute,
     "generated-natural-language-supported", only applies to generated
     messages, not Client-supplied messages.  The IPP object MUST
     remember that natural language for all Client-supplied attributes,
     and when returning those attributes in response to a query, the
     IPP object MUST indicate that natural language.

     Each value whose attribute syntax type is 'text' or 'name' (see
     Sections 5.1.2 and 5.1.3) has an Associated Natural Language.
     This document does not specify how this association is stored in a
     Printer or Job object.  When such a value is encoded in a request
     or response, the natural language is either implicit or explicit:

     *  In the implicit case, the value contains only the text/name
        value, and the language is specified by the
        "attributes-natural-language" operation attribute in the
        request or response (see Sections 5.1.2.1 and 5.1.3.1).

     *  In the explicit case (also known as the Natural Language
        Override case), the value contains both the language and the
        text/name value (see Sections 5.1.2.2 and 5.1.3.2).




Sweet & McDonald             Standards Track                   [Page 36]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


     For example, the "job-name" attribute MAY be supplied by the
     Client in a Job Creation request.  The text value for this
     attribute will be in the natural language identified by the
     "attribute-natural-language" attribute, or if different, as
     identified by the Natural Language Override mechanism.  If
     supplied, the IPP object will use the value of the "job-name"
     attribute to populate the Job's "job-name" attribute.  Whenever
     any Client queries the Job's "job-name" attribute, the IPP object
     returns the attribute as stored and uses the Natural Language
     Override mechanism to specify the natural language, if it is
     different from that reported in the "attributes-natural-language"
     operation attribute of the response.  The IPP object MAY use the
     Natural Language Override mechanism redundantly, i.e., use it even
     when the value is in the same natural language as the value
     supplied in the "attributes-natural-language" operation attribute
     of the response.

     An IPP object MUST NOT reject a request based on a supplied
     natural language in an "attributes-natural-language" operation
     attribute or in any attribute that uses the Natural Language
     Override.

     Note: Supplying 'text' or 'name' attributes with an incompatible
     combination of natural language and charset can cause undesired
     behavior.  For example, suppose a Printer supports charsets
     'utf-8', 'iso-8859-1', and 'iso-8859-7'.  Suppose also that it
     supports natural languages 'en' (English), 'fr' (French), and 'el'
     (Greek).  Although the Printer supports the charset 'iso-8859-1'
     and natural language 'el', it probably does not support the
     combination of Greek text strings using the 'iso-8859-1' charset.
     The Printer handles this apparent incompatibility differently,
     depending on the context in which it occurs:

     *  In a Job Creation request: If the Client supplies a 'text' or
        'name' attribute (for example, the "job-name" operation
        attribute) that uses an apparently incompatible combination, it
        is a Client choice that does not affect the Printer or its
        correct operation.  Therefore, the Printer simply accepts the
        Client-supplied value, stores it with the Job, and responds
        back with the same combination whenever the Client (or any
        Client) queries for that attribute.

     *  In a query-type operation, like Get-Printer-Attributes: If the
        Client requests an apparently incompatible combination, the
        Printer responds (as described in Section 4.1.4.2) using the
        Printer's configured natural language rather than the natural
        language requested by the Client.




Sweet & McDonald             Standards Track                   [Page 37]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


     In either case, the Printer does not reject the request because of
     the apparent incompatibility.  The potential incompatible
     combination of charset and natural language can occur either at
     the global operation level or at the Natural Language Override
     attribute-by-attribute level.  In addition, since the response
     always includes explicit charset and natural language information,
     there is never any question or ambiguity in how the Client
     interprets the response.

4.1.4.2.  Response Operation Attributes

  The Printer MUST supply and the Client MUST support the following
  REQUIRED operation attributes in every IPP/1.1 operation response:

  "attributes-charset" (charset):

     This operation attribute identifies the charset used by any 'text'
     and 'name' attributes that the Printer object is returning in this
     response.  The value in this response MUST be the same value as
     the "attributes-charset" operation attribute supplied by the
     Client in the request.  If this is not possible (i.e., the charset
     requested is not supported), the request would have been rejected.
     See "attributes-charset" described in Section 4.1.4.1 above.

     If the Printer object supports more than just the 'utf-8' charset,
     the Printer object MUST be able to perform code conversion between
     each of the charsets supported on a "highest fidelity possible"
     basis in order to return the 'text' and 'name' attributes in the
     charset requested by the Client.  However, some information loss
     can occur during the charset conversion, depending on the charsets
     involved.  For example, depending on implementation, the Printer
     object can convert from a UTF-8 'a' to a US-ASCII 'a' (with no
     loss of information); from an ISO Latin 1 CAPITAL LETTER A WITH
     ACUTE ACCENT to US-ASCII 'A' (losing the accent); or from a UTF-8
     Japanese Kanji character to some ISO Latin 1 error character
     indication such as '?', a decimal code equivalent, or the absence
     of a character.

     Whether an implementation that supports more than one charset
     stores the data in the charset supplied by the Client or performs
     code conversion to one of the other supported charsets depends on
     implementation.  The strategy should try to minimize loss of
     information during code conversion.  On each response, such an
     implementation converts from its internal charset to that
     requested.






Sweet & McDonald             Standards Track                   [Page 38]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  "attributes-natural-language" (naturalLanguage):

     This operation attribute identifies the natural language used by
     any 'text' and 'name' attributes that the IPP object is returning
     in this response.  Unlike the "attributes-charset" operation
     attribute, the IPP object MAY return the natural language of the
     Job object or the Printer's configured natural language as
     identified by the Printer's "natural-language-configured"
     attribute, rather than the natural language supplied by the
     Client.  For any 'text' or 'name' attribute or status message in
     the response that is in a different natural language than the
     value returned in the "attributes-natural-language" operation
     attribute, the IPP object MUST use the Natural Language Override
     mechanism (see Sections 5.1.2.2 and 5.1.3.2) on each attribute
     value returned.  The IPP object MAY use the Natural Language
     Override mechanism redundantly, i.e., use it even when the value
     is in the same natural language as the value supplied in the
     "attributes-natural-language" operation attribute of the response.

4.1.5.  Operation Targets

  All IPP operations are directed at IPP objects.  For Printer
  operations, the operation is always directed at a Printer object
  using one of its URIs, i.e., one of the values in the Printer's
  "printer-uri-supported" attribute.  Even if the Printer object
  supports more than one URI, the Client supplies only one URI as the
  target of the operation.  The Client identifies the target object by
  supplying the correct URI in the "printer-uri" operation attribute.

  For Job operations, the operation is directed at either:

  o  The Printer object that created the Job object using the Printer
     object's URI and the Job's numeric identifier (Job ID).  Since the
     Printer object that created the Job object generated the Job ID,
     it MUST be able to correctly associate the Client-supplied Job ID
     with the correct Job object.  The Client supplies the Printer's
     URI in the "printer-uri" operation attribute and the Job ID in the
     "job-id" operation attribute.

  o  The Job object itself using the Job's URI.  In this case, the
     Client identifies the target object by supplying the correct URI
     in the "job-uri" (uri) operation attribute (Section 5.3.2).

  Clients SHOULD send the "printer-uri" and "job-id" operation
  attributes in Job operations.






Sweet & McDonald             Standards Track                   [Page 39]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  If the operation is directed at the Job object directly using the
  Job's URI, the Client MUST NOT include the redundant "job-id"
  operation attribute.

  The operation target attributes are REQUIRED operation attributes
  that are included in every operation request.  Like the charset and
  natural language attributes (see Section 4.1.4), the operation target
  attributes are specially ordered operation attributes.  In all cases,
  the operation target attributes immediately follow the
  "attributes-charset" and "attributes-natural-language" attributes
  within the Operation Attributes group; however, the specific ordering
  rules are as follows:

  o  In the case where there is only one operation target attribute
     (i.e., either only the "printer-uri" attribute or only the
     "job-uri" attribute), that attribute MUST be the third attribute
     in the Operation Attributes group.

  o  In the case where Job operations use two operation target
     attributes (i.e., the "printer-uri" and "job-id" attributes), the
     "printer-uri" attribute MUST be the third attribute and the
     "job-id" attribute MUST be the fourth attribute.

  In all cases, the target URIs contained within the body of IPP
  operation requests and responses MUST be in absolute format rather
  than relative format (a relative URL identifies a resource with the
  scope of the HTTP server, but does not include scheme, host,
  or port).

  The following rules apply to the use of port numbers in URIs that
  identify IPP objects:

  1.  If the URI scheme allows the port number to be explicitly
      included in the URI string, and a port number is specified within
      the URI, then that port number MUST be used by the Client to
      contact the IPP object.

  2.  If the URI scheme allows the port number to be explicitly
      included in the URI string, and a port number is not specified
      within the URI, then the default port number implied by that URI
      scheme MUST be used by the Client to contact the IPP object.

  3.  If the URI scheme does not allow an explicit port number to be
      specified within the URI, then the default port number implied by
      that URI MUST be used by the Client to contact the IPP object.






Sweet & McDonald             Standards Track                   [Page 40]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  Note: "Internet Printing Protocol/1.1: IPP URL Scheme" [RFC3510] and
  "Internet Printing Protocol (IPP) over HTTPS Transport Binding and
  the 'ipps' URI Scheme" [RFC7472] define the mapping of IPP onto HTTP
  and HTTPS, respectively, and define and register a default port
  number.

4.1.6.  Operation Response Status-Code Values and Status Messages

  Every operation response includes a REQUIRED "status-code" parameter,
  SHOULD include the "status-message" operation attribute, and MAY
  include the "detailed-status-message" operation attribute.  The
  Print-URI and Send-URI response MAY also include the
  "document-access-error" operation attribute.

4.1.6.1.  "status-code" (type2 enum)

  The REQUIRED "status-code" parameter provides information on the
  processing of a request.

  The status-code is intended for use by automata.  A Client
  implementation of IPP SHOULD convert status-code values into any
  localized message that has semantic meaning to the End User.

  The "status-code" value is a numeric value that has semantic meaning.
  The "status-code" syntax is similar to a "type2 enum" (see
  Section 5.1 ("Attribute Syntaxes")), except that values can range
  only from 0x0000 to 0x7fff.  Appendix B describes and assigns the
  status-code values, and suggests a corresponding status message for
  each status-code for use by the Client when the user's natural
  language is English.

  If the Printer performs an operation with no errors and it encounters
  no problems, it MUST return the status-code 'successful-ok' in the
  response.  See Appendix B.

















Sweet & McDonald             Standards Track                   [Page 41]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  If the Client supplies unsupported values for the following
  parameters or operation attributes, the Printer object MUST reject
  the operation, MAY return the unsupported attribute value in the
  Unsupported Attributes group, and MUST return the indicated
  status-code:

  +---------------------+---------------------------------------------+
  | Parameter/Attribute | Status-Code                                 |
  +---------------------+---------------------------------------------+
  | version-number      | server-error-version-not-supported          |
  +---------------------+---------------------------------------------+
  | operation-id        | server-error-operation-not-supported        |
  +---------------------+---------------------------------------------+
  | attributes-charset  | client-error-charset-not-supported          |
  +---------------------+---------------------------------------------+
  | compression         | client-error-compression-not-supported      |
  +---------------------+---------------------------------------------+
  | document-format     | client-error-document-format-not-supported  |
  +---------------------+---------------------------------------------+
  | document-uri        | client-error-uri-scheme-not-supported,      |
  |                     | client-error-document-access-error          |
  +---------------------+---------------------------------------------+

              Table 1: Status-Code Values for All Requests

  If the Client supplies unsupported values for other attributes, or
  unsupported attributes, the Printer returns the status-code defined
  in Section 4.1.7 ("Unsupported Attributes").

4.1.6.2.  "status-message" (text(255))

  The RECOMMENDED "status-message" operation attribute provides a short
  textual description of the status of the operation.  The
  "status-message" attribute's syntax is "text(255)", so the maximum
  length is 255 octets (see Section 5.1.2).  The status message is
  intended for the human End User.  If a response does include a
  "status-message" attribute, an IPP Client can examine or display the
  messages in some implementation-specific manner.  The
  "status-message" attribute is especially useful for a later version
  of a Printer to return as supplemental information for the human
  user, to accompany a status-code that an earlier version of a Client
  might not understand.

  If the Printer supports the "status-message" operation attribute, it
  MUST be able to generate this message in any of the natural languages
  identified by the Printer's "generated-natural-language-supported"
  attribute and MUST honor any supported value for the
  "attributes-natural-language" operation attribute (Section 4.1.4.1)



Sweet & McDonald             Standards Track                   [Page 42]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  of the Client request.  Appendix B suggests the text for the status
  message returned by the Printer for use with the English natural
  language.

  As described in Section 4.1.4.1, for any returned 'text' attribute,
  if there is a choice for generating this message, the Printer uses
  the natural language indicated by the value of
  "attributes-natural-language" in the Client request, if supported;
  otherwise, the Printer uses the value in the Printer's own
  "natural-language-configured" attribute.

  If the Printer supports the "status-message" operation attribute, it
  SHOULD use the REQUIRED 'utf-8' charset to return a status message
  for the following error status-code values (see Appendix B):
  'client-error-bad-request', 'client-error-charset-not-supported',
  'server-error-internal-error',
  'server-error-operation-not-supported', and
  'server-error-version-not-supported'.  In this case, it MUST set the
  value of the "attributes-charset" operation attribute to 'utf-8' in
  the error response.

4.1.6.3.  "detailed-status-message" (text(MAX))

  The OPTIONAL "detailed-status-message" operation attribute provides
  additional more-detailed technical and implementation-specific
  information about the operation for Administrators or other
  experienced technical people.  The "detailed-status-message"
  attribute's syntax is "text(MAX)", so the maximum length is
  1023 octets (see Section 5.1.2).  If the Printer supports the
  "detailed-status-message" operation attribute, the Printer SHOULD
  localize the message, unless such localization would obscure the
  technical meaning of the message.  Clients MUST NOT attempt to parse
  the value of this attribute.  See the "document-access-error"
  operation attribute (Section 4.1.6.4) for additional errors that a
  program can process.

4.1.6.4.  "document-access-error" (text(MAX))

  This OPTIONAL operation attribute provides additional information
  about any Document access errors encountered by the Printer before it
  returned a response to the Print-URI (Section 4.2.2) or Send-URI
  (Section 4.3.2) operation.  For errors in the protocol identified by
  the URI scheme in the "document-uri" operation attribute, such as
  'http:' or 'ftp:', the error code is returned in parentheses,
  followed by the URI.  For example:

  (404) http://www.example.com/filename.pdf




Sweet & McDonald             Standards Track                   [Page 43]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  Most Internet protocols use decimal error codes (unlike IPP), so the
  ASCII error code representation is in decimal.

4.1.7.  Unsupported Attributes

  The Unsupported Attributes group contains attributes that are not
  supported by the operation.  This group is primarily for the Job
  Creation operations, but all operations can return this group.

  A Printer MUST include an Unsupported Attributes group in a response
  if the status-code is one of the following:
  'successful-ok-ignored-or-substituted-attributes',
  'successful-ok-conflicting-attributes',
  'client-error-attributes-or-values-not-supported', or
  'client-error-conflicting-attributes'.

  If the status-code is one of the four specified in the preceding
  paragraph, the Unsupported Attributes group MUST contain all of those
  attributes and only those attributes that are:

  a.  an operation or Job Template attribute supplied in the request,
      and

  b.  unsupported by the Printer.  See below for details on the three
      categories of "unsupported" attributes.

  If the status-code is one of those in Table 1 in Section 4.1.6.1, the
  OPTIONAL Unsupported Attributes group contains the unsupported
  parameter or attribute indicated in that table.

  If the Printer is not returning any unsupported attributes in the
  response, the Printer SHOULD omit the Unsupported Attributes group
  rather than sending an empty group.  However, a Client MUST be able
  to accept an empty group.

  Unsupported attributes fall into three categories:

  1.  The Printer does not support the supplied attribute (no matter
      what the attribute syntax or value).

  2.  The Printer does support the attribute, but it does not support
      some or all of the particular attribute syntaxes or values
      supplied by the Client, i.e., the Printer does not have those
      attribute syntaxes or values in its corresponding "xxx-supported"
      attribute.






Sweet & McDonald             Standards Track                   [Page 44]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  3.  The Printer does support the attributes and values supplied, but
      the particular values are in conflict with one another, because
      they violate a constraint, such as not being able to staple
      transparencies.

  In the case of an unsupported attribute name, the Printer returns the
  Client-supplied attribute with a substituted value of 'unsupported'.
  This value's syntax type is "out-of-band", and its encoding is
  defined by special rules for "out-of-band" values in the Encoding and
  Transport document [RFC8010].  Its value indicates no support for the
  attribute itself -- see the beginning of Section 5.1 in this
  document.

  In the case of a supported attribute with one or more unsupported
  attribute syntaxes or values, the Printer simply returns the
  Client-supplied attribute with the unsupported attribute syntaxes or
  values as supplied by the Client.  This indicates support for the
  attribute but no support for that particular attribute syntax or
  value.  If the Client supplies a multi-valued attribute with more
  than one value and the Printer supports the attribute but only
  supports a subset of the Client-supplied attribute syntaxes or
  values, the Printer MUST return only those attribute syntaxes or
  values that are unsupported.

  In the case of two (or more) supported attribute values that are in
  conflict with one another (although each is supported independently,
  the values conflict when requested together within the same Job), the
  Printer MUST return all the values that it ignores or substitutes to
  resolve the conflict but not any of the values that it is still
  using.  The choice for exactly how to resolve the conflict is
  implementation dependent.  See Section 4.2.1.2 and Appendix C.  See
  the Implementor's Guides [RFC3196] [PWG5100.19] for examples.

4.1.8.  Versions

  Each operation request and response carries with it a
  "version-number" parameter.  Each value of the "version-number"
  parameter is in the form "X.Y" where X is the major version number
  and Y is the minor version number.  By including a version number in
  the Client request, it allows the Client to identify which version of
  IPP it is interested in using, i.e., the version whose conformance
  requirements the Client can depend upon the Printer to meet.

  If the IPP object does not support that major version number supplied
  by the Client, i.e., the "major version number" portion of the
  "version-number" parameter does not match any of the values of the
  Printer's "ipp-versions-supported" attribute (see Section 5.4.14),
  the object MUST respond with a status-code of



Sweet & McDonald             Standards Track                   [Page 45]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  'server-error-version-not-supported' along with the closest version
  number that is supported (see Appendix B.1.5.4).  If the major
  version number is supported but the minor version number is not, the
  IPP object SHOULD accept the request and attempt to perform it (or
  reject the request if the operation is not supported); otherwise, it
  rejects the request and returns the
  'server-error-version-not-supported' status-code.  In all cases, the
  IPP object MUST return the "version-number" value that it supports
  that is closest to the version number supplied by the Client in the
  request.

  There is no version negotiation per se.  However, if a Client has
  received a 'server-error-version-not-supported' status-code from an
  IPP object, the Client SHOULD try again with a different version
  number.  A Client MAY also determine the versions supported either
  from a directory that conforms to Appendix D or by querying the
  Printer's "ipp-versions-supported" attribute (see Section 5.4.14) to
  determine which versions are supported.

  An IPP/1.1 object implementation MUST support version '1.1', i.e.,
  meet the conformance requirements for IPP/1.1 as specified in this
  document and [RFC8010].  IPP implementations SHOULD accept any
  request with the major version '1' or '2', or reject the request if
  the operation is not supported.

  There is only one notion of "version number" that covers both IPP
  Model and IPP protocol changes.  Changes to the major version number
  of the Model and Semantics document can indicate structural or
  syntactic changes that make it impossible for older versions of IPP
  Clients and Printers to correctly parse and correctly process the new
  or changed attributes, operations, and responses.  If the major
  version number changes, the minor version number is set to zero.  As
  an example, adding the REQUIRED "ipp-attribute-fidelity" attribute to
  version '1.1' (if it had not been part of version '1.0') would have
  required a change to the major version number, since an IPP/1.0
  Printer would not have processed a request with the correct semantics
  that contained the "ipp-attribute-fidelity" attribute that it did not
  know about.  Items that might affect the changing of the major
  version number include any changes to the Model and Semantics
  document (this document) or the Encoding and Transport document
  [RFC8010] itself, such as:

  o  reordering of ordered attributes or attribute sets

  o  changes to the syntax of existing attributes

  o  adding REQUIRED (for an IPP object to support) Operation
     Attributes groups



Sweet & McDonald             Standards Track                   [Page 46]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  o  adding values to existing REQUIRED operation attributes

  o  adding REQUIRED operations

  Changes to the minor version number indicate the addition of new
  features, attributes, and attribute values that might not be
  understood by all IPP objects but that can be ignored if not
  understood.  Items that might affect the changing of the minor
  version number include any changes to the model objects and
  attributes but not the encoding and transport rules [RFC8010] (except
  adding attribute syntaxes).  Examples of such changes are:

  o  grouping all extensions not included in a previous version into a
     new version

  o  adding new attribute values

  o  adding new object attributes

  o  adding OPTIONAL (for an IPP object to support) operation
     attributes (i.e., those attributes that an IPP object can ignore
     without confusing Clients)

  o  adding OPTIONAL (for an IPP object to support) Operation
     Attributes groups (i.e., those attributes that an IPP object can
     ignore without confusing Clients)

  o  adding new attribute syntaxes

  o  adding OPTIONAL operations

  o  changing Job attributes or Printer attributes from OPTIONAL to
     REQUIRED or vice versa

  o  adding OPTIONAL attribute syntaxes to an existing attribute

  The encoding [RFC8010] of the "version-number" parameter MUST NOT
  change over any version number (either major or minor).  This rule
  guarantees that all future versions will be backwards compatible with
  all previous versions (at least for checking the "version-number"
  parameter).  In addition, any protocol elements (attributes, error
  codes, tags, etc.) that are not carried forward from one version to
  the next are DEPRECATED so that they can never be reused with new
  semantics.







Sweet & McDonald             Standards Track                   [Page 47]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  Implementations that support a certain version SHOULD support all
  previous Standards Track versions.  As each new version is defined
  (through the release of a new IPP specification document), that
  version will specify which previous versions MUST and which versions
  SHOULD be supported in compliant implementations.

4.1.9.  Job Creation Operations

  In order to "submit a Print Job" and create a new Job, a Client
  issues a Job Creation request.  A Job Creation request is any one of
  the following three operation requests:

  o  The Print-Job Request: A Client that wants to submit a Print Job
     with only a single Document can use the Print-Job operation.  The
     operation allows for the Client to "push" the Document data to the
     Printer by including the Document data in the request itself.
     Note that Clients SHOULD instead use the Create-Job and
     Send-Document requests, if supported by the Printer, since they
     allow for Job monitoring and control during submission of the
     Document data.

  o  The Print-URI Request: A Client that wants to submit a Print Job
     with only a single Document (where the Printer "pulls" the
     Document data instead of the Client "pushing" the data to the
     Printer) uses the Print-URI operation.  In this case, the Client
     includes in the request only a URI reference to the Document data
     (not the Document data itself).

  o  The Create-Job Request: A Client that wants to submit a Print Job
     with zero or more Documents uses the Create-Job operation.  This
     operation is followed by an arbitrary number of Send-Document
     and/or Send-URI operations, each creating another Document for the
     newly created Job.  The Send-Document operation includes the
     Document data in the request (the Client "pushes" the Document
     data to the Printer), and the Send-URI operation includes only a
     URI reference to the Document data in the request (the Printer
     "pulls" the Document data from the referenced location).  The last
     Send-Document or Send-URI request for a given Job includes a
     "last-document" operation attribute set to 'true' indicating that
     this is the last request.

  Throughout this document, the term "Job Creation request" is used to
  refer to any of these three operation requests.

  A Create-Job operation followed by only one Send-Document operation
  is semantically equivalent to a Print-Job operation; however, the
  Client SHOULD use the Create-Job and Send-Document operations (when
  supported) for all Jobs with a single Document to allow for reliable



Sweet & McDonald             Standards Track                   [Page 48]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  Job control and monitoring.  Print-Job is a REQUIRED operation (all
  implementations MUST support it), whereas Create-Job is a RECOMMENDED
  operation and hence some implementations might not support it.

  Job submission time is the point in time when a Client issues a Job
  Creation request.  The initial state of every Job is the 'pending',
  'pending-held', or 'processing' state (see Section 5.3.7).  When the
  Printer begins processing the Print Job, the Job's state moves to
  'processing'.  This is known as Job processing time.

  At Job submission time and at the time a Validate-Job operation is
  received, the Printer MUST do the following:

  1.  Process the Client-supplied attributes and either accept or
      reject the request

  2.  Validate the syntax of and support for the scheme of any
      Client-supplied URI

  At Job submission time, the Printer MUST validate whether the
  supplied attributes, attribute syntaxes, and values are supported by
  matching them with the Printer's corresponding "xxx-supported"
  attributes.  See Section 4.1.7 for details.  See the Implementor's
  Guides [RFC3196] [PWG5100.19] for guidance on processing Job Creation
  requests.

  At Job submission time, the Printer MAY perform the validation checks
  reserved for Job processing time, such as:

  1.  Validating the format of the Document data

  2.  Validating the actual contents of any Client-supplied URI
      (resolve the reference and follow the link to the Document data)

  At Job submission time, these additional Job processing time
  validation checks are essentially useless, since they require
  actually parsing and interpreting the Document data, are not
  guaranteed to be 100% accurate, and MUST be done, yet again, at Job
  processing time.  Also, in the case of a URI, checking for
  availability at Job submission time does not guarantee availability
  at Job processing time.  In addition, at Job processing time, the
  Printer might discover any of the following conditions that were not
  detectable at Job submission time:

  o  runtime errors in the Document data,

  o  nested Document data that is in an unsupported format,




Sweet & McDonald             Standards Track                   [Page 49]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  o  the URI reference is no longer valid (i.e., the server hosting the
     Document might be down), or

  o  any other Job processing error.

  At Job submission time, a Printer, especially a non-spooling Printer,
  MAY accept Jobs for which it does not have enough space.  In such a
  situation, a Printer MAY stop reading data from a Client for an
  indefinite period of time.  A Client MUST be prepared for a write
  operation to block for an indefinite period of time (see Section 6.1
  ("Client Conformance Requirements")).

  When a Printer has too little space for starting a new Job, it MAY
  reject a new Job Creation request.  In this case, a Printer MUST
  return a response (in reply to the rejected request) with a
  status-code of 'server-error-busy' (see Appendix B.1.5.8), and it MAY
  close the connection before receiving all bytes of the operation.  A
  Printer SHOULD indicate that it is temporarily unable to accept Jobs
  by setting the 'spool-space-full' value in its
  "printer-state-reasons" attribute and removing the value when it can
  accept another Job (see Section 5.4.12).

  When receiving a 'server-error-busy' status-code in an operation
  response, a Client MUST be prepared for the Printer to close the
  connection before the Client has sent all of the data (especially for
  the Print-Job operation).  A Client MUST be prepared to keep
  submitting a Job Creation request until the Printer accepts the Job
  Creation request.

  At Job processing time, since the Printer has already responded with
  a successful status-code in the response to the Job Creation request,
  if the Printer detects an error, the Printer is unable to inform the
  End User of the error with an operation status-code.  In this case,
  the Printer, depending on the error, can set the Job's "job-state",
  "job-state-reasons", and/or "job-state-message" attributes to the
  appropriate value(s) so that later queries can report the correct Job
  status.

  Note: Asynchronous notification of events is defined in "Internet
  Printing Protocol (IPP): Event Notifications and Subscriptions"
  [RFC3995].

4.2.  Printer Operations

  All Printer operations are directed at Printers.  A Client MUST
  always supply the "printer-uri" operation attribute in order to
  identify the correct target of the operation.




Sweet & McDonald             Standards Track                   [Page 50]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


4.2.1.  Print-Job Operation

  This REQUIRED operation allows a Client to submit a Print Job with
  only one Document and supply the Document data (rather than just a
  reference to the data).  See Appendix C for the suggested steps for
  processing Job Creation requests and their operation and Job Template
  attributes.

4.2.1.1.  Print-Job Request

  The following groups of attributes are supplied as part of the
  Print-Job request:

  Group 1: Operation Attributes

     Natural Language and Character Set:

        The "attributes-charset" and "attributes-natural-language"
        attributes as described in Section 4.1.4.1.  The Printer MUST
        copy these values to the corresponding Job Status attributes
        described in Sections 5.3.19 and 5.3.20.

     Target:

        The "printer-uri" (uri) operation attribute, which is the
        target for this operation as described in Section 4.1.5.

     Requesting User Name:

        The "requesting-user-name" (name(MAX)) attribute SHOULD be
        supplied by the Client as described in Section 9.3.

     "job-name" (name(MAX)):

        The Client MAY supply and the Printer MUST support this
        attribute.  It contains the Client-supplied Job name.  If this
        attribute is supplied by the Client, its value is used for the
        "job-name" attribute of the newly created Job.  The Client MAY
        automatically include any information that will help the
        End User distinguish amongst his/her Jobs, such as the name of
        the application program along with information from the
        Document, such as the Document name, Document subject, or
        source file name.  If this attribute is not supplied by the
        Client, the Printer generates a name to use in the "job-name"
        attribute of the newly created Job (see Section 5.3.5).






Sweet & McDonald             Standards Track                   [Page 51]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


     "ipp-attribute-fidelity" (boolean):

        The Client MAY supply and the Printer MUST support this
        attribute.  The value 'true' indicates that total fidelity to
        Client-supplied Job Template attributes and values is required;
        otherwise, the Printer MUST reject the Print-Job request.  The
        value 'false' indicates that a reasonable attempt to print the
        Job is acceptable and the Printer MUST accept the Print-Job
        request.  If not supplied, the Printer assumes that the value
        is 'false'.  All Printers MUST support both types of Job
        processing.  See Appendix C for a full description of
        "ipp-attribute-fidelity" and its relationship to other
        attributes, especially the Printer's "pdl-override-supported"
        attribute.

     "document-name" (name(MAX)):

        The Client MAY supply and the Printer MUST support this
        attribute.  It contains the Client-supplied Document name.  The
        Document name MAY be different than the Job name.  Typically,
        the Client software automatically supplies the Document name on
        behalf of the End User by using a file name or an
        application-generated name.  If this attribute is supplied, its
        value can be used in a manner defined by each implementation.
        Examples include the following: printed along with the Job (Job
        start sheet, page adornments, etc.), used by accounting or
        resource-tracking management tools, or even stored along with
        the Document as a Document-level attribute.

     "compression" (type2 keyword):

        The Client MAY supply and the Printer MUST support this
        attribute.  The Client-supplied "compression" operation
        attribute identifies the compression algorithm used on the
        Document data.  The following cases exist:

        a.  If the Client omits this attribute, the Printer MUST assume
            that the data is not compressed, i.e., the Printer follows
            the rules below as if the Client supplied the "compression"
            attribute with a value of 'none'.

        b.  If the Client supplies this attribute but the value is not
            supported by the Printer, i.e., the value is not one of the
            values of the Printer's "compression-supported" attribute,
            the Printer MUST reject the request and return the
            'client-error-compression-not-supported' status-code.  See
            Section 4.1.7 for details on returning unsupported
            attributes and values.



Sweet & McDonald             Standards Track                   [Page 52]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


        c.  If the Client supplies the attribute and the Printer
            supports the attribute value, the Printer uses the
            corresponding decompression algorithm on the Document data.

        d.  If the decompression algorithm fails before the Printer
            returns an operation response, the Printer MUST reject the
            request and return the 'client-error-compression-error'
            status-code.

        e.  If the decompression algorithm fails after the Printer
            returns an operation response, the Printer MUST abort the
            Job and add the 'compression-error' value to the Job's
            "job-state-reasons" attribute.

        f.  If the decompression algorithm succeeds, the Document data
            MUST then have the format specified by the Job's
            "document-format" attribute, if supplied (see the
            "document-format" operation attribute definition below).

     "document-format" (mimeMediaType):

        The Client MAY supply and the Printer MUST support this
        attribute.  The value identifies the format of the supplied
        Document data.  The following cases exist:

        a.  If the Client does not supply this attribute, the Printer
            assumes that the Document data is in the format defined by
            the Printer's "document-format-default" attribute (i.e.,
            the Printer follows the rules below as if the Client
            supplied the "document-format" attribute with a value equal
            to the Printer's default value).

        b.  If the Client supplies this attribute but the value is not
            supported by the Printer, i.e., the value is not one of the
            values of the Printer's "document-format-supported"
            attribute, the Printer MUST reject the request and return
            the 'client-error-document-format-not-supported'
            status-code.

        c.  If the Client supplies this attribute and its value is
            'application/octet-stream' (i.e., to be auto-sensed; see
            Section 5.1.10.1), and the format is not one of the
            Document formats that the Printer can auto-sense, and this
            check occurs before the Printer returns an operation
            response, then the Printer MUST reject the request and
            return the 'client-error-document-format-not-supported'
            status-code.




Sweet & McDonald             Standards Track                   [Page 53]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


        d.  If the Client supplies this attribute and the value is
            supported by the Printer, the Printer is capable of
            interpreting the Document data.

        e.  If interpretation of the Document data fails before the
            Printer returns an operation response, the Printer MUST
            reject the request and return the
            'client-error-document-format-error' status-code.

        f.  If interpretation of the Document data fails after the
            Printer returns an operation response, the Printer MUST
            abort the Job and add the 'document-format-error' value to
            the Job's "job-state-reasons" attribute.

     "document-natural-language" (naturalLanguage):

        The Client MAY supply and the Printer SHOULD support this
        attribute.  The value specifies the natural language of the
        Document content for those Document formats that require a
        specification of the natural language in order to properly
        image the Document.

     "job-k-octets" (integer(0:MAX)):

        The Client MAY supply and the Printer SHOULD support this
        attribute.  The Client-supplied "job-k-octets" operation
        attribute identifies the total size of the Document(s) in
        K octets being submitted (see Section 5.3.17.1 for the complete
        semantics).  If the Client supplies the attribute and the
        Printer supports the attribute, the value of the attribute is
        used to populate the Job's "job-k-octets" Job Description
        attribute.

        For this attribute and the following two attributes
        ("job-impressions" and "job-media-sheets"), if the Client
        supplies the attribute but the Printer does not support the
        attribute, the Printer ignores the Client-supplied value.  If
        the Client supplies the attribute and the Printer supports the
        attribute, and the value is within the range of the
        corresponding Printer's "xxx-supported" attribute, the Printer
        MUST use the value to populate the Job's "xxx" attribute.  If
        the Client supplies the attribute and the Printer supports the
        attribute, but the value is outside the range of the
        corresponding Printer's "xxx-supported" attribute, the Printer
        MUST copy the attribute and its value to the Unsupported
        Attributes group, reject the request, and return the
        'client-error-attributes-or-values-not-supported' status-code.
        If the Client does not supply the attribute, the Printer SHOULD



Sweet & McDonald             Standards Track                   [Page 54]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


        populate the corresponding Job attribute if it supports the
        attribute and is able to calculate or discern the correct
        value.

     "job-impressions" (integer(0:MAX)):

        The Client MAY supply and the Printer SHOULD support this
        attribute.  The Client-supplied "job-impressions" operation
        attribute identifies the total size in number of Impressions of
        the Document(s) being submitted (see Section 5.3.17.2 for the
        complete semantics).

        See the last paragraph under "job-k-octets".

     "job-media-sheets" (integer(1:MAX)):

        The Client MAY supply and the Printer SHOULD support this
        attribute.  The Client-supplied "job-media-sheets" operation
        attribute identifies the total number of Media Sheets to be
        produced for this Job (see Section 5.3.17.3 for the complete
        semantics).

        See the last paragraph under "job-k-octets".

  Group 2: Job Template Attributes

     The Client MAY supply a set of Job Template attributes as defined
     in Section 5.2.  If the Client is not supplying any Job Template
     attributes in the request, the Client SHOULD omit Group 2 rather
     than sending an empty group.  However, a Printer MUST be able to
     accept an empty group.

  Group 3: Document Data

     The Client MUST supply the Document data to be processed.

  The simplest Print-Job request consists of just the
  "attributes-charset" and "attributes-natural-language" operation
  attributes, the "printer-uri" target operation attribute, and the
  Document data.  In this simple case, the Printer:

  o  creates a new Job containing a single Document,

  o  stores a generated Job name in the "job-name" attribute in the
     natural language and charset requested (see Section 4.1.4.1) (if
     those are supported; otherwise, using the Printer's default
     natural language and charset), and




Sweet & McDonald             Standards Track                   [Page 55]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  o  at Job processing time, uses its corresponding default value
     attributes for the supported Job Template attributes that were not
     supplied by the Client as an IPP attribute or embedded
     instructions in the Document data.

4.2.1.2.  Print-Job Response

  The Printer MUST return to the Client the following sets of
  attributes as part of the Print-Job response:

  Group 1: Operation Attributes

     Natural Language and Character Set:

        The "attributes-charset" and "attributes-natural-language"
        attributes as described in Section 4.1.4.2.

     Status Message:

        In addition to the REQUIRED status-code returned in every
        response, the response MAY include a "status-message"
        (text(255)) and/or a "detailed-status-message" (text(MAX))
        operation attribute as described in Appendix B and
        Section 4.1.6.  If the Client supplies unsupported or
        conflicting Job Template attributes or values, the Printer MUST
        reject or accept the Print-Job request, depending on whether
        the Client supplied a 'true' or 'false' value for the
        "ipp-attribute-fidelity" operation attribute.  See the
        Implementor's Guides [RFC3196] [PWG5100.19] for guidance on
        processing Job Creation requests.

  Group 2: Unsupported Attributes

     See Section 4.1.7 for details on returning unsupported attributes.

     The value of "ipp-attribute-fidelity" supplied by the Client does
     not affect what attributes the Printer returns in this group.  The
     value of "ipp-attribute-fidelity" only affects whether the
     Print-Job operation is accepted or rejected.  If the Job is
     accepted, the Client can query the Job using the
     Get-Job-Attributes operation, requesting the unsupported
     attributes that were returned in the Print-Job response to see
     which attributes were ignored (not stored in the Job) and which
     attributes were stored with other (substituted) values.







Sweet & McDonald             Standards Track                   [Page 56]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  Group 3: Job Attributes

     "job-id" (integer(1:MAX)):

        The Printer MUST return the Job's ID in the REQUIRED "job-id"
        Job attribute.  The Client uses this "job-id" attribute in
        conjunction with the "printer-uri" attribute used in the
        Print-Job request when directing Job operations at the Printer.

     "job-uri" (uri):

        The Printer MUST return the Job's URI by returning the contents
        of the REQUIRED "job-uri" Job attribute.

     "job-state" (type1 enum):

        The Printer MUST return the Job's REQUIRED "job-state"
        attribute.  The value of this attribute along with the value of
        the "job-state-reasons" attribute is a "snapshot" of the new
        Job's state when the Printer returns the response.

     "job-state-reasons" (1setOf type2 keyword):

        The Printer MUST return the Job's REQUIRED "job-state-reasons"
        attribute.

     "job-state-message" (text(MAX)):

        The Printer SHOULD return the Job's RECOMMENDED
        "job-state-message" attribute.  If the Printer supports this
        attribute, then it MUST be returned in the response.  If this
        attribute is not returned in the response, the Client can
        assume that the "job-state-message" attribute is not supported
        and will not be returned in a subsequent Job query.

     "number-of-intervening-jobs" (integer(0:MAX)):

        The Printer SHOULD return the Job's RECOMMENDED
        "number-of-intervening-jobs" attribute.  If the Printer
        supports this attribute, then it MUST be returned in the
        response.  If this attribute is not returned in the response,
        the Client can assume that the "number-of-intervening-jobs"
        attribute is not supported and will not be returned in a
        subsequent Job query.







Sweet & McDonald             Standards Track                   [Page 57]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  Note: Since any Printer state information that affects a Job's state
  is reflected in the "job-state" and "job-state-reasons" attributes,
  it is sufficient to return only these attributes and no additional
  Printer Status attributes.

  Note: The simplest response consists of just the "attributes-charset"
  and "attributes-natural-language" operation attributes and the
  "job-uri", "job-id", and "job-state" Job attributes.  In this
  simplest case, the status-code is 'successful-ok' and there is no
  "status-message" or "detailed-status-message" operation attribute.

4.2.2.  Print-URI Operation

  This OPTIONAL operation is identical to the Print-Job operation
  (Section 4.2.1), except that a Client supplies a URI reference to the
  Document data using the "document-uri" (uri) operation attribute (in
  Group 1) rather than including the Document data itself.  Before
  returning the response, the Printer MUST validate that the Printer
  supports the retrieval method (e.g., 'http', 'ftp', etc.) implied by
  the URI and MUST check for valid URI syntax.  If the Client-supplied
  URI scheme is not supported, i.e., the value is not in the Printer's
  "referenced-uri-scheme-supported" attribute, the Printer MUST reject
  the request and return the 'client-error-uri-scheme-not-supported'
  status-code.

  The Printer MAY validate the accessibility of the Document as part of
  the operation, or subsequently.  If the Printer discovers an
  accessibility problem before returning an operation response, it MUST
  reject the request and return the
  'client-error-document-access-error' status-code.  The Printer MAY
  also return a specific Document access error code using the
  "document-access-error" operation attribute (see Section 4.1.6.4).

  If the Printer discovers this Document accessibility problem after
  accepting the request and returning an operation response with one of
  the successful status-code values, the Printer MUST add the
  "document-access-error" value to the Job's "job-state-reasons"
  attribute and MAY populate the Job's "job-document-access-errors" Job
  Status attribute (see Section 5.3.11).  See the Implementor's Guides
  [RFC3196] [PWG5100.19] for guidance on processing Job Creation
  requests.

  If the Printer supports this operation, it MUST support the
  "reference-uri-schemes-supported" Printer attribute (see
  Section 5.4.27).

  It is up to the Printer to interpret the URI and subsequently "pull"
  the Document data from the source referenced by the URI string.



Sweet & McDonald             Standards Track                   [Page 58]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


4.2.3.  Validate-Job Operation

  This REQUIRED operation is similar to the Print-Job operation
  (Section 4.2.1), except that a Client supplies no Document data and
  the Printer allocates no resources, i.e., it does not create a new
  Job.  This operation is used only to verify the capabilities of a
  Printer against whatever attributes are supplied by the Client in the
  Validate-Job request.  By using the Validate-Job operation, a Client
  can validate that an identical Job Creation request (with the
  Document data) would be accepted.  The Validate-Job operation also
  performs the same security negotiation as the Print-Job, Print-URI,
  and Create-Job operations (see Section 9) so that a Client can check
  that the Client and Printer security requirements can be met before
  performing a Job Creation request.

  The Validate-Job operation does not accept a "document-uri" attribute
  in order to allow a Client to check that the same Print-URI operation
  will be accepted, since the Client doesn't send the data with the
  Print-URI operation.  The Client SHOULD just issue the Print-URI
  request.

  The Printer returns the same status-code values, Operation Attributes
  (Group 1), and Unsupported Attributes (Group 2) as the Print-Job
  operation.  However, no Job Attributes (Group 3) are returned, since
  no Job is created.

4.2.4.  Create-Job Operation

  This RECOMMENDED operation is similar to the Print-Job operation
  (Section 4.2.1), except that in the Create-Job request, a Client does
  not supply Document data or any reference to Document data.  Also,
  the Client does not supply any of the "document-name",
  "document-format", "compression", or "document-natural-language"
  operation attributes.  This operation is followed by one or more
  Send-Document or Send-URI operations.  In each of those operation
  requests, the Client MAY supply the "document-name",
  "document-format", and "document-natural-language" attributes for
  each Document in the Job.

  If a Printer supports the Create-Job operation, it MUST also support
  the Send-Document operation.  If the Printer supports the Create-Job
  and Print-URI operations, it MUST also support the Send-URI
  operation.

  If the Printer supports this operation, it MUST support the
  "multiple-operation-time-out" Printer attribute (see Section 5.4.31).





Sweet & McDonald             Standards Track                   [Page 59]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  If the Printer supports this operation, then it MUST support the
  "multiple-document-jobs-supported" Printer Description attribute
  (see Section 5.4.16) and indicate whether it supports multiple
  Documents in a Job.

  If the Printer supports this operation and supports multiple
  Documents in a Job, then it MUST support the
  "multiple-document-handling" Job Template attribute with at least
  one value (see Section 5.2.4), and the associated
  "multiple-document-handling-default" and
  "multiple-document-handling-supported" Printer attributes
  (see Section 5.2).

  After the Create-Job operation has completed, the value of the
  "job-state" attribute is similar to the "job-state" after a Print-Job
  operation, even though no Document data has arrived.  A Printer MAY
  set the 'job-data-insufficient' value of the Job's
  "job-state-reasons" attribute to indicate that processing cannot
  begin until sufficient data has arrived and set the "job-state" to
  either 'pending' or 'pending-held'.  A non-spooling Printer that
  doesn't implement the 'pending' Job state can set "job-state" to
  'processing', even though there is not yet any data to process.
  See Sections 5.3.7 and 5.3.8.

4.2.5.  Get-Printer-Attributes Operation

  This REQUIRED operation allows a Client to request the values of the
  attributes of a Printer.  In the request, the Client supplies the set
  of Printer attribute names and/or attribute group names in which the
  requester is interested.  In the response, the Printer returns a
  corresponding attribute set with the appropriate attribute values
  filled in.

  For Printers, the possible names of attribute groups are:

  o  'job-template': the subset of the Job Template attributes that
     apply to a Printer (the last two columns of Table 8 in
     Section 5.2) that the implementation supports for Printers.

  o  'printer-description': the subset of the attributes specified in
     Section 5.4 that the implementation supports for Printers.

  o  'all': the special group 'all' that includes all attributes that
     the implementation supports for Printers.

  Since a Client MAY request specific attributes or named groups, there
  is a potential for some overlap.  For example, if a Client requests
  'printer-name' and 'all', the Client is actually requesting the



Sweet & McDonald             Standards Track                   [Page 60]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  "printer-name" attribute twice: once by naming it explicitly, and
  once by inclusion in the 'all' group.  In such cases, the Printer
  returns each attribute only once in the response even if it is
  requested multiple times.  The Client SHOULD NOT request the same
  attribute in multiple ways.

  Printers MUST support all group names and MUST return all supported
  attributes belonging to the group.

4.2.5.1.  Get-Printer-Attributes Request

  The following sets of attributes are part of the
  Get-Printer-Attributes request:

  Group 1: Operation Attributes

     Natural Language and Character Set:

        The "attributes-charset" and "attributes-natural-language"
        attributes as described in Section 4.1.4.1.

     Target:

        The "printer-uri" (uri) operation attribute, which is the
        target for this operation as described in Section 4.1.5.

     Requesting User Name:

        The "requesting-user-name" (name(MAX)) attribute SHOULD be
        supplied by the Client as described in Section 9.3.

     "requested-attributes" (1setOf keyword):

        The Client MAY supply a set of attribute names and/or attribute
        group names in whose values the requester is interested.  The
        Printer MUST support this attribute.  If the Client omits this
        attribute, the Printer MUST respond as if this attribute had
        been supplied with a value of 'all'.

     "document-format" (mimeMediaType):

        The Client MAY supply and the Printer MUST support this
        attribute.  It is useful for a Client to determine the set of
        supported attribute values that relate to the requested
        Document format.  The Printer MUST return the attributes and
        values that it uses to validate a Job in a Job Creation or
        Validate-Job operation in which this Document format is
        supplied.  The Printer SHOULD return only (1) those attributes



Sweet & McDonald             Standards Track                   [Page 61]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


        that are supported for the specified format and (2) the
        attribute values that are supported for the specified Document
        format.  By specifying the Document format, the Client can get
        the Printer to eliminate the attributes and values that are not
        supported for a specific Document format.  For example, a
        Printer might have multiple interpreters to support both
        'application/postscript' (for PostScript) and 'text/plain' (for
        text) Documents.  However, only one of those interpreters might
        support the "number-up" Job Template attribute with values of
        '1', '2', and '4'.  The other interpreter might only be able to
        support the "number-up" Job Template attribute with a value of
        '1'.  Thus, a Client can use the Get-Printer-Attributes
        operation to obtain the attributes and values that will be used
        to accept/reject a Job Creation request.

        If the Printer does not distinguish between different sets of
        supported values for each different Document format when
        validating Jobs in the Create-Job, Print-Job, Print-URI, and
        Validate-Job operations, it MUST NOT distinguish between
        different Document formats in the Get-Printer-Attributes
        operation.  If the Printer does distinguish between different
        sets of supported values for each different Document format
        specified by the Client, this specialization applies only to
        the following Printer attributes:

        +  Printer attributes that are Job Template attributes
           ("xxx-default", "xxx-supported", and "xxx-ready")
           (see Table 8 in Section 5.2),

        +  "pdl-override-supported",

        +  "compression-supported",

        +  "job-k-octets-supported",

        +  "job-impressions-supported,

        +  "job-media-sheets-supported",

        +  "printer-driver-installer",

        +  "color-supported", and

        +  "reference-uri-schemes-supported"







Sweet & McDonald             Standards Track                   [Page 62]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


        The values of all other Printer attributes (including
        "document-format-supported") remain invariant with respect to
        the Client-supplied Document format (except for new Printer
        Description attributes as registered according to Section 7.2).

        If the Client omits this "document-format" operation attribute,
        the Printer MUST respond as if the attribute had been supplied
        with the value of the Printer's "document-format-default"
        attribute.  Clients SHOULD always supply a value for
        "document-format", since the Printer's
        "document-format-default" value can be
        'application/octet-stream', in which case the returned
        attributes and values are for the union of the Document formats
        that the Printer can automatically sense.  For more details,
        see the description of the 'mimeMediaType' attribute syntax in
        Section 5.1.10.

        If the Client supplies a value for the "document-format"
        operation attribute that is not supported by the Printer, i.e.,
        is not among the values of the Printer's
        "document-format-supported" attribute, the Printer MUST reject
        the operation and return the
        'client-error-document-format-not-supported' status-code.

4.2.5.2.  Get-Printer-Attributes Response

  The Printer returns the following sets of attributes as part of the
  Get-Printer-Attributes response:

  Group 1: Operation Attributes

     Natural Language and Character Set:

        The "attributes-charset" and "attributes-natural-language"
        attributes as described in Section 4.1.4.2.

     Status Message:

        In addition to the REQUIRED status-code returned in every
        response, the response MAY include a "status-message"
        (text(255)) and/or a "detailed-status-message" (text(MAX))
        operation attribute as described in Appendix B and
        Section 4.1.6.








Sweet & McDonald             Standards Track                   [Page 63]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  Group 2: Unsupported Attributes

     See Section 4.1.7 for details on returning unsupported attributes.

     The response MAY contain the "requested-attributes" operation
     attribute with any supplied values (attribute keywords) that were
     requested by the Client but are not supported by the Printer.  If
     the Printer does return unsupported attributes referenced in the
     "requested-attributes" operation attribute and that attribute
     included group names, such as 'all', the unsupported attributes
     MUST NOT include attributes described in this document but not
     supported by the implementation.

  Group 3: Printer Attributes

     This is the set of requested attributes and their current values.
     The Printer ignores (does not respond with) any requested
     attribute that is not supported.  The Printer MAY respond with a
     subset of the supported attributes and values, depending on the
     security policy in force.  However, the Printer MUST respond with
     the 'unknown' value for any supported attribute (including all
     REQUIRED attributes) for which the Printer does not know the
     value.  Also, the Printer MUST respond with 'no-value' for any
     supported attribute (including all REQUIRED attributes) for which
     the Administrator has not configured a value.  See the description
     of the "out-of-band" values in the beginning of Section 5.1.

4.2.6.  Get-Jobs Operation

  This REQUIRED operation allows a Client to retrieve the list of Jobs
  belonging to the target Printer.  The Client can also supply a list
  of Job attribute names and/or attribute group names.  A group of Job
  attributes will be returned for each Job that is returned.

  This operation is similar to the Get-Job-Attributes operation, except
  that this Get-Jobs operation returns attributes from possibly more
  than one Job.














Sweet & McDonald             Standards Track                   [Page 64]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


4.2.6.1.  Get-Jobs Request

  The Client submits the Get-Jobs request to a Printer.

  The following groups of attributes are part of the Get-Jobs request:

  Group 1: Operation Attributes

     Natural Language and Character Set:

        The "attributes-charset" and "attributes-natural-language"
        attributes as described in Section 4.1.4.1.

     Target:

        The "printer-uri" (uri) operation attribute, which is the
        target for this operation as described in Section 4.1.5.

     Requesting User Name:

        The "requesting-user-name" (name(MAX)) attribute SHOULD be
        supplied by the Client as described in Section 9.3.

     "limit" (integer(1:MAX)):

        The Client MAY supply and the Printer MUST support this
        attribute.  It is an integer value that determines the maximum
        number of Jobs that a Client will receive from the Printer even
        if "which-jobs" or "my-jobs" (described below) constrain which
        Jobs are returned.  The limit is a "stateless limit" in that if
        the value supplied by the Client is 'N', then only the first
        'N' Jobs are returned in the Get-Jobs response.  If the Client
        does not supply this attribute, the Printer responds with all
        applicable Jobs.

     "requested-attributes" (1setOf type2 keyword):

        The Client MAY supply and the Printer MUST support this
        attribute.  It is a set of Job attribute names and/or attribute
        group names in whose values the requester is interested.  This
        set of attributes is returned for each Job that is returned.
        The allowed attribute group names are the same as those defined
        in the Get-Job-Attributes operation in Section 4.3.4.  If the
        Client does not supply this attribute, the Printer MUST respond
        as if the Client had supplied this attribute with two values:
        "job-uri" and "job-id".





Sweet & McDonald             Standards Track                   [Page 65]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


     "which-jobs" (type2 keyword):

        The Client MAY supply and the Printer MUST support this
        attribute.  It indicates which Jobs MUST be returned by the
        Printer.  The values for this attribute include:

        +  'completed': Any Job whose state is 'completed', 'canceled',
           or 'aborted'.

        +  'not-completed': Any Job whose state is 'pending',
           'processing', 'processing-stopped', or 'pending-held'.

        A Printer MUST support both values.  However, if the
        implementation does not keep Jobs in the 'completed',
        'canceled', and 'aborted' states, then it returns no Jobs when
        the 'completed' value is supplied.

        If a Client supplies some other value that is not supported by
        the Printer, the Printer MUST copy the attribute and the
        unsupported value to the Unsupported Attributes group, reject
        the request, and return the
        'client-error-attributes-or-values-not-supported' status-code.

        If the Client does not supply this attribute, the Printer MUST
        respond as if the Client had supplied the attribute with a
        value of 'not-completed'.

     "my-jobs" (boolean):

        The Client MAY supply and the Printer MUST support this
        attribute.  It indicates whether Jobs from all users or just
        the Jobs submitted by the requesting user of this request MUST
        be considered as candidate Jobs to be returned by the Printer.
        If the Client does not supply this attribute, the Printer MUST
        respond as if the Client had supplied the attribute with a
        value of 'false', i.e., Jobs from all users.  The means for
        authenticating the requesting user and matching the Jobs is
        described in Section 9.

4.2.6.2.  Get-Jobs Response

  The Printer returns all of the Jobs up to the number specified by the
  "limit" attribute that match the criteria as defined by the attribute
  values supplied by the Client in the request.  It is possible that no
  Jobs are returned, since there can literally be no Jobs at the
  Printer or there can be no Jobs that match the criteria supplied by
  the Client.  If the Client requests any Job attributes at all, there
  is a set of Job Attributes returned for each Job.



Sweet & McDonald             Standards Track                   [Page 66]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  It is not an error for the Printer to return 0 Jobs.  If the response
  returns 0 Jobs because there are no Jobs matching the criteria, and
  the request would have returned one or more Jobs with a status-code
  of 'successful-ok' if there had been Jobs matching the criteria, then
  the status-code for 0 Jobs MUST be 'successful-ok'.

  Group 1: Operation Attributes

     Natural Language and Character Set:

        The "attributes-charset" and "attributes-natural-language"
        attributes as described in Section 4.1.4.2.

     Status Message:

        In addition to the REQUIRED status-code returned in every
        response, the response MAY include a "status-message"
        (text(255)) and/or a "detailed-status-message" (text(MAX))
        operation attribute as described in Appendix B and
        Section 4.1.6.

  Group 2: Unsupported Attributes

     See Section 4.1.7 for details on returning unsupported attributes.

     The response MAY contain the "requested-attributes" operation
     attribute with any supplied values (attribute keywords) that were
     requested by the Client but are not supported by the Printer.  If
     the Printer does return unsupported attributes referenced in the
     "requested-attributes" operation attribute and that attribute
     included group names, such as 'all', the unsupported attributes
     MUST NOT include attributes described in this document but not
     supported by the implementation.

  Groups 3 to N: Job Attributes

     The Printer responds with one set of Job Attributes for each
     returned Job.  The Printer ignores (does not respond with) any
     requested attribute or value that is not supported or that is
     restricted by the security policy in force, including whether the
     requesting user is the user that submitted the Job
     (Job-originating user) or not (see Section 9).  However, the
     Printer MUST respond with the 'unknown' value for any supported
     attribute (including all REQUIRED attributes) for which the
     Printer does not know the value, unless it would violate the
     security policy.  See the description of the "out-of-band" values
     in the beginning of Section 5.1.




Sweet & McDonald             Standards Track                   [Page 67]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


     Jobs are returned in the following order:

     *  If the Client requests all 'completed' Jobs (Jobs in the
        'completed', 'aborted', or 'canceled' states), then the Jobs
        are returned newest to oldest (with respect to actual
        completion time).

     *  If the Client requests all 'not-completed' Jobs (Jobs in the
        'pending', 'processing', 'pending-held', and
        'processing-stopped' states), then Jobs are returned in
        relative chronological order of expected time to complete
        (based on whatever scheduling algorithm is configured for the
        Printer).

4.2.7.  Pause-Printer Operation

  This OPTIONAL operation allows a Client to stop the Printer from
  scheduling Jobs on all its devices.  Depending on implementation, the
  Pause-Printer operation MAY also stop the Printer from processing the
  current Job or Jobs.  Any Job that is currently being printed is
  either (1) stopped as soon as the implementation permits or
  (2) completed, depending on implementation.  The Printer MUST still
  accept Job Creation requests to create new Jobs but MUST prevent any
  Jobs from entering the 'processing' state.

  If the Pause-Printer operation is supported, then the Resume-Printer
  operation MUST be supported, and vice versa.

  The IPP Printer stops the current Job(s) on its device or devices
  that were in the 'processing' or 'processing-stopped' state as soon
  as the implementation permits.  If the implementation will take
  appreciable time to stop, the IPP Printer adds the 'moving-to-paused'
  value to the Printer's "printer-state-reasons" attribute (see
  Section 5.4.12).  When the device or devices have all stopped, the
  IPP Printer transitions the Printer to the 'stopped' state; removes
  the 'moving-to-paused' value, if present; and adds the 'paused' value
  to the Printer's "printer-state-reasons" attribute.

  When the current Job or Jobs complete that were in the 'processing'
  state, the IPP Printer transitions them to the 'completed' state.
  When the current Job or Jobs stop in mid-processing that were in the
  'processing' state, the IPP Printer transitions them to the
  'processing-stopped' state and adds the 'printer-stopped' value to
  the Jobs' "job-state-reasons" attribute.







Sweet & McDonald             Standards Track                   [Page 68]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  For any Jobs that are 'pending' or 'pending-held', the
  'printer-stopped' value of the Jobs' "job-state-reasons" attribute
  also applies.  However, the IPP Printer MAY update those Jobs'
  "job-state-reasons" values when those Jobs are queried (so-called
  "lazy evaluation").

  The IPP Printer MUST accept the request in any state and transition
  the Printer to the indicated new "printer-state" before returning, as
  shown in Table 2.

  Access Rights: The authenticated user (see Section 9.3) performing
  this operation MUST be an Operator or Administrator of the Printer
  (see Sections 1 and 9.5).  Otherwise, the IPP Printer MUST reject the
  operation and return 'client-error-forbidden',
  'client-error-not-authenticated', or 'client-error-not-authorized'
  as appropriate.



































Sweet & McDonald             Standards Track                   [Page 69]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  +--------------+--------------+-----------------+-------------------+
  | Current      | New          | "printer-state- | IPP Printer's     |
  | "printer-    | "printer-    | reasons"        | response status-  |
  | state"       | state"       |                 | code and action:  |
  +--------------+--------------+-----------------+-------------------+
  | 'idle'       | 'stopped'    | 'paused'        | 'successful-ok'   |
  +--------------+--------------+-----------------+-------------------+
  | 'processing' | 'processing' | 'moving-to-     | Option 1:         |
  |              |              | paused'         | 'successful-ok';  |
  |              |              |                 | Later, when all   |
  |              |              |                 | output has        |
  |              |              |                 | stopped, the      |
  |              |              |                 | "printer-state"   |
  |              |              |                 | becomes           |
  |              |              |                 | 'stopped', and    |
  |              |              |                 | the 'paused'      |
  |              |              |                 | value replaces    |
  |              |              |                 | the 'moving-to-   |
  |              |              |                 | paused' value in  |
  |              |              |                 | the "printer-     |
  |              |              |                 | state-reasons"    |
  |              |              |                 | attribute         |
  +--------------+--------------+-----------------+-------------------+
  | 'processing' | 'stopped'    | 'paused'        | Option 2:         |
  |              |              |                 | 'successful-ok';  |
  |              |              |                 | all device output |
  |              |              |                 | stopped           |
  |              |              |                 | immediately       |
  +--------------+--------------+-----------------+-------------------+
  | 'stopped'    | 'stopped'    | 'paused'        | 'successful-ok'   |
  +--------------+--------------+-----------------+-------------------+

                Table 2: Pause-Printer State Transitions


















Sweet & McDonald             Standards Track                   [Page 70]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


4.2.7.1.  Pause-Printer Request

  The following groups of attributes are part of the Pause-Printer
  request:

  Group 1: Operation Attributes

     Natural Language and Character Set:

        The "attributes-charset" and "attributes-natural-language"
        attributes as described in Section 4.1.4.1.

     Target:

        The "printer-uri" (uri) operation attribute, which is the
        target for this operation as described in Section 4.1.5.

     Requesting User Name:

        The "requesting-user-name" (name(MAX)) attribute SHOULD be
        supplied by the Client as described in Section 9.3.

4.2.7.2.  Pause-Printer Response

  The following groups of attributes are part of the Pause-Printer
  response:

  Group 1: Operation Attributes

     Natural Language and Character Set:

        The "attributes-charset" and "attributes-natural-language"
        attributes as described in Section 4.1.4.2.

     Status Message:

        In addition to the REQUIRED status-code returned in every
        response, the response MAY include a "status-message"
        (text(255)) and/or a "detailed-status-message" (text(MAX))
        operation attribute as described in Appendix B and
        Section 4.1.6.

  Group 2: Unsupported Attributes

     See Section 4.1.7 for details on returning unsupported attributes.






Sweet & McDonald             Standards Track                   [Page 71]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


4.2.8.  Resume-Printer Operation

  This OPTIONAL operation allows a Client to resume the Printer
  scheduling Jobs on all its devices.  The Printer MUST remove the
  'paused' and 'moving-to-paused' values from the Printer's
  "printer-state-reasons" attribute, if present.  If there are no other
  reasons to keep a device paused (such as a media jam), the IPP
  Printer is free to transition itself to the 'processing' or 'idle'
  state, depending on whether there are Jobs to be processed or not,
  respectively, and the device(s) resumes processing Jobs.

  If the Pause-Printer operation is supported, then the Resume-Printer
  operation MUST be supported, and vice versa.

  The IPP Printer removes the 'printer-stopped' value from any Job's
  "job-state-reasons" attributes contained in that Printer.

  The IPP Printer MUST accept the request in any state and transition
  the Printer to the indicated new state as shown in Table 3.

  Access Rights: The authenticated user (see Section 9.3) performing
  this operation MUST be an Operator or Administrator of the Printer
  (see Sections 1 and 9.5).  Otherwise, the IPP Printer MUST reject the
  operation and return 'client-error-forbidden',
  'client-error-not-authenticated', or 'client-error-not-authorized'
  as appropriate.

  The Resume-Printer request and Resume-Printer response have the same
  attribute groups and attributes as the Pause-Printer operation (see
  Sections 4.2.7.1 and 4.2.7.2).

  +-----------------+-----------------+-------------------------------+
  | Current         | New "printer-   | IPP Printer's response        |
  | "printer-state" | state"          | status-code and action:       |
  +-----------------+-----------------+-------------------------------+
  | 'idle'          | 'idle'          | 'successful-ok'               |
  +-----------------+-----------------+-------------------------------+
  | 'processing'    | 'processing'    | 'successful-ok'               |
  +-----------------+-----------------+-------------------------------+
  | 'stopped'       | 'processing'    | 'successful-ok', when there   |
  |                 |                 | are Jobs to be processed      |
  +-----------------+-----------------+-------------------------------+
  | 'stopped'       | 'idle'          | 'successful-ok', when there   |
  |                 |                 | are no Jobs to be processed   |
  +-----------------+-----------------+-------------------------------+

                Table 3: Resume-Printer State Transitions




Sweet & McDonald             Standards Track                   [Page 72]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


4.2.9.  Purge-Jobs Operation

  This DEPRECATED operation allows a Client to remove all Jobs from a
  Printer, regardless of their Job states, including Jobs in the
  Printer's Job History (see Section 5.3.7.2).  After a Purge-Jobs
  operation has been performed, a Printer MUST return no Jobs in
  subsequent Get-Job-Attributes and Get-Jobs responses (until new Jobs
  are submitted).

  Note: This operation SHOULD NOT be supported in new implementations,
  since it destroys Printer accounting information.

  Whether the Purge-Jobs (and Get-Jobs) operation affects Jobs that
  were submitted to the device from sources other than the IPP Printer
  in the same way that the Purge-Jobs operation affects Jobs that were
  submitted to the IPP Printer using IPP depends on implementation,
  i.e., on whether IPP is being used as a universal management protocol
  or just to manage IPP Jobs, respectively.

  Note: If an Operator wants to cancel all Jobs without clearing out
  the Job History, the Operator uses the Cancel-Job operation on each
  Job instead of using the Purge-Jobs operation.

  If this OPTIONAL operation is supported, the Printer MUST accept this
  operation in any state and transition the Printer to the 'idle'
  state.

  Access Rights: The authenticated user (see Section 9.3) performing
  this operation MUST be an Operator or Administrator of the Printer
  (see Sections 1 and 9.5).  Otherwise, the Printer MUST reject the
  operation and return 'client-error-forbidden',
  'client-error-not-authenticated', and 'client-error-not-authorized'
  as appropriate.

  The Purge-Jobs request and Purge-Jobs response have the same
  attribute groups and attributes as the Pause-Printer operation (see
  Sections 4.2.7.1 and 4.2.7.2).

4.3.  Job Operations

  All Job operations are directed at Jobs.  A Client MUST always supply
  some means of identifying the Job object in order to identify the
  correct target of the operation.  That Job identification SHOULD be
  the combination of a Printer URI with a Job ID but MAY be the
  (single) Job URI.  The IPP implementation MUST support both forms of
  identification for every Job.





Sweet & McDonald             Standards Track                   [Page 73]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


4.3.1.  Send-Document Operation

  This RECOMMENDED operation allows a Client to add a Document to a Job
  that was created using the Create-Job operation.  In the Create-Job
  response, the Printer returns the Job's URI (the "job-uri" attribute)
  and the Job's 32-bit identifier (the "job-id" attribute).  For each
  new Document that the Client desires to add, the Client uses a
  Send-Document operation.  Each Send-Document request contains the
  entire stream of Document data for one Document.

  If the Printer supports this operation but does not support multiple
  Documents per Job, the Printer MUST reject subsequent Send-Document
  operations supplied with data and return the
  'server-error-multiple-document-jobs-not-supported' status-code.
  However, the Printer MUST accept the first Document with a 'true' or
  'false' value for the "last-document" operation attribute (see
  below), so that Clients MAY always submit one Document Job with a
  'false' value for "last-document" in the first Send-Document and a
  'true' value for "last-document" in the second Send-Document (with
  no data).

  Since the Create-Job and the send operations (Send-Document or
  Send-URI operations) that follow could occur over an arbitrarily long
  period of time for a particular Job, a Client MUST send another send
  operation within a minimum time interval, as defined by the IPP
  Printer, after the receipt of the previous request for the Job.  If a
  Printer supports the Create-Job and Send-Document operations, the
  Printer MUST support the "multiple-operation-time-out" attribute (see
  Section 5.4.31).  This attribute indicates the minimum number of
  seconds the Printer will wait for the next send operation before
  taking some recovery action.

  A Printer MUST recover from an errant Client that does not supply a
  send operation, sometime after the minimum time interval specified by
  the Printer's "multiple-operation-time-out" attribute.  Such recovery
  MAY include any of the following actions or other recovery actions:

  1.  Assume that the Job is an invalid Job, start the process of
      changing the Job state to 'aborted', add the 'aborted-by-system'
      value to the Job's "job-state-reasons" attribute (see
      Section 5.3.8), and clean up all resources associated with the
      Job.  In this case, if another send operation is finally
      received, the Printer responds with a 'client-error-not-possible'
      or 'client-error-not-found' status-code, depending on whether the
      Job is still around when the send operation finally arrives.






Sweet & McDonald             Standards Track                   [Page 74]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  2.  Assume that the last send operation received was in fact the last
      Document (as if the "last-document" flag had been set to 'true'),
      close the Job, and proceed to process it (i.e., move the Job's
      state to 'pending').

  3.  Assume that the last send operation received was in fact the last
      Document and close the Job, but move it to the 'pending-held'
      state and add the 'submission-interrupted' value to the Job's
      "job-state-reasons" attribute (see Section 5.3.8).  This action
      allows the user or an Operator to determine whether to continue
      processing the Job by moving it back to the 'pending' state using
      the Release-Job operation (see Section 4.3.6) or to cancel the
      Job using the Cancel-Job operation (see Section 4.3.3).

  Each implementation is free to decide the "best" action to take,
  depending on the following: local policy, whether any Documents have
  been added, whether the implementation spools Jobs or not, and/or any
  other piece of information available to it.  If the choice is to
  abort the Job, it is possible that the Job has already been processed
  to the point that some Media Sheet pages have been printed.

  Access Rights: The authenticated user (see Section 9.3) performing
  this operation must be either the Job owner (as determined in the
  Create-Job operation) or an Operator or Administrator of the Printer
  (see Sections 1 and 9.5).  Otherwise, the Printer MUST reject the
  operation and return 'client-error-forbidden',
  'client-error-not-authenticated', or 'client-error-not-authorized'
  as appropriate.

4.3.1.1.  Send-Document Request

  The following attribute sets are part of the Send-Document request:

  Group 1: Operation Attributes

     Natural Language and Character Set:

        The "attributes-charset" and "attributes-natural-language"
        attributes as described in Section 4.1.4.1.

     Target:

        Either the "printer-uri" (uri) plus "job-id" (integer(1:MAX)),
        or the "job-uri" (uri) operation attribute(s), which define the
        target for this operation as described in Section 4.1.5.






Sweet & McDonald             Standards Track                   [Page 75]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


     Requesting User Name:

        The "requesting-user-name" (name(MAX)) attribute SHOULD be
        supplied by the Client as described in Section 9.3.

     "document-name" (name(MAX)):

        The Client MAY supply and the Printer MUST support this
        attribute.  It contains the Client-supplied Document name.  The
        Document name MAY be different than the Job name and is not
        guaranteed to be unique across multiple Documents in the same
        Job.  Typically, the Client software automatically supplies the
        Document name on behalf of the End User by using a file name or
        an application-generated name.  See the description of the
        "document-name" operation attribute in the Print-Job request
        (Section 4.2.1.1) for more information about this attribute.

     "compression" (type2 keyword):

        See the description of "compression" for the Print-Job
        operation in Section 4.2.1.1.

     "document-format" (mimeMediaType):

        See the description of "document-format" for the Print-Job
        operation in Section 4.2.1.1.

     "document-natural-language" (naturalLanguage):

        The Client MAY supply and the Printer MAY support this
        attribute.  It specifies the natural language of the Document
        content for those Document formats that require a specification
        of the natural language in order to properly image the
        Document.

     "last-document" (boolean):

        The Client MUST supply and the Printer MUST support this
        attribute.  It is a boolean flag that is set to 'true' if this
        is the last Document for the Job; otherwise, it is set to
        'false'.










Sweet & McDonald             Standards Track                   [Page 76]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  Group 2: Document Data

     The Client MUST supply the Document data if the "last-document"
     flag is set to 'false'.  However, since a Client might not know
     that the previous Document sent with a Send-Document (or Send-URI)
     operation was the last Document (i.e., the "last-document"
     attribute was set to 'false'), it is legal to send a Send-Document
     request with no Document data where the "last-document" flag is
     set to 'true'.  Such a request MUST NOT increment the value of the
     Job's "number-of-documents" attribute, since no real Document was
     added to the Job.  It is not an error for a Client to submit a Job
     with no actual Document data, i.e., only a single Create-Job and
     Send-Document request with a "last-document" operation attribute
     set to 'true' with no Document data.

4.3.1.2.  Send-Document Response

  The following sets of attributes are part of the Send-Document
  response:

  Group 1: Operation Attributes

     Natural Language and Character Set:

        The "attributes-charset" and "attributes-natural-language"
        attributes as described in Section 4.1.4.2.

     Status Message:

        In addition to the REQUIRED status-code returned in every
        response, the response MAY include a "status-message"
        (text(255)) and/or a "detailed-status-message" (text(MAX))
        operation attribute as described in Appendix B and
        Section 4.1.6.

  Group 2: Unsupported Attributes

     See Section 4.1.7 for details on returning unsupported attributes.

  Group 3: Job Object Attributes

     This is the same set of attributes as those described in the
     Print-Job response (see Section 4.2.1.2).








Sweet & McDonald             Standards Track                   [Page 77]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


4.3.2.  Send-URI Operation

  This RECOMMENDED operation is identical to the Send-Document
  operation (see Section 4.3.1), except that a Client MUST supply a URI
  reference ("document-uri" operation attribute) rather than the
  Document data itself.  If a Printer supports this operation, Clients
  can use both Send-URI and Send-Document operations to add new
  Documents to an existing Job.  However, if a Client needs to indicate
  that the previous Send-URI or Send-Document was the last Document,
  the Client MUST use the Send-Document operation with no Document data
  and the "last-document" flag set to 'true' (rather than using a
  Send-URI operation with no "document-uri" operation attribute).

  If a Printer supports this operation, it MUST also support the
  Print-URI operation (see Section 4.2.2).

  The Printer MUST validate the syntax and URI scheme of the supplied
  URI before returning a response, just as in the Print-URI operation.
  The Printer MAY validate the accessibility of the Document as part of
  the operation, or subsequently (see Section 4.2.2).

4.3.3.  Cancel-Job Operation

  This REQUIRED operation allows a Client to cancel a Print Job from
  the time the Job is created up to the time it is completed, canceled,
  or aborted.  Since a Job might already be printing by the time a
  Cancel-Job is received, some Media Sheet pages might be printed
  before the Job is actually terminated.

  The Printer MUST accept or reject the request based on the Job's
  current state and transition the Job to the indicated new state as
  shown in Table 4.

  Access Rights: The authenticated user (see Section 9.3) performing
  this operation must be either the Job owner or an Operator or
  Administrator of the Printer (see Sections 1 and 9.5).  Otherwise,
  the Printer MUST reject the operation and return
  'client-error-forbidden', 'client-error-not-authenticated', or
  'client-error-not-authorized' as appropriate.












Sweet & McDonald             Standards Track                   [Page 78]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  +-------------------+--------------------+--------------------------+
  | Current "job-     | New "job-state"    | Printer's response       |
  | state"            |                    | status-code and action:  |
  +-------------------+--------------------+--------------------------+
  | 'pending'         | 'canceled'         | 'successful-ok'          |
  +-------------------+--------------------+--------------------------+
  | 'pending-held'    | 'canceled'         | 'successful-ok'          |
  +-------------------+--------------------+--------------------------+
  | 'processing'      | 'canceled'         | 'successful-ok'          |
  +-------------------+--------------------+--------------------------+
  | 'processing'      | 'processing'       | 'successful-ok' (note 1) |
  +-------------------+--------------------+--------------------------+
  | 'processing'      | 'processing'       | 'client-error-not-       |
  |                   |                    | possible' (note 2)       |
  +-------------------+--------------------+--------------------------+
  | 'processing-      | 'canceled'         | 'successful-ok'          |
  | stopped'          |                    |                          |
  +-------------------+--------------------+--------------------------+
  | 'processing-      | 'processing-       | 'successful-ok' (note 1) |
  | stopped'          | stopped'           |                          |
  +-------------------+--------------------+--------------------------+
  | 'processing-      | 'processing-       | 'client-error-not-       |
  | stopped'          | stopped'           | possible' (note 2)       |
  +-------------------+--------------------+--------------------------+
  | 'completed'       | 'completed'        | 'client-error-not-       |
  |                   |                    | possible'                |
  +-------------------+--------------------+--------------------------+
  | 'canceled'        | 'canceled'         | 'client-error-not-       |
  |                   |                    | possible'                |
  +-------------------+--------------------+--------------------------+
  | 'aborted'         | 'aborted'          | 'client-error-not-       |
  |                   |                    | possible'                |
  +-------------------+--------------------+--------------------------+

                  Table 4: Cancel-Job State Transitions

  Note 1: If the implementation requires some measurable time to cancel
  the Job in the 'processing' or 'processing-stopped' Job state, the
  Printer MUST add the 'processing-to-stop-point' value to the Job's
  "job-state-reasons" attribute and then transition the Job to the
  'canceled' state when the processing ceases (see Section 5.3.8).

  Note 2: If the Job already has the 'processing-to-stop-point' value
  in its "job-state-reasons" attribute, then the Printer MUST reject a
  Cancel-Job operation.






Sweet & McDonald             Standards Track                   [Page 79]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


4.3.3.1.  Cancel-Job Request

  The following groups of attributes are part of the Cancel-Job
  request:

  Group 1: Operation Attributes

     Natural Language and Character Set:

        The "attributes-charset" and "attributes-natural-language"
        attributes as described in Section 4.1.4.1.

     Target:

        Either the "printer-uri" (uri) plus "job-id" (integer(1:MAX)),
        or the "job-uri" (uri) operation attribute(s), which define the
        target for this operation as described in Section 4.1.5.

     Requesting User Name:

        The "requesting-user-name" (name(MAX)) attribute SHOULD be
        supplied by the Client as described in Section 9.3.

     "message" (text(127)):

        The Client MAY supply and the Printer MAY support this
        attribute.  It is a message to the Operator.  This "message"
        attribute is not the same as the "job-message-from-operator"
        attribute.  That attribute is used to report a message from the
        Operator to the End User that queries that attribute.  This
        "message" operation attribute is used to send a message from
        the Client to the Operator along with the operation request.
        How or where to display this message to the Operator (if
        at all) is an implementation decision.

















Sweet & McDonald             Standards Track                   [Page 80]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


4.3.3.2.  Cancel-Job Response

  The following sets of attributes are part of the Cancel-Job response:

  Group 1: Operation Attributes

     Natural Language and Character Set:

        The "attributes-charset" and "attributes-natural-language"
        attributes as described in Section 4.1.4.2.

     Status Message:

        In addition to the REQUIRED status-code returned in every
        response, the response MAY include a "status-message"
        (text(255)) and/or a "detailed-status-message" (text(MAX))
        operation attribute as described in Appendix B and
        Section 4.1.6.

  Group 2: Unsupported Attributes

     See Section 4.1.7 for details on returning unsupported attributes.

     Once a successful response has been sent, the implementation
     guarantees that the Job will eventually end up in the 'canceled'
     state.  Between the time that the Cancel-Job operation is accepted
     and when the Job enters the 'canceled' job-state (see
     Section 5.3.7), the "job-state-reasons" attribute SHOULD contain
     the 'processing-to-stop-point' value, which indicates to later
     queries that although the Job might still be 'processing' it will
     eventually end up in the 'canceled' state, not the 'completed'
     state.

4.3.4.  Get-Job-Attributes Operation

  This REQUIRED operation allows a Client to request the values of
  attributes of a Job, and it is almost identical to the
  Get-Printer-Attributes operation (see Section 4.2.5).  The only
  differences are that the operation is directed at a Job rather than a
  Printer, there is no "document-format" operation attribute used when
  querying a Job, and the returned attribute group is a set of Job
  attributes rather than a set of Printer attributes.









Sweet & McDonald             Standards Track                   [Page 81]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  For Jobs, the possible names of attribute groups are:

  o  'job-template': the subset of the Job Template attributes that
     apply to a Job (the first column of Table 8 in Section 5.2) that
     the implementation supports for Jobs.

  o  'job-description': the subset of the Job Description and Status
     attributes specified in Section 5.3 that the implementation
     supports for Jobs.

  o  'all': the special group 'all' that includes all attributes that
     the implementation supports for Jobs.

  Since a Client MAY request specific attributes or named groups, there
  is a potential for some overlap.  For example, if a Client requests
  'job-name' and 'job-description', the Client is actually requesting
  the "job-name" attribute once by naming it explicitly, and once by
  inclusion in the 'job-description' group.  In such cases, the Printer
  returns the attribute only once in the response even if it is
  requested multiple times.  The Client SHOULD NOT request the same
  attribute in multiple ways.

  Jobs MUST support all group names and MUST return all supported
  attributes belonging to the group.

4.3.4.1.  Get-Job-Attributes Request

  The following groups of attributes are part of the Get-Job-Attributes
  request when the request is directed at a Job:

  Group 1: Operation Attributes

     Natural Language and Character Set:

        The "attributes-charset" and "attributes-natural-language"
        attributes as described in Section 4.1.4.1.

     Target:

        Either the "printer-uri" (uri) plus "job-id" (integer(1:MAX)),
        or the "job-uri" (uri) operation attribute(s), which define the
        target for this operation as described in Section 4.1.5.

     Requesting User Name:

        The "requesting-user-name" (name(MAX)) attribute SHOULD be
        supplied by the Client as described in Section 9.3.




Sweet & McDonald             Standards Track                   [Page 82]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


     "requested-attributes" (1setOf keyword):

        The Client MAY supply and the Printer MUST support this
        attribute.  It is a set of attribute names and/or attribute
        group names in whose values the requester is interested.  If
        the Client omits this attribute, the Printer MUST respond as if
        this attribute had been supplied with a value of 'all'.

4.3.4.2.  Get-Job-Attributes Response

  The Printer returns the following sets of attributes as part of the
  Get-Job-Attributes response:

  Group 1: Operation Attributes

     Natural Language and Character Set:

        The "attributes-charset" and "attributes-natural-language"
        attributes as described in Section 4.1.4.2.
        "attributes-natural-language" MAY be the natural language of
        the Job, rather than the one requested.

     Status Message:

        In addition to the REQUIRED status-code returned in every
        response, the response MAY include a "status-message"
        (text(255)) and/or a "detailed-status-message" (text(MAX))
        operation attribute as described in Appendix B and
        Section 4.1.6.

  Group 2: Unsupported Attributes

     See Section 4.1.7 for details on returning unsupported attributes.

     The response MAY contain the "requested-attributes" operation
     attribute with any supplied values (attribute keywords) that were
     requested by the Client but are not supported by the Printer.  If
     the Printer does return unsupported attributes referenced in the
     "requested-attributes" operation attribute and that attribute
     included group names, such as 'all', the unsupported attributes
     MUST NOT include attributes described in this document but not
     supported by the implementation.









Sweet & McDonald             Standards Track                   [Page 83]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  Group 3: Job Attributes

     This is the set of requested attributes and their current values.
     The Printer ignores (does not respond with) any requested
     attribute or value that is not supported or that is restricted by
     the security policy in force, including whether the requesting
     user is the user that submitted the Job (Job-originating user) or
     not (see Section 9).  However, the Printer MUST respond with the
     'unknown' value for any supported attribute (including all
     REQUIRED attributes) for which the Printer does not know the
     value, unless it would violate the security policy.  See the
     description of the "out-of-band" values in the beginning of
     Section 5.1.

4.3.5.  Hold-Job Operation

  This OPTIONAL operation allows a Client to hold a pending Job in the
  queue so that it is not eligible for scheduling.  If the Hold-Job
  operation is supported, then the Release-Job operation MUST be
  supported, and vice versa.  The OPTIONAL "job-hold-until" operation
  attribute allows a Client to specify whether to hold the Job
  indefinitely or until a specified time period, if supported.

  The Printer MUST accept or reject the request based on the Job's
  current state and transition the Job to the indicated new state as
  shown in Table 5.

  Note: In order to keep the Hold-Job operation simple, such a request
  is rejected when the Job is in the 'processing' or
  'processing-stopped' state.  If an operation is needed to hold Jobs
  while in either of these states, it will be added as an additional
  operation, rather than overloading the Hold-Job operation.  Then it
  is clear to Clients by querying the Printer's "operations-supported"
  (see Section 5.4.15) and the Job's "job-state" (see Section 5.3.7)
  attributes which operations are possible.

  Access Rights: The authenticated user (see Section 9.3) performing
  this operation must be either the Job owner or an Operator or
  Administrator of the Printer (see Sections 1 and 9.5).  Otherwise,
  the Printer MUST reject the operation and return
  'client-error-forbidden', 'client-error-not-authenticated', or
  'client-error-not-authorized' as appropriate.









Sweet & McDonald             Standards Track                   [Page 84]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  +-------------------+--------------------+--------------------------+
  | Current "job-     | New "job-state"    | Printer's response       |
  | state"            |                    | status-code and action:  |
  +-------------------+--------------------+--------------------------+
  | 'pending'         | 'pending-held'     | 'successful-ok' (note 1) |
  +-------------------+--------------------+--------------------------+
  | 'pending'         | 'pending'          | 'successful-ok' (note 2) |
  +-------------------+--------------------+--------------------------+
  | 'pending-held'    | 'pending-held'     | 'successful-ok' (note 1) |
  +-------------------+--------------------+--------------------------+
  | 'pending-held'    | 'pending'          | 'successful-ok' (note 2) |
  +-------------------+--------------------+--------------------------+
  | 'processing'      | 'processing'       | 'client-error-not-       |
  |                   |                    | possible'                |
  +-------------------+--------------------+--------------------------+
  | 'processing-      | 'processing-       | 'client-error-not-       |
  | stopped'          | stopped'           | possible'                |
  +-------------------+--------------------+--------------------------+
  | 'completed'       | 'completed'        | 'client-error-not-       |
  |                   |                    | possible'                |
  +-------------------+--------------------+--------------------------+
  | 'canceled'        | 'canceled'         | 'client-error-not-       |
  |                   |                    | possible'                |
  +-------------------+--------------------+--------------------------+
  | 'aborted'         | 'aborted'          | 'client-error-not-       |
  |                   |                    | possible'                |
  +-------------------+--------------------+--------------------------+

                   Table 5: Hold-Job State Transitions

  Note 1: If the implementation supports multiple reasons for a Job to
  be in the 'pending-held' state, the Printer MUST add the
  "job-hold-until-specified" value to the Job's "job-state-reasons"
  attribute.

  Note 2: If the Printer supports the "job-hold-until" operation
  attribute, but the specified time period has already started (or is
  the 'no-hold' value) and there are no other reasons to hold the Job,
  the Printer MUST make the Job be a candidate for processing
  immediately (see Section 5.2.2) by putting the Job in the 'pending'
  state.










Sweet & McDonald             Standards Track                   [Page 85]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


4.3.5.1.  Hold-Job Request

  The groups and operation attributes are the same as those defined for
  a Cancel-Job request (see Section 4.3.3.1), with the addition of the
  following Group 1 operation attribute:

     "job-hold-until" (type2 keyword | name(MAX)):

     The Client MAY supply and the Printer MUST support this operation
     attribute in a Hold-Job request if it supports the
     "job-hold-until" Job Template attribute in Job Creation requests.
     See Section 5.2.2.  The Printer SHOULD support the
     "job-hold-until" Job Template attribute for use in Job Creation
     requests with at least the 'indefinite' value, if it supports the
     Hold-Job operation.  Otherwise, a Client cannot create a Job and
     hold it immediately (without picking some supported time period in
     the future).

     If supplied and supported as specified in the Printer's
     "job-hold-until-supported" attribute, the Printer copies the
     supplied operation attribute to the Job, replacing the Job's
     previous "job-hold-until" attribute, if present, and makes the Job
     a candidate for scheduling during the supplied named time period.

     If supplied but either the "job-hold-until" operation attribute
     itself or the value supplied is not supported, the Printer accepts
     the request, returns the unsupported attribute or value in the
     Unsupported Attributes group according to Section 4.1.7, returns
     the 'successful-ok-ignored-or-substituted-attributes' status-code,
     and holds the Job indefinitely until a Client performs a
     subsequent Release-Job operation.

     If (1) the Client supplies either a value that specifies a time
     period that has already started or the 'no-hold' value (meaning
     don't hold the Job) and (2) the Printer supports the
     "job-hold-until" operation attribute and there are no other
     reasons to hold the Job, the Printer MUST accept the operation and
     make the Job be a candidate for processing immediately (see
     Section 5.2.2).

     If the Client does not supply a "job-hold-until" operation
     attribute in the request, the Printer MUST populate the Job with a
     "job-hold-until" attribute with the 'indefinite' value (if the
     Printer supports the "job-hold-until" attribute) and hold the Job
     indefinitely, until a Client performs a Release-Job operation.






Sweet & McDonald             Standards Track                   [Page 86]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


4.3.5.2.  Hold-Job Response

  The groups and attributes are the same as those defined for a
  Cancel-Job response (see Section 4.3.3.2).

4.3.6.  Release-Job Operation

  This OPTIONAL operation allows a Client to release a previously held
  Job so that it is again eligible for scheduling.  If the Hold-Job
  operation is supported, then the Release-Job operation MUST be
  supported, and vice versa.

  This operation removes the "job-hold-until" Job attribute, if
  present, from the Job that had been supplied in the Create-Job or
  most recent Hold-Job or Restart-Job operation and removes its effect
  on the Job.  The Printer MUST remove the "job-hold-until-specified"
  value from the Job's "job-state-reasons" attribute, if present.  See
  Section 5.3.8.

  The Printer MUST accept or reject the request based on the Job's
  current state and transition the Job to the indicated new state as
  shown in Table 6.

  Access Rights: The authenticated user (see Section 9.3) performing
  this operation must be either the Job owner or an Operator or
  Administrator of the Printer (see Sections 1 and 9.5).  Otherwise,
  the Printer MUST reject the operation and return
  'client-error-forbidden', 'client-error-not-authenticated', or
  'client-error-not-authorized' as appropriate.

  The Release-Job request and Release-Job response have the same
  attribute groups and attributes as the Cancel-Job operation (see
  Sections 4.3.3.1 and 4.3.3.2).


















Sweet & McDonald             Standards Track                   [Page 87]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  +-------------------+--------------------+--------------------------+
  | Current "job-     | New "job-state"    | Printer's response       |
  | state"            |                    | status-code and action:  |
  +-------------------+--------------------+--------------------------+
  | 'pending'         | 'pending'          | 'successful-ok'.  No     |
  |                   |                    | effect on the Job.       |
  +-------------------+--------------------+--------------------------+
  | 'pending-held'    | 'pending-held'     | 'successful-ok' (note 1) |
  +-------------------+--------------------+--------------------------+
  | 'pending-held'    | 'pending'          | 'successful-ok'          |
  +-------------------+--------------------+--------------------------+
  | 'processing'      | 'processing'       | 'successful-ok'.  No     |
  |                   |                    | effect on the Job.       |
  +-------------------+--------------------+--------------------------+
  | 'processing-      | 'processing-       | 'successful-ok'.  No     |
  | stopped'          | stopped'           | effect on the Job.       |
  +-------------------+--------------------+--------------------------+
  | 'completed'       | 'completed'        | 'client-error-not-       |
  |                   |                    | possible'                |
  +-------------------+--------------------+--------------------------+
  | 'canceled'        | 'canceled'         | 'client-error-not-       |
  |                   |                    | possible'                |
  +-------------------+--------------------+--------------------------+
  | 'aborted'         | 'aborted'          | 'client-error-not-       |
  |                   |                    | possible'                |
  +-------------------+--------------------+--------------------------+

                 Table 6: Release-Job State Transitions

  Note 1: If there are other reasons to keep the Job in the
  'pending-held' state, such as 'resources-are-not-ready', the Job
  remains in the 'pending-held' state.  Thus, the 'pending-held' state
  is not just for Jobs that have the "job-hold-until" attribute applied
  to them but is also used for any reason that will keep the Job from
  being a candidate for scheduling and processing, such as
  'resources-are-not-ready'.  See the "job-hold-until" attribute
  (Section 5.2.2).














Sweet & McDonald             Standards Track                   [Page 88]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


4.3.7.  Restart-Job Operation

  This DEPRECATED operation allows a Client to restart a Job that is
  retained in the queue after processing has completed (see
  Section 5.3.7.2).

  Note: This operation SHOULD NOT be supported in new implementations,
  since it destroys Printer accounting information.  The Resubmit-Job
  operation [PWG5100.11] is the safe replacement for this operation and
  makes a copy of the Job, assigns a new "job-uri" and "job-id" to the
  copy, and resets the Job progress attributes in the new copy only.

  The Restart-Job operation moves the Job to the 'pending' or
  'pending-held' Job state and restarts at the beginning on the same
  Printer with the same attribute values.  If any of the Documents in
  the Job were passed by reference (Print-URI or Send-URI), the Printer
  MUST refetch the data, since the semantics of Restart-Job are to
  repeat all Job processing.  The Job Status attributes that accumulate
  Job progress, such as "job-impressions-completed",
  "job-media-sheets-completed", and "job-k-octets-processed", MUST be
  reset to 0 so that they give an accurate record of the Job from its
  restart point.  The Job MUST continue to use the same "job-uri" and
  "job-id" attribute values.

  The Printer MUST accept or reject the request based on the Job's
  current state and transition the Job to the indicated new state as
  shown in Table 7.

  Note: In order to prevent a user from inadvertently restarting a Job
  in the middle, the Restart-Job request is rejected when the Job is in
  the 'processing' or 'processing-stopped' state.  If in the future an
  operation is needed to hold or restart Jobs while in either of these
  states, it will be added as an additional operation, rather than
  overloading the Restart-Job operation, so that it is clear that the
  user intended that the current Job not be completed.

  Access Rights: The authenticated user (see Section 9.3) performing
  this operation must be either the Job owner or an Operator or
  Administrator of the Printer (see Sections 1 and 9.5).  Otherwise,
  the Printer MUST reject the operation and return
  'client-error-forbidden', 'client-error-not-authenticated', or
  'client-error-not-authorized' as appropriate.









Sweet & McDonald             Standards Track                   [Page 89]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  +-------------------+--------------------+--------------------------+
  | Current "job-     | New "job-state"    | Printer's response       |
  | state"            |                    | status-code and action:  |
  +-------------------+--------------------+--------------------------+
  | 'pending'         | 'pending'          | 'client-error-not-       |
  |                   |                    | possible'                |
  +-------------------+--------------------+--------------------------+
  | 'pending-held'    | 'pending-held'     | 'client-error-not-       |
  |                   |                    | possible'                |
  +-------------------+--------------------+--------------------------+
  | 'processing'      | 'processing'       | 'client-error-not-       |
  |                   |                    | possible'                |
  +-------------------+--------------------+--------------------------+
  | 'processing-      | 'processing-       | 'client-error-not-       |
  | stopped'          | stopped'           | possible'                |
  +-------------------+--------------------+--------------------------+
  | 'completed'       | 'pending' or       | 'successful-ok' - Job is |
  |                   | 'pending-held'     | started over.            |
  +-------------------+--------------------+--------------------------+
  | 'completed'       | 'completed'        | 'client-error-not-       |
  |                   |                    | possible' - see Rule 1.  |
  +-------------------+--------------------+--------------------------+
  | 'canceled'        | 'pending' or       | 'successful-ok' - Job is |
  |                   | 'pending-held'     | started over.            |
  +-------------------+--------------------+--------------------------+
  | 'canceled'        | 'canceled'         | 'client-error-not-       |
  |                   |                    | possible' - see Rule 1.  |
  +-------------------+--------------------+--------------------------+
  | 'aborted'         | 'pending' or       | 'successful-ok' - Job is |
  |                   | 'pending-held'     | started over.            |
  +-------------------+--------------------+--------------------------+
  | 'aborted'         | 'aborted'          | 'client-error-not-       |
  |                   |                    | possible' - see Rule 1.  |
  +-------------------+--------------------+--------------------------+

                 Table 7: Restart-Job State Transitions

  Rule 1: If the Job Retention Period has expired for the Job in this
  state, then the Printer rejects the operation.  See Section 5.3.7.2.












Sweet & McDonald             Standards Track                   [Page 90]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


4.3.7.1.  Restart-Job Request

  The groups and attributes are the same as those defined for a
  Cancel-Job request (see Section 4.3.3.1), with the addition of the
  following Group 1 operation attribute:

     "job-hold-until" (type2 keyword | name(MAX)):

     The Client MAY supply and the Printer MUST support this operation
     attribute in a Restart-Job request if it supports the
     "job-hold-until" Job Template attribute in Job Creation requests.
     See Section 5.2.2.

     If supplied and supported as specified in the Printer's
     "job-hold-until-supported" attribute, the Printer copies the
     supplied operation attribute to the Job, replacing the Job's
     previous "job-hold-until" attribute, if present, and makes the Job
     a candidate for scheduling during the supplied named time period.
     See Section 5.2.2.

     If supplied but the value is not supported, the Printer accepts
     the request, returns the unsupported attribute or value in the
     Unsupported Attributes group according to Section 4.1.7, returns
     the 'successful-ok-ignored-or-substituted-attributes' status-code,
     and holds the Job indefinitely until a Client performs a
     subsequent Release-Job operation.

     If supplied but the "job-hold-until" operation attribute itself is
     not supported, the Printer accepts the request, returns the
     unsupported attribute with the out-of-band 'unsupported' value in
     the Unsupported Attributes group according to Section 4.1.7,
     returns the 'successful-ok-ignored-or-substituted-attributes'
     status-code, and restarts the Job, i.e., ignores the
     "job-hold-until" attribute.

     If (1) the Client supplies either a value that specifies a time
     period that has already started or the 'no-hold' value (meaning
     don't hold the Job) and (2) the Printer supports the
     "job-hold-until" operation attribute and there are no other
     reasons to hold the Job, the Printer makes the Job a candidate for
     processing immediately (see Section 5.2.2).

     If the Client does not supply a "job-hold-until" operation
     attribute in the request, the Printer removes the "job-hold-until"
     attribute, if present, from the Job.  If there are no other
     reasons to hold the Job, the Restart-Job operation makes the Job a
     candidate for processing immediately (see Section 5.2.2).




Sweet & McDonald             Standards Track                   [Page 91]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


4.3.7.2.  Restart-Job Response

  The groups and attributes are the same as those defined for a
  Cancel-Job response (see Section 4.3.3.2).

5.  Object Attributes

  This section describes the attributes with their corresponding
  attribute syntaxes and values that are part of the IPP Model.  The
  sections below show the objects and their associated attributes that
  are included within the scope of this protocol.  Many of these
  attributes are derived from other relevant documents:

  o  Document Printing Application (DPA) [ISO10175]

  o  Printer MIB v2 [RFC3805]

  Each attribute is uniquely identified in this document using a
  "keyword" (see Section 2.3.7) that is the name of the attribute.  The
  keyword is included in the section title describing that attribute.

  Note: Not only are keywords used to identify attributes, but one of
  the attribute syntaxes described below is "keyword" so that some
  attributes have 'keyword' values.  Therefore, these attributes are
  defined as having an attribute syntax that is a set of keywords.

5.1.  Attribute Syntaxes

  This section defines the basic attribute syntax types that all
  Clients and IPP objects MUST be able to accept in responses and
  accept in requests, respectively.  Each attribute description in
  Sections 4 and 5 includes in the section title the name of the
  attribute with its syntax(es) in parentheses.  A conforming
  implementation of an attribute MUST include the semantics of the
  attribute syntax(es) so identified.  Section 7.7 describes how the
  protocol can be extended with new attribute syntaxes.

  The attribute syntaxes are specified in the following subsections,
  where the subsection title is the keyword name of the attribute
  syntax inside the single quotes.  In operation requests and
  responses, each attribute value MUST be represented as one of the
  attribute syntaxes specified in the subsection title for the
  attribute.  In addition, the value of an attribute in a response (but
  not in a request) MAY be one of the "out-of-band" values
  (Section 5.1.1) whose special encoding rules are defined in the
  Encoding and Transport document [RFC8010].





Sweet & McDonald             Standards Track                   [Page 92]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  All attributes in a request MUST have one or more values as defined
  in Sections 5.2, 5.3, and 5.4.  All attributes in a response MUST
  have either (1) one or more values as defined in Sections 5.2, 5.3,
  and 5.4 or (2) a single "out-of-band" value.

  Most attributes are defined to have a single attribute syntax.
  However, a few attributes (e.g., "job-sheet", "media",
  "job-hold-until") are defined to have several attribute syntaxes,
  depending on the value.  These multiple attribute syntaxes are
  separated by the "|" character in the subsection title to indicate
  the choice.  Since each value MUST be tagged as to its attribute
  syntax in the protocol, a single-valued attribute instance can have
  any one of its attribute syntaxes and a multi-valued attribute
  instance can have a mixture of its defined attribute syntaxes.

5.1.1.  Out-of-Band Values - 'unknown', 'unsupported', and 'no-value'

  This document defines three "out-of-band" values that are used in
  place of an attribute's defined syntax:

  o  'unknown': The attribute is supported by the IPP object, but the
     value is unknown to the IPP object for some reason.  This
     out-of-band value is used for attributes that have an intrinsic,
     physical value that cannot be determined by the IPP object at a
     given time, e.g., sheet count, geo-location, etc.

  o  'unsupported': The attribute is unsupported by the IPP object.
     This value MUST be returned only as the value of an attribute in
     the Unsupported Attributes group.

  o  'no-value': The attribute is supported by the Printer, but the
     Administrator has not yet configured a value.

5.1.2.  'text'

  A 'text' attribute is an attribute whose value is a sequence of zero
  or more characters encoded in a maximum of 1023 ('MAX') octets.  MAX
  is the maximum length for each value of any 'text' attribute.
  However, if an attribute will always contain values whose maximum
  length is much less than MAX, the definition of that attribute will
  include a qualifier that defines the maximum length for values of
  that attribute.  For example, the "printer-location" attribute is
  specified as "printer-location (text(127))".  In this case, text
  values for "printer-location" MUST NOT exceed 127 octets; if supplied
  with a longer text string via some external interface (other than the
  protocol), implementations are free to truncate to this shorter
  length limitation.




Sweet & McDonald             Standards Track                   [Page 93]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  In this document, all 'text' attributes are defined using the 'text'
  syntax.  However, 'text' is used only for brevity; the formal
  interpretation of 'text' is 'textWithoutLanguage | textWithLanguage'.
  That is, for any attribute defined in this document using the 'text'
  attribute syntax, all IPP objects and Clients MUST support both the
  'textWithoutLanguage' and 'textWithLanguage' attribute syntaxes.
  However, in actual usage and protocol execution, IPP objects and
  Clients accept and return only one of the two syntaxes per attribute.
  The syntax 'text' never appears "on-the-wire".

  Both 'textWithoutLanguage' and 'textWithLanguage' are needed to
  support the real-world needs of interoperability between sites and
  systems that use different natural languages as the basis for human
  communication.  Generally, one natural language applies to all 'text'
  attributes in a given request or response.  The language is indicated
  by the "attributes-natural-language" operation attribute defined in
  Section 4.1.4 or the "attributes-natural-language" Job attribute
  defined in Section 5.3.20, and there is no need to identify the
  natural language for each text string on a value-by-value basis.  In
  these cases, the attribute syntax 'textWithoutLanguage' is used for
  'text' attributes.  In other cases, the Client needs to supply or the
  Printer needs to return a text value in a natural language that is
  different from the rest of the text values in the request or
  response.  In these cases, the Client or Printer uses the attribute
  syntax 'textWithLanguage' for 'text' attributes (this is the Natural
  Language Override mechanism described in Section 4.1.4).

  The 'textWithoutLanguage' and 'textWithLanguage' attribute syntaxes
  are described in more detail in the following sections.

5.1.2.1.  'textWithoutLanguage'

  The 'textWithoutLanguage' syntax indicates a value that is a sequence
  of zero or more characters encoded in a maximum of 1023 (MAX) octets.
  Text strings are encoded using the rules of some charset.  The
  Printer MUST support the UTF-8 charset [RFC3629] and MAY support
  additional charsets to represent 'text' values, provided that the
  charsets are registered with IANA [IANA-CS].  See Section 5.1.8 for
  the definition of the 'charset' attribute syntax, including
  restricted semantics and examples of charsets.

5.1.2.2.  'textWithLanguage'

  The 'textWithLanguage' attribute syntax is a compound attribute
  syntax consisting of two parts: a 'textWithoutLanguage' part encoded
  in a maximum of 1023 (MAX) octets plus an additional
  'naturalLanguage' (see Section 5.1.9) part that overrides the natural
  language in force.  The 'naturalLanguage' part explicitly identifies



Sweet & McDonald             Standards Track                   [Page 94]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  the natural language that applies to the text part of that value and
  that value alone.  For any given 'text' attribute, the
  'textWithoutLanguage' part is limited to the maximum length defined
  for that 'text' attribute, and the 'naturalLanguage' part is always
  limited to 63 (additional) octets.  Using the 'textWithLanguage'
  attribute syntax rather than the normal 'textWithoutLanguage' syntax
  is the so-called "Natural Language Override mechanism" and MUST be
  supported by all IPP objects and Clients.

  If the attribute is multi-valued (1setOf text), then the
  'textWithLanguage' attribute syntax MUST be used to explicitly
  specify each attribute value whose natural language needs to be
  overridden.  Other values in a multi-valued 'text' attribute in a
  request or a response revert to the natural language of the operation
  attribute.

  In a Job Creation request, the Printer MUST accept and store with the
  Job any natural language in the "attributes-natural-language"
  operation attribute, whether the Printer supports that natural
  language or not.  Furthermore, the Printer MUST accept and store any
  'textWithLanguage' attribute value, whether the Printer supports that
  natural language or not.  These requirements are independent of the
  value of the "ipp-attribute-fidelity" operation attribute that the
  Client MAY supply.

  Example: If the Client supplies the "attributes-natural-language"
  operation attribute with the value 'en' indicating English but the
  value of the "job-name" attribute is in French, the Client MUST use
  the 'textWithLanguage' attribute syntax with the following two
  values:

     'fr': Natural Language Override indicating French

     'Rapport Mensuel': the Job name in French

  See the Encoding and Transport document [RFC8010] for the encoding of
  the two parts and a detailed example of the 'textWithLanguage'
  attribute syntax.

5.1.3.  'name'

  This syntax type is used for user-friendly strings, such as a Printer
  name, that, for humans, are more meaningful than identifiers.  Names
  are never translated from one natural language to another.  The
  'name' attribute syntax is essentially the same as 'text', including
  the REQUIRED support of UTF-8, except that the sequence of characters
  is limited so that its encoded form MUST NOT exceed 255 (MAX) octets.




Sweet & McDonald             Standards Track                   [Page 95]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  Also, like 'text', 'name' is really an abbreviated notation for
  either 'nameWithoutLanguage' or 'nameWithLanguage'.  That is, all IPP
  objects and Clients MUST support both the 'nameWithoutLanguage' and
  'nameWithLanguage' attribute syntaxes.  However, in actual usage and
  protocol execution, IPP objects and Clients accept and return only
  one of the two syntaxes per attribute.  The syntax 'name' never
  appears "on-the-wire".

  Only the 'text' and 'name' attribute syntaxes permit the Natural
  Language Override mechanism.

  Some attributes are defined as 'type2 keyword | name'.  These
  attributes support values that are either type2 keywords or names.
  This dual-syntax mechanism enables a site Administrator to extend
  these attributes to legally include values that are locally defined
  by the site Administrator.  Such names are not registered with IANA.

5.1.3.1.  'nameWithoutLanguage'

  The 'nameWithoutLanguage' syntax indicates a value that is a sequence
  of zero or more characters encoded in a maximum of 255 (MAX) octets.

5.1.3.2.  'nameWithLanguage'

  The 'nameWithLanguage' attribute syntax is a compound attribute
  syntax consisting of two parts: a 'nameWithoutLanguage' (see
  Section 5.1.3.1) part plus an additional 'naturalLanguage' (see
  Section 5.1.9) part that overrides the natural language in force.
  The 'naturalLanguage' part explicitly identifies the natural language
  that applies to that name value and that name value alone.  For any
  given 'name' attribute, the 'nameWithoutLanguage' part is limited to
  the maximum length defined for that 'name' attribute, and the
  'naturalLanguage' part is always limited to 63 (additional) octets.
  Using the 'nameWithLanguage' attribute syntax rather than the normal
  'nameWithoutLanguage' syntax is the Natural Language Override
  mechanism and MUST be supported by all IPP objects and Clients.

  The 'nameWithLanguage' attribute syntax behaves the same as the
  'textWithLanguage' syntax.  If a name is in a language that is
  different than the rest of the object or operation, then this
  'nameWithLanguage' syntax is used rather than the generic
  'nameWithoutLanguage' syntax.

  If the attribute is multi-valued (1setOf name), then the
  'nameWithLanguage' attribute syntax MUST be used to explicitly
  specify each attribute value whose natural language needs to be





Sweet & McDonald             Standards Track                   [Page 96]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  overridden.  Other values in a multi-valued 'name' attribute in a
  request or a response revert to the natural language of the operation
  attribute.

  In a Job Creation request, the Printer MUST accept and store with the
  Job any natural language in the "attributes-natural-language"
  operation attribute, whether the Printer supports that natural
  language or not.  Furthermore, the Printer MUST accept and store any
  'nameWithLanguage' attribute value, whether the Printer supports that
  natural language or not.  These requirements are independent of the
  value of the "ipp-attribute-fidelity" operation attribute that the
  Client MAY supply.

  Example: If the Client supplies the "attributes-natural-language"
  operation attribute with the value 'en' indicating English but the
  "printer-name" attribute is in German, the Client MUST use the
  'nameWithLanguage' attribute syntax as follows:

     'de': Natural Language Override indicating German

     'Farbdrucker': the Printer name in German

  See the Encoding and Transport document [RFC8010] for the encoding of
  the two parts and a detailed example of the 'nameWithLanguage'
  attribute syntax.

5.1.3.3.  Matching 'name' Attribute Values

  For purposes of matching two 'name' attribute values for equality,
  such as in Job validation (where a Client-supplied value for
  attribute "xxx" is checked to see if the value is among the values of
  the Printer's corresponding "xxx-supported" attribute), the following
  match rules apply:

  1.  'keyword' values never match 'name' values.

  2.  'name' ('nameWithoutLanguage' and 'nameWithLanguage') values
      match if (1) the name parts match and (2) the Associated
      Natural Language parts (see Section 4.1.4.1) match.  The matching
      rules are as follows:

      2a.  The name parts match if the two names are identical
           character by character, except that it is RECOMMENDED that
           case be ignored as defined in "i;unicode-casemap - Simple
           Unicode Collation Algorithm" [RFC5051].  For example,
           'Ajax-letter-head-white' MUST match 'Ajax-letter-head-white'
           and SHOULD match 'ajax-letter-head-white' and
           'AJAX-LETTER-HEAD-WHITE'.



Sweet & McDonald             Standards Track                   [Page 97]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


      2b.  The Associated Natural Language parts match if the shorter
           of the two meets the syntactic requirements defined in
           Section 2.1 of RFC 5646 [RFC5646] and matches (byte for
           byte, since IPP language tags are lowercase) with the
           longer.  For example, 'en' matches 'en', 'en-us', and
           'en-gb' but matches neither 'fr' nor 'e'.

5.1.4.  'keyword'

  The 'keyword' attribute syntax is a sequence of characters, of length
  1 to 255, containing only the US-ASCII [RFC20] encoded values for
  lowercase letters ("a"-"z"), digits ("0"-"9"), hyphen ("-"), dot
  ("."), and underscore ("_").  The first character MUST be a lowercase
  letter.  Furthermore, keywords MUST be in US English.

  This syntax type is used for enumerating semantic identifiers of
  entities in the abstract protocol, i.e., entities identified in this
  document.  Keywords are used as attribute names or values of
  attributes.  Unlike 'text' and 'name' attribute values, 'keyword'
  values MUST NOT use the Natural Language Override mechanism, since
  they MUST always be US-ASCII and US English.

  Keywords are for use in the protocol.  A user interface will likely
  provide a mapping between protocol keywords and displayable
  user-friendly words and phrases that are localized to the natural
  language of the user.  While the keywords specified in this document
  MAY be displayed to users whose natural language is US English, they
  MAY be mapped to other US English words for US English users, since
  the user interface is outside the scope of this document.

  In the definition for each attribute of this syntax type, the full
  set of 'keyword' values being defined for that attribute is listed.
  The IANA IPP registry will always contain the complete and current
  list of 'keyword' values for the attribute.

  When a keyword is used to represent an attribute (its name), it MUST
  be unique within the full scope of all IPP objects and attributes.
  When a keyword is used to represent a value of an attribute, it MUST
  be unique just within the scope of that attribute.  That is, the same
  keyword MUST NOT be used for two different values within the same
  attribute to mean two different semantic ideas.  However, the same
  keyword MAY be used across two or more attributes, representing









Sweet & McDonald             Standards Track                   [Page 98]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  different semantic ideas for each attribute.  Section 7.3 describes
  how the protocol can be extended with new 'keyword' values.  Examples
  of attribute name keywords are:

     "job-name"

     "attributes-charset"

  Note: This document uses "type1" and "type2" prefixes to the
  "keyword" basic syntax to indicate different levels of review for
  extensions (see Section 7.3).

5.1.5.  'enum'

  The 'enum' attribute syntax is an enumerated integer value that is in
  the range from 1 to 2**31 - 1 (MAX).  Each value has an associated
  'keyword' name.  In the definition for each attribute of this syntax
  type, the full set of possible values for that attribute is listed.
  This syntax type is used for attributes for which there are enum
  values assigned by other standards, such as SNMP MIBs.  A number of
  attribute enum values in this document are also used for
  corresponding attributes in other standards [RFC3805].  This syntax
  type is not used for attributes to which the Administrator can assign
  values.  Section 7.4 describes how the protocol can be extended with
  new enum values.

  Enum values are for use in the protocol.  A user interface will
  provide a mapping between protocol enum values and displayable
  user-friendly words and phrases that are localized to the natural
  language of the user.  While the enum symbols specified in this
  document MAY be displayed to users whose natural language is
  US English, they MAY be mapped to other US English words for
  US English users, since the user interface is outside the scope of
  this document.

  Note: Some SNMP MIBs use '2' for 'unknown', which corresponds to the
  IPP "out-of-band" value 'unknown'.  See the description of the
  "out-of-band" values at the beginning of Section 5.1.  Therefore,
  attributes of type 'enum' typically start at '3'.

  Note: This document uses "type1" and "type2" prefixes to the "enum"
  basic syntax to indicate different levels of review for extensions
  (see Section 7.4).








Sweet & McDonald             Standards Track                   [Page 99]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


5.1.6.  'uri'

  The 'uri' attribute syntax is any valid Uniform Resource Identifier
  (URI) [RFC3986].  Most often, URIs are simply Uniform Resource
  Locators (URLs).  The maximum length of URIs used as values of IPP
  attributes is 1023 octets.  Although most other IPP attribute syntax
  types allow for only lowercase values, this attribute syntax type
  conforms to the case-sensitive and case-insensitive rules specified
  in [RFC3986].  See also [RFC3196] for a discussion of case in URIs.

5.1.7.  'uriScheme'

  The 'uriScheme' attribute syntax is a sequence of characters
  representing a URI scheme according to RFC 3986 [RFC3986].  Though
  RFC 3986 requires that the values be case insensitive, IPP requires
  all lowercase values in IPP attributes, to simplify comparing by IPP
  Clients and Printers.

  Standard values for this syntax type include the following keywords:

  o  'ipp': for IPP schemed URIs, e.g., "ipp://example.com/ipp/..."
     [RFC3510]

  o  'ipps': for IPPS schemed URIs, e.g., "ipps://example.com/ipp/..."
     [RFC7472]

  o  'http': for HTTP schemed URIs, e.g., "http://example.com/path/to/
     filename" [RFC7230]

  o  'https': for HTTPS schemed URIs, e.g.,
     "https://example.com/path/to/filename" [RFC7230]

  o  'ftp': for FTP schemed URIs, e.g., "ftp://example.com/path/to/
     filename" [RFC1738]

  o  'mailto': for SMTP schemed URIs, e.g., "mailto:[email protected]"
     [RFC6068]

  o  'file': for file schemed URIs, e.g., "file:///path/to/filename"
     [RFC1738]

  o  'urn': for Uniform Resource Name schemed URIs, e.g.,
     "urn:uuid:01234567-89ab-cdef-fedc-ba9876543210" [RFC4122]

  A Printer MAY support any URI 'scheme' that has been registered with
  IANA [IANA-MT].  The maximum length of URI 'scheme' values used to
  represent IPP attribute values is 63 octets.




Sweet & McDonald             Standards Track                  [Page 100]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


5.1.8.  'charset'

  The 'charset' attribute syntax is a standard identifier for a
  charset.  A charset is a coded character set and encoding scheme.
  Charsets are used for labeling certain Document contents, 'text'
  attribute values, and 'name' attribute values.  The syntax and
  semantics of this attribute syntax are specified in RFC 2046
  [RFC2046] and contained in the IANA "Character Sets" registry
  [IANA-CS] according to the IANA procedures [RFC2978].  Though
  RFC 2046 requires that the values be case-insensitive US-ASCII
  [RFC20], IPP requires all lowercase values in IPP attributes, to
  simplify comparing by IPP Clients and Printers.  When a character set
  in the IANA registry has more than one name (alias), the name labeled
  as "(preferred MIME name)", if present, MUST be used.

  The maximum length of 'charset' values used to represent IPP
  attribute values is 63 octets.

  Some examples are:

  o  'utf-8': ISO 10646 Universal Multiple-Octet Coded Character Set
     (UCS) [ISO10646] represented as the UTF-8 [RFC3629] transfer
     encoding scheme in which US-ASCII [RFC20] is a subset charset.

  o  'us-ascii': 7-bit American Standard Code for Information
     Interchange (ASCII) [RFC20].

  o  'iso-8859-1': 8-bit One-Byte Coded Character Set, Latin Alphabet
     No. 1 [ISO8859-1].  That standard defines a coded character set
     that is used by Latin languages in the Western Hemisphere and
     Western Europe.  US-ASCII is a subset charset.

  Some attribute descriptions MAY place additional requirements on
  charset values that can be used, such as REQUIRED values that MUST be
  supported or additional restrictions, such as requiring that the
  charset have US-ASCII as a subset charset.















Sweet & McDonald             Standards Track                  [Page 101]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


5.1.9.  'naturalLanguage'

  The 'naturalLanguage' attribute syntax is a standard identifier for a
  natural language and, optionally, a country or region.  The values
  for this syntax type are defined by RFC 5646 [RFC5646].  Though
  RFC 5646 requires that the values be case-insensitive US-ASCII, IPP
  requires all lowercase values in IPP attributes, to simplify
  comparing by IPP Clients and Printers.  Examples include:

  o  'en': for English

  o  'en-us': for US English

  o  'fr': for French

  o  'de': for German

  The maximum length of 'naturalLanguage' values used to represent IPP
  attribute values is 63 octets.

  Note: While any standard natural language identifier defined in
  RFC 5646 can be used, Clients typically only support a subset of
  these identifiers.  When comparing two identifiers or performing
  lookups, Printers SHOULD be prepared to match legacy identifiers with
  their corresponding modern equivalents and vice versa.

5.1.10.  'mimeMediaType'

  The 'mimeMediaType' attribute syntax is the Internet media type
  (sometimes called "MIME type") as defined by RFC 2046 [RFC2046] and
  registered according to the procedures of RFC 6838 [RFC6838] for
  identifying a Document format.  The value MAY include a charset
  parameter, or some other parameter, depending on the specification of
  the media type in the IANA "Media Types" registry [IANA-MT].
  Although most other IPP syntax types allow for only lowercase values,
  this syntax type allows for mixed-case values that are
  case insensitive.

  Examples are:

  o  'text/html': An HTML Document

  o  'text/plain': A plain text Document in US-ASCII (RFC 2046
     indicates that in the absence of the charset parameter MUST mean
     US-ASCII rather than simply unspecified) [RFC2046]

  o  'text/plain; charset = US-ASCII': A plain text Document in
     US-ASCII



Sweet & McDonald             Standards Track                  [Page 102]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  o  'text/plain; charset = ISO-8859-1': A plain text Document in
     ISO 8859-1 (Latin 1) [ISO8859-1]

  o  'text/plain; charset = utf-8': A plain text Document in ISO 10646
     represented as UTF-8 [RFC3629]

  o  'application/postscript': A PostScript Document [RFC2046]

  o  'application/vnd.hp-PCL': A PCL Document [IANA-MT] (charset escape
     sequence embedded in the Document data)

  o  'application/pdf': Portable Document Format [ISO32000]

  o  'application/octet-stream': Auto-sense - see Section 5.1.10.1

  The maximum length of a 'mimeMediaType' value to represent IPP
  attribute values is 255 octets.

5.1.10.1.  'application/octet-stream' - Auto-Sensing the Document Format

  One special type is 'application/octet-stream'.  If the Printer
  supports this value, the Printer MUST be capable of auto-sensing the
  format of the Document data using an implementation-dependent method
  that examines some number of octets of the Document data, either as
  part of the Job Creation request and/or at Document processing time.
  During auto-sensing, a Printer can determine that the Document data
  has a format that the Printer doesn't recognize.  If the Printer
  determines this problem before returning an operation response, it
  rejects the request and returns the
  'client-error-document-format-not-supported' status-code.  If the
  Printer determines this problem after accepting the request and
  returning an operation response with one of the successful
  status-code values, the Printer adds the
  'unsupported-document-format' value to the Job's "job-state-reasons"
  attribute.

  If the Printer's default value attribute "document-format-default" is
  set to 'application/octet-stream', the Printer not only supports
  auto-sensing of the Document format but will depend on the result of
  applying its auto-sensing when the Client does not supply the
  "document-format" attribute.  If the Client supplies a Document
  format value, the Printer MUST rely on the supplied attribute, rather
  than trust its auto-sensing algorithm.  To summarize:

  1.  If the Client does not supply a Document format value, the
      Printer MUST rely on its default value setting (which can be
      'application/octet-stream' indicating an auto-sensing mechanism).




Sweet & McDonald             Standards Track                  [Page 103]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  2.  If the Client supplies a value other than
      'application/octet-stream', the Client is supplying valid
      information about the format of the Document data and the Printer
      MUST trust the Client-supplied value more than the outcome of
      applying an automatic format detection mechanism.  For example,
      the Client can request the printing of a PostScript file as a
      'text/plain' Document.  The Printer MUST print a text
      representation of the PostScript commands rather than interpret
      the stream of PostScript commands and print the result.

  3.  If the Client supplies a value of 'application/octet-stream', the
      Client is indicating that the Printer MUST use its auto-sensing
      mechanism on the Client-supplied Document data whether
      auto-sensing is the Printer's default or not.

  Note: Since the auto-sensing algorithm is probabilistic, if the
  Client requests both auto-sensing ("document-format" set to
  'application/octet-stream') and true fidelity
  ("ipp-attribute-fidelity" set to 'true'), the Printer might not be
  able to guarantee exactly what the End User intended (the
  auto-sensing algorithm might mistake one Document format for
  another), but it is able to guarantee that its auto-sensing mechanism
  will be used.

5.1.11.  'octetString'

  The 'octetString' attribute syntax is a sequence of octets encoded in
  a maximum of 1023 octets that is indicated in syntax definitions
  using the notation 'octetString(MAX)'.  This syntax type is used for
  opaque data.

5.1.12.  'boolean'

  The 'boolean' attribute syntax has only two values: 'true' and
  'false'.

5.1.13.  'integer'

  The 'integer' attribute syntax is an integer value that is in the
  range from -2**31 (MIN) to 2**31 - 1 (MAX).  Each individual
  attribute can specify the range constraint explicitly if the range is
  different from the full range of possible integer values -- for
  example, job-priority (integer(1:100)) for the "job-priority"
  attribute, as shown in the title of Section 5.2.1.  However, the
  enforcement of that additional constraint is up to the IPP objects,
  not the protocol.





Sweet & McDonald             Standards Track                  [Page 104]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


5.1.14.  'rangeOfInteger'

  The 'rangeOfInteger' attribute syntax is an ordered pair of integers
  that defines an inclusive range of integer values.  The first integer
  specifies the lower bound, and the second specifies the upper bound.
  If a range constraint is specified in the attribute definition, i.e.,
  'rangeOfInteger(X:Y)' indicating X as a minimum value and Y as a
  maximum value, then the constraint applies to both integers.

5.1.15.  'dateTime'

  The 'dateTime' attribute syntax is a standard, fixed-length, 11-octet
  representation of the "DateAndTime" syntax as defined in RFC 2579
  [RFC2579].  RFC 2579 also identifies an 8-octet representation of a
  "DateAndTime" value, but IPP objects MUST use the 11-octet
  representation.  A user interface will provide a mapping between
  protocol dateTime values and displayable user-friendly words or
  presentation values and phrases that are localized to the natural
  language and date format of the user, including time zone.

5.1.16.  'resolution'

  The 'resolution' attribute syntax specifies a two-dimensional
  resolution in the indicated units.  It consists of three values: a
  cross-feed direction resolution (positive integer value), a feed
  direction resolution (positive integer value), and a units value.
  The semantics of these three components are taken from the suggested
  values in the Printer MIB [RFC3805].  That is, the cross-feed
  direction resolution component is the same as the
  prtMarkerAddressabilityXFeedDir object in the Printer MIB, the feed
  direction resolution component is the same as the
  prtMarkerAddressabilityFeedDir in the Printer MIB, and the units
  component is the same as the prtMarkerAddressabilityUnit object in
  the Printer MIB (namely, '3' indicates dots per inch and '4'
  indicates dots per centimeter).  All three values MUST be present
  even if the first two values are the same.  For example, '300',
  '600', '3' indicates a 300-dpi cross-feed direction resolution and a
  600-dpi feed direction resolution, since a '3' indicates dots per
  inch (dpi).

5.1.17.  'collection'

  The 'collection' attribute syntax is a container holding one or more
  named values (i.e., attributes), which are called "member
  attributes".  Each 'collection' attribute definition Document lists
  the mandatory and optional member attributes of each collection
  value.  A collection value is similar to an IPP attribute group in a




Sweet & McDonald             Standards Track                  [Page 105]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  request or a response, such as the Operation Attributes group -- they
  both consist of a set of attributes.  Collections can also be nested,
  i.e., a collection in a collection.

  A collection value consists of three separate components:

  o  A 'begCollection' value with an optional octet string value
     starting the collection,

  o  Zero or more member attributes defined using a series of unnamed
     values starting with a 'memberAttrName' value that specifies the
     member attribute name, and

  o  An 'endCollection' value with an optional name plus octet string
     value finishing the collection.

5.1.18.  '1setOf X'

  The '1setOf X' attribute syntax is one or more values of attribute
  syntax type X.  This syntax type is used for multi-valued attributes.
  The syntax type is called '1setOf' rather than just 'setOf' as a
  reminder that the set of values MUST NOT be empty (i.e., a set of
  size 0).  Sets are normally unordered; however, each attribute
  description of this type can specify that the values MUST be in a
  certain order for that attribute.

5.2.  Job Template Attributes

  Job Template attributes describe Job processing intent.  Clients MAY
  supply (in Job Creation requests) and Printers SHOULD support Job
  Template attributes.  See Section 2.3.11 for a description of support
  for OPTIONAL attributes.

  Job Template attributes conform to the following rules.  For each Job
  Template attribute called "xxx":

  1.  If the Printer supports "xxx", then it MUST support both an
      "xxx-default" attribute (unless there is a "No" in Table 8 below)
      and an "xxx-supported" attribute.  If the Printer doesn't support
      "xxx", then it MUST support neither an "xxx-default" attribute
      nor an "xxx-supported" attribute, and it MUST treat an attribute
      "xxx" supplied by a Client as unsupported.  An attribute "xxx"
      can be supported for some Document formats and not supported for
      other Document formats.  For example, it is expected that a
      Printer would only support "orientation-requested" for some
      Document formats (such as 'text/plain' or 'text/html') but not
      others (such as 'application/postscript').




Sweet & McDonald             Standards Track                  [Page 106]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  2.  Clients MAY supply "xxx" in a Job Creation request.  If "xxx" is
      supplied, the Client is indicating a desired Job processing
      behavior for this Job.  When "xxx" is not supplied, the Client is
      indicating that the Printer apply its default Job processing
      behavior at Job processing time if the Document content does not
      contain an embedded instruction indicating an xxx-related
      behavior.

      Since an Administrator MAY change the default value attribute
      after a Job has been submitted but before it has been processed,
      the default value used by the Printer at Job processing time can
      be different than the default value in effect at Job submission
      time.

  3.  The "xxx-supported" attribute is a Printer attribute that
      describes which Job processing behaviors are supported by that
      Printer.  A Client can query the Printer to find out what
      xxx-related behaviors are supported by inspecting the returned
      values of the "xxx-supported" attribute.

      Note: The "xxx" in each "xxx-supported" attribute name is
      singular, even though an "xxx-supported" attribute usually has
      more than one value, such as "print-quality-supported", unless
      the "xxx" Job Template attribute is plural, such as "finishings"
      or "sides".  In such cases, the "xxx-supported" attribute names
      are "finishings-supported" and "sides-supported".

  4.  The "xxx-default" default value attribute describes what will be
      done at Job processing time when no other Job processing
      information is supplied by the Client (either explicitly as an
      IPP attribute in the Job Creation request or implicitly as an
      embedded instruction within the Document data).

  If an application wishes to present an End User with a list of
  supported values from which to choose, the application SHOULD query
  the Printer for its supported value attributes.  The application
  SHOULD also query the default value attributes.  If the application
  then limits selectable values to only those values that are
  supported, the application can guarantee that the values supplied by
  the Client in the Job Creation request all fall within the set of
  supported values at the Printer.  When querying the Printer, the
  Client MAY enumerate each attribute by name in the
  Get-Printer-Attributes request, or the Client MAY just name the
  "job-template" group in order to get the complete set of supported
  attributes (both supported and default attributes).






Sweet & McDonald             Standards Track                  [Page 107]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  The "finishings" attribute is an example of a Job Template attribute.
  It can take on a set of values such as '4' ('staple'), '5' ('punch'),
  and/or '6' ('cover'); see Table 10 in Section 5.2.6.  A Client can
  query the Printer for the "finishings-supported" attribute and the
  "finishings-default" attribute.  The supported attribute contains a
  set of supported values.  The default value attribute contains the
  finishing value(s) that will be used for a new Job if the Client does
  not supply a "finishings" attribute in the Job Creation request and
  the Document data does not contain any corresponding finishing
  instructions.  If the Client does supply the "finishings" attribute
  in the Job Creation request, the Printer validates the value or
  values to make sure that they are a subset of the supported values
  identified in the Printer's "finishings-supported" attribute.  See
  Section 4.1.7.

  Table 8 below summarizes the names and relationships for all Job
  Template attributes.  The first column of the table (labeled "Job
  Attribute") shows the name and syntax for each Job Template attribute
  in the Job.  These are the attributes that can optionally be supplied
  by the Client in a Job Creation request.  The last two columns
  (labeled "Printer: Default Value Attribute" and "Printer: "Supported
  Values" Attribute") show the name and syntax for each Job Template
  attribute in the Printer (the default value attributes and the
  "supported values" attributes).  A "No" in the table means the
  Printer MUST NOT support the attribute (that is, the attribute is
  simply not applicable).  For brevity in the table, the 'text' and
  'name' entries do not show the maximum length for each attribute.

  +------------------+----------------------+-------------------------+
  | Job Attribute    | Printer: Default     | Printer: "Supported     |
  |                  | Value Attribute      | Values" Attribute       |
  +------------------+----------------------+-------------------------+
  | job-priority     | job-priority-default | job-priority-supported  |
  | (integer 1:100)  | (integer 1:100)      | (integer 1:100)         |
  +------------------+----------------------+-------------------------+
  | job-hold-until   | job-hold-until-      | job-hold-until-         |
  | (type2 keyword | | default (type2       | supported (1setOf       |
  | name)            | keyword | name)      | (type2 keyword | name)) |
  +------------------+----------------------+-------------------------+
  | job-sheets       | job-sheets-default   | job-sheets-supported    |
  | (type2 keyword | | (type2 keyword |     | (1setOf (type2 keyword  |
  | name)            | name)                | | name))                |
  +------------------+----------------------+-------------------------+
  | multiple-        | multiple-document-   | multiple-document-      |
  | document-        | handling-default     | handling-supported      |
  | handling (type2  | (type2 keyword)      | (1setOf type2 keyword)  |
  | keyword)         |                      |                         |




Sweet & McDonald             Standards Track                  [Page 108]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  +------------------+----------------------+-------------------------+
  | copies           | copies-default       | copies-supported        |
  | (integer(1:MAX)) | (integer(1:MAX))     | (rangeOfInteger(1:MAX)) |
  +------------------+----------------------+-------------------------+
  | finishings       | finishings-default   | finishings-supported    |
  | (1setOf type2    | (1setOf type2 enum)  | (1setOf type2 enum)     |
  | enum)            |                      |                         |
  +------------------+----------------------+-------------------------+
  | page-ranges      | No                   | page-ranges-supported   |
  | (1setOf          |                      | (boolean)               |
  | rangeOfInteger   |                      |                         |
  | (1:MAX))         |                      |                         |
  +------------------+----------------------+-------------------------+
  | sides (type2     | sides-default (type2 | sides-supported (1setOf |
  | keyword)         | keyword)             | type2 keyword)          |
  +------------------+----------------------+-------------------------+
  | number-up        | number-up-default    | number-up-supported     |
  | (integer(1:MAX)) | (integer(1:MAX))     | (1setOf                 |
  |                  |                      | (integer(1:MAX) |       |
  |                  |                      | rangeOfInteger(1:MAX))) |
  +------------------+----------------------+-------------------------+
  | orientation-     | orientation-         | orientation-requested-  |
  | requested (type2 | requested-default    | supported (1setOf type2 |
  | enum)            | (type2 enum)         | enum)                   |
  +------------------+----------------------+-------------------------+
  | media (type2     | media-default (type2 | media-supported (1setOf |
  | keyword | name)  | keyword | name)      | (type2 keyword | name)) |
  |                  |                      | media-ready (1setOf     |
  |                  |                      | (type2 keyword | name)) |
  +------------------+----------------------+-------------------------+
  | printer-         | printer-resolution-  | printer-resolution-     |
  | resolution       | default (resolution) | supported (1setOf       |
  | (resolution)     |                      | resolution)             |
  +------------------+----------------------+-------------------------+
  | print-quality    | print-quality-       | print-quality-supported |
  | (type2 enum)     | default (type2 enum) | (1setOf type2 enum)     |
  +------------------+----------------------+-------------------------+

                    Table 8: Job Template Attributes

5.2.1.  job-priority (integer(1:100))

  This attribute specifies a priority for scheduling the Job.  A higher
  value specifies a higher priority.  The value 1 indicates the lowest
  possible priority.  The value 100 indicates the highest possible
  priority.  Among those Jobs that are ready to print, a Printer MUST
  print all Jobs with a priority value of n before printing those with
  a priority value of n - 1 for all n.



Sweet & McDonald             Standards Track                  [Page 109]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  If the Printer supports this attribute, it MUST always support the
  full range from 1 to 100.  No administrative restrictions are
  permitted.  This way, an End User can always make full use of the
  entire range with any Printer.  If privileged Jobs are implemented
  outside IPP, they MUST have priorities higher than 100, rather than
  restricting the range available to End Users.

  If the Client does not supply this attribute and this attribute is
  supported by the Printer, the Printer MUST use the value of the
  Printer's "job-priority-default" attribute at Job submission time
  (unlike most Job Template attributes that are used if necessary at
  Job processing time).

  The syntax for the "job-priority-supported" attribute is also
  integer(1:100).  This single integer value indicates the number of
  priority levels supported.  The Printer MUST take the value supplied
  by the Client and map it to the closest integer in a sequence of
  n integer values that are evenly distributed over the range from
  1 to 100 using the formula:

     roundToNearestInt((100x + 50) / n)

  where n is the value of "job-priority-supported" and x ranges from
  0 through (n - 1).

  For example, if n = 1, the sequence of values is 50; if n = 2, the
  sequence of values is 25 and 75; if n = 3, the sequence of values is
  17, 50, and 83; if n = 10, the sequence of values is 5, 15, 25, 35,
  45, 55, 65, 75, 85, and 95; if n = 100, the sequence of values is
  1, 2, 3, ... 100.





















Sweet & McDonald             Standards Track                  [Page 110]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  Table 9 shows how a Printer maps Client-supplied "job-priority"
  values for example values of n.

                +--------------+-------+-------+--------+
                | job-priority | n = 1 | n = 2 | n = 10 |
                +--------------+-------+-------+--------+
                | 1            | 50    | 17    | 5      |
                +--------------+-------+-------+--------+
                | 10           | 50    | 17    | 5      |
                +--------------+-------+-------+--------+
                | 20           | 50    | 17    | 15     |
                +--------------+-------+-------+--------+
                | 30           | 50    | 17    | 25     |
                +--------------+-------+-------+--------+
                | 40           | 50    | 50    | 35     |
                +--------------+-------+-------+--------+
                | 50           | 50    | 50    | 45     |
                +--------------+-------+-------+--------+
                | 60           | 50    | 50    | 55     |
                +--------------+-------+-------+--------+
                | 70           | 50    | 50    | 65     |
                +--------------+-------+-------+--------+
                | 80           | 50    | 83    | 75     |
                +--------------+-------+-------+--------+
                | 90           | 50    | 83    | 85     |
                +--------------+-------+-------+--------+
                | 100          | 50    | 83    | 95     |
                +--------------+-------+-------+--------+

                     Table 9: "job-priority" Values

5.2.2.  job-hold-until (type2 keyword | name(MAX))

  This attribute specifies the named time period during which the Job
  MUST become a candidate for printing.

  Standard 'keyword' values for named time periods are:

  o  'no-hold': immediately, if there are no other reasons to hold
     the job

  o  'indefinite': the Job is held indefinitely, until a Client
     performs a Release-Job (Section 4.3.6)

  o  'day-time': during the day

  o  'evening': evening




Sweet & McDonald             Standards Track                  [Page 111]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  o  'night': night

  o  'weekend': weekend

  o  'second-shift': second shift (after close of business)

  o  'third-shift': third shift (after midnight)

  An Administrator MUST associate allowable print times with a named
  time period (by means outside the scope of this IPP/1.1 document).
  An Administrator is encouraged to pick names that suggest the type of
  time period.  An Administrator MAY define additional values using the
  'name' or 'keyword' attribute syntax, depending on implementation.

  If the value of this attribute specifies a time period that is in the
  future, the Printer SHOULD add the "job-hold-until-specified" value
  to the Job's "job-state-reasons" attribute, MUST move the Job to the
  'pending-held' state, and MUST NOT schedule the Job for printing
  until the specified time period arrives.

  When the specified time period arrives, the Printer MUST remove the
  "job-hold-until-specified" value from the Job's "job-state-reasons"
  attribute, if present.  If there are no other Job state reasons that
  keep the Job in the 'pending-held' state, the Printer MUST consider
  the Job as a candidate for processing by moving the Job to the
  'pending' state.

  If this Job attribute value is the named value 'no-hold' or the
  specified time period has already started, the Job MUST be a
  candidate for processing immediately.

  If the Client does not supply this attribute and this attribute is
  supported by the Printer, the Printer MUST use the value of the
  Printer's "job-hold-until-default" at Job submission time (unlike
  most Job Template attributes that are used if necessary at Job
  processing time).

5.2.3.  job-sheets (type2 keyword | name(MAX))

  This attribute determines which Job start/end sheet(s), if any, MUST
  be printed with a Job.

  Standard 'keyword' values are:

  o  'none': no Job sheet is printed

  o  'standard': one or more site-specific standard Job sheets are
     printed, e.g., a single start sheet or both start and end sheets



Sweet & McDonald             Standards Track                  [Page 112]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  An Administrator MAY define additional values using the 'name' or
  'keyword' attribute syntax, depending on implementation.

  The effect of this attribute on Jobs with multiple Documents MAY be
  affected by the "multiple-document-handling" Job attribute
  (Section 5.2.4), depending on the Job sheet semantics.

5.2.4.  multiple-document-handling (type2 keyword)

  This RECOMMENDED attribute controls which Impressions and Media
  Sheets constitute a Set for copy generation and finishing processes.
  When the value of the "copies" attribute exceeds '1', it also
  controls the order in which the copies that result from processing
  the Documents are produced.  For the purposes of this explanation, if
  "a" represents an instance of Document data, then the result of
  processing the data in Document "a" is a sequence of Media Sheets
  represented by "a(*)".  This attribute MUST be supported with at
  least one value if the Printer supports multiple Documents per Job
  (see Sections 4.2.4 and 4.3.1).

  Standard 'keyword' values are:

  o  'single-document': If a Job has multiple Documents, say, the
     Document data is called "a" and "b", then the result of processing
     all the Document data (a and then b) MUST be treated as a single
     sequence of Media Sheets for finishing processes; that is,
     finishing is performed on the concatenation of the sequences
     a(*),b(*).  The Printer MUST NOT force the data in each Document
     instance to be formatted onto a new Impression, nor to start a new
     Impression on a new Media Sheet.  If more than one copy is made,
     the ordering of the sets of Media Sheets resulting from processing
     the Document data MUST be a(*), b(*), a(*), b(*), ..., and the
     Printer MUST force each copy (a(*),b(*)) to start on a new Media
     Sheet.

  o  'separate-documents-uncollated-copies': If a Job has multiple
     Documents, say, the Document data is called "a" and "b", then the
     result of processing the data in each Document instance MUST be
     treated as a single sequence of Media Sheets for finishing
     processes; that is, the sets a(*) and b(*) would each be finished
     separately.  The Printer MUST force each copy of the result of
     processing the data in a single Document to start on a new Media
     Sheet.  If more than one copy is made, the ordering of the sets of
     Media Sheets resulting from processing the Document data MUST be
     a(*), a(*), ..., b(*), b(*), ... .






Sweet & McDonald             Standards Track                  [Page 113]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  o  'separate-documents-collated-copies': If a Job has multiple
     Documents, say, the Document data is called "a" and "b", then the
     result of processing the data in each Document instance MUST be
     treated as a single sequence of Media Sheets for finishing
     processes; that is, the sets a(*) and b(*) would each be finished
     separately.  The Printer MUST force each copy of the result of
     processing the data in a single Document to start on a new Media
     Sheet.  If more than one copy is made, the ordering of the sets of
     Media Sheets resulting from processing the Document data MUST be
     a(*), b(*), a(*), b(*), ... .

  o  'single-document-new-sheet': Same as 'single-document', except
     that the Printer MUST ensure that the first Impression of each
     Document instance in the Job is placed on a new Media Sheet.  This
     value allows multiple Documents to be stapled together with a
     single staple where each Document starts on a new Media Sheet.

  The 'single-document' value is the same as
  'separate-documents-collated-copies' with respect to the ordering of
  Input Pages, but not Media Sheet generation, since 'single-document'
  will put the first page of the next Document on the back side of a
  Media Sheet if an odd number of pages have been produced so far for
  the Job, while 'separate-documents-collated-copies' always forces the
  next Document or Document copy on to a new Media Sheet.  In addition,
  if the "finishings" attribute specifies 'staple', then with
  'single-document', Documents a and b are stapled together as a single
  Set with no regard to a new Media Sheet, while with
  'single-document-new-sheet', Documents a and b are stapled together
  as a single Set but Document b starts on a new Media Sheet.  With
  'separate-documents-uncollated-copies' and
  'separate-documents-collated-copies', Documents a and b are stapled
  separately.

  Note: The value 'separate-documents-uncollated-copies' produces
  uncollated Media Sheets within a Set, e.g., when "copies" is '2' a
  two-Document Job will be printed as Media Sheets a(1), a(1), a(2),
  a(2), ... a(n), a(n), b(1), b(1), ..., b(n), b(n).  All other values
  produce collated Media Sheets within a Set.

  The relationship of this attribute and the other attributes that
  control Document processing is described in Appendix C.3.










Sweet & McDonald             Standards Track                  [Page 114]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


5.2.5.  copies (integer(1:MAX))

  This RECOMMENDED attribute specifies the number of copies to be
  printed.

  On many devices, the supported number of collated copies will be
  limited by the number of physical output bins on the device and can
  be different from the number of uncollated copies that can be
  supported.

  Note: The effect of this attribute on Jobs with multiple Documents is
  controlled by the "multiple-document-handling" Job attribute
  (Section 5.2.4).  The relationship of this attribute and the other
  attributes that control Document processing is described in
  Appendix C.3.

5.2.6.  finishings (1setOf type2 enum)

  This RECOMMENDED attribute identifies the finishing processes that
  the Printer uses for each copy of each printed Document in the Job.
  For Jobs with multiple Documents, the "multiple-document-handling"
  attribute determines what constitutes a "copy" for purposes of
  finishing.

  Standard enum values defined in this document are listed in Table 10.
  The 'staple-xxx' values are specified with respect to the Document as
  if the Document were in portrait orientation with the origin of each
  Media Sheet at the top left corner.  If the Document is actually in
  landscape or reverse-landscape orientation, the Client supplies the
  appropriate transformed value.  For example, to position a staple in
  the upper left-hand corner of a landscape Document when held for
  reading, the Client supplies the 'staple-bottom-left' value, since
  landscape is defined as a +90 degree rotation of the image with
  respect to the media from portrait, i.e., counterclockwise.  On the
  other hand, to position a staple in the upper left-hand corner of a
  reverse-landscape Document when held for reading, the Client supplies
  the 'staple-top-right' value, since reverse-landscape is defined as
  a -90 degree rotation of the image with respect to the media from
  portrait, i.e., clockwise.

  The angle (vertical, horizontal, angled) of each staple with respect
  to the Document depends on the implementation, which can in turn
  depend on the value of the attribute.








Sweet & McDonald             Standards Track                  [Page 115]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  Note: The effect of this attribute on Jobs with multiple Documents is
  controlled by the "multiple-document-handling" Job attribute
  (Section 5.2.4).  The relationship of this attribute and the other
  attributes that control Document processing is described in
  Appendix C.3.

  Note: The value of '3' ('none') has no effect when combined with any
  other values.

  Note: The "finishings-col" attribute [PWG5100.1] is an alternative to
  the "finishings" attribute that allows the Client to specify
  finishing intent in greater detail.

  +-----------+-------------------------------------------------------+
  | Value     | Symbolic Name and Description                         |
  +-----------+-------------------------------------------------------+
  | '3'       | 'none': Perform no finishing.                         |
  +-----------+-------------------------------------------------------+
  | '4'       | 'staple': Bind the Document(s) with one or more       |
  |           | staples.  The exact number and placement of the       |
  |           | staples are site defined.                             |
  +-----------+-------------------------------------------------------+
  | '5'       | 'punch': This value indicates that holes are required |
  |           | in the finished Document.  The exact number and       |
  |           | placement of the holes are site defined.  The punch   |
  |           | specification MAY be satisfied (in a site-specific    |
  |           | and implementation-specific manner) either by         |
  |           | drilling/punching or by substituting pre-drilled      |
  |           | media.                                                |
  +-----------+-------------------------------------------------------+
  | '6'       | 'cover': This value is specified when it is desired   |
  |           | to select a non-printed (or pre-printed) cover for    |
  |           | the Document.  This does not supplant the             |
  |           | specification of a printed cover (on cover stock      |
  |           | medium) by the Document itself.                       |
  +-----------+-------------------------------------------------------+
  | '7'       | 'bind': This value indicates that a binding is to be  |
  |           | applied to the Document; the type and placement of    |
  |           | the binding are site defined.                         |
  +-----------+-------------------------------------------------------+
  | '8'       | 'saddle-stitch': Bind the Document(s) with one or     |
  |           | more staples (wire stitches) along the middle fold.   |
  |           | The exact number and placement of the staples and the |
  |           | middle fold are implementation defined and/or site    |
  |           | defined.                                              |






Sweet & McDonald             Standards Track                  [Page 116]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  +-----------+-------------------------------------------------------+
  | '9'       | 'edge-stitch': Bind the Document(s) with one or more  |
  |           | staples (wire stitches) along one edge.  The exact    |
  |           | number and placement of the staples are               |
  |           | implementation defined and/or site defined.           |
  +-----------+-------------------------------------------------------+
  | '10'-'19' | reserved for future generic finishing enum values.    |
  +-----------+-------------------------------------------------------+
  | '20'      | 'staple-top-left': Bind the Document(s) with one or   |
  |           | more staples in the top left corner.                  |
  +-----------+-------------------------------------------------------+
  | '21'      | 'staple-bottom-left': Bind the Document(s) with one   |
  |           | or more staples in the bottom left corner.            |
  +-----------+-------------------------------------------------------+
  | '22'      | 'staple-top-right': Bind the Document(s) with one or  |
  |           | more staples in the top right corner.                 |
  +-----------+-------------------------------------------------------+
  | '23'      | 'staple-bottom-right': Bind the Document(s) with one  |
  |           | or more staples in the bottom right corner.           |
  +-----------+-------------------------------------------------------+
  | '24'      | 'edge-stitch-left': Bind the Document(s) with one or  |
  |           | more staples (wire stitches) along the left edge.     |
  |           | The exact number and placement of the staples are     |
  |           | implementation defined and/or site defined.           |
  +-----------+-------------------------------------------------------+
  | '25'      | 'edge-stitch-top': Bind the Document(s) with one or   |
  |           | more staples (wire stitches) along the top edge.  The |
  |           | exact number and placement of the staples are         |
  |           | implementation defined and/or site defined.           |
  +-----------+-------------------------------------------------------+
  | '26'      | 'edge-stitch-right': Bind the Document(s) with one or |
  |           | more staples (wire stitches) along the right edge.    |
  |           | The exact number and placement of the staples are     |
  |           | implementation defined and/or site defined.           |
  +-----------+-------------------------------------------------------+
  | '27'      | 'edge-stitch-bottom': Bind the Document(s) with one   |
  |           | or more staples (wire stitches) along the bottom      |
  |           | edge.  The exact number and placement of the staples  |
  |           | are implementation defined and/or site defined.       |
  +-----------+-------------------------------------------------------+
  | '28'      | 'staple-dual-left': Bind the Document(s) with two     |
  |           | staples (wire stitches) along the left edge, assuming |
  |           | a portrait Document (see above).                      |








Sweet & McDonald             Standards Track                  [Page 117]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  +-----------+-------------------------------------------------------+
  | '29'      | 'staple-dual-top': Bind the Document(s) with two      |
  |           | staples (wire stitches) along the top edge, assuming  |
  |           | a portrait Document (see above).                      |
  +-----------+-------------------------------------------------------+
  | '30'      | 'staple-dual-right': Bind the Document(s) with two    |
  |           | staples (wire stitches) along the right edge,         |
  |           | assuming a portrait Document (see above).             |
  +-----------+-------------------------------------------------------+
  | '31'      | 'staple-dual-bottom': Bind the Document(s) with two   |
  |           | staples (wire stitches) along the bottom edge,        |
  |           | assuming a portrait Document (see above).             |
  +-----------+-------------------------------------------------------+

                   Table 10: "finishings" Enum Values

5.2.7.  page-ranges (1setOf rangeOfInteger(1:MAX))

  This RECOMMENDED attribute identifies the range(s) of Input Pages
  that the Printer uses for each Set to be printed prior to imposition
  of those pages onto Impressions.  Nothing is printed for any pages
  identified that do not exist in the Set/Document(s).  Ranges MUST be
  in ascending order (1-3, 5-7, 15-19, etc.) and MUST NOT overlap so
  that a non-spooling Printer can process the Job in a single pass.  If
  the ranges are not ascending or are overlapping, the Printer MUST
  reject the request and return the 'client-error-bad-request'
  status-code.  The attribute is associated with Input Pages and not
  application-numbered pages such as the page numbers found in the
  headers and/or footers for certain word processing applications.

  For Jobs with multiple Documents, the "multiple-document-handling"
  attribute determines what constitutes a Set for purposes of the
  specified page range(s).  When "multiple-document-handling" is
  'single-document', the Printer MUST apply each supplied page range
  once to the concatenation of the Input Pages.  For example, if there
  are 8 Documents of 10 pages each, the page range '41-60' prints the
  pages in the 5th and 6th Documents as a single Document, and none of
  the pages of the other Documents are printed.  When
  "multiple-document-handling" is
  'separate-documents-uncollated-copies' or
  'separate-documents-collated-copies', the Printer MUST apply each
  supplied page range repeatedly to each Document copy.  For the same
  Job, the page range '1-3, 10-10' would print the first 3 pages
  and the 10th page of each of the 8 Documents in the Job, as 8
  separate Sets.






Sweet & McDonald             Standards Track                  [Page 118]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  "page-ranges-supported" is a boolean value indicating whether the
  Printer is capable of supporting the printing of page ranges.  This
  capability can differ from one PDL to another.  There is no
  "page-ranges-default" attribute.  If the "page-ranges" attribute is
  not supplied by the Client, all pages of the Document are printed.

  Note: In many cases, the Client supplies only those Input Pages that
  need to be printed in the Document data, and the "page-ranges" Job
  Template attribute is not used.  However, Clients that submit
  already-generated Document data (either static content from some web
  site or previously submitted content the End User wishes to reprint)
  can use this attribute to print just a subset of the pages contained
  in the Document.  In this case, if a "page-ranges" value of 'n-m' is
  specified, the first page to be printed will be page n.  All
  subsequent pages of the Document will be printed through and
  including page m.

  Note: The effect of this attribute on Jobs with multiple Documents is
  controlled by the "multiple-document-handling" Job attribute
  (Section 5.2.4).  The relationship of this attribute and the other
  attributes that control Document processing is described in
  Appendix C.3.

5.2.8.  sides (type2 keyword)

  This RECOMMENDED attribute specifies how Impressions are placed upon
  the sides of a Media Sheet.

  The standard 'keyword' values are:

  o  'one-sided': imposes each consecutive Impression upon the same
     side of consecutive Media Sheets.

  o  'two-sided-long-edge': imposes each consecutive pair of
     Impressions upon front and back sides of consecutive Media Sheets,
     such that the orientation of each pair of Impressions on the
     medium would be correct for the reader as if for binding on the
     long edge.  This imposition is sometimes called 'duplex' or
     'head-to-head'.

  o  'two-sided-short-edge': imposes each consecutive pair of
     Impressions upon front and back sides of consecutive Media Sheets,
     such that the orientation of each pair of Impressions on the
     medium would be correct for the reader as if for binding on the
     short edge.  This imposition is sometimes called 'tumble' or
     'head-to-toe'.





Sweet & McDonald             Standards Track                  [Page 119]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  Note: The effect of this attribute on Jobs with multiple Documents is
  controlled by the "multiple-document-handling" Job attribute
  (Section 5.2.4).  The relationship of this attribute and the other
  attributes that control Document processing is described in
  Appendix C.3.

5.2.9.  number-up (integer(1:MAX))

  This attribute specifies the number of Input Pages to impose upon a
  single Impression.  For example, if the value is:

  o  '1': the Printer MUST place one Input Page on a single Impression.

  o  '2': the Printer MUST place two Input Pages on a single
     Impression.

  o  '4': the Printer MUST place four Input Pages on a single
     Impression.

  In all cases, the Printer MAY add some sort of translation, scaling,
  or rotation of Input Pages when imposing them.

  Note: The effect of this attribute on Jobs with multiple Documents is
  controlled by the "multiple-document-handling" Job attribute
  (Section 5.2.4).  The relationship of this attribute and the other
  attributes that control Document processing is described in
  Appendix C.3.

5.2.10.  orientation-requested (type2 enum)

  This RECOMMENDED attribute indicates the desired orientation for
  printed Input Pages; it does not describe the orientation of the
  Client-supplied Input Pages.

  For some Document formats (such as 'application/postscript'), the
  desired orientation of the Input Pages is sometimes specified within
  the Document data.  This information is generated by a Printer driver
  prior to the submission of the Print Job.  Other Document formats
  such as 'text/plain' do not include the notion of desired orientation
  within the Document data.  In the latter case, it is possible for the
  Printer to bind the desired orientation to the Document data after it
  has been submitted.  Printers MAY only support
  "orientation-requested" for some Document formats (e.g., 'text/plain'
  or 'text/html') but not others (e.g., 'application/postscript').
  This is no different than any other Job Template attribute, since
  Section 5.2, item 1, points out that a Printer can support or not
  support any Job Template attribute based on the Document format




Sweet & McDonald             Standards Track                  [Page 120]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  supplied by the Client.  However, a special mention is made here,
  since it is very likely that a Printer will support
  "orientation-requested" for only a subset of the supported Document
  formats.

  Standard enum values are listed in Table 11.

  Note: The effect of this attribute on Jobs with multiple Documents is
  controlled by the "multiple-document-handling" Job attribute
  (Section 5.2.4).  The relationship of this attribute and the other
  attributes that control Document processing is described in
  Appendix C.3.







































Sweet & McDonald             Standards Track                  [Page 121]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  +-------+-----------------------------------------------------------+
  | Value | Symbolic Name and Description                             |
  +-------+-----------------------------------------------------------+
  | '3'   | 'portrait': The content will be imaged across the short   |
  |       | edge of the medium.                                       |
  +-------+-----------------------------------------------------------+
  | '4'   | 'landscape': The content will be imaged across the long   |
  |       | edge of the medium.  Landscape is defined to be a         |
  |       | rotation of the Input Page to be imaged by +90 degrees    |
  |       | with respect to the medium (i.e., counterclockwise) from  |
  |       | the portrait orientation.  Note: The +90 direction was    |
  |       | chosen because simple finishing on the long edge is the   |
  |       | same edge whether portrait or landscape.                  |
  +-------+-----------------------------------------------------------+
  | '5'   | 'reverse-landscape': The content will be imaged across    |
  |       | the long edge of the medium.  Reverse-landscape is        |
  |       | defined to be a rotation of the Input Page to be imaged   |
  |       | by -90 degrees with respect to the medium (i.e.,          |
  |       | clockwise) from the portrait orientation.  Note: The      |
  |       | 'reverse-landscape' value was added because some          |
  |       | applications rotate landscape -90 degrees from portrait,  |
  |       | rather than +90 degrees.                                  |
  +-------+-----------------------------------------------------------+
  | '6'   | 'reverse-portrait': The content will be imaged across the |
  |       | short edge of the medium.  Reverse-portrait is defined to |
  |       | be a rotation of the Input Page to be imaged by 180       |
  |       | degrees with respect to the medium from the portrait      |
  |       | orientation.  Note: The 'reverse-portrait' value was      |
  |       | added for use with the "finishings" attribute in cases    |
  |       | where the opposite edge is desired for finishing a        |
  |       | portrait Document on simple finishing devices that have   |
  |       | only one finishing position.  Thus, a 'text'/plain'       |
  |       | portrait Document can be stapled "on the right" by a      |
  |       | simple finishing device, as is common use with some       |
  |       | Middle Eastern languages such as Hebrew.                  |
  +-------+-----------------------------------------------------------+

              Table 11: "orientation-requested" Enum Values













Sweet & McDonald             Standards Track                  [Page 122]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


5.2.11.  media (type2 keyword | name(MAX))

  This RECOMMENDED attribute identifies the medium that the Printer
  uses for all Impressions of the Job.

  The values for "media" historically have included medium names,
  medium sizes, input trays, and electronic forms so that one attribute
  specifies the media.  However, the Client SHOULD only use the media
  attribute to specify medium sizes using PWG Media Standardized Names
  [PWG5101.1].

  If a Printer supports a medium name as a value of this attribute,
  such a medium name implicitly selects an input tray that contains the
  specified medium.  If a Printer supports a medium size as a value of
  this attribute, such a medium size implicitly selects a medium name
  that in turn implicitly selects an input tray that contains the
  medium with the specified size.  If a Printer supports an input tray
  as the value of this attribute, such an input tray implicitly selects
  the medium that is in that input tray at the time the Job prints.
  This case includes manual-feed input trays.  If a Printer supports an
  electronic form as the value of this attribute, such an electronic
  form implicitly selects a medium name that in turn implicitly selects
  an input tray that contains the medium specified by the electronic
  form.  The electronic form also implicitly selects an image that the
  Printer MUST merge with the Document data as it prints each page.

  PWG Media Standardized Names [PWG5101.1] SHOULD be used.  Legacy
  'keyword' values are taken from ISO DPA [ISO10175], the Printer MIB
  [RFC3805], and ASME-Y14.1M [ASME-Y14.1M].  An Administrator MAY
  define additional values using the 'name' or 'keyword' attribute
  syntax, depending on implementation.

  There is also an additional Printer attribute named "media-ready",
  which differs from "media-supported" in that legal values only
  include the subset of "media-supported" values that are physically
  loaded and ready for printing with no Operator intervention required.

  The relationship of this attribute and the other attributes that
  control Document processing is described in Appendix C.3.

  Note: If supported by the Printer, Clients MAY use the alternative
  "media-col" attribute [PWG5100.3] [PWG5100.13] to specify medium
  requirements in greater detail.








Sweet & McDonald             Standards Track                  [Page 123]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


5.2.12.  printer-resolution (resolution)

  This RECOMMENDED attribute identifies the output resolution that the
  Printer uses for the Job.

  Note: This attribute and the "print-quality" attribute
  (Section 5.2.13) are both used to specify the overall output quality
  of the Job.  If a Client specifies conflicting "printer-resolution"
  and "print-quality" values, Printers SHOULD use the "print-quality"
  value.

5.2.13.  print-quality (type2 enum)

  This RECOMMENDED attribute specifies the print quality that the
  Printer uses for the Job.

  The standard enum values are listed in Table 12.

  Note: This attribute and the "printer-resolution" attribute
  (Section 5.2.12) are both used to specify the overall output quality
  of the Job.  If a Client specifies conflicting "printer-resolution"
  and "print-quality" values, Printers SHOULD use the "print-quality"
  value.

   +-------+---------------------------------------------------------+
   | Value | Symbolic Name and Description                           |
   +-------+---------------------------------------------------------+
   | '3'   | 'draft': lowest quality available on the Printer        |
   +-------+---------------------------------------------------------+
   | '4'   | 'normal': normal or intermediate quality on the Printer |
   +-------+---------------------------------------------------------+
   | '5'   | 'high': highest quality available on the Printer        |
   +-------+---------------------------------------------------------+

                  Table 12: "print-quality" Enum Values

5.3.  Job Description and Status Attributes

  The attributes in this section form the attribute group called
  "job-description".  Tables 13 and 14 summarize these attributes.  The
  third column of each table indicates whether the attribute is a
  REQUIRED attribute that MUST be supported by Printers.  If it is not
  indicated as REQUIRED, then it is OPTIONAL.  The maximum size in
  octets for 'text' and 'name' attributes is indicated in parentheses.







Sweet & McDonald             Standards Track                  [Page 124]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


            +------------------+----------------+-----------+
            | Attribute        | Syntax         | REQUIRED? |
            +------------------+----------------+-----------+
            | job-impressions  | integer(0:MAX) |           |
            +------------------+----------------+-----------+
            | job-k-octets     | integer(0:MAX) |           |
            +------------------+----------------+-----------+
            | job-media-sheets | integer(1:MAX) |           |
            +------------------+----------------+-----------+
            | job-name         | name(MAX)      | REQUIRED  |
            +------------------+----------------+-----------+

            Table 13: Job Description Attributes (READ-WRITE)

  +-----------------------------+-------------------------+-----------+
  | Attribute                   | Syntax                  | REQUIRED? |
  +-----------------------------+-------------------------+-----------+
  | attributes-charset          | charset                 | REQUIRED  |
  +-----------------------------+-------------------------+-----------+
  | attributes-natural-language | naturalLanguage         | REQUIRED  |
  +-----------------------------+-------------------------+-----------+
  | date-time-at-completed      | dateTime|unknown|no-    |           |
  |                             | value                   |           |
  +-----------------------------+-------------------------+-----------+
  | date-time-at-creation       | dateTime|unknown        |           |
  +-----------------------------+-------------------------+-----------+
  | date-time-at-processing     | dateTime|unknown|no-    |           |
  |                             | value                   |           |
  +-----------------------------+-------------------------+-----------+
  | job-detailed-status-        | 1setOf text(MAX)        |           |
  | messages                    |                         |           |
  +-----------------------------+-------------------------+-----------+
  | job-document-access-errors  | 1setOf text(MAX)        |           |
  +-----------------------------+-------------------------+-----------+
  | job-id                      | integer(1:MAX)          | REQUIRED  |
  +-----------------------------+-------------------------+-----------+
  | job-impressions-completed   | integer(0:MAX)          |           |
  +-----------------------------+-------------------------+-----------+
  | job-k-octets-processed      | integer(0:MAX)          |           |
  +-----------------------------+-------------------------+-----------+
  | job-media-sheets-completed  | integer(0:MAX)          |           |
  +-----------------------------+-------------------------+-----------+
  | job-message-from-operator   | text(127)               |           |
  +-----------------------------+-------------------------+-----------+
  | job-more-info               | uri                     |           |
  +-----------------------------+-------------------------+-----------+
  | job-originating-user-name   | name(MAX)               | REQUIRED  |




Sweet & McDonald             Standards Track                  [Page 125]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  +-----------------------------+-------------------------+-----------+
  | job-printer-up-time         | integer(1:MAX)          | REQUIRED  |
  +-----------------------------+-------------------------+-----------+
  | job-printer-uri             | uri                     | REQUIRED  |
  +-----------------------------+-------------------------+-----------+
  | job-state                   | type1 enum              | REQUIRED  |
  +-----------------------------+-------------------------+-----------+
  | job-state-message           | text(MAX)               |           |
  +-----------------------------+-------------------------+-----------+
  | job-state-reasons           | 1setOf type2 keyword    | REQUIRED  |
  +-----------------------------+-------------------------+-----------+
  | job-uri                     | uri                     | REQUIRED  |
  +-----------------------------+-------------------------+-----------+
  | number-of-documents         | integer(0:MAX)          |           |
  +-----------------------------+-------------------------+-----------+
  | number-of-intervening-jobs  | integer(0:MAX)          |           |
  +-----------------------------+-------------------------+-----------+
  | output-device-assigned      | name(127)               |           |
  +-----------------------------+-------------------------+-----------+
  | time-at-completed           | integer(MIN:MAX)        | REQUIRED  |
  +-----------------------------+-------------------------+-----------+
  | time-at-creation            | integer(MIN:MAX)        | REQUIRED  |
  +-----------------------------+-------------------------+-----------+
  | time-at-processing          | integer(MIN:MAX)        | REQUIRED  |
  +-----------------------------+-------------------------+-----------+

               Table 14: Job Status Attributes (READ-ONLY)

5.3.1.  job-id (integer(1:MAX))

  This REQUIRED attribute contains the ID of the Job.  The Printer, on
  receipt of a new Job, generates an ID that identifies the new Job on
  that Printer.  The Printer returns the value of the "job-id"
  attribute as part of the response to a Job Creation request.

  For a description of this attribute and its relationship to the
  "job-uri" and "job-printer-uri" attributes, see the discussion in
  Section 3.4 ("Object Identity").

5.3.2.  job-uri (uri)

  This REQUIRED attribute contains the URI for the Job.  The Printer,
  on receipt of a new Job, generates a URI that identifies the new Job.
  The Printer returns the value of the "job-uri" attribute as part of
  the response to a Job Creation request.  The precise format of a Job
  URI is implementation dependent [RFC3510] [RFC7472].  If the Printer
  supports more than one URI and there is some relationship between the
  newly formed Job URI and the Printer's URI, the Printer uses the



Sweet & McDonald             Standards Track                  [Page 126]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  Printer URI supplied by the Client in the Job Creation request.  For
  example, if the Job Creation request comes in over a secure channel,
  the new Job URI MUST use the same secure channel.  This can be
  guaranteed because the Printer is responsible for generating the Job
  URI and the Printer is aware of its security configuration and policy
  as well as the Printer URI used in the Job Creation request.

  For a description of this attribute and its relationship to the
  "job-id" and "job-printer-uri" attributes, see the discussion in
  Section 3.4 ("Object Identity").

5.3.3.  job-printer-uri (uri)

  This REQUIRED attribute identifies the Printer that created this Job.
  When a Printer creates a Job, it populates this attribute with the
  Printer URI that was used in the Job Creation request.  This
  attribute permits a Client to identify the Printer that created this
  Job when only the Job's URI is available to the Client.  The Client
  queries the creating Printer to determine which languages, charsets,
  and operations are supported for this Job.

  For a description of this attribute and its relationship to the
  "job-uri" and "job-id" attributes, see the discussion in Section 3.4
  ("Object Identity").

5.3.4.  job-more-info (uri)

  Similar to "printer-more-info", this attribute contains the URI
  referencing some resource with more information about this Job,
  perhaps an HTML page containing status information about the Job.

5.3.5.  job-name (name(MAX))

  This REQUIRED attribute is the name of the Job.  It is a name that is
  more user friendly than the "job-uri" or "job-id" attribute values.
  It does not need to be unique between Jobs.  The Job's "job-name"
  attribute is set to the value supplied by the Client in the
  "job-name" operation attribute in the Job Creation request (see
  Section 4.2.1.1).  If, however, the "job-name" operation attribute is
  not supplied by the Client in the Job Creation request, the Printer,
  on creation of the Job, MUST generate a name.  The Printer SHOULD
  generate the value of the Job's "job-name" attribute from the first
  of the following sources that produces a value: (1) the
  "document-name" operation attribute of the first (or only) Document,
  (2) the "document-URI" attribute of the first (or only) Document, or
  (3) any other piece of Job-specific and/or Document data.





Sweet & McDonald             Standards Track                  [Page 127]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


5.3.6.  job-originating-user-name (name(MAX))

  This REQUIRED attribute contains the name of the End User that
  submitted the Print Job.  The Printer sets this attribute to the most
  authenticated printable name that it can obtain from the
  authentication service over which the IPP operation was received.
  Only if such a name is not available does the Printer use the value
  supplied by the Client in the "requesting-user-name" operation
  attribute of the Job Creation request (see Sections 5.4.2, 5.4.3,
  and 9).

  Note: The Printer needs to keep an internal originating user ID of
  some form, typically as a credential of a principal, with the Job.
  Since such an internal attribute is implementation dependent and not
  of interest to Clients, it is not specified as a Job attribute.  This
  originating user ID is used for authorization checks (if any) on all
  subsequent operations.

5.3.7.  job-state (type1 enum)

  This REQUIRED attribute identifies the current state of the Job.
  Even though IPP defines seven values for Job states (plus the
  out-of-band 'unknown' value -- see Section 5.1), implementations only
  need to support those states that are appropriate for the particular
  implementation.  In other words, a Printer supports only those Job
  states implemented by the Output Device and available to the Printer
  implementation.

  Standard enum values are listed in Table 15.

  The final value for this attribute MUST be one of the following --
  'completed', 'canceled', or 'aborted' -- before the Printer removes
  the Job altogether.  The length of time that Jobs remain in the
  'canceled', 'aborted', and 'completed' states depends on
  implementation.  See Section 5.3.7.2.
















Sweet & McDonald             Standards Track                  [Page 128]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  Figure 3 shows the normal Job state transitions.  Normally, a Job
  progresses from left to right.  Other state transitions are unlikely
  but are not forbidden.  Not shown are the transitions to the
  'canceled' state from the 'pending', 'pending-held', and
  'processing-stopped' states.

                                                     +----> canceled
                                                    /
      +----> pending  -------> processing ---------+------> completed
      |         ^                   ^               \
  --->+         |                   |                +----> aborted
      |         v                   v               /
      +----> pending-held    processing-stopped ---+

                      Figure 3: IPP Job Life Cycle

  Jobs reach one of the three terminal states -- 'completed',
  'canceled', or 'aborted' -- after the Jobs have completed all
  activity, including stacking output media, and all Job Status
  attributes have reached their final values for the Job.































Sweet & McDonald             Standards Track                  [Page 129]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  +--------+----------------------------------------------------------+
  | Values | Symbolic Name and Description                            |
  +--------+----------------------------------------------------------+
  | '3'    | 'pending': The Job is a candidate to start processing    |
  |        | but is not yet processing.                               |
  +--------+----------------------------------------------------------+
  | '4'    | 'pending-held': The Job is not a candidate for           |
  |        | processing for any number of reasons but will return to  |
  |        | the 'pending' state as soon as the reasons are no longer |
  |        | present.  The Job's "job-state-reasons" attribute MUST   |
  |        | indicate why the Job is no longer a candidate for        |
  |        | processing.                                              |
  +--------+----------------------------------------------------------+
  | '5'    | 'processing': One or more of the following: (1) the Job  |
  |        | is using, or is attempting to use, one or more purely    |
  |        | software processes that are analyzing, creating, or      |
  |        | interpreting a PDL, etc.; (2) the Job is using, or is    |
  |        | attempting to use, one or more hardware devices that are |
  |        | interpreting a PDL; making marks on a medium; and/or     |
  |        | performing finishing, such as stapling, etc.; (3) the    |
  |        | Printer has made the Job ready for printing, but the     |
  |        | Output Device is not yet printing it, either because the |
  |        | Job hasn't reached the Output Device or because the Job  |
  |        | is queued in the Output Device or some other spooler,    |
  |        | waiting for the Output Device to print it.  When the Job |
  |        | is in the 'processing' state, the entire Job state       |
  |        | includes the detailed status represented in the          |
  |        | Printer's "printer-state", "printer-state-reasons", and  |
  |        | "printer-state-message" attributes.  Implementations MAY |
  |        | include additional values in the Job's "job-state-       |
  |        | reasons" attribute to indicate the progress of the Job,  |
  |        | such as adding the 'job-printing' value to indicate when |
  |        | the Output Device is actually making marks on paper      |
  |        | and/or the 'processing-to-stop-point' value to indicate  |
  |        | that the Printer is in the process of canceling or       |
  |        | aborting the Job.                                        |















Sweet & McDonald             Standards Track                  [Page 130]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  +--------+----------------------------------------------------------+
  | '6'    | 'processing-stopped': The Job has stopped while          |
  |        | processing for any number of reasons and will return to  |
  |        | the 'processing' state as soon as the reasons are no     |
  |        | longer present.  The Job's "job-state-reasons" attribute |
  |        | MAY indicate why the Job has stopped processing.  For    |
  |        | example, if the Output Device is stopped, the 'printer-  |
  |        | stopped' value MAY be included in the Job's "job-state-  |
  |        | reasons" attribute.  Note: When an Output Device is      |
  |        | stopped, the device usually indicates its condition in   |
  |        | human-readable form locally at the device.  A Client can |
  |        | obtain more complete device status remotely by querying  |
  |        | the Printer's "printer-state", "printer-state-reasons",  |
  |        | and "printer-state-message" attributes.                  |
  +--------+----------------------------------------------------------+
  | '7'    | 'canceled':  The Job has been canceled by a Cancel-Job   |
  |        | operation, and the Printer has completed canceling the   |
  |        | Job.  All Job Status attributes have reached their final |
  |        | values for the Job.  While the Printer is canceling the  |
  |        | Job, the Job remains in its current state, but the Job's |
  |        | "job-state-reasons" attribute SHOULD contain the         |
  |        | 'processing-to-stop-point' value and one of the          |
  |        | 'canceled-by-user', 'canceled-by-operator', or           |
  |        | 'canceled-at-device' values.  When the Job moves to the  |
  |        | 'canceled' state, the 'processing-to-stop-point' value,  |
  |        | if present, MUST be removed, but 'canceled-by-xxx', if   |
  |        | present, MUST remain.                                    |
  +--------+----------------------------------------------------------+
  | '8'    | 'aborted': The Job has been aborted by the system,       |
  |        | usually while the Job was in the 'processing' or         |
  |        | 'processing-stopped' state, and the Printer has          |
  |        | completed aborting the Job; all Job Status attributes    |
  |        | have reached their final values for the Job.  While the  |
  |        | Printer is aborting the Job, the Job remains in its      |
  |        | current state, but the Job's "job-state-reasons"         |
  |        | attribute SHOULD contain the 'processing-to-stop-point'  |
  |        | and 'aborted-by-system' values.  When the Job moves to   |
  |        | the 'aborted' state, the 'processing-to-stop-point'      |
  |        | value, if present, MUST be removed, but the 'aborted-by- |
  |        | system' value, if present, MUST remain.                  |











Sweet & McDonald             Standards Track                  [Page 131]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  +--------+----------------------------------------------------------+
  | '9'    | 'completed': The Job has completed successfully or with  |
  |        | warnings or errors after processing, all of the Job      |
  |        | Media Sheets have been successfully stacked in the       |
  |        | appropriate output bin(s), and all Job Status attributes |
  |        | have reached their final values for the Job.  The Job's  |
  |        | "job-state-reasons" attribute SHOULD contain one of the  |
  |        | 'completed-successfully', 'completed-with-warnings', or  |
  |        | 'completed-with-errors' values.                          |
  +--------+----------------------------------------------------------+

                    Table 15: "job-state" Enum Values

5.3.7.1.  Forwarding Servers

  As with all other IPP attributes, if the implementation cannot
  determine the correct value for this attribute, it SHOULD respond
  with the out-of-band 'unknown' value (see Section 5.1) rather than
  try to guess at some possibly incorrect value and confuse the
  End User about the state of the Job.  For example, if the
  implementation is just a gateway into some printing system from which
  it can normally get status, but temporarily is unable, then the
  implementation should return the 'unknown' value.  However, if the
  implementation is a gateway to a printing system that never provides
  detailed status about the Print Job, the implementation MAY set the
  IPP Job's state to 'completed', provided that it also sets the
  'queued-in-device' value in the Job's "job-state-reasons" attribute
  (see Section 5.3.8).

5.3.7.2.  Partitioning of Job States

  This section describes the partitioning of the seven Job states into
  phases: Job Not Completed, Job Retention, Job History, and Job
  Removal.  This section also explains the 'job-restartable' value of
  the "job-state-reasons" Job Status attribute for use with the
  Restart-Job and Resubmit-Job [PWG5100.11] operations.

  Job Not Completed: When a Job is in the 'pending', 'pending-held',
  'processing', or 'processing-stopped' state, the Job is not
  completed.

  Job Retention: When a Job enters one of the three terminal Job states
  -- 'completed', 'canceled', or 'aborted' -- the IPP Printer MAY
  "retain" the Job in a restartable condition for an implementation-
  defined time period.  This time period MAY be zero seconds and MAY
  depend on the terminal Job state.  This phase is called "Job
  Retention".  While in the Job Retention phase, the Job's Document
  data is retained and a Client can restart the Job using the



Sweet & McDonald             Standards Track                  [Page 132]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  Restart-Job operation.  If the Printer supports the Restart-Job or
  Resubmit-Job operation, then it SHOULD indicate that the Job is
  restartable by adding the 'job-restartable' value to the Job's
  "job-state-reasons" attribute (see Section 5.3.8) during the Job
  Retention phase.

  Job History: After the Job Retention phase expires for a Job, the
  Printer deletes the Document data for the Job and the Job becomes
  part of the Job History.  The Printer MAY also delete any number of
  the Job attributes.  Since the Job is no longer restartable, the
  Printer MUST remove the 'job-restartable' value from the Job's
  "job-state-reasons" attribute, if present.  Printers SHOULD keep the
  Job in the Job History phase for at least 60 seconds to allow Clients
  to discover the final disposition of the Job.

  Job Removal: After the Job has remained in the Job History for an
  implementation-defined time, such as when the number of Jobs exceeds
  a fixed number or after a fixed time period (which MAY be
  zero seconds), the IPP Printer removes the Job from the system.

  Using the Get-Jobs operation and supplying the 'not-completed' value
  for the "which-jobs" operation attribute, a Client is requesting Jobs
  in the Job Not Completed phase.  Using the Get-Jobs operation and
  supplying the 'completed' value for the "which-jobs" operation
  attribute, a Client is requesting Jobs in the Job Retention and Job
  History phases.  Using the Get-Job-Attributes operation, a Client is
  requesting a Job in any phase except Job Removal.  After Job Removal,
  the Get-Job-Attributes and Get-Jobs operations no longer are capable
  of returning any information about a Job.

5.3.8.  job-state-reasons (1setOf type2 keyword)

  This REQUIRED attribute provides additional information about the
  Job's current state, i.e., information that augments the value of the
  Job's "job-state" attribute.

  These values MAY be used with any Job state or states for which the
  reason makes sense.  Some of these value definitions indicate
  conformance requirements; the rest are OPTIONAL.  Furthermore, when
  implemented, the Printer MUST return these values when the reason
  applies and MUST NOT return them when the reason no longer applies,
  whether the value of the Job's "job-state" attribute changed or not.
  When the Job does not have any reasons for being in its current
  state, the value of the Job's "job-state-reasons" attribute MUST be
  'none'.






Sweet & McDonald             Standards Track                  [Page 133]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  Note: While values cannot be added to the "job-state" attribute
  without impacting deployed Clients that take actions upon receiving
  "job-state" values, it is the intent that additional
  "job-state-reasons" values can be defined and registered without
  impacting such deployed Clients.  In other words, the
  "job-state-reasons" attribute is intended to be extensible.

  The following standard 'keyword' values are defined.  For ease of
  understanding, the values are presented in the order in which the
  reasons are likely to occur (if implemented):

  o  'none': There are no reasons for the Job's current state.  This
     state reason is semantically equivalent to "job-state-reasons"
     without any value and MUST be used when there is no other value,
     since the '1setOf' attribute syntax requires at least one value.

  o  'job-incoming': Either (1) the Printer has accepted the Create-Job
     operation and is expecting additional Send-Document and/or
     Send-URI operations or (2) the Printer is retrieving/accepting
     Document data as a result of a Print-Job, Print-URI,
     Send-Document, or Send-URI operation.

  o  'job-data-insufficient': The Create-Job operation has been
     accepted by the Printer, but the Printer is expecting additional
     Document data before it can move the Job into the 'processing'
     state.  If a Printer starts processing before it has received all
     data, the Printer removes the 'job-data-insufficient' reason, but
     the 'job-incoming' reason remains.  If a Printer starts processing
     after it has received all data, the Printer removes the
     'job-data-insufficient' reason and the 'job-incoming' reason at
     the same time.

  o  'document-access-error': After accepting a Print-URI or Send-URI
     request, the Printer could not access one or more Documents passed
     by reference.  This reason is intended to cover any file access
     problem, including 'file does not exist' and 'access denied'
     because of an access control problem.  The Printer MAY also
     indicate the Document access error using the
     "job-document-access-errors" Job Status attribute (see
     Section 5.3.11).  The Printer can (1) abort the Job and move the
     Job to the 'aborted' Job state or (2) print all Documents that are
     accessible and move the Job to the 'completed' Job state with the
     'completed-with-errors' value in the Job's "job-state-reasons"
     attribute.  This value SHOULD be supported if the Print-URI or
     Send-URI operations are supported.






Sweet & McDonald             Standards Track                  [Page 134]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  o  'submission-interrupted': The Job was not completely submitted for
     some unforeseen reason, such as (1) the Printer has crashed before
     the Job was closed by the Client, (2) the Printer or the Document
     transfer method has crashed in some non-recoverable way before the
     Document data was entirely transferred to the Printer, or (3) the
     Client crashed or failed to close the Job before the time-out
     period.  See Section 5.4.31.

  o  'job-outgoing': The Printer is transmitting the Job to the Output
     Device.

  o  'job-hold-until-specified': The value of the Job's
     "job-hold-until" attribute was specified with a time period that
     is still in the future.  The Job MUST NOT be a candidate for
     processing until this reason is removed and there are no other
     reasons to hold the Job.  This value SHOULD be supported if the
     "job-hold-until" Job Template attribute is supported.

  o  'resources-are-not-ready': At least one of the resources needed by
     the Job, such as media, fonts, resource objects, etc., is not
     ready on any of the physical Output Devices for which the Job is a
     candidate.  This condition MAY be detected when the Job is
     accepted, or subsequently while the Job is pending or processing,
     depending on implementation.  The Job can remain in its current
     state or be moved to the 'pending-held' state, depending on
     implementation and/or Job scheduling policy.

  o  'printer-stopped-partly': The value of the Printer's
     "printer-state-reasons" attribute contains the value
     'stopped-partly'.

  o  'printer-stopped': The value of the Printer's "printer-state"
     attribute is 'stopped'.

  o  'job-interpreting': The Job is in the 'processing' state, but,
     more specifically, the Printer is interpreting the Document data.

  o  'job-queued': The Job is in the 'processing' state, but, more
     specifically, the Printer has queued the Document data.

  o  'job-transforming': The Job is in the 'processing' state, but,
     more specifically, the Printer is interpreting Document data and
     producing another electronic representation.

  o  'job-queued-for-marker': The Job is in any of the 'pending-held',
     'pending', or 'processing' states, but, more specifically, the
     Printer has completed enough processing of the Document to be able
     to start marking, and the Job is waiting for the marker.  Systems



Sweet & McDonald             Standards Track                  [Page 135]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


     that require human intervention to release Jobs using the
     Release-Job operation put the Job into the 'pending-held' Job
     state.  Systems that automatically select a Job to use the marker
     put the Job into the 'pending' Job state or keep the Job in the
     'processing' Job state while waiting for the marker, depending on
     implementation.  All implementations put the Job into the
     'processing' state when marking does begin.

  o  'job-printing': The Output Device is marking media.  This value is
     useful for Printers that spend a great deal of time processing
     (1) when no marking is happening and they want to show that
     marking is now happening or (2) when the Job is in the process of
     being canceled or aborted while the Job remains in the
     'processing' state, but the marking has not yet stopped so that
     Impression or sheet counts are still increasing for the Job.

  o  'job-canceled-by-user': The Job was canceled by the owner of the
     Job using the Cancel-Job request, i.e., by a user whose
     authenticated identity is the same as the value of the originating
     user that created the Job, or by some other authorized End User,
     such as a member of the Job owner's security group.  This value
     SHOULD be supported.

  o  'job-canceled-by-operator': The Job was canceled by the Operator
     using the Cancel-Job request, i.e., by a user who has been
     authenticated as having Operator privileges (whether local or
     remote).  If the security policy is to allow anyone to cancel
     anyone's Job, then this value can be used when the Job is canceled
     by other than the owner of the Job.  For such a security policy,
     in effect, everyone is an Operator as far as canceling Jobs with
     IPP is concerned.  This value SHOULD be supported if the
     implementation permits canceling by other than the owner of
     the Job.

  o  'job-canceled-at-device': The Job was canceled by an unidentified
     local user, i.e., a user at a console at the device.  This value
     SHOULD be supported if the implementation supports canceling Jobs
     at the console.

  o  'aborted-by-system': The Job (1) is in the process of being
     aborted, (2) has been aborted by the system and placed in the
     'aborted' state, or (3) has been aborted by the system and placed
     in the 'pending-held' state, so that a user or Operator can
     manually try the Job again.  This value SHOULD be supported.







Sweet & McDonald             Standards Track                  [Page 136]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  o  'unsupported-compression': The Job was aborted by the system
     because the Printer determined, while attempting to decompress the
     Document data, that the compression algorithm is actually not
     among those supported by the Printer.  This value MUST be
     supported, since "compression" is a REQUIRED operation attribute.

  o  'compression-error': The Job was aborted by the system because the
     Printer encountered an error in the Document data while
     decompressing it.  If the Printer posts this reason, the Document
     data has already passed any tests that would have led to the
     'unsupported-compression' "job-state-reasons" value.

  o  'unsupported-document-format': The Job was aborted by the system
     because the Document data's "document-format" attribute is not
     among those supported by the Printer.  If the Client specifies
     "document-format" as 'application/octet-stream', the Printer MAY
     abort the Job and post this reason even though the
     "document-format" value is among the values of the Printer's
     "document-format-supported" Printer attribute but not among the
     auto-sensed Document formats.  This value MUST be supported, since
     "document-format" is a REQUIRED operation attribute.

  o  'document-format-error': The Job was aborted by the system because
     the Printer encountered an error in the Document data while
     processing it.  If the Printer posts this reason, the Document
     data has already passed any tests that would have led to the
     'unsupported-document-format' "job-state-reasons" value.

  o  'processing-to-stop-point': The requester has issued a Cancel-Job
     operation or the Printer has aborted the Job, but the Printer is
     still performing some actions on the Job until a specified stop
     point occurs or Job termination/cleanup is completed.

     If the implementation requires some measurable time to cancel the
     Job in the 'processing' or 'processing-stopped' Job state, the
     Printer MUST use this value to indicate that the Printer is still
     performing some actions on the Job while the Job remains in the
     'processing' or 'processing-stopped' state.  Once at the stop
     point, the Printer moves the Job from the 'processing' state to
     the 'canceled' or 'aborted' Job state.

  o  'service-off-line': The Printer is offline and accepting no Jobs.
     All 'pending' Jobs are put into the 'pending-held' state.  This
     situation could be true if the service's or Document transform's
     input is impaired or broken.

  o  'job-completed-successfully': The Job completed successfully.
     This value SHOULD be supported.



Sweet & McDonald             Standards Track                  [Page 137]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  o  'job-completed-with-warnings': The Job completed with warnings.
     This value SHOULD be supported if the implementation detects
     warnings.

  o  'job-completed-with-errors': The Job completed with errors (and
     possibly warnings too).  This value SHOULD be supported if the
     implementation detects errors.

  o  'job-restartable': This Job is retained (see Section 5.3.7.2) and
     is currently able to be restarted using the Restart-Job (see
     Section 4.3.7) or Resubmit-Job [PWG5100.11] operation.  If
     'job-restartable' is a value of the Job's "job-state-reasons"
     attribute, then the Printer MUST accept a Restart-Job operation
     for that Job.  This value SHOULD be supported if the Restart-Job
     operation is supported.

  o  'queued-in-device': The Job has been forwarded to a device or
     print system that is unable to send back status.  The Printer sets
     the Job's "job-state" attribute to 'completed' and adds the
     'queued-in-device' value to the Job's "job-state-reasons"
     attribute to indicate that the Printer has no additional
     information about the Job and never will have any better
     information.  See Section 5.3.7.1.

5.3.9.  job-state-message (text(MAX))

  This RECOMMENDED attribute specifies information about the
  "job-state" and "job-state-reasons" attributes in human-readable
  text.  If the Printer supports this attribute, the Printer MUST be
  able to generate this message in any of the natural languages
  identified by the Printer's "generated-natural-language-supported"
  attribute (see the "attributes-natural-language" operation attribute
  specified in Section 4.1.4.1).

  The value SHOULD NOT contain additional information not contained in
  the values of the "job-state" and "job-state-reasons" attributes,
  such as interpreter error information.  Otherwise, application
  programs might attempt to parse the (localized) text.  For such
  additional information, such as interpreter errors for application
  program consumption or specific Document access errors, new
  attributes with 'keyword' values need to be developed and registered.










Sweet & McDonald             Standards Track                  [Page 138]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


5.3.10.  job-detailed-status-messages (1setOf text(MAX))

  This attribute specifies additional detailed and technical
  information about the Job.  The Printer SHOULD localize the message,
  unless such localization would obscure the technical meaning of the
  message.  Clients MUST NOT attempt to parse the value of this
  attribute.  See "job-document-access-errors" (Section 5.3.11) for
  additional errors that a program can process.

5.3.11.  job-document-access-errors (1setOf text(MAX))

  This attribute provides additional information about each Document
  access error for this Job encountered by the Printer after it
  returned a response to the Print-URI or Send-URI operation and
  subsequently attempted to access document(s) supplied in the
  Print-URI or Send-URI operation.  For errors in the protocol that is
  identified by the URI scheme in the "document-uri" operation
  attribute, such as 'http:' or 'ftp:', the error code is returned in
  parentheses, followed by the URI.  For example:

  (404) http://www.example.com/filename.pdf

  Most Internet protocols use decimal error codes (unlike IPP), so the
  ASCII error code representation is in decimal.

5.3.12.  number-of-documents (integer(0:MAX))

  This attribute indicates the number of Documents in the Job, i.e.,
  the number of Send-Document, Send-URI, Print-Job, or Print-URI
  operations that the Printer has accepted for this Job, regardless of
  whether the Document data has reached the Printer.

  Implementations supporting the RECOMMENDED Create-Job/Send-Document/
  Send-URI operations SHOULD support this attribute so that Clients can
  query the number of Documents in each Job.

5.3.13.  output-device-assigned (name(127))

  This attribute identifies the Output Device to which the Printer has
  assigned this Job.  If an Output Device implements an embedded
  Printer, the Printer SHOULD set this attribute.  If a print server
  implements a Printer, the value MAY be empty (zero-length string) or
  not returned until the Printer assigns an Output Device to the Job.
  This attribute is particularly useful when a single Printer supports
  multiple devices (so-called "fan-out" -- see Section 3.1).






Sweet & McDonald             Standards Track                  [Page 139]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


5.3.14.  Event Time Job Status Attributes

  This section defines the Job Status attributes that indicate the time
  at which certain events occur for a Job.  If the Job event has not
  yet occurred, then the Printer MUST return the 'no-value' out-of-band
  value (see the beginning of Section 5.1).  The
  "time-at-xxx (integer)" attributes represent time as an 'integer'
  representing the number of seconds since the device was powered up
  (informally called "time ticks").  The "date-time-at-xxx (dateTime)"
  attributes represent time as 'dateTime' representing date and time
  (including an offset from UTC).

  In order to populate these attributes, the Printer copies the
  value(s) of the following Printer Status attributes at the time the
  event occurs:

  1.  the value in the Printer's "printer-up-time" attribute for the
      "time-at-xxx (integer)" attributes.

  2.  the value in the Printer's "printer-current-time" attribute for
      the "date-time-at-xxx (dateTime)" attributes.

  If the Printer resets its "printer-up-time" attribute to 1 on
  power-up (see Section 5.4.29) and has persistent Jobs, then it MUST
  change all of those Jobs' "time-at-xxx (integer)" (time tick) Job
  attributes whose events have occurred either to:

  1.  0 to indicate that the event happened before the most recent
      power-up, or

  2.  the negative of the number of seconds before the most recent
      power-up that the event took place, if the Printer knows the
      exact number of seconds.

  If a Client queries a "time-at-xxx (integer)" time tick Job attribute
  and finds the value to be 0 or negative, the Client MUST assume that
  the event occurred in some life other than the Printer's current
  life.

  Note: A Printer does not change the values of any
  "date-time-at-xxx (dateTime)" Job attributes on power-up.

5.3.14.1.  time-at-creation (integer(MIN:MAX))

  This REQUIRED attribute indicates the time at which the Job was
  created.





Sweet & McDonald             Standards Track                  [Page 140]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


5.3.14.2.  time-at-processing (integer(MIN:MAX))

  This REQUIRED attribute indicates the time at which the Job first
  began processing after the Job Creation request or the most recent
  Restart-Job operation.  The out-of-band 'no-value' value is returned
  if the Job has not yet been in the 'processing' state (see the
  beginning of Section 5.1).

5.3.14.3.  time-at-completed (integer(MIN:MAX))

  This REQUIRED attribute indicates the time at which the Job entered a
  Terminating State ('completed', 'canceled', or 'aborted').  The
  out-of-band 'no-value' value is returned if the Job has not yet
  completed, been canceled, or aborted (see the beginning of
  Section 5.1).

5.3.14.4.  job-printer-up-time (integer(1:MAX))

  This REQUIRED Job Status attribute indicates the amount of time (in
  seconds) that the Printer implementation has been up and running.
  This attribute is an alias for the "printer-up-time" Printer Status
  attribute (see Section 5.4.29).

  A Client MAY request this attribute in a Get-Job-Attributes or
  Get-Jobs request and use the value returned in combination with other
  requested Event Time Job Status attributes in order to display time
  attributes to a user.  The difference between this attribute and the
  'integer' value of a "time-at-xxx" attribute is the number of seconds
  ago that the "time-at-xxx" event occurred.  A Client can compute the
  wall-clock time at which the "time-at-xxx" event occurred by
  subtracting this difference from the Client's wall-clock time.

5.3.14.5.  date-time-at-creation (dateTime|unknown)

  This RECOMMENDED attribute indicates the date and time at which the
  Job was created.

5.3.14.6.  date-time-at-processing (dateTime|unknown|no-value)

  This RECOMMENDED attribute indicates the date and time at which the
  Job first began processing after the Job Creation request or the most
  recent Restart-Job operation.

5.3.14.7.  date-time-at-completed (dateTime|unknown|no-value)

  This RECOMMENDED attribute indicates the date and time at which the
  Job entered a Terminating State ('completed', 'canceled', or
  'aborted').



Sweet & McDonald             Standards Track                  [Page 141]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


5.3.15.  number-of-intervening-jobs (integer(0:MAX))

  This attribute indicates the number of Jobs that are "ahead" of this
  Job in the relative chronological order of expected time to complete
  (i.e., the current scheduled order).  For efficiency, it is only
  necessary to calculate this value when an operation is performed that
  requests this attribute.

5.3.16.  job-message-from-operator (text(127))

  This attribute provides a message from an Operator, Administrator, or
  "intelligent" process to indicate to the End User the reasons for
  modification or other management action taken on a Job.

5.3.17.  Job Size Attributes

  This subsection defines Job attributes that describe the size of the
  Job.  These attributes are not intended to be counters; they are
  intended to be useful routing and scheduling information if known.
  For these attributes, the Printer can try to compute the value if it
  is not supplied in the Job Creation request.  Even if the Client does
  supply a value for these three attributes in the Job Creation
  request, the Printer MAY choose to change the value if the Printer is
  able to compute a value that is more accurate than the
  Client-supplied value.  The Printer can determine the correct value
  for these attributes either right at Job submission time or at any
  later point in time.

5.3.17.1.  job-k-octets (integer(0:MAX))

  This attribute specifies the total size of the Document(s) in
  K octets, i.e., in units of 1024 octets requested to be processed
  in the Job.  The value MUST be rounded up, so that a Job between
  1 and 1024 octets MUST be indicated as being 1, 1025 to 2048 MUST
  be 2, etc.

  This value MUST NOT include the multiplicative factors contributed by
  the number of copies specified by the "copies" attribute, independent
  of whether the device can process multiple copies without making
  multiple passes over the Job or Document data and independent of
  whether the output is collated or not.  Thus, the value is
  independent of the implementation and indicates the size of the
  Document(s) measured in K octets independent of the number of copies.








Sweet & McDonald             Standards Track                  [Page 142]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  This value also MUST NOT include the multiplicative factor due to a
  copies instruction embedded in the Document data.  If the Document
  data actually includes replications of the Document data, this value
  will include such replication.  In other words, this value is always
  the size of the source Document data, rather than a measure of the
  hardcopy output to be produced.

5.3.17.2.  job-impressions (integer(0:MAX))

  This RECOMMENDED attribute specifies the total size in number of
  Impressions of the Document(s) being submitted (see the definition of
  "Impression" in Section 2.3.4).

  As with "job-k-octets", this value MUST NOT include the
  multiplicative factors contributed by the number of copies specified
  by the "copies" attribute, independent of whether the device can
  process multiple copies without making multiple passes over the Job
  or Document data and independent of whether the output is collated or
  not.  Thus, the value is independent of the implementation and
  reflects the size of the Document(s) measured in Impressions
  independent of the number of copies.

  As with "job-k-octets", this value also MUST NOT include the
  multiplicative factor due to a copies instruction embedded in the
  Document data.  If the Document data actually includes replications
  of the Document data, this value will include such replication.  In
  other words, this value is always the number of Impressions in the
  source Document data, rather than a measure of the number of
  Impressions to be produced by the Job.

5.3.17.3.  job-media-sheets (integer(1:MAX))

  This RECOMMENDED attribute specifies the total number of Media Sheets
  to be produced for this Job.

  Unlike the "job-k-octets" and the "job-impressions" attributes, this
  value MUST include the multiplicative factors contributed by the
  number of copies specified by the "copies" attribute and a 'number of
  copies' instruction embedded in the Document data, if any.  This
  difference allows the Administrator to control the lower and upper
  bounds of both (1) the size of the Document(s) with
  "job-k-octets-supported" and "job-impressions-supported" and
  (2) the size of the Job with "job-media-sheets-supported".








Sweet & McDonald             Standards Track                  [Page 143]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


5.3.18.  Job Progress Attributes

  This subsection defines Job attributes that describe the progress of
  the Job.  These attributes are intended to be counters.  That is, the
  values for a Job that has not started processing MUST be 0.  When the
  Job's "job-state" is 'processing' or 'processing-stopped', this value
  is intended to contain the amount of the Job that has been processed
  to the time at which the attributes are requested.  When the Job
  enters the 'completed', 'canceled', or 'aborted' states, these values
  are the final values for the Job.

5.3.18.1.  job-k-octets-processed (integer(0:MAX))

  This attribute specifies the total number of octets processed in
  K octets, i.e., in units of 1024 octets so far.  The value MUST be
  rounded up, so that a Job between 1 and 1024 octets inclusive MUST be
  indicated as being 1, 1025 to 2048 inclusive MUST be 2, etc.

  For implementations where multiple copies are produced by the
  interpreter with only a single pass over the data, the final value
  MUST be equal to the value of the "job-k-octets" attribute.  For
  implementations where multiple copies are produced by the interpreter
  by processing the data for each copy, the final value MUST be a
  multiple of the value of the "job-k-octets" attribute.

5.3.18.2.  job-impressions-completed (integer(0:MAX))

  This RECOMMENDED attribute specifies the number of Impressions
  completed for the Job so far.  For printing devices, the Impressions
  completed includes interpreting, marking, and stacking the output.

5.3.18.3.  job-media-sheets-completed (integer(0:MAX))

  This RECOMMENDED Job attribute specifies the number of Media Sheets
  that have been marked and stacked for the entire Job so far, whether
  those sheets have been processed on one side or on both.

5.3.19.  attributes-charset (charset)

  This REQUIRED attribute is populated using the value in the
  Client-supplied "attributes-charset" attribute in the Job Creation
  request.  It identifies the charset (coded character set and encoding
  method) used by any Job attributes with attribute syntaxes 'text' and
  'name' that were supplied by the Client in the Job Creation request.
  See Section 4.1.4 for a complete description of the
  "attributes-charset" operation attribute.





Sweet & McDonald             Standards Track                  [Page 144]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  This attribute does not indicate the charset in which the 'text' and
  'name' values are stored internally in the Job.  The internal charset
  is implementation defined.  The Printer MUST convert from whatever
  the internal charset is to that being requested in an operation as
  specified in Section 4.1.4.

5.3.20.  attributes-natural-language (naturalLanguage)

  This REQUIRED attribute is populated using the value in the
  Client-supplied "attributes-natural-language" attribute in the Job
  Creation request.  It identifies the natural language used for any
  Job attributes with attribute syntaxes 'text' and 'name' that were
  supplied by the Client in the Job Creation request.  See
  Section 4.1.4 for a complete description of the
  "attributes-natural-language" operation attribute.  See
  Sections 5.1.2.2 and 5.1.3.2 for how a Natural Language Override can
  be supplied explicitly for each 'text' and 'name' attribute value
  that differs from the value identified by the
  "attributes-natural-language" attribute.

5.4.  Printer Description and Status Attributes

  These attributes form the attribute group called
  "printer-description".  Tables 16 and 17 summarize these attributes,
  their syntax, and whether they are REQUIRED for a Printer to support.
  If they are not indicated as REQUIRED, they are OPTIONAL.  The
  maximum size in octets for 'text' and 'name' attributes is indicated
  in parentheses.

  Note: How these attributes are set by an Administrator is outside the
  scope of this document.

  +-----------------------------+-----------------------+-------------+
  | Attribute                   | Syntax                | REQUIRED?   |
  +-----------------------------+-----------------------+-------------+
  | charset-configured          | charset               | REQUIRED    |
  +-----------------------------+-----------------------+-------------+
  | charset-supported           | 1setOf charset        | REQUIRED    |
  +-----------------------------+-----------------------+-------------+
  | color-supported             | boolean               | RECOMMENDED |
  +-----------------------------+-----------------------+-------------+
  | compression-supported       | 1setOf type2 keyword  | REQUIRED    |
  +-----------------------------+-----------------------+-------------+
  | document-format-default     | mimeMediaType         | REQUIRED    |
  +-----------------------------+-----------------------+-------------+
  | document-format-supported   | 1setOf mimeMediaType  | REQUIRED    |





Sweet & McDonald             Standards Track                  [Page 145]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  +-----------------------------+-----------------------+-------------+
  | generated-natural-language- | 1setOf                | REQUIRED    |
  | supported                   | naturalLanguage       |             |
  +-----------------------------+-----------------------+-------------+
  | ipp-versions-supported      | 1setOf type2 keyword  | REQUIRED    |
  +-----------------------------+-----------------------+-------------+
  | job-impressions-supported   | rangeOfInteger(0:MAX) | RECOMMENDED |
  +-----------------------------+-----------------------+-------------+
  | job-k-octets-supported      | rangeOfInteger(0:MAX) |             |
  +-----------------------------+-----------------------+-------------+
  | job-media-sheets-supported  | rangeOfInteger(1:MAX) |             |
  +-----------------------------+-----------------------+-------------+
  | multiple-document-jobs-     | boolean               | RECOMMENDED |
  | supported                   |                       |             |
  +-----------------------------+-----------------------+-------------+
  | multiple-operation-time-out | integer(1:MAX)        | RECOMMENDED |
  +-----------------------------+-----------------------+-------------+
  | natural-language-configured | naturalLanguage       | REQUIRED    |
  +-----------------------------+-----------------------+-------------+
  | operations-supported        | 1setOf type2 enum     | REQUIRED    |
  +-----------------------------+-----------------------+-------------+
  | pdl-override-supported      | type2 keyword         | REQUIRED    |
  +-----------------------------+-----------------------+-------------+
  | printer-driver-installer    | uri                   |             |
  +-----------------------------+-----------------------+-------------+
  | printer-info                | text(127)             | RECOMMENDED |
  +-----------------------------+-----------------------+-------------+
  | printer-location            | text(127)             | RECOMMENDED |
  +-----------------------------+-----------------------+-------------+
  | printer-make-and-model      | text(127)             | RECOMMENDED |
  +-----------------------------+-----------------------+-------------+
  | printer-message-from-       | text(127)             |             |
  | operator                    |                       |             |
  +-----------------------------+-----------------------+-------------+
  | printer-more-info-          | uri                   |             |
  | manufacturer                |                       |             |
  +-----------------------------+-----------------------+-------------+
  | printer-name                | name(127)             | REQUIRED    |
  +-----------------------------+-----------------------+-------------+
  | reference-uri-schemes-      | 1setOf uriScheme      |             |
  | supported                   |                       |             |
  +-----------------------------+-----------------------+-------------+

          Table 16: Printer Description Attributes (READ-WRITE)







Sweet & McDonald             Standards Track                  [Page 146]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  +------------------------------+----------------------+-------------+
  | Attribute                    | Syntax               | REQUIRED?   |
  +------------------------------+----------------------+-------------+
  | pages-per-minute-color       | integer(0:MAX)       | RECOMMENDED |
  +------------------------------+----------------------+-------------+
  | pages-per-minute             | integer(0:MAX)       | RECOMMENDED |
  +------------------------------+----------------------+-------------+
  | printer-current-time         | dateTime|unknown     | RECOMMENDED |
  +------------------------------+----------------------+-------------+
  | printer-is-accepting-jobs    | boolean              | REQUIRED    |
  +------------------------------+----------------------+-------------+
  | printer-more-info            | uri                  | RECOMMENDED |
  +------------------------------+----------------------+-------------+
  | printer-state                | type1 enum           | REQUIRED    |
  +------------------------------+----------------------+-------------+
  | printer-state-message        | text(MAX)            | RECOMMENDED |
  +------------------------------+----------------------+-------------+
  | printer-state-reasons        | 1setOf type2 keyword | REQUIRED    |
  +------------------------------+----------------------+-------------+
  | printer-up-time              | integer(1:MAX)       | REQUIRED    |
  +------------------------------+----------------------+-------------+
  | printer-uri-supported        | 1setOf uri           | REQUIRED    |
  +------------------------------+----------------------+-------------+
  | queued-job-count             | integer(0:MAX)       | REQUIRED    |
  +------------------------------+----------------------+-------------+
  | uri-authentication-supported | 1setOf type2 keyword | REQUIRED    |
  +------------------------------+----------------------+-------------+
  | uri-security-supported       | 1setOf type2 keyword | REQUIRED    |
  +------------------------------+----------------------+-------------+

             Table 17: Printer Status Attributes (READ-ONLY)

5.4.1.  printer-uri-supported (1setOf uri)

  This REQUIRED Printer attribute contains one or more URIs for the
  Printer.  It MAY contain more than one URI for the Printer.  An
  Administrator determines a Printer's URIs and configures this
  attribute to contain those URIs by some means outside the scope of
  this IPP/1.1 document.  The precise format of the URIs is
  implementation dependent and depends on the protocol.  See
  Sections 5.4.2 and 5.4.3 for a description of the
  "uri-authentication-supported" and "uri-security-supported"
  attributes, both of which are the REQUIRED companion attributes to
  this "printer-uri-supported" attribute.  See Sections 3.4 ("Object
  Identity") and 9.2 ("URIs in Operation, Job, and Printer Attributes")
  for more information.





Sweet & McDonald             Standards Track                  [Page 147]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


5.4.2.  uri-authentication-supported (1setOf type2 keyword)

  This REQUIRED Printer attribute MUST have the same cardinality
  (contain the same number of values) as the "printer-uri-supported"
  attribute.  This attribute identifies the Client Authentication
  mechanism associated with each URI listed in the
  "printer-uri-supported" attribute.  The Printer uses the specified
  mechanism to identify the authenticated user (see Section 9.3).  The
  "i-th" value in "uri-authentication-supported" corresponds to the
  "i-th" value in "printer-uri-supported", and it describes the
  authentication mechanisms used by the Printer when accessed via that
  URI.  See [RFC8010] for more details on Client Authentication.

  The following standard 'keyword' values are defined:

  o  'none': There is no authentication mechanism associated with the
     URI.  The Printer assumes that the authenticated user is
     'anonymous'.

  o  'requesting-user-name': When a Client performs an operation whose
     target is the associated URI, the Printer assumes that the
     authenticated user is specified by the "requesting-user-name"
     operation attribute (see Section 9.3).  If the
     "requesting-user-name" attribute is absent in a request, the
     Printer assumes that the authenticated user is 'anonymous'.

  o  'basic': When a Client performs an operation whose target is the
     associated URI, the Printer challenges the Client with HTTP Basic
     authentication [RFC7617].  The Printer assumes that the
     authenticated user is the name received via the Basic
     authentication mechanism.

  o  'digest': When a Client performs an operation whose target is the
     associated URI, the Printer challenges the Client with HTTP Digest
     authentication [RFC7616].  The Printer assumes that the
     authenticated user is the name received via the Digest
     authentication mechanism.

  o  'certificate': When a Client performs an operation whose target is
     the associated URI, the Printer expects the Client to provide an
     X.509 certificate.  The Printer assumes that the authenticated
     user is one of the textual names (Common Name or Subject Alternate
     Names) contained within the certificate.








Sweet & McDonald             Standards Track                  [Page 148]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


5.4.3.  uri-security-supported (1setOf type2 keyword)

  This REQUIRED Printer attribute MUST have the same cardinality
  (contain the same number of values) as the "printer-uri-supported"
  attribute.  This attribute identifies the security mechanisms used
  for each URI listed in the "printer-uri-supported" attribute.  The
  "i-th" value in "uri-security-supported" corresponds to the "i-th"
  value in "printer-uri-supported", and it describes the security
  mechanisms used for accessing the Printer via that URI.  See
  [RFC8010] for more details on security mechanisms.

  The following standard 'keyword' values are defined:

  o  'none': There are no secure communication channel protocols in use
     for the given URI.

  o  'tls': TLS [RFC5246] [RFC7525] is the secure communications
     channel protocol in use for the given URI.

  This attribute is orthogonal to the definition of a Client
  Authentication mechanism.  Specifically, 'none' does not exclude
  Client Authentication.  See Section 5.4.2.

  Consider the following example.  For a single Printer, an
  Administrator configures the "printer-uri-supported",
  "uri-authentication-supported", and "uri-security-supported"
  attributes as follows:

     "printer-uri-supported": 'ipp://printer.example.com/ipp/print/
     open-use-printer', 'ipp://printer.example.com/ipp/print/
     restricted-use-printer', 'ipps://printer.example.com/ipp/print/
     private-printer'

     "uri-authentication-supported": 'none', 'digest', 'basic'

     "uri-security-supported": 'none', 'none', 'tls'

  In this case, one Printer has three URIs.

  o  For the first URI, 'ipp://printer.example.com/ipp/print/
     open-use-printer', the value 'none' in "uri-security-supported"
     indicates that there is no secure channel protocol configured to
     run under HTTP.  The value of 'none' in
     "uri-authentication-supported" indicates that all users are
     'anonymous'.  There will be no challenge, and the Printer will
     ignore "requesting-user-name".





Sweet & McDonald             Standards Track                  [Page 149]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  o  For the second URI, 'ipp://printer.example.com/ipp/print/
     restricted-use-printer', the value 'none' in
     "uri-security-supported" indicates that there is no secure channel
     protocol configured to run under HTTP.  The value of 'digest' in
     "uri-authentication-supported" indicates that the Printer will
     issue a challenge and that the Printer will use the name supplied
     by the Digest mechanism to determine the authenticated user (see
     Section 9.3).

  o  For the third URI, 'ipps://printer.example.com/ipp/print/
     private-printer', the value 'tls' in "uri-security-supported"
     indicates that TLS is being used to secure the channel.  The
     Client SHOULD be prepared to use TLS framing to negotiate an
     acceptable ciphersuite to use while communicating with the
     Printer.  In this case, the name implies the use of a secure
     communications channel, but the fact is made explicit by the
     presence of the 'tls' value in "uri-security-supported".  The
     Client does not need to resort to understanding which security
     mechanisms it must use by following naming conventions or by
     parsing the URI to determine which security mechanisms are
     implied.  The value of 'basic' in "uri-authentication-supported"
     indicates that the Printer will issue a challenge and that the
     Printer will use the name supplied by the Basic mechanism to
     determine the authenticated user (see Section 9.3).  Because this
     challenge occurs in a TLS session, the channel is secure.

  Some Printers will be configured to support only one channel (either
  configured to use TLS access or not) and only one authentication
  mechanism.  Such Printers only have one URI listed in the
  "printer-uri-supported" attribute.  No matter the configuration of
  the Printer (whether it has only one URI or more than one URI), a
  Client MUST supply only one URI in the target "printer-uri" operation
  attribute.

5.4.4.  printer-name (name(127))

  This REQUIRED Printer attribute contains the name of the Printer.  It
  is a name that is more End User friendly than a URI.  An
  Administrator determines a Printer's name and sets this attribute to
  that name.  This name can be the last part of the Printer's URI, or
  it can be unrelated.  In non-US-English locales, a name can contain
  characters that are not allowed in a URI.

5.4.5.  printer-location (text(127))

  This RECOMMENDED Printer attribute identifies the location of the
  device.  This could include things like 'in Room 123A, second floor
  of building XYZ'.



Sweet & McDonald             Standards Track                  [Page 150]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


5.4.6.  printer-info (text(127))

  This RECOMMENDED Printer attribute provides descriptive information
  about this Printer.  This could include things like 'This printer can
  be used for printing color transparencies for HR presentations', or
  'Out of courtesy for others, please print only small (1-5 page) jobs
  at this printer', or even 'This printer is going away on July 1;
  please find a new printer'.

5.4.7.  printer-more-info (uri)

  This RECOMMENDED Printer attribute contains a URI used to obtain more
  information about this specific Printer.  For example, this could be
  an HTTP URI referencing an HTML page accessible to a web browser.
  The information obtained from this URI is intended for End User
  consumption.  Features outside the scope of IPP can be accessed from
  this URI.  The information is intended to be specific to this Printer
  instance and site-specific services, e.g., Job pricing, services
  offered, and End User assistance.  The device manufacturer can
  initially populate this attribute.

5.4.8.  printer-driver-installer (uri)

  This Printer attribute contains a URI to use to locate the driver
  installer for this Printer.  This attribute is intended for
  consumption by automata.  The mechanics of Printer driver
  installation are outside the scope of this document.  The device
  manufacturer can initially populate this attribute.

5.4.9.  printer-make-and-model (text(127))

  This RECOMMENDED Printer attribute identifies the make and model of
  the device.  The device manufacturer can initially populate this
  attribute.

5.4.10.  printer-more-info-manufacturer (uri)

  This Printer attribute contains a URI used to obtain more information
  about this type of device.  The information obtained from this URI is
  intended for End User consumption.  Features outside the scope of IPP
  can be accessed from this URI (e.g., latest firmware, upgrades,
  Printer drivers, optional features available, details on color
  support).  The information is intended to be germane to this Printer
  without regard to site-specific modifications or services.  The
  device manufacturer can initially populate this attribute.






Sweet & McDonald             Standards Track                  [Page 151]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


5.4.11.  printer-state (type1 enum)

  This REQUIRED Printer attribute identifies the current state of the
  device.  The "printer-state reasons" attribute augments the
  "printer-state" attribute to give more detailed information about the
  Printer in the given Printer state.

  A Printer updates this attribute continually if asynchronous event
  notification [RFC3995] is supported.

  Standard enum values are defined in Table 18.  Values of
  "printer-state-reasons", such as 'spool-area-full' and
  'stopped-partly', MAY be used to provide further information.

  +-------+-----------------------------------------------------------+
  | Value | Symbolic Name and Description                             |
  +-------+-----------------------------------------------------------+
  | '3'   | 'idle': Indicates that new Jobs can start processing      |
  |       | without waiting.                                          |
  +-------+-----------------------------------------------------------+
  | '4'   | 'processing': Indicates that Jobs are processing; new     |
  |       | Jobs will wait before processing.                         |
  +-------+-----------------------------------------------------------+
  | '5'   | 'stopped': Indicates that no Jobs can be processed and    |
  |       | intervention is required.                                 |
  +-------+-----------------------------------------------------------+

                  Table 18: "printer-state" Enum Values

5.4.12.  printer-state-reasons (1setOf type2 keyword)

  This REQUIRED Printer attribute supplies additional detail about the
  device's state.  Some of the value definitions indicate conformance
  requirements; the rest are OPTIONAL.

  Each 'keyword' value MAY have a suffix to indicate its level of
  severity.  The three levels are 'report' (least severe), 'warning',
  and 'error' (most severe):

  o  '-report': This suffix indicates that the reason is a "report".
     An implementation can choose to omit some or all reports.  Some
     reports specify finer granularity about the Printer state; others
     serve as a precursor to a warning.  A report MUST contain nothing
     that could affect the printed output.  Reports correspond to the
     'other' value for the prtAlertSeverityLevel property in the
     Printer MIB [RFC3805].





Sweet & McDonald             Standards Track                  [Page 152]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  o  '-warning': This suffix indicates that the reason is a "warning".
     An implementation can choose to omit some or all warnings.
     Warnings serve as a precursor to an error.  A warning MUST contain
     nothing that prevents a Job from completing, though in some cases
     the output can be of lower quality.  Warnings correspond to the
     'warning' value for the prtAlertSeverityLevel property in the
     Printer MIB [RFC3805].

  o  '-error': This suffix indicates that the reason is an "error".  An
     implementation MUST include all errors.  If this attribute
     contains one or more errors, the Printer MUST be in the 'stopped'
     state.  Errors correspond to the 'critical' value for the
     prtAlertSeverityLevel property in the Printer MIB [RFC3805].

  If the implementation does not add any one of the three suffixes and
  the value is not 'none', Clients can assume that the reason is an
  "error" if the Printer is in the 'stopped' state and a "warning" if
  the Printer is in any other state.

  If a Printer controls more than one Output Device, each value of this
  attribute MAY apply to one or more of the Output Devices.  An error
  on one Output Device that does not stop the Printer as a whole MAY
  appear as a warning in the Printer's "printer-state-reasons"
  attribute.  If "printer-state" for such a Printer has a value of
  'stopped', then there MUST be an error reason among the values in the
  "printer-state-reasons" attribute.

  The following standard 'keyword' values are defined:

  o  'none': There are no reasons.  This state reason is semantically
     equivalent to "printer-state-reasons" without any value and MUST
     be used, since the '1setOf' attribute syntax requires at least one
     value.

  o  'other': The device has detected a condition other than one listed
     in this document.

  o  'connecting-to-device': The Printer has scheduled a Job on the
     Output Device and is in the process of connecting to a shared
     network Output Device (and might not be able to actually start
     printing the Job for an arbitrarily long time, depending on the
     usage of the Output Device by other servers on the network).

  o  'cover-open': One or more covers on the device are open,
     equivalent to a prtCoverStatus [RFC3805] of 3 (coverOpen).

  o  'developer-empty: The device is out of developer.




Sweet & McDonald             Standards Track                  [Page 153]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  o  'developer-low': The device is low on developer.

  o  'door-open': One or more doors on the device are open, equivalent
     to a prtCoverStatus [RFC3805] of 3 (coverOpen).

  o  'fuser-over-temp': The fuser temperature is above normal,
     equivalent to a prtMarkerStatus [RFC3805] of 19 (the sum of
     "Unavailable because Broken" (3) and "Critical Alerts" (16)).

  o  'fuser-under-temp': The fuser temperature is below normal,
     equivalent to a prtMarkerStatus [RFC3805] of 19 (the sum of
     "Unavailable because Broken" (3) and "Critical Alerts" (16)).

  o  'input-tray-missing': One or more input trays are not in the
     device, equivalent to a prtInputStatus [RFC3805] of 19 (the sum of
     "Unavailable because Broken" (3) and "Critical Alerts" (16)).

  o  'interlock-open': One or more interlock devices on the Printer are
     unlocked, equivalent to a prtCoverStatus [RFC3805] of 5
     (interlockOpen).

  o  'interpreter-resource-unavailable': An interpreter resource is
     unavailable (i.e., font, form).

  o  'marker-supply-empty: The device is out of at least one marker
     supply, e.g., toner, ink, ribbon.

  o  'marker-supply-low': The device is low on at least one marker
     supply, e.g., toner, ink, ribbon.

  o  'marker-waste-almost-full': The device marker supply waste
     receptacle is almost full.

  o  'marker-waste-full': The device marker supply waste receptacle is
     full.

  o  'media-empty': At least one input tray is empty, equivalent to a
     prtInputStatus [RFC3805] of 19 (the sum of "Unavailable because
     Broken" (3) and "Critical Alerts" (16)).

  o  'media-jam': The device has a media jam, equivalent to a
     prtInputStatus [RFC3805] of 19 (the sum of "Unavailable because
     Broken" (3) and "Critical Alerts" (16)).

  o  'media-low': At least one input tray is low on media, equivalent
     to a prtInputStatus [RFC3805] of 8 (Non-Critical Alerts).





Sweet & McDonald             Standards Track                  [Page 154]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  o  'media-needed': A tray has run out of media, equivalent to a
     prtInputStatus [RFC3805] value of 17 (the sum of "Unavailable and
     OnRequest" (1) and "Critical Alerts" (16)).

  o  'moving-to-paused': Someone has paused the Printer using the
     Pause-Printer operation (see Section 4.2.7) or other means, but
     the device(s) is taking an appreciable time to stop.  Later, when
     all output has stopped, "printer-state" becomes 'stopped', and the
     'paused' value replaces the 'moving-to-paused' value in the
     "printer-state-reasons" attribute.  This value MUST be supported
     if the Pause-Printer operation is supported and the implementation
     takes significant time to pause a device in certain circumstances.

  o  'opc-life-over': The optical photo conductor is no longer
     functioning, equivalent to a prtMarkerStatus [RFC3805] of 19
     (the sum of "Unavailable because Broken" (3) and
     "Critical Alerts" (16)).

  o  'opc-near-eol': The optical photo conductor is near its end of
     life, equivalent to a prtMarkerStatus [RFC3805] of 8 (Non-Critical
     Alerts).

  o  'output-area-almost-full': One or more output areas are almost
     full, e.g., tray, stacker, collator, equivalent to a
     prtOutputStatus [RFC3805] of 8 (Non-Critical Alerts).

  o  'output-area-full': One or more output areas are full, e.g., tray,
     stacker, collator, equivalent to a prtInputStatus [RFC3805] of 19
     (the sum of "Unavailable because Broken" (3) and
     "Critical Alerts" (16)).

  o  'output-tray-missing': One or more output trays are not in the
     device, equivalent to a prtOutputStatus [RFC3805] of 19 (the sum
     of "Unavailable because Broken" (3) and "Critical Alerts" (16)).

  o  'paused': Someone has paused the Printer using the Pause-Printer
     operation (see Section 4.2.7) or other means, and the Printer's
     "printer-state" is 'stopped'.  In this state, a Printer MUST NOT
     produce printed output, but it MUST perform other operations
     requested by a Client.  If a Printer had been printing a Job when
     the Printer was paused, the Printer MUST resume printing that Job
     when the Printer is no longer paused and leave no evidence in the
     printed output of such a pause.  This value MUST be supported if
     the Pause-Printer operation is supported.







Sweet & McDonald             Standards Track                  [Page 155]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  o  'shutdown': Someone has removed a Printer from service, and the
     device can be powered down or physically removed.  In this state,
     a Printer MUST NOT produce printed output, and unless the Printer
     is realized by a print server that is still active, the Printer
     MUST perform no other operations requested by a Client, including
     returning this value.  If a Printer had been printing a Job when
     it was shut down, the Printer MAY resume printing that Job when
     the Printer is restarted.  If the Printer resumes printing such a
     Job, it can leave evidence in the printed output of such a
     shutdown, e.g., the part printed before the shutdown can be
     printed a second time after the shutdown.

  o  'spool-area-full': The limit of persistent storage allocated for
     spooling has been reached.  The Printer is temporarily unable to
     accept more Jobs.  The Printer will remove this value when it is
     able to accept more Jobs.  This value SHOULD be used by a
     non-spooling Printer that only accepts one or a small number of
     Jobs at a time or by a spooling Printer that has filled the spool
     space.

  o  'stopped-partly': When a Printer controls more than one Output
     Device, this reason indicates that one or more Output Devices are
     stopped.  If the reason is a report, fewer than half of the Output
     Devices are stopped.  If the reason is a warning, fewer than all
     of the Output Devices are stopped.

  o  'stopping': The Printer is in the process of stopping the device
     and will be stopped in a while.  When the device is stopped, the
     Printer will change the Printer's state to 'stopped'.  The
     'stopping-warning' reason is never an error, even for a Printer
     with a single Output Device.  When an Output Device ceases
     accepting Jobs, the Printer will have this reason while the Output
     Device completes printing.

  o  'timed-out': The server was able to connect to the Output Device
     (or is always connected) but was unable to get a response from the
     Output Device.

  o  'toner-empty': The device is out of toner.

  o  'toner-low': The device is low on toner.










Sweet & McDonald             Standards Track                  [Page 156]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


5.4.13.  printer-state-message (text(MAX))

  This RECOMMENDED Printer attribute specifies information about the
  "printer-state" and "printer-state-reasons" attributes in human-
  readable text.  If the Printer supports this attribute, the Printer
  MUST be able to generate this message in any of the natural languages
  identified by the Printer's "generated-natural-language-supported"
  attribute (see the "attributes-natural-language" operation attribute
  specified in Section 4.1.4.1).

5.4.14.  ipp-versions-supported (1setOf type2 keyword)

  This REQUIRED attribute identifies the IPP version(s) that this
  Printer supports, including major and minor versions, i.e., the
  version numbers for which this Printer implementation meets the
  conformance requirements.  For version number validation, the Printer
  matches the (2-octet binary) "version-number" parameter supplied by
  the Client in each request (see Sections 4.1.1 and 4.1.8) with the
  (US-ASCII) 'keyword' values of this attribute.

  The following standard 'keyword' values are defined in this document:

  o  '1.0': Meets the conformance requirements of IPP version 1.0 as
     specified in RFC 2566 [RFC2566] and RFC 2565 [RFC2565], including
     any extensions registered according to Section 7 and any extension
     defined in this version or any future version of the IPP Model and
     Semantics document (this document) or the IPP Encoding and
     Transport document [RFC8010] following the rules, if any, when the
     "version-number" parameter is '1.0'.

  o  '1.1': Meets the conformance requirements of IPP version 1.1 as
     specified in this document and [RFC8010], including any extensions
     registered according to Section 7 and any extension defined in any
     future versions of this document or [RFC8010] following the rules,
     if any, when the "version-number" parameter is '1.1'.

  Additional values are defined in "IPP Version 2.0, 2.1, and 2.2"
  [PWG5100.12].

5.4.15.  operations-supported (1setOf type2 enum)

  This REQUIRED Printer attribute specifies the set of supported
  operations for this Printer and contained Jobs.

  This attribute is encoded as any other enum attribute syntax
  according to [RFC8010] as 32 bits.  However, all 32-bit enum values
  for this attribute MUST NOT exceed 0x00007fff, since these same
  values are also passed in two octets in the "operation-id" field (see



Sweet & McDonald             Standards Track                  [Page 157]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  Section 4.1.1) in each Protocol request with the two high-order
  octets omitted in order to indicate the operation being performed
  [RFC8010].

  Table 19 lists the "operations-supported" attribute and
  "operation-id" parameter (see Section 4.1.2) enum values that are
  defined in this document.

  +---------------+---------------------------------------------------+
  | Value         | Operation Name                                    |
  +---------------+---------------------------------------------------+
  | 0x0000        | reserved, not used                                |
  +---------------+---------------------------------------------------+
  | 0x0001        | reserved, not used                                |
  +---------------+---------------------------------------------------+
  | 0x0002        | Print-Job                                         |
  +---------------+---------------------------------------------------+
  | 0x0003        | Print-URI                                         |
  +---------------+---------------------------------------------------+
  | 0x0004        | Validate-Job                                      |
  +---------------+---------------------------------------------------+
  | 0x0005        | Create-Job                                        |
  +---------------+---------------------------------------------------+
  | 0x0006        | Send-Document                                     |
  +---------------+---------------------------------------------------+
  | 0x0007        | Send-URI                                          |
  +---------------+---------------------------------------------------+
  | 0x0008        | Cancel-Job                                        |
  +---------------+---------------------------------------------------+
  | 0x0009        | Get-Job-Attributes                                |
  +---------------+---------------------------------------------------+
  | 0x000a        | Get-Jobs                                          |
  +---------------+---------------------------------------------------+
  | 0x000b        | Get-Printer-Attributes                            |
  +---------------+---------------------------------------------------+
  | 0x000c        | Hold-Job                                          |
  +---------------+---------------------------------------------------+
  | 0x000d        | Release-Job                                       |
  +---------------+---------------------------------------------------+
  | 0x000e        | Restart-Job                                       |
  +---------------+---------------------------------------------------+
  | 0x000f        | reserved for a future operation                   |









Sweet & McDonald             Standards Track                  [Page 158]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  +---------------+---------------------------------------------------+
  | 0x0010        | Pause-Printer                                     |
  +---------------+---------------------------------------------------+
  | 0x0011        | Resume-Printer                                    |
  +---------------+---------------------------------------------------+
  | 0x0012        | Purge-Jobs                                        |
  +---------------+---------------------------------------------------+
  | 0x0013-0x3fff | additional registered operations (see the IANA    |
  |               | IPP registry and Section 7.8)                     |
  +---------------+---------------------------------------------------+
  | 0x4000-0x7fff | reserved for vendor extensions (see Section 7.8)  |
  +---------------+---------------------------------------------------+

              Table 19: "operations-supported" Enum Values

5.4.16.  multiple-document-jobs-supported (boolean)

  This RECOMMENDED Printer attribute indicates whether the Printer
  supports more than one Document per Job, i.e., more than one
  Send-Document operation with Document data and/or Send-URI
  operations.  If the Printer supports the Create-Job and Send-Document
  operations (see Sections 4.2.4 and 4.3.1), it MUST support this
  attribute.

5.4.17.  charset-configured (charset)

  This REQUIRED Printer attribute identifies the charset that the
  Printer has been configured to represent 'text' and 'name' Printer
  attributes that are set by the Operator, Administrator, or
  manufacturer, i.e., for "printer-name" (name), "printer-location"
  (text), "printer-info" (text), and "printer-make-and-model" (text).
  Therefore, the value of the Printer's "charset-configured" attribute
  MUST also be among the values of the Printer's "charset-supported"
  attribute.

5.4.18.  charset-supported (1setOf charset)

  This REQUIRED Printer attribute identifies the set of charsets that
  the Printer and contained Jobs support in attributes with attribute
  syntaxes 'text' and 'name'.  At least the value 'utf-8' MUST be
  present, since IPP objects MUST support the UTF-8 [RFC3629] charset.
  If a Printer supports a charset, it means that for all attributes of
  syntaxes 'text' and 'name' the Printer MUST (1) accept the charset in
  requests and (2) return the charset in responses as needed.

  If more charsets than UTF-8 are supported, the Printer MUST perform
  charset conversion between the charsets as described in
  Section 4.1.4.2.



Sweet & McDonald             Standards Track                  [Page 159]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


5.4.19.  natural-language-configured (naturalLanguage)

  This REQUIRED Printer attribute identifies the natural language that
  the Printer has been configured to represent 'text' and 'name'
  Printer attributes that are set by the Operator, Administrator, or
  manufacturer, i.e., for "printer-name" (name), "printer-location"
  (text), "printer-info" (text), and "printer-make-and-model" (text).
  When returning these Printer attributes, the Printer MAY return them
  in the configured natural language specified by this attribute,
  instead of the natural language requested by the Client in the
  "attributes-natural-language" operation attribute.  See
  Section 4.1.4.1 for the specification of the OPTIONAL support for
  multiple natural languages.  Therefore, the value of the Printer's
  "natural-language-configured" attribute MUST also be among the values
  of the Printer's "generated-natural-language-supported" attribute.

5.4.20.  generated-natural-language-supported (1setOf naturalLanguage)

  This REQUIRED Printer attribute identifies the natural language(s)
  that the Printer and contained Jobs support in attributes with
  attribute syntaxes 'text' and 'name'.  The natural language(s)
  supported depends on implementation and/or configuration.  Unlike
  charsets, Printers MUST accept requests with any natural language or
  any Natural Language Override whether the natural language is
  supported or not.

  If a Printer supports a natural language, it means that for any of
  the attributes for which the Printer or Job generates messages, i.e.,
  for the "job-state-message" and "printer-state-message" attributes
  and operation messages (see Section 4.1.5) in operation responses,
  the Printer and Job MUST be able to generate messages in any of the
  Printer's supported natural languages.  See Sections 4.1.4, 5.1.2,
  and 5.1.3 for the definitions of 'text' and 'name' attributes in
  operation requests and responses.

  Note: A Printer that supports multiple natural languages often has
  separate catalogs of messages, one for each natural language
  supported.

5.4.21.  document-format-default (mimeMediaType)

  This REQUIRED Printer attribute identifies the Document format that
  the Printer has been configured to assume if the Client does not
  supply a "document-format" operation attribute in any of the
  operation requests that supply Document data.  The standard values
  for this attribute are Internet media types (sometimes called "MIME
  media types").  For further details, see the description of the
  'mimeMediaType' attribute syntax in Section 5.1.10.



Sweet & McDonald             Standards Track                  [Page 160]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


5.4.22.  document-format-supported (1setOf mimeMediaType)

  This REQUIRED Printer attribute identifies the set of Document
  formats that the Printer and contained Jobs can support.  For further
  details, see the description of the 'mimeMediaType' attribute syntax
  in Section 5.1.10.

5.4.23.  printer-is-accepting-jobs (boolean)

  This REQUIRED Printer attribute indicates whether the Printer is
  currently able to accept Jobs, i.e., is accepting Print-Job,
  Print-URI, and Create-Job requests.  If the value is 'true', the
  Printer is accepting Jobs.  If the value is 'false', the Printer is
  currently rejecting any Jobs submitted to it.  In this case, the
  Printer returns the 'server-error-not-accepting-jobs' status-code.

  This value is independent of the "printer-state" and
  "printer-state-reasons" attributes because its value does not affect
  the current Job; rather, it affects future Jobs.  This attribute,
  when 'false', causes the Printer to reject Jobs even when
  "printer-state" is 'idle' or, when 'true', causes the Printer to
  accept Jobs even when "printer-state" is 'stopped'.

5.4.24.  queued-job-count (integer(0:MAX))

  This REQUIRED Printer attribute contains a count of the number of
  Jobs that are either 'pending', 'processing', 'pending-held', or
  'processing-stopped' and is set by the Printer.

5.4.25.  printer-message-from-operator (text(127))

  This Printer attribute provides a message from an Operator,
  Administrator, or "intelligent" process to indicate to the End User
  information or status of the Printer, such as why it is unavailable
  or when it is expected to be available.

5.4.26.  color-supported (boolean)

  This RECOMMENDED Printer attribute identifies whether the device is
  capable of any type of color printing at all, including highlight
  color.  All Document instructions having to do with color are
  embedded within the Document PDL, although IPP attributes can affect
  the rendering of those colors.

  Note: End Users are able to determine the nature and details of the
  color support by querying the "printer-more-info-manufacturer"
  Printer attribute.




Sweet & McDonald             Standards Track                  [Page 161]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


5.4.27.  reference-uri-schemes-supported (1setOf uriScheme)

  This Printer attribute specifies which URI schemes are supported for
  use in the "document-uri" operation attribute of the Print-URI or
  Send-URI operations.  If a Printer supports these OPTIONAL
  operations, it MUST support the "reference-uri-schemes-supported"
  Printer attribute with at least the following URI scheme value:

  o  'ftp': The Printer will use an FTP 'get' operation as defined in
     [RFC959] using FTP URLs as defined by [RFC3986].

  The Printer MAY support other URI schemes (see Section 5.1.7).

5.4.28.  pdl-override-supported (type2 keyword)

  This REQUIRED Printer attribute expresses the ability of a particular
  Printer implementation to override Document data instructions with
  IPP attributes.  The following 'keyword' values are defined in this
  document:

  o  'attempted': This value indicates that the Printer attempts to
     make the IPP attribute values take precedence over embedded
     instructions in the Document data; however, there is no guarantee.

  o  'not-attempted': This value indicates that the Printer makes no
     attempt to make the IPP attribute values take precedence over
     embedded instructions in the Document data.

  Appendix C contains a full description of how this attribute
  interacts with and affects other IPP attributes, especially the
  "ipp-attribute-fidelity" attribute.

5.4.29.  printer-up-time (integer(1:MAX))

  This REQUIRED Printer attribute indicates the amount of time (in
  seconds) that this Printer instance has been up and running.  The
  value is a monotonically increasing value starting from 1 when the
  Printer is started up (initialized, booted, etc.).  This value is
  used to populate the Event Time Job Status attributes
  "time-at-creation", "time-at-processing", and "time-at-completed"
  (see Section 5.3.14).










Sweet & McDonald             Standards Track                  [Page 162]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  If the Printer goes down at some value 'n' and comes back up, the
  implementation MAY:

  1.  know how long it has been down and resume at some value greater
      than 'n', or

  2.  restart from 1.

  In other words, if the device or devices that the Printer is
  representing are restarted or power-cycled, the Printer MAY continue
  counting this value or MAY reset this value to 1, depending on
  implementation.  However, if the Printer software ceases running and
  restarts without knowing the last value for "printer-up-time", the
  implementation MUST reset this value to 1.  If this value is reset
  and the Printer has persistent Jobs, the Printer MUST reset the
  "time-at-xxx (integer)" Event Time Job Status attributes according to
  Section 5.3.14.  An implementation MAY use both implementation
  alternatives, depending on warm versus cold start, respectively.

5.4.30.  printer-current-time (dateTime|unknown)

  This RECOMMENDED Printer attribute indicates the current date and
  time.  This value is used to populate the Event Time Job Status
  attributes "date-time-at-creation", "date-time-at-processing", and
  "date-time-at-completed" (see Section 5.3.14).

  This value is obtained on a "best effort" basis and in practice does
  not have to be precise in order to be useful.  A Printer
  implementation sets the value of this attribute by obtaining the date
  and time via some implementation-dependent means, such as getting the
  value from a network time server, initialization at time of
  manufacture, or setting by an Administrator.  See [RFC3196] and
  [PWG5100.19] for examples.  If an implementation supports this
  attribute and the implementation knows that it has not yet been set,
  then the implementation MUST return the value of this attribute using
  the out-of-band 'unknown', meaning the value is not yet known.  See
  the beginning of Section 5.1.

  The time zone of this attribute might not be the time zone used by
  people located near the Printer or device.  The Client MUST NOT
  expect the time zone of any received 'dateTime' value to be in the
  time zone of the Client or in the time zone of the people located
  near the Printer.








Sweet & McDonald             Standards Track                  [Page 163]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  The Client SHOULD display any dateTime attributes to the user in the
  Client's local time by converting the 'dateTime' value returned by
  the server to the time zone of the Client, rather than using the time
  zone returned by the Printer in attributes that use the 'dateTime'
  attribute syntax.

  Note: Prior versions of this document incorrectly specified the use
  of the 'no-value' out-of-band value when the current date and time
  had not been set.  The correct out-of-band value is 'unknown', since
  there is always an intrinsic current date and time.

5.4.31.  multiple-operation-time-out (integer(1:MAX))

  This RECOMMENDED Printer attribute identifies the minimum time (in
  seconds) that the Printer waits for additional Send-Document or
  Send-URI operations to follow a still-open Job before taking any
  recovery actions, such as the ones indicated in Section 4.3.1.  If
  the Printer supports the Create-Job and Send-Document operations (see
  Sections 4.2.4 and 4.3.1), it MUST support this attribute.

  Printers SHOULD use a value between '60' and '240' (seconds).  An
  implementation MAY allow an Administrator to set this attribute by
  means not defined in this document.  If so, the Administrator MAY be
  able to set values outside this range.

5.4.32.  compression-supported (1setOf type2 keyword)

  This REQUIRED Printer attribute identifies the set of supported
  compression algorithms for Document data.  Compression only applies
  to the Document data; compression does not apply to the encoding of
  the IPP operation itself.  The supported values are used to validate
  the Client-supplied "compression" operation attributes in Print-Job
  and Send-Document requests.

  Standard 'keyword' values defined in this document are:

  o  'none': no compression is used.

  o  'deflate': ZIP inflate/deflate compression technology described in
     RFC 1951 [RFC1951].

  o  'gzip': GNU zip compression technology described in RFC 1952
     [RFC1952].

  o  'compress': UNIX compression technology described in RFC 1977
     [RFC1977].





Sweet & McDonald             Standards Track                  [Page 164]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


5.4.33.  job-k-octets-supported (rangeOfInteger(0:MAX))

  This Printer attribute specifies the upper and lower bounds of total
  sizes of Jobs in K octets, i.e., in units of 1024 octets.  The
  supported values are used to validate the Client-supplied
  "job-k-octets" operation attribute in Job Creation requests.  The
  corresponding Job Description attribute "job-k-octets" is defined in
  Section 5.3.17.1.

5.4.34.  job-impressions-supported (rangeOfInteger(0:MAX))

  This RECOMMENDED Printer attribute specifies the upper and lower
  bounds for the number of Impressions per Job.  The supported values
  are used to validate the Client-supplied "job-impressions" operation
  attribute in Job Creation requests.  The corresponding Job
  Description attribute "job-impressions" is defined in
  Section 5.3.17.2.

5.4.35.  job-media-sheets-supported (rangeOfInteger(1:MAX))

  This Printer attribute specifies the upper and lower bounds for the
  number of Media Sheets per Job.  The supported values are used to
  validate the Client-supplied "job-media-sheets" operation attribute
  in Job Creation requests.  The corresponding Job attribute
  "job-media-sheets" is defined in Section 5.3.17.3.

5.4.36.  pages-per-minute (integer(0:MAX))

  This RECOMMENDED Printer attribute specifies the nominal number of
  pages per minute to the nearest whole number that can be generated by
  this Printer (e.g., simplex, black-and-white).  This attribute is
  informative, not a service guarantee.  Generally, it is the value
  used in the marketing literature to describe the speed of the device.

  A value of 0 indicates a device that takes more than two minutes to
  process a page.

5.4.37.  pages-per-minute-color (integer(0:MAX))

  This RECOMMENDED Printer attribute specifies the nominal number of
  pages per minute to the nearest whole number that can be generated by
  this Printer when printing color (e.g., simplex, color).  For
  purposes of this attribute, the meaning of "color" is the same as
  that for the "color-supported" attribute; namely, the device is
  capable of any type of color printing at all, including highlight
  color.  This attribute is informative, not a service guarantee.
  Generally, it is the value used in the marketing literature to
  describe the color capabilities of this device.



Sweet & McDonald             Standards Track                  [Page 165]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  A value of 0 indicates a device that takes more than two minutes to
  process a page in color.

  If a color device has several color modes, it MAY use the
  "pages-per-minute" value for this attribute that corresponds to the
  mode that produces the highest number.

  Printers that are black-and-white only MUST NOT support this
  attribute.  If this attribute is present, then the "color-supported"
  Printer Description attribute MUST be present and have a 'true'
  value.

  The values of the "pages-per-minute" and "pages-per-minute-color"
  attributes returned by the Get-Printer-Attributes operation MAY be
  affected by the "document-format" attribute supplied by the Client in
  the Get-Printer-Attributes request.  In other words, the
  implementation MAY have different speeds, depending on the Document
  format being processed.  See Section 4.2.5.1 ("Get-Printer-Attributes
  Request").

6.  Conformance

  This section describes conformance issues and requirements.  This
  document introduces model entities such as objects, operations,
  attributes, attribute syntaxes, and attribute values.  The following
  sections describe the conformance requirements that apply to these
  model entities.

6.1.  Client Conformance Requirements

  This section describes the conformance requirements for a Client (see
  Section 3.1), whether it be:

  1.  contained within software controlled by an End User, e.g.,
      activated by the "Print" menu item in an application that sends
      IPP requests, or

  2.  the print server component that sends IPP requests to either an
      Output Device or another "downstream" print server.

  A conforming Client supports all REQUIRED operations as defined in
  this document.  For each attribute included in an operation request,
  a conforming Client MUST supply a value whose type and value syntax
  conforms to the requirements specified in Sections 4 and 5 of this
  document.  A conforming Client MAY supply any Standards Track
  extensions and/or vendor extensions in an operation request, as long
  as the extensions meet the requirements in Section 7.




Sweet & McDonald             Standards Track                  [Page 166]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  While this document does not define conformance requirements for the
  user interfaces provided by IPP Clients or their applications, best
  practices for user interfaces are defined in [PWG5100.19].

  A Client MUST be able to accept any of the attribute syntaxes defined
  in Section 5.1, including their full range, that can be returned to
  it in a response from a Printer.  In particular, for each attribute
  that the Client supports whose attribute syntax is 'text', the Client
  MUST accept and process both the 'textWithoutLanguage' and
  'textWithLanguage' forms.  Similarly, for each attribute that the
  Client supports whose attribute syntax is 'name', the Client MUST
  accept and process both the 'nameWithoutLanguage' and
  'nameWithLanguage' forms.  For presentation purposes, truncation of
  long attribute values is not recommended.  A recommended approach
  would be for the Client implementation to allow the user to scroll
  through long attribute values.

  A response MAY contain attribute groups, attributes, attribute
  syntaxes, values, and status-code values that the Client does not
  expect.  Therefore, a Client implementation MUST gracefully handle
  such responses and not refuse to interoperate with a conforming
  Printer that is returning Standards Track extensions or vendor
  extensions, including attribute groups, attributes, attribute
  syntaxes, attribute values, status-code values, and out-of-band
  attribute values that conform to Section 7.  Clients can choose to
  ignore any parameters, attribute groups, attributes, attribute
  syntaxes, or values that they do not understand.

  While a Client is sending data to a Printer, it SHOULD do its best to
  prevent a channel from being closed by a lower layer when the channel
  is blocked (i.e., flow-controlled off) for whatever reason, e.g.,
  'out of paper' or 'Job ahead hasn't freed up enough memory'.
  However, the layer that launched the print submission (e.g., an
  End User) MAY close the channel in order to cancel the Job.  When a
  Client closes a channel, a Printer MAY print all or part of the
  received portion of the Document.  See the Encoding and Transport
  document [RFC8010] for more details.

  A Client MUST support Client Authentication as defined in [RFC8010].
  A Client SHOULD support Operation Privacy and Server Authentication
  as defined in [RFC8010].  See also Section 9 of this document.










Sweet & McDonald             Standards Track                  [Page 167]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


6.2.  IPP Object Conformance Requirements

  This section specifies the conformance requirements for conforming
  implementations of IPP objects (see Section 3).  These requirements
  apply to an IPP object whether it is:

  1)  an (embedded) device component that accepts IPP requests and
      controls the device, or

  2)  a component of a print server that accepts IPP requests (where
      the print server controls one or more networked devices using IPP
      or other protocols).

6.2.1.  Objects

  Conforming implementations MUST implement all of the model objects as
  defined in this document in the indicated sections:

  Section 3.1 - Printer Object

  Section 3.2 - Job Object

6.2.2.  Operations

  Conforming IPP object implementations MUST implement all of the
  REQUIRED model operations, including REQUIRED responses, as defined
  in this document in the indicated sections.  Table 20 lists the
  operations for a Printer, while Table 21 lists the operations for
  a Job.






















Sweet & McDonald             Standards Track                  [Page 168]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


        +----------------------------------------+-------------+
        | Operation                              | Conformance |
        +----------------------------------------+-------------+
        | Print-Job (Section 4.2.1)              | REQUIRED    |
        +----------------------------------------+-------------+
        | Print-URI (Section 4.2.2)              | OPTIONAL    |
        +----------------------------------------+-------------+
        | Validate-Job (Section 4.2.3)           | REQUIRED    |
        +----------------------------------------+-------------+
        | Create-Job (Section 4.2.4)             | RECOMMENDED |
        +----------------------------------------+-------------+
        | Get-Printer-Attributes (Section 4.2.5) | REQUIRED    |
        +----------------------------------------+-------------+
        | Get-Jobs (Section 4.2.6)               | REQUIRED    |
        +----------------------------------------+-------------+
        | Pause-Printer (Section 4.2.7)          | OPTIONAL    |
        +----------------------------------------+-------------+
        | Resume-Printer (Section 4.2.8)         | OPTIONAL    |
        +----------------------------------------+-------------+
        | Purge-Jobs (Section 4.2.9)             | SHOULD NOT  |
        +----------------------------------------+-------------+

        Table 20: Conformance Requirements for Printer Operations

          +------------------------------------+-------------+
          | Operation                          | Conformance |
          +------------------------------------+-------------+
          | Send-Document (Section 4.3.1)      | RECOMMENDED |
          +------------------------------------+-------------+
          | Send-URI (Section 4.3.2)           | RECOMMENDED |
          +------------------------------------+-------------+
          | Cancel-Job (Section 4.3.3)         | REQUIRED    |
          +------------------------------------+-------------+
          | Get-Job-Attributes (Section 4.3.4) | REQUIRED    |
          +------------------------------------+-------------+
          | Hold-Job (Section 4.3.5)           | OPTIONAL    |
          +------------------------------------+-------------+
          | Release-Job (Section 4.3.6)        | OPTIONAL    |
          +------------------------------------+-------------+
          | Restart-Job (Section 4.3.7)        | SHOULD NOT  |
          +------------------------------------+-------------+

          Table 21: Conformance Requirements for Job Operations








Sweet & McDonald             Standards Track                  [Page 169]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  Conforming IPP objects MUST support all REQUIRED operation attributes
  and all values of such attributes if so indicated in the description.
  Conforming IPP objects MUST ignore all unsupported or unknown
  operation attributes or Operation Attributes groups received in a
  request but MUST reject a request that contains a supported operation
  attribute that contains an unsupported value.

  Conforming IPP objects MAY return operation responses that contain
  attribute groups, attribute names, attribute syntaxes, attribute
  values, and status-code values that are extensions to this
  specification.  The additional attribute groups MAY occur in any
  order.

  The following section on object attributes specifies the support
  required for object attributes.

6.2.3.  IPP Object Attributes

  Conforming IPP objects MUST support all of the REQUIRED object
  attributes, as defined in this document in the indicated sections.

  If an object supports an attribute, it MUST support only those values
  specified in this document or through the extension mechanism
  described in Section 6.2.5.  It MAY support any non-empty subset of
  these values.  That is, it MUST support at least one of the specified
  values and at most all of them.

6.2.4.  Versions

  IPP/1.1 Clients MUST meet the conformance requirements for Clients
  specified in this document and [RFC8010].  IPP/1.1 Clients MUST be
  capable of sending requests containing a "version-number" parameter
  with a value of '1.1'.

  IPP/1.1 Printer and Job objects MUST meet the conformance
  requirements for IPP objects specified in this document and
  [RFC8010].  IPP/1.1 objects MUST accept requests containing a
  "version-number" parameter with a '1.1' value or reject the request
  if the operation is not supported.












Sweet & McDonald             Standards Track                  [Page 170]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  It is beyond the scope of this specification to mandate conformance
  with other IPP versions.  However, IPP was deliberately designed to
  make supporting different versions easy.  IPP/1.1 Printer
  implementations MUST:

  o  decode and process any well-formed IPP/1.1 request, and

  o  respond appropriately with a response containing the same
     "version-number" parameter value used by the Client in the
     request.

  IPP/1.1 Client implementations MUST:

  o  decode and process any well-formed IPP/1.1 response.

  IPP Clients SHOULD try supplying alternate version numbers if they
  receive a 'server-error-version-not-supported' error in a response.

6.2.5.  Extensions

  A conforming IPP object MAY support Standards Track extensions and
  vendor extensions, as long as the extensions meet the requirements
  specified in Section 7.

  For each attribute included in an operation response, a conforming
  IPP object MUST return a value whose type and value syntax conforms
  to the requirements specified in Sections 4 and 5 of this document.

6.2.6.  Attribute Syntaxes

  An IPP object MUST be able to accept any of the attribute syntaxes
  defined in Section 5.1, including their full range, in any operation
  in which a Client can supply attributes or the Administrator can
  configure attributes (by means outside the scope of this IPP/1.1
  document).  In particular, for each attribute that the IPP object
  supports whose attribute syntax is 'text', the IPP object MUST accept
  and process both the 'textWithoutLanguage' and 'textWithLanguage'
  forms.  Similarly, for each attribute that the IPP object supports
  whose attribute syntax is 'name', the IPP object MUST accept and
  process both the 'nameWithoutLanguage' and 'nameWithLanguage' forms.
  Furthermore, an IPP object MUST return attributes to the Client in
  operation responses that conform to the syntaxes specified in
  Section 5.1, including their full range if supplied previously by a
  Client.







Sweet & McDonald             Standards Track                  [Page 171]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


6.2.7.  Security

  An IPP Printer implementation SHOULD contain support for Client
  Authentication as defined in the IPP/1.1 Encoding and Transport
  document [RFC8010].  A Printer implementation MAY allow an
  Administrator to configure the Printer so that all, some, or none of
  the users are authenticated.  See also Section 9 of this document.

  An IPP Printer implementation SHOULD contain support for Operation
  Privacy and Server Authentication as defined in [RFC8010].  A Printer
  implementation MAY allow an Administrator to configure the degree of
  support for Operation Privacy and Server Authentication.  See also
  Section 9 of this document.

  Security MUST NOT be compromised when a Client supplies a lower
  "version-number" parameter in a request.  For example, if a Printer
  conforming to IPP/1.1 accepts version '1.0' requests and is
  configured to enforce Digest Authentication, it MUST do the same for
  a version '1.0' request.

6.3.  Charset and Natural Language Requirements

  All Clients and IPP objects MUST support the 'utf-8' charset as
  defined in Section 5.1.8.

  IPP objects MUST be able to accept any Client request that correctly
  uses the "attributes-natural-language" operation attribute or the
  Natural Language Override mechanism on any individual attribute
  whether or not the natural language is supported by the IPP object.
  If an IPP object supports a natural language, then it MUST be able to
  translate (perhaps by table lookup) all generated 'text' or 'name'
  attribute values into one of the supported languages (see
  Section 4.1.4).


















Sweet & McDonald             Standards Track                  [Page 172]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


7.  IANA Considerations

  This section describes the procedures for defining Standards Track
  and vendor extensions to this document.  This affects the following
  subregistries of the IANA IPP registry:

  1.  Objects

  2.  Attributes

  3.  Keyword Attribute Values

  4.  Enum Attribute Values

  5.  Attribute Group Tags

  6.  Out-of-Band Attribute Value Tags

  7.  Attribute Syntaxes

  8.  Operations

  9.  Status-Code Values

  Extensions registered for use with IPP are OPTIONAL for Client and
  IPP object conformance to the IPP/1.1 Model and Semantics document
  (this document).

  These extension procedures are aligned with the guidelines as set
  forth in "Guidelines for Writing an IANA Considerations Section in
  RFCs" [RFC5226].  Appendix A describes how to propose new
  registrations for consideration.  IANA will reject registration
  proposals that leave out required information or do not follow the
  appropriate format described in Appendix A.  The IPP/1.1 Model and
  Semantics document can also be extended by an appropriate
  Standards Track document that specifies any of the above extensions.

  The IANA policy (using terms defined in [RFC5226]) for all extensions
  is Specification Required, Expert Review, or First Come First Served
  as documented in the following subsections.  Registrations submitted
  to IANA are forwarded to the IPP Designated Expert(s) who reviews the
  proposal on a mailing list that the Designated Expert(s) keeps for
  this purpose.  Initially, that list is the mailing list used by the
  PWG IPP WG:

     [email protected]





Sweet & McDonald             Standards Track                  [Page 173]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  The IPP Designated Expert(s) is appointed by the IESG Area Director
  responsible for IPP, according to [RFC5226].

  In addition, the IANA-PRINTER-MIB [RFC3805] has been updated to
  reference this document; the current version is available from
  <http://www.iana.org>.

7.1.  Object Extensions

  The IANA policy (using terms defined in [RFC5226]) for object
  extensions was formerly Expert Review; this document changes the
  policy to Specification Required.

7.2.  Attribute Extensibility

  Since attribute names are type2 keywords (see Section 5.1.4), the
  IANA policy (using terms defined in [RFC5226]) for attribute
  extensions is Expert Review.

  For vendor attribute extensions, implementors SHOULD use keywords
  with a suitable distinguishing prefix such as 'smiNNN-' where NNN is
  an SMI Private Enterprise Number (PEN) [IANA-PEN].  For example, if
  the company Example Corp. had obtained the SMI PEN 32473, then a
  vendor attribute 'foo' would be 'smi32473-foo'.

     Note: Prior versions of this document recommended using a fully
     qualified domain name [RFC1035] as the prefix (e.g.,
     'example.com-foo'), and many IPP implementations have also used
     reversed domain names (e.g., 'com.example-foo').  Domain names
     have proven problematic due to the length of some domain names,
     parallel use of country-specific domain names (e.g.,
     'example.co.jp-foo'), and changes in ownership of domain names.

  If a new Printer attribute is defined and its values can be affected
  by a specific Document format, its specification needs to contain the
  following sentence:

     "The value of this attribute returned in a Get-Printer-Attributes
     response MAY depend on the "document-format" attribute supplied
     (see Section 4.2.5.1) of the IPP/1.1 Model and Semantics
     document."

  If the specification does not, then its value in the
  Get-Printer-Attributes response MUST NOT depend on the
  "document-format" attribute supplied in the request.






Sweet & McDonald             Standards Track                  [Page 174]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  When a new Job Template attribute is registered, the value of the
  Printer attributes MAY vary with "document-format" supplied in the
  request without the specification having to indicate so.

7.3.  Keyword Extensibility

  The IANA policy (using terms defined in [RFC5226]) for type1 keyword
  extensions is Specification Required.  The IANA policy for type2
  keyword extensions is Expert Review.  The IANA policy for vendor
  keyword extensions is First Come First Served.  Only attributes using
  the type1 and type2 keyword syntax can be registered in the IANA IPP
  registry.

     Note: The type1 or type2 prefix on the basic attribute syntax is
     provided only to communicate the IANA policy required for
     registration and is not represented in IPP messages.  Both type1
     and type2 'keyword' values are represented using the same
     'keyword' value tag.

  For type1 and type2 keywords, the proposer includes the name of the
  keyword in the registration proposal, and the name is part of the
  technical review.

  For vendor keyword extensions, implementors SHOULD either:

  a.  follow attribute-specific guidance such as the guidance defined
      in [PWG5101.1], or

  b.  use keywords with a suitable distinguishing prefix, such as
      'smiNNN-' where NNN is an SMI Private Enterprise Number (PEN)
      [IANA-PEN].

  For example, if the company Example Corp. had obtained the
  SMI PEN 32473, then a vendor keyword 'foo' would be 'smi32473-foo'.

     Note: Prior versions of this document recommended using a fully
     qualified domain name [RFC1035] as the prefix (e.g.,
     'example.com-foo'), and many IPP implementations have also used
     reversed domain names (e.g., 'com.example-foo').  Domain names
     have proven problematic due to the length of some domain names,
     parallel use of country-specific domain names (e.g.,
     'example.co.jp-foo'), and changes in ownership of domain names.

  When a type2 keyword extension is approved, the IPP Designated
  Expert(s) becomes the point of contact for any future maintenance
  that might be required for that registration.





Sweet & McDonald             Standards Track                  [Page 175]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


7.4.  Enum Extensibility

  The IANA policy (using terms defined in [RFC5226]) for type1 enum
  extensions is Specification Required.  The IANA policy for type2 enum
  extensions is Expert Review.  The IANA policy for vendor enum
  extensions is First Come First Served.  Only attributes using the
  type1 and type2 enum syntax can be registered in the IANA IPP
  registry.

     Note: The type1 or type2 prefix on the basic attribute syntax is
     provided only to communicate the IANA policy required for
     registration and is not represented in IPP messages.  Both type1
     and type2 enum values are represented using the same enum
     value tag.

  For vendor enum extensions, implementors MUST use values in the
  reserved integer range, which is 0x40000000 to 0x7fffffff.
  Implementors SHOULD consult with the IPP Designated Expert(s) to
  reserve vendor extension value(s) for their usage.

  When a type1 or type2 enum extension is approved, the IPP Designated
  Expert(s), in consultation with IANA, assigns the next available enum
  number for each enum value.

  When a type2 enum extension is approved, the IPP Designated Expert(s)
  becomes the point of contact for any future maintenance that might be
  required for that registration.

7.5.  Attribute Group Extensibility

  The IANA policy (using terms defined in [RFC5226]) for attribute
  group extensions was formerly Expert Review; this document changes
  the policy to Specification Required.

  For attribute groups, the IPP Designated Expert(s), in consultation
  with IANA, assigns the next attribute group tag code in the
  appropriate range as specified in [RFC8010].

7.6.  Out-of-Band Attribute Value Extensibility

  The IANA policy (using terms defined in [RFC5226]) for out-of-band
  attribute value extensions was formerly Expert Review; this document
  changes the policy to Specification Required.

  For out-of-band attribute value tags, the IPP Designated Expert(s),
  in consultation with IANA, assigns the next out-of-band attribute
  value tag code in the appropriate range as specified in [RFC8010].




Sweet & McDonald             Standards Track                  [Page 176]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


7.7.  Attribute Syntax Extensibility

  The IANA policy (using terms defined in [RFC5226]) for attribute
  syntax extensions was formerly Expert Review; this document changes
  the policy to Specification Required.  The IANA policy for vendor
  attribute syntax extensions (tags 0x40000000 to 0x7fffffff) is First
  Come First Served.  Only attribute syntaxes in the range of
  0x00000000 to 0x3fffffff can be registered in the IANA IPP registry.

  For vendor attribute syntax extensions, implementors MUST use values
  in the reserved integer range, which is 0x40000000 to 0x7fffffff.
  Implementors SHOULD consult with the IPP Designated Expert(s) to
  reserve vendor extension value(s) for their usage.

  For registered attribute syntaxes, the IPP Designated Expert(s), in
  consultation with IANA, assigns the next attribute syntax tag in the
  appropriate range as specified in [RFC8010].

7.8.  Operation Extensibility

  The IANA policy (using terms defined in [RFC5226]) for operation
  extensions is Expert Review.  The IANA policy for vendor operation
  extensions (values 0x4000 to 0x7fff) is First Come First Served.
  Only operation codes in the range of 0x0000 to 0x3fff can be
  registered in the IANA IPP registry.

  For vendor operation extensions, implementors MUST use values in the
  reserved integer range, which is 0x4000 to 0x7fff.  Implementors
  SHOULD consult with the IPP Designated Expert(s) to reserve vendor
  extension value(s) for their usage.

  For registered operation extensions, the IPP Designated Expert(s), in
  consultation with IANA, assigns the next "operation-id" code as
  specified in Section 5.4.15.

















Sweet & McDonald             Standards Track                  [Page 177]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


7.9.  Status-Code Extensibility

  The IANA policy (using terms defined in [RFC5226]) for status-code
  extensions is Expert Review.  The IANA policy for vendor status-code
  extensions (codes 0x0n80 to 0x0nff, for n = 0 to 5) is First Come
  First Served.  Only status-code values in the range of 0x0n00 to
  0x0n7f can be registered in the IANA IPP registry.

  The status-code values are allocated in ranges as specified in
  Appendix B for each status-code class:

  "informational" - Request received, continuing process

  "successful" - The action was successfully received, understood, and
  accepted

  "redirection" - Further action is taken in order to complete the
  request

  "client-error" - The request contains bad syntax or cannot be
  fulfilled

  "server-error" - The IPP object failed to fulfill an apparently valid
  request

  For vendor operation status-code extensions, implementors MUST use
  the top of each range (0x0n80 to 0x0nff) as specified in Appendix B.
  Implementors SHOULD consult with the IPP Designated Expert(s) to
  reserve vendor extension value(s) for their usage.

  For registered operation status-code values, the IPP Designated
  Expert(s), in consultation with IANA, assigns the next status-code in
  the appropriate class range as specified in Appendix B.


















Sweet & McDonald             Standards Track                  [Page 178]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


8.  Internationalization Considerations

  Some of the attributes have values that are text strings and names
  that are intended for human understanding rather than machine
  understanding (see the 'text' and 'name' attribute syntaxes in
  Sections 5.1.2 and 5.1.3).

  In each operation request, the Client

  o  identifies the charset and natural language of the request that
     affects each supplied 'text' and 'name' attribute value, and

  o  requests the charset and natural language for attributes returned
     by the IPP object in operation responses (as described in
     Section 4.1.4.1).

  In addition, the Client MAY separately and individually identify the
  Natural Language Override of a supplied 'text' or 'name' attribute
  using the 'textWithLanguage' and 'nameWithLanguage' techniques
  described in Sections 5.1.2.2 and 5.1.3.2, respectively.

  All IPP objects MUST support the UTF-8 [RFC3629] charset in all
  'text' and 'name' attributes supported.  If an IPP object supports
  more than the UTF-8 charset, the object MUST convert between them in
  order to return the requested charset to the Client according to
  Section 4.1.4.2.  If an IPP object supports more than one natural
  language, the object SHOULD return 'text' and 'name' values in the
  natural language requested where those values are generated by the
  Printer (see Section 4.1.4.1).

  For Printers that support multiple charsets and/or multiple natural
  languages in 'text' and 'name' attributes, different Jobs might have
  been submitted in differing charsets and/or natural languages.  All
  responses MUST be returned in the charset requested by the Client.
  However, the Get-Jobs operation uses the 'textWithLanguage' and
  'nameWithLanguage' mechanisms to identify the differing natural
  languages with each Job attribute returned.

  The Printer also has configured charset and natural language
  attributes.  The Client can query the Printer to determine the list
  of charsets and natural languages supported by the Printer and what
  the Printer's configured values are.  See the "charset-configured",
  "charset-supported", "natural-language-configured", and
  "generated-natural-language-supported" Printer Description attributes
  for more details.






Sweet & McDonald             Standards Track                  [Page 179]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  The "charset-supported" attribute identifies the supported charsets.
  If a charset is supported, the IPP object MUST be capable of
  converting to and from that charset into any other supported charset.
  In many cases, an IPP object will support only one charset, and it
  MUST be the UTF-8 charset.

  The "charset-configured" attribute identifies the one supported
  charset that is the native charset, given the current configuration
  of the IPP object (Administrator defined).

  The "generated-natural-language-supported" attribute identifies the
  set of supported natural languages for generated messages; it is not
  related to the set of natural languages that MUST be accepted for
  Client-supplied 'text' and 'name' attributes.  For Client-supplied
  'text' and 'name' attributes, an IPP object MUST accept ALL supplied
  natural languages.  For example, if a Client supplies a Job name that
  is in 'fr-ca' but the Printer only generates 'en-us', the Printer
  object MUST still accept the Job name value.

  The "natural-language-configured" attribute identifies the one
  supported natural language for generated messages that is the native
  natural language, given the current configuration of the IPP object
  (Administrator defined).

  Attributes of types 'text' and 'name' are populated from different
  sources.  These attributes can be categorized into the following
  groups (depending on the source of the attribute):

  1.  Some attributes are supplied by the Client (e.g., the
      Client-supplied "job-name", "document-name", and
      "requesting-user-name" operation attributes along with the
      corresponding Job's "job-name" and "job-originating-user-name"
      attributes).  The IPP object MUST accept these attributes in any
      natural language no matter what the set of supported languages
      for generated messages.

  2.  Some attributes are supplied by the Administrator (e.g., the
      Printer's "printer-name" and "printer-location" attributes).
      These can also be in any natural language.  If the natural
      language for these attributes is different than what a Client
      requests, then they MUST be reported using the Natural Language
      Override mechanism.









Sweet & McDonald             Standards Track                  [Page 180]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  3.  Some attributes are supplied by the device manufacturer (e.g.,
      the Printer's "printer-make-and-model" attribute).  These can
      also be in any natural language.  If the natural language for
      these attributes is different than what a Client requests, then
      they MUST be reported using the Natural Language Override
      mechanism.

  4.  Some attributes are supplied by the Operator (e.g., the Job's
      "job-message-from-operator" attribute).  These can also be in any
      natural language.  If the natural language for these attributes
      is different than what a Client requests, then they MUST be
      reported using the Natural Language Override mechanism.

  5.  Some attributes are generated by the IPP object (e.g., the Job's
      "job-state-message" attribute, the Printer's
      "printer-state-message" attribute, and the "status-message"
      operation attribute).  These attributes can only be in one of the
      "generated-natural-language-supported" natural languages.  If a
      Client requests some natural language for these attributes other
      than one of the supported values, the IPP object SHOULD respond
      using the value of the "natural-language-configured" attribute
      (using the Natural Language Override mechanism if needed).

  The 'text' and 'name' attributes specified in this version of this
  document (additional ones will be registered according to the
  procedures in Section 7) are shown in Table 22.

  +-----------------------------------+-------------------------------+
  | Attributes                        | Source                        |
  +-----------------------------------+-------------------------------+
  | Operation Attributes:             |                               |
  |                                   |                               |
  | job-name (name)                   | Client                        |
  | document-name (name)              | Client                        |
  | requesting-user-name (name)       | Client                        |
  | status-message (text)             | Job or Printer                |
  | detailed-status-message (text)    | Job or Printer (note 1)       |
  | document-access-error (text)      | Job or Printer (note 1)       |
  |                                   |                               |
  | Job Template Attributes:          |                               |
  |                                   |                               |
  | job-hold-until (keyword | name)   | Client matches Administrator- |
  |                                   | configured                    |
  | job-hold-until-default (keyword | | Client matches Administrator- |
  | name)                             | configured                    |
  | job-hold-until-supported (keyword | Client matches Administrator- |
  | | name)                           | configured                    |




Sweet & McDonald             Standards Track                  [Page 181]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  | job-sheets (keyword | name)       | Client matches Administrator- |
  |                                   | configured                    |
  | job-sheets-default (keyword |     | Client matches Administrator- |
  | name)                             | configured                    |
  | job-sheets-supported (keyword |   | Client matches Administrator- |
  | name)                             | configured                    |
  | media (keyword | name)            | Client matches Administrator- |
  |                                   | configured                    |
  | media-default (keyword | name)    | Client matches Administrator- |
  |                                   | configured                    |
  | media-supported (keyword | name)  | Client matches Administrator- |
  |                                   | configured                    |
  | media-ready (keyword | name)      | Client matches Administrator- |
  |                                   | configured                    |
  |                                   |                               |
  | Job Description Attributes:       |                               |
  |                                   |                               |
  | job-name (name)                   | Client or Printer             |
  | job-originating-user-name (name)  | Printer                       |
  | job-state-message (text)          | Job or Printer                |
  | output-device-assigned            | Administrator                 |
  | (name(127))                       |                               |
  | job-message-from-operator         | Operator                      |
  | (text(127))                       |                               |
  | job-detailed-status-messages      | Job or Printer (note 1)       |
  | (1setOf text)                     |                               |
  | job-document-access-errors        | Job or Printer (note 1)       |
  | (1setOf text)                     |                               |
  |                                   |                               |
  | Printer Description Attributes:   |                               |
  |                                   |                               |
  | printer-name (name(127))          | Administrator                 |
  | printer-location (text(127))      | Administrator                 |
  | printer-info (text(127))          | Administrator                 |
  | printer-make-and-model            | Administrator or manufacturer |
  | (text(127))                       |                               |
  | printer-state-message (text)      | Printer                       |
  | printer-message-from-operator     | Operator                      |
  | (text(127))                       |                               |
  +-----------------------------------+-------------------------------+

                 Table 22: 'text' and 'name' Attributes

  Note 1: Neither the Printer nor the Client localizes these message
  attributes, since they are intended for use by the Administrator or
  other experienced technical persons.





Sweet & McDonald             Standards Track                  [Page 182]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


9.  Security Considerations

  It is difficult to anticipate the security risks that might exist in
  any given IPP environment.  For example, if IPP is used within a
  given small business over a private LAN with physical security, the
  risks of exposing Document data can be low enough that the business
  will choose not to use encryption on that data.  However, if the
  connection between the Client and the IPP object is over a public
  network, the Client can protect the content of the information during
  transmission through the network with encryption.

  Furthermore, the value of the information being printed can vary from
  one IPP environment to the next.  Printing payroll checks, for
  example, would have a different value than printing public
  information from a file.  There is also the possibility of denial-of-
  service attacks, but denial-of-service attacks against printing
  resources are not well understood, and there are no published
  precedents regarding this scenario.

  Once the authenticated identity of the requester has been supplied to
  the IPP object, the object uses that identity to enforce any
  authorization policy that might be in place.  For example, one site's
  policy might be that only the Job owner is allowed to cancel a Job.
  The details and mechanisms to set up a particular access control
  policy are not part of this document and are typically established
  via some other type of administrative or access control framework.
  However, there are operation status-code values that allow an IPP
  server to return information back to a Client about any potential
  access control violations for an IPP object.

  During a Job Creation request, the Client's identity is recorded in
  the Job object in an implementation-defined attribute.  This
  information can be used to verify a Client's identity for subsequent
  operations on that Job object in order to enforce any access control
  policy that might be in effect.  See Section 9.3 below for more
  details.  This and other information stored in the Job object can
  also be considered personal or sensitive in nature and can be
  filtered out as part of a configured privacy policy (Section 9.4).

  Since the security levels or the specific threats that an
  Administrator can be concerned with cannot be anticipated, IPP
  implementations MUST be capable of operating with different security
  mechanisms and security policies as required by the individual
  installation.  Security policies might vary from very strong to very
  weak, or to none at all, and corresponding security mechanisms will
  be required.





Sweet & McDonald             Standards Track                  [Page 183]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


9.1.  Security Scenarios

  The following sections describe specific security attacks for IPP
  environments.  Where examples are provided, they are illustrative of
  the environment and not an exhaustive set.

9.1.1.  Client and Server in the Same Security Domain

  This environment is typical of internal networks where traditional
  office workers print the output of personal productivity applications
  on shared workgroup Printers, or where batch applications print their
  output on large production Printers.  Although the identity of the
  user has been authenticated and can be trusted in this environment, a
  user might want to protect the content of a Document against such
  attacks as eavesdropping, replaying, or tampering by using a secure
  transport such as TLS [RFC5246].

9.1.2.  Client and Server in Different Security Domains

  Examples of this environment include printing a Document created by
  the Client on a publicly available Printer, such as at a commercial
  print shop, or printing a Document remotely on a business associate's
  Printer.  This latter operation is functionally equivalent to sending
  the Document to the business associate as a facsimile.  Printing
  sensitive information on a Printer in a different security domain
  requires strong security measures.  In this environment,
  authentication of the Printer is required as well as protection
  against unauthorized use of print resources.  Since the Document
  crosses security domains, protection against eavesdropping and
  Document tampering is also required.  It will also be important in
  this environment to protect Printers against "spamming" and malicious
  Document content -- authentication and Document data pre-scanning can
  be used to minimize those threats.

9.1.3.  Print by Reference

  When the Document is not stored on the Client, printing can be done
  by reference.  That is, the print request can contain a reference, or
  pointer, to the Document instead of the actual Document itself -- see
  Sections 4.2.2 and 4.3.2.  Standard methods currently do not exist
  for remote entities to "assume" the credentials of a Client for
  forwarding requests to a third party.  It is anticipated that print
  by reference will be used to access "public" Documents.  Note that
  sophisticated methods for authenticating "proxies" are beyond the
  scope of this IPP/1.1 document.  Because Printers typically process
  Jobs serially, print by reference is not seen as a serious denial-of-
  service threat to the referenced servers.




Sweet & McDonald             Standards Track                  [Page 184]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


9.2.  URIs in Operation, Job, and Printer Attributes

  The "printer-uri-supported" attribute contains the Printer's URI(s).
  Its companion attribute, "uri-security-supported", identifies the
  security mechanism used for each URI listed in the
  "printer-uri-supported" attribute.  For each Printer operation
  request, a Client MUST supply only one URI in the "printer-uri"
  operation attribute.  In other words, even though the Printer
  supports more than one URI, the Client only interacts with the
  Printer using one of its URIs.  This duality is not needed for Job
  objects, since Printers will act as the "factory" for Job objects and
  a given Printer will, depending on the Printer's security
  configuration, generate the correct URI for new Job objects.

9.3.  URIs for Each Authentication Mechanism

  Each URI has an authentication mechanism associated with it.  If the
  URI is the "i-th" element of "printer-uri-supported", then the
  authentication mechanism is the "i-th" element of
  "uri-authentication-supported".  For a list of possible
  authentication mechanisms, see Section 5.4.2.

  The Printer uses an authentication mechanism to determine the name of
  the user performing an operation.  This user is called the
  "authenticated user".  The credibility of authentication depends on
  the mechanism that the Printer uses to obtain the user's name.  When
  the authentication mechanism is 'none', all authenticated users are
  'anonymous'.

  During Job Creation requests, the Printer initializes the value of
  the "job-originating-user-name" attribute (see Section 5.3.6) to be
  the authenticated user.  The authenticated user in this case is
  called the "Job owner".

  If an implementation can be configured to support more than one
  authentication mechanism (see Section 5.4.2), then it MUST implement
  rules for determining equality of authenticated user names that have
  been authenticated via different authentication mechanisms.  One
  possible policy is that identical names that are authenticated via
  different mechanisms are different.  For example, a user can cancel
  his Job only if he uses the same authentication mechanism for both
  Cancel-Job and Print-Job.  Another policy is that identical names
  that are authenticated via different mechanisms are the same if the
  authentication mechanism for the later operation is not less strong
  than the authentication mechanism for the earlier Job Creation
  operation.  For example, a user can cancel his Job only if he uses
  the same or stronger authentication mechanism for Cancel-Job and
  Print-Job.  With this second policy, a Job submitted via



Sweet & McDonald             Standards Track                  [Page 185]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  'requesting-user-name' authentication could be canceled via 'digest'
  authentication.  With the first policy, the Job could not be canceled
  in this way.

  A Client is able to determine the authentication mechanism used to
  create a Job.  It is the "i-th" value of the Printer's
  "uri-authentication-supported" attribute (see Section 5.4.2),
  where "i" is the index of the element of the Printer's
  "printer-uri-supported" attribute (see Section 5.4.1) equal to the
  Job's "job-printer-uri" attribute (see Section 5.3.3).

9.4.  Restricted Queries

  In many IPP operations, a Client supplies a list of attributes to be
  returned in the response.  For security reasons, an IPP object can be
  configured not to return all attributes (or all values) that a Client
  requests.  The Job attributes returned MAY depend on whether the
  requesting user is the same as the user that submitted the Job.  The
  IPP object MAY even return none of the requested attributes.  In such
  cases, the status returned is the same as if the object had returned
  all requested attributes.  The Client cannot tell by such a response
  whether the requested attribute was present or absent in the object.

9.5.  Operations Performed by Operators and Administrators

  For the three Printer operations Pause-Printer, Resume-Printer, and
  Purge-Jobs (see Sections 4.2.7, 4.2.8, and 4.2.9), the requesting
  user is intended to be an Operator or Administrator of the Printer
  (see Section 1).  Otherwise, the IPP Printer MUST reject the
  operation and return 'client-error-forbidden',
  'client-error-not-authenticated', or 'client-error-not-authorized'
  as appropriate.  For operations on Jobs, the requesting user is
  intended to be the Job owner or can be an Operator or Administrator
  of the Printer.  The means for authorizing an Operator or
  Administrator of the Printer are not specified in this document.

9.6.  Queries on Jobs Submitted Using Non-IPP Protocols

  If the device that an IPP Printer is representing is able to accept
  Jobs using other Job submission protocols in addition to IPP, such an
  implementation SHOULD at least allow such "foreign" Jobs to be
  queried using Get-Jobs returning "job-id" and "job-uri" as 'unknown'.
  Such an implementation MAY support all of the same IPP Job attributes
  as for IPP Jobs.  The IPP object returns the 'unknown' out-of-band
  value for any requested attribute of a foreign Job that is supported
  for IPP Jobs but not for foreign Jobs.





Sweet & McDonald             Standards Track                  [Page 186]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  IPP Printers SHOULD also generate "job-id" and "job-uri" values for
  such foreign Jobs, if possible, so that they can be targets of other
  IPP operations, such as Get-Job-Attributes and Cancel-Job.  Such an
  implementation also needs to deal with the problem of authentication
  of such foreign Jobs.  One approach would be to treat all such
  foreign Jobs as belonging to users other than the user of the IPP
  Client.  Another approach would be for the foreign Job to belong to
  'anonymous' -- then only authenticated Operators or Administrators of
  the IPP Printer could query the foreign Jobs with an IPP request.
  Alternatively, if the security policy is to allow users to query
  other users' Jobs, then the foreign Jobs would also be visible to an
  End User IPP Client using Get-Jobs and Get-Job-Attributes.

10.  Changes since RFC 2911

  The following changes have been made since RFC 2911:

  o  Errata ID 364: Fixed range of "redirection" status-code values (to
     0x03xx).

  o  Errata ID 694: Fixed range of vendor status-code values (0x0n80 to
     0x0nff).

  o  Errata ID 3072: Reworded multiple-document-handling definition,
     since it also applies to Jobs with a single Document and is the
     only interoperable way to request uncollated copies.

  o  Errata ID 3365: Fixed bad 'nameWithLanguage' maximum length by
     referencing the 'nameWithoutLanguage' section (i.e.,
     Section 5.1.3.1).

  o  Errata ID 4173: Fixed range of vendor operation codes (0x4000 to
     0x7fff).

  o  Updated obsoleted RFC references.

  o  Changed the IPP/1.1 Implementor's Guide reference to RFC 3196.

  o  Updated Create-Job, Send-Document, and Send-URI to RECOMMENDED.

  o  Incorporated 'collection' attribute content from RFC 3382.

  o  Obsoleted all attributes and values defined in RFC 3381, as they
     do not interact well with the "finishings" attribute and have
     never been widely implemented.

  o  Deprecated the Purge-Jobs and Restart-Job operations, which
     destroy accounting information.



Sweet & McDonald             Standards Track                  [Page 187]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  o  Dropped type3 registration procedures.

  o  Changed the vendor attribute and keyword naming recommendations to
     use SMI Private Enterprise Numbers ("smiNNN-foo") instead of
     domain names.

  o  Split READ-ONLY Job Description and Printer Description attributes
     into Job Status and Printer Status attributes to match the current
     IANA IPP registry organization.

  o  Referenced all IETF and PWG IPP standards.

  o  Updated OPTIONAL operations, attributes, and values to RECOMMENDED
     for consistency with IPP 2.0, IPP Everywhere, and the IPP
     Implementor's Guide v2.0.

  o  Removed the appendix on media names.  Readers are directed to
     "PWG Media Standardized Names 2.0 (MSN2)" [PWG5101.1].

11.  References

11.1.  Normative References

  [ASME-Y14.1M]
             ASME Y14.1M-2012, "Metric Drawing Sheet Size and Format",
             March 2013.

  [ISO10175] ISO/IEC 10175, "Information technology -- Text and office
             systems -- Document Printing Application (DPA) -- Part 1:
             Abstract service definition and procedures",
             September 1996.

  [ISO10646] ISO/IEC 10646:2014, JTC1/SC2, "Information technology --
             Universal Coded Character Set (UCS)", September 2014.

  [ISO8859-1]
             ISO/IEC 8859-1:1998, "Information technology -- 8-bit
             single-byte coded graphic character sets -- Part 1: Latin
             alphabet No. 1", April 1998.

  [PWG5100.1]
             Sweet, M., "IPP Finishings 2.0 (FIN)", December 2014,
             <http://ftp.pwg.org/pub/pwg/candidates/
             cs-ippfinishings20-20141219-5100.1.pdf>.







Sweet & McDonald             Standards Track                  [Page 188]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  [PWG5100.11]
             Hastings, T. and D. Fullman, "Internet Printing Protocol
             (IPP): Job and Printer Extensions -- Set 2 (JPS2)",
             October 2010, <http://ftp.pwg.org/pub/pwg/candidates/
             cs-ippjobprinterext10-20101030-5100.11.pdf>.

  [PWG5100.12]
             Sweet, M. and I. McDonald, "IPP Version 2.0, 2.1, and
             2.2", October 2015, <http://ftp.pwg.org/pub/pwg/standards/
             std-ipp20-20151030-5100.12.pdf>.

  [PWG5100.13]
             Sweet, M., McDonald, I., and P. Zehler, "IPP: Job and
             Printer Extensions -- Set 3 (JPS3)", July 2012,
             <http://ftp.pwg.org/pub/pwg/candidates/
             cs-ippjobprinterext3v10-20120727-5100.13.pdf>.

  [PWG5100.14]
             Sweet, M., McDonald, I., Mitchell, A., and J. Hutchings,
             "IPP Everywhere", January 2013,
             <http://ftp.pwg.org/pub/pwg/candidates/
             cs-ippeve10-20130128-5100.14.pdf>.

  [PWG5100.15]
             Sweet, M., "IPP FaxOut Service", June 2014,
             <http://ftp.pwg.org/pub/pwg/candidates/
             cs-ippfaxout10-20140618-5100.15.pdf>.

  [PWG5100.16]
             Sweet, M., "IPP Transaction-Based Printing Extensions",
             November 2013, <http://ftp.pwg.org/pub/pwg/candidates/
             cs-ipptrans10-20131108-5100.16.pdf>.

  [PWG5100.17]
             Zehler, P. and M. Sweet, "IPP Scan Service (SCAN)",
             September 2014, <http://ftp.pwg.org/pub/pwg/candidates/
             cs-ippscan10-20140918-5100.17.pdf>.

  [PWG5100.18]
             Sweet, M. and I. McDonald, "IPP Shared Infrastructure
             Extensions (INFRA)", June 2015,
             <http://ftp.pwg.org/pub/pwg/candidates/
             cs-ippinfra10-20150619-5100.18.pdf>.

  [PWG5100.19]
             Kennedy, S., "IPP Implementor's Guide v2.0 (IG)",
             August 2015, <http://ftp.pwg.org/pub/pwg/candidates/
             cs-ippig20-20150821-5100.19.pdf>.



Sweet & McDonald             Standards Track                  [Page 189]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  [PWG5100.2]
             Hastings, T. and R. Bergman, "Internet Printing Protocol
             (IPP): "output-bin" attribute extension", February 2001,
             <http://ftp.pwg.org/pub/pwg/candidates/
             cs-ippoutputbin10-20010207-5100.2.pdf>.

  [PWG5100.3]
             Ocke, K. and T. Hastings, "Internet Printing Protocol
             (IPP): Production Printing Attributes -- Set1",
             February 2001, <http://ftp.pwg.org/pub/pwg/candidates/
             cs-ippprodprint10-20010212-5100.3.pdf>.

  [PWG5100.5]
             Carney, D., Hastings, T., and P. Zehler, "Standard for The
             Internet Printing Protocol (IPP): Document Object",
             October 2003, <http://ftp.pwg.org/pub/pwg/candidates/
             cs-ippdocobject10-20031031-5100.5.pdf>.

  [PWG5100.6]
             Zehler, P., Herriot, R., and K. Ocke, "Standard for The
             Internet Printing Protocol (IPP): Page Overrides",
             October 2003, <http://ftp.pwg.org/pub/pwg/candidates/
             cs-ipppageoverride10-20031031-5100.6.pdf>.

  [PWG5100.7]
             Hastings, T. and P. Zehler, "Standard for The Internet
             Printing Protocol (IPP): Job Extensions", October 2003,
             <http://ftp.pwg.org/pub/pwg/candidates/
             cs-ippjobext10-20031031-5100.7.pdf>.

  [PWG5100.8]
             Carney, D. and H. Lewis, "Standard for Internet Printing
             Protocol (IPP): "-actual" attributes", March 2003,
             <http://ftp.pwg.org/pub/pwg/candidates/
             cs-ippactuals10-20030313-5100.8.pdf>.

  [PWG5100.9]
             McDonald, I. and C. Whittle, "Internet Printing Protocol
             (IPP): Printer State Extensions v1.0", July 2009,
             <http://ftp.pwg.org/pub/pwg/candidates/
             cs-ippstate10-20090731-5100.9.pdf>.

  [PWG5101.1]
             Sweet, M., Bergman, R., and T. Hastings, "PWG Media
             Standardized Names 2.0 (MSN2)", March 2013,
             <http://ftp.pwg.org/pub/pwg/candidates/
             cs-pwgmsn20-20130328-5101.1.pdf>.




Sweet & McDonald             Standards Track                  [Page 190]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  [RFC20]    Cerf, V., "ASCII format for network interchange", STD 80,
             RFC 20, DOI 10.17487/RFC0020, October 1969,
             <http://www.rfc-editor.org/info/rfc20>.

  [RFC793]   Postel, J., "Transmission Control Protocol", STD 7,
             RFC 793, DOI 10.17487/RFC0793, September 1981,
             <http://www.rfc-editor.org/info/rfc793>.

  [RFC1035]  Mockapetris, P., "Domain names - implementation and
             specification", STD 13, RFC 1035, DOI 10.17487/RFC1035,
             November 1987, <http://www.rfc-editor.org/info/rfc1035>.

  [RFC1951]  Deutsch, P., "DEFLATE Compressed Data Format Specification
             version 1.3", RFC 1951, DOI 10.17487/RFC1951, May 1996,
             <http://www.rfc-editor.org/info/rfc1951>.

  [RFC1952]  Deutsch, P., "GZIP file format specification version 4.3",
             RFC 1952, DOI 10.17487/RFC1952, May 1996,
             <http://www.rfc-editor.org/info/rfc1952>.

  [RFC1977]  Schryver, V., "PPP BSD Compression Protocol", RFC 1977,
             DOI 10.17487/RFC1977, August 1996,
             <http://www.rfc-editor.org/info/rfc1977>.

  [RFC2046]  Freed, N. and N. Borenstein, "Multipurpose Internet Mail
             Extensions (MIME) Part Two: Media Types", RFC 2046,
             DOI 10.17487/RFC2046, November 1996,
             <http://www.rfc-editor.org/info/rfc2046>.

  [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
             Requirement Levels", BCP 14, RFC 2119,
             DOI 10.17487/RFC2119, March 1997,
             <http://www.rfc-editor.org/info/rfc2119>.

  [RFC2818]  Rescorla, E., "HTTP Over TLS", RFC 2818,
             DOI 10.17487/RFC2818, May 2000,
             <http://www.rfc-editor.org/info/rfc2818>.

  [RFC3196]  Hastings, T., Manros, C., Zehler, P., Kugler, C., and H.
             Holst, "Internet Printing Protocol/1.1: Implementor's
             Guide", RFC 3196, DOI 10.17487/RFC3196, November 2001,
             <http://www.rfc-editor.org/info/rfc3196>.

  [RFC3380]  Hastings, T., Herriot, R., Kugler, C., and H. Lewis,
             "Internet Printing Protocol (IPP): Job and Printer Set
             Operations", RFC 3380, DOI 10.17487/RFC3380,
             September 2002, <http://www.rfc-editor.org/info/rfc3380>.




Sweet & McDonald             Standards Track                  [Page 191]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  [RFC3510]  Herriot, R. and I. McDonald, "Internet Printing
             Protocol/1.1: IPP URL Scheme", RFC 3510,
             DOI 10.17487/RFC3510, April 2003,
             <http://www.rfc-editor.org/info/rfc3510>.

  [RFC3629]  Yergeau, F., "UTF-8, a transformation format of
             ISO 10646", STD 63, RFC 3629, DOI 10.17487/RFC3629,
             November 2003, <http://www.rfc-editor.org/info/rfc3629>.

  [RFC3805]  Bergman, R., Lewis, H., and I. McDonald, "Printer MIB v2",
             RFC 3805, DOI 10.17487/RFC3805, June 2004,
             <http://www.rfc-editor.org/info/rfc3805>.

  [RFC3986]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
             Resource Identifier (URI): Generic Syntax", STD 66,
             RFC 3986, DOI 10.17487/RFC3986, January 2005,
             <http://www.rfc-editor.org/info/rfc3986>.

  [RFC3995]  Herriot, R. and T. Hastings, "Internet Printing Protocol
             (IPP): Event Notifications and Subscriptions", RFC 3995,
             DOI 10.17487/RFC3995, March 2005,
             <http://www.rfc-editor.org/info/rfc3995>.

  [RFC3996]  Herriot, R., Hastings, T., and H. Lewis, "Internet
             Printing Protocol (IPP): The 'ippget' Delivery Method for
             Event Notifications", RFC 3996, DOI 10.17487/RFC3996,
             March 2005, <http://www.rfc-editor.org/info/rfc3996>.

  [RFC3998]  Kugler, C., Lewis, H., and T. Hastings, Ed., "Internet
             Printing Protocol (IPP): Job and Printer Administrative
             Operations", RFC 3998, DOI 10.17487/RFC3998, March 2005,
             <http://www.rfc-editor.org/info/rfc3998>.

  [RFC5051]  Crispin, M., "i;unicode-casemap - Simple Unicode Collation
             Algorithm", RFC 5051, DOI 10.17487/RFC5051, October 2007,
             <http://www.rfc-editor.org/info/rfc5051>.

  [RFC5234]  Crocker, D., Ed., and P. Overell, "Augmented BNF for
             Syntax Specifications: ABNF", STD 68, RFC 5234,
             DOI 10.17487/RFC5234, January 2008,
             <http://www.rfc-editor.org/info/rfc5234>.

  [RFC5246]  Dierks, T. and E. Rescorla, "The Transport Layer Security
             (TLS) Protocol Version 1.2", RFC 5246,
             DOI 10.17487/RFC5246, August 2008,
             <http://www.rfc-editor.org/info/rfc5246>.





Sweet & McDonald             Standards Track                  [Page 192]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  [RFC5646]  Phillips, A., Ed., and M. Davis, Ed., "Tags for
             Identifying Languages", BCP 47, RFC 5646,
             DOI 10.17487/RFC5646, September 2009,
             <http://www.rfc-editor.org/info/rfc5646>.

  [RFC6838]  Freed, N., Klensin, J., and T. Hansen, "Media Type
             Specifications and Registration Procedures", BCP 13,
             RFC 6838, DOI 10.17487/RFC6838, January 2013,
             <http://www.rfc-editor.org/info/rfc6838>.

  [RFC7230]  Fielding, R., Ed., and J. Reschke, Ed., "Hypertext
             Transfer Protocol (HTTP/1.1): Message Syntax and Routing",
             RFC 7230, DOI 10.17487/RFC7230, June 2014,
             <http://www.rfc-editor.org/info/rfc7230>.

  [RFC7472]  McDonald, I. and M. Sweet, "Internet Printing Protocol
             (IPP) over HTTPS Transport Binding and the 'ipps' URI
             Scheme", RFC 7472, DOI 10.17487/RFC7472, March 2015,
             <http://www.rfc-editor.org/info/rfc7472>.

  [RFC7612]  Fleming, P. and I. McDonald, "Lightweight Directory Access
             Protocol (LDAP): Schema for Printer Services", RFC 7612,
             DOI 10.17487/RFC7612, June 2015,
             <http://www.rfc-editor.org/info/rfc7612>.

  [RFC7616]  Shekh-Yusef, R., Ed., Ahrens, D., and S. Bremer, "HTTP
             Digest Access Authentication", RFC 7616,
             DOI 10.17487/RFC7616, September 2015,
             <http://www.rfc-editor.org/info/rfc7616>.

  [RFC7617]  Reschke, J., "The 'Basic' HTTP Authentication Scheme",
             RFC 7617, DOI 10.17487/RFC7617, September 2015,
             <http://www.rfc-editor.org/info/rfc7617>.

  [RFC8010]  Sweet, M. and I. McDonald, "Internet Printing
             Protocol/1.1: Encoding and Transport", RFC 8010,
             DOI 10.17487/RFC8010, January 2017,
             <http://www.rfc-editor.org/info/rfc8010>.













Sweet & McDonald             Standards Track                  [Page 193]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


11.2.  Informative References

  [HTPP]     Barnett, J., Carter, K., and R. deBry, "Internet Print
             Protocol Proposal: HTPP -- Hypertext Print Protocol
             (HTPP/1.0 Initial Draft)", October 1996,
             <ftp://ftp.pwg.org/pub/pwg/ipp/historic/htpp/
             overview.ps.gz>.

  [IANA-CS]  IANA, "Registry of Coded Character Sets",
             <http://www.iana.org/assignments/character-sets/>.

  [IANA-MT]  IANA, "Media Types",
             <http://www.iana.org/assignments/media-types/>.

  [IANA-PEN]
             IANA, "Private Enterprise Numbers",
             <http://www.iana.org/assignments/enterprise-numbers/>.

  [ISO32000] "Document management -- Portable document format --
             Part 1: PDF 1.7", July 2008, <http://www.adobe.com/
             devnet/acrobat/pdfs/PDF32000_2008.pdf>.

  [LDPA]     Isaacson, S., Taylor, D., MacKay, M., Zehler, P.,
             Hastings, T., and C. Manros, "LDPA - Lightweight Document
             Printing Application", Proposed Internet-Draft,
             October 1996, <ftp://ftp.pwg.org/pub/pwg/ipp/
             historic/ldpa/ldpa8.pdf.gz>.

  [P1387.4]  Kirk, M., "POSIX Systems Administration - Part 4: Printing
             Interfaces, POSIX 1387.4 D8", 1998.

  [PSIS]     Herriot, R., Ed., "X/Open: A Printing System
             Interoperability Specification (PSIS)", August 1995.

  [PWG-IPP-WG]
             IEEE-ISTO Printer Working Group, "Internet Printing
             Protocol Workgroup", <http://www.pwg.org/ipp>.

  [RFC959]   Postel, J. and J. Reynolds, "File Transfer Protocol",
             STD 9, RFC 959, DOI 10.17487/RFC0959, October 1985,
             <http://www.rfc-editor.org/info/rfc959>.

  [RFC1179]  McLaughlin, L., "Line printer daemon protocol", RFC 1179,
             DOI 10.17487/RFC1179, August 1990,
             <http://www.rfc-editor.org/info/rfc1179>.






Sweet & McDonald             Standards Track                  [Page 194]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  [RFC1738]  Berners-Lee, T., Masinter, L., and M. McCahill, "Uniform
             Resource Locators (URL)", RFC 1738, DOI 10.17487/RFC1738,
             December 1994, <http://www.rfc-editor.org/info/rfc1738>.

  [RFC2565]  Herriot, R., Ed., Butler, S., Moore, P., and R. Turner,
             "Internet Printing Protocol/1.0: Encoding and Transport",
             RFC 2565, DOI 10.17487/RFC2565, April 1999,
             <http://www.rfc-editor.org/info/rfc2565>.

  [RFC2566]  deBry, R., Hastings, T., Herriot, R., Isaacson, S., and P.
             Powell, "Internet Printing Protocol/1.0: Model and
             Semantics", RFC 2566, DOI 10.17487/RFC2566, April 1999,
             <http://www.rfc-editor.org/info/rfc2566>.

  [RFC2567]  Wright, F., "Design Goals for an Internet Printing
             Protocol", RFC 2567, DOI 10.17487/RFC2567, April 1999,
             <http://www.rfc-editor.org/info/rfc2567>.

  [RFC2568]  Zilles, S., "Rationale for the Structure of the Model and
             Protocol for the Internet Printing Protocol", RFC 2568,
             DOI 10.17487/RFC2568, April 1999,
             <http://www.rfc-editor.org/info/rfc2568>.

  [RFC2569]  Herriot, R., Ed., Hastings, T., Jacobs, N., and J. Martin,
             "Mapping between LPD and IPP Protocols", RFC 2569,
             DOI 10.17487/RFC2569, April 1999,
             <http://www.rfc-editor.org/info/rfc2569>.

  [RFC2579]  McCloghrie, K., Ed., Perkins, D., Ed., and J.
             Schoenwaelder, Ed., "Textual Conventions for SMIv2",
             STD 58, RFC 2579, DOI 10.17487/RFC2579, April 1999,
             <http://www.rfc-editor.org/info/rfc2579>.

  [RFC2978]  Freed, N. and J. Postel, "IANA Charset Registration
             Procedures", BCP 19, RFC 2978, DOI 10.17487/RFC2978,
             October 2000, <http://www.rfc-editor.org/info/rfc2978>.

  [RFC3239]  Kugler, C., Lewis, H., and T. Hastings, "Internet Printing
             Protocol (IPP): Requirements for Job, Printer, and Device
             Administrative Operations", RFC 3239,
             DOI 10.17487/RFC3239, February 2002,
             <http://www.rfc-editor.org/info/rfc3239>.

  [RFC3997]  Hastings, T., Ed., deBry, R., and H. Lewis, "Internet
             Printing Protocol (IPP): Requirements for IPP
             Notifications", RFC 3997, DOI 10.17487/RFC3997,
             March 2005, <http://www.rfc-editor.org/info/rfc3997>.




Sweet & McDonald             Standards Track                  [Page 195]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  [RFC4122]  Leach, P., Mealling, M., and R. Salz, "A Universally
             Unique IDentifier (UUID) URN Namespace", RFC 4122,
             DOI 10.17487/RFC4122, July 2005,
             <http://www.rfc-editor.org/info/rfc4122>.

  [RFC5226]  Narten, T. and H. Alvestrand, "Guidelines for Writing an
             IANA Considerations Section in RFCs", BCP 26, RFC 5226,
             DOI 10.17487/RFC5226, May 2008,
             <http://www.rfc-editor.org/info/rfc5226>.

  [RFC6068]  Duerst, M., Masinter, L., and J. Zawinski, "The 'mailto'
             URI Scheme", RFC 6068, DOI 10.17487/RFC6068, October 2010,
             <http://www.rfc-editor.org/info/rfc6068>.

  [RFC7525]  Sheffer, Y., Holz, R., and P. Saint-Andre,
             "Recommendations for Secure Use of Transport Layer
             Security (TLS) and Datagram Transport Layer Security
             (DTLS)", BCP 195, RFC 7525, DOI 10.17487/RFC7525,
             May 2015, <http://www.rfc-editor.org/info/rfc7525>.

  [SWP]      Moore, P. and S. Butler, "Simple Web Printing (SWP/1.0)",
             May 1997, <ftp://ftp.pwg.org/pub/pwg/ipp/new_PRO/
             swp9705.pdf>.




























Sweet & McDonald             Standards Track                  [Page 196]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


Appendix A.  Formats for IPP Registration Proposals

  In order to propose an IPP extension for registration, the proposer
  must submit an application to IANA by email to "[email protected]" or by
  filling out the appropriate form on the IANA web pages
  (http://www.iana.org).  This section specifies the required
  information and the formats for proposing registrations of extensions
  to IPP as provided in Section 7 for:

  1.  attributes

  2.  type2 'keyword' attribute values

  3.  type2 'enum' attribute values

  4.  operations

  5.  status-code values

A.1.  Attribute Registration

  Type of registration: attribute

  Proposed keyword name of this attribute:

  Types of attributes (Document Description, Document Status, Document
  Template, Event Notifications, Job Description, Job Status, Job
  Template, Operation, Printer Description, Printer Status,
  Subscription Description, Subscription Status, Subscription
  Template):

  Operations to be used if the attribute is an operation attribute:

  Object (Document, Job, Printer, Subscription, etc. if bound to an
  object):

  Attribute syntax(es) (include '1setOf' and range; see Section 5.2):

  If attribute syntax is 'keyword' or 'enum', is it type1 or type2?

  If this is a Printer attribute, MAY the value returned depend on
  "document-format"?  (See Section 7.2.)

  If this is a Job Template attribute, how does its specification
  depend on the value of the "multiple-document-handling" attribute?






Sweet & McDonald             Standards Track                  [Page 197]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  Specification of this attribute (follow the style of Section 5.2):

  Name of proposer:

  Email address of proposer:

  Note: For attributes, the IPP Designated Expert will be the point of
  contact and change controller for the approved registration
  specification, if any maintenance of the registration specification
  is needed.

A.2.  type2 'keyword' Attribute Value Registration

  Type of registration: type2 keyword attribute value

  Name of attribute to which this keyword specification is to be added:

  Proposed keyword name of this 'keyword' value:

  Specification of this 'keyword' value (follow the style of
  Section 5.1.4):

  Name of proposer:

  Email address of proposer:

  Note: For type2 keywords, the Designated Expert will be the point of
  contact and change controller for the approved registration
  specification, if any maintenance of the registration specification
  is needed.

A.3.  type2 'enum' Attribute Value Registration

  Type of registration: type2 enum attribute value

  Name of attribute to which this enum specification is to be added:

  Keyword symbolic name of this enum value:

  Numeric value (to be assigned by the IPP Designated Expert in
  consultation with IANA):

  Specification of this enum value (follow the style of Section 5.1.5):

  Name of proposer:

  Email address of proposer:




Sweet & McDonald             Standards Track                  [Page 198]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  Note: For type2 enums, the Designated Expert will be the point of
  contact and change controller for the approved registration
  specification, if any maintenance of the registration specification
  is needed.

A.4.  Operation Registration

  Type of registration: operation

  Proposed name of this operation:

  Numeric "operation-id" value according to Section 5.4.15 (to be
  assigned by the IPP Designated Expert in consultation with IANA):

  Object Target (Document, Job, Printer, Subscription, etc. that
  operation is upon):

  Specification of this operation (follow the style of Section 4):

  Name of proposer:

  Email address of proposer:

  Note: For operations, the IPP Designated Expert will be the point of
  contact and change controller for the approved registration
  specification, if any maintenance of the registration specification
  is needed.

A.5.  Status-Code Registration

  Type of registration: status-code

  Keyword symbolic name of this status-code value:

  Numeric value (to be assigned by the IPP Designated Expert in
  consultation with IANA):

  Operations that this status-code can be used with:

  Specification of this status-code (follow the style of Appendix B):

  Name of proposer:

  Email address of proposer:







Sweet & McDonald             Standards Track                  [Page 199]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  Note: For status-code values, the Designated Expert will be the point
  of contact and change controller for the approved registration
  specification, if any maintenance of the registration specification
  is needed.

Appendix B.  Status-Code Values and Suggested Status-Code Messages

  This section defines status-code enum keywords and values that are
  used to provide semantic information on the results of an operation
  request.  Each operation response MUST include a status-code.  The
  response MAY also contain a status message that provides a short
  textual description of the status.  The status-code is intended for
  use by automata, and the status message is intended for the human
  End User.

  The prefix of the status keyword defines the class of response as
  follows:

  "informational" - Request received, continuing process

  "successful" - The action was successfully received, understood, and
  accepted

  "redirection" - Further action is taken in order to complete the
  request

  "client-error" - The request contains bad syntax or cannot be
  fulfilled

  "server-error" - The IPP object failed to fulfill an apparently valid
  request

  As with type2 enums, IPP status-code values are extensible.
  Regardless of whether all status-code values are recognized, IPP
  Clients MUST understand the class of any status-code, as indicated by
  the prefix, and treat any unrecognized response as being equivalent
  to the first status-code of that class, with the exception that an
  unrecognized response MUST NOT be cached.  For example, if an
  unrecognized status-code of 'client-error-xxx-yyy' is received by the
  Client, it can safely assume that there was something wrong with its
  request and treat the response as if it had received a
  'client-error-bad-request' status-code.  The name of the enum is the
  suggested status message for US English.

  See [PWG5100.19] for guidelines on presenting status messages to
  End Users.





Sweet & McDonald             Standards Track                  [Page 200]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  The status-code values range from 0x0000 to 0x7fff.  The value ranges
  for each status-code class are as follows:

  "successful" - 0x0000 to 0x00ff

  "informational" - 0x0100 to 0x01ff

  "redirection" - 0x0300 to 0x03ff

  "client-error" - 0x0400 to 0x04ff

  "server-error" - 0x0500 to 0x05ff

  The top half (128 values) of each range (0x0n80 to 0x0nff, for n = 0
  to 5) is reserved for vendor use within each status-code class.
  Values 0x0600 to 0x7fff are reserved for future assignment by
  Standards Track documents and MUST NOT be used.

B.1.  Status-Code Values

  Each status-code is described below.  Appendix B.2 contains a table
  that indicates which status-code values apply to which operations.
  The Implementor's Guides [RFC3196] [PWG5100.19] provide guidance for
  processing IPP attributes for all operations, including status-code
  values.

B.1.1.  Informational

  This class of status-code values indicates a provisional response and
  is to be used for informational purposes only.

  There are no values defined in this document for this class of
  status-code values.

B.1.2.  Successful Status-Code Values

  This class of status-code values indicates that the Client's request
  was successfully received, understood, and accepted.

B.1.2.1.  successful-ok (0x0000)

  The request has succeeded, and no request attributes were substituted
  or ignored.  In the case of a response to a Job Creation request, the
  'successful-ok' status-code indicates that the request was
  successfully received and validated, and that the Job object has been
  created; it does not indicate that the Job has been processed.  The
  transition of the Job object into the 'completed' state is the only
  indicator that the Job has been printed.



Sweet & McDonald             Standards Track                  [Page 201]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


B.1.2.2.  successful-ok-ignored-or-substituted-attributes (0x0001)

  The request has succeeded, but some supplied (1) attributes were
  ignored or (2) unsupported values were substituted with supported
  values or were ignored in order to perform the operation without
  rejecting it.  Unsupported attributes, attribute syntaxes, or values
  MUST be returned in the Unsupported Attributes group of the response
  for all operations.  There is an exception to this rule for the query
  operations Get-Printer-Attributes, Get-Jobs, and Get-Job-Attributes
  for the "requested-attributes" operation attribute only.  When the
  supplied values of the "requested-attributes" operation attribute are
  requesting attributes that are not supported, the IPP object SHOULD
  return the "requested-attributes" operation attribute in the
  Unsupported Attributes group of the response (with the unsupported
  values only).  See Sections 4.1.7 and 4.2.1.2.

B.1.2.3.  successful-ok-conflicting-attributes (0x0002)

  The request has succeeded, but some supplied attribute values
  conflicted with the values of other supplied attributes.  Either
  (1) these conflicting values were substituted with (supported) values
  or (2) the attributes were removed in order to process the Job
  without rejecting it.  Attributes or values that conflict with other
  attributes and have been substituted or ignored MUST be returned in
  the Unsupported Attributes group of the response for all operations
  as supplied by the Client.  See Sections 4.1.7 and 4.2.1.2.

B.1.3.  Redirection Status-Code Values

  This class of status-code values indicates that further action needs
  to be taken to fulfill the request.

  There are no values defined in this document for this class of
  status-code values.

B.1.4.  Client Error Status-Code Values

  This class of status-code values is intended for cases in which the
  Client seems to have erred.  The IPP object SHOULD return a message
  containing an explanation of the error situation and whether it is a
  temporary or permanent condition.










Sweet & McDonald             Standards Track                  [Page 202]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


B.1.4.1.  client-error-bad-request (0x0400)

  The request could not be understood by the IPP object due to
  malformed syntax (such as the value of a fixed-length attribute whose
  length does not match the prescribed length for that attribute -- see
  the Implementor's Guides [RFC3196] [PWG5100.19]).  The IPP
  application SHOULD NOT repeat the request without modifications.

B.1.4.2.  client-error-forbidden (0x0401)

  The IPP object understood the request but is refusing to fulfill it.
  Additional authentication information or authorization credentials
  will not help, and the request SHOULD NOT be repeated.  This
  status-code is commonly used when the IPP object does not wish to
  reveal exactly why the request has been refused or when no other
  response is applicable.

B.1.4.3.  client-error-not-authenticated (0x0402)

  The request requires user authentication.  The IPP Client can repeat
  the request with suitable authentication information.  If the request
  already included authentication information, then this status-code
  indicates that authorization has been refused for those credentials.
  If this response contains the same challenge as the prior response
  and the user agent has already attempted authentication at least
  once, then the response message can contain relevant diagnostic
  information.  This status-code reveals more information than
  'client-error-forbidden'.

B.1.4.4.  client-error-not-authorized (0x0403)

  The requester is not authorized to perform the request.  Additional
  authentication information or authorization credentials will not
  help, and the request SHOULD NOT be repeated.  This status-code is
  used when the IPP object wishes to reveal that the authentication
  information is understandable; however, the requester is explicitly
  not authorized to perform the request.  This status-code reveals more
  information than 'client-error-forbidden' and
  'client-error-not-authenticated'.

B.1.4.5.  client-error-not-possible (0x0404)

  This status-code is used when the request is for something that
  cannot happen.  For example, there might be a request to cancel a Job
  that has already been canceled or aborted by the system.  The IPP
  Client SHOULD NOT repeat the request.





Sweet & McDonald             Standards Track                  [Page 203]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


B.1.4.6.  client-error-timeout (0x0405)

  The Client did not produce a request within the time that the IPP
  object was prepared to wait.  For example, a Client issued a
  Create-Job operation and then, after a long period of time, issued a
  Send-Document operation; this error status-code was returned in
  response to the Send-Document request (see Section 4.3.1).  The IPP
  object might have been forced to clean up resources that had been
  held for the waiting additional Documents.  The IPP object was forced
  to close the Job, since the Client took too long.  The Client
  SHOULD NOT repeat the request without modifications.

B.1.4.7.  client-error-not-found (0x0406)

  The IPP object has not found anything matching the request URI.  No
  indication is given of whether the condition is temporary or
  permanent.  For example, a Client with an old reference to a Job
  (a URI) tries to cancel the Job; however, in the meantime the Job
  might have been completed and all record of it at the Printer has
  been deleted.  This status-code, 'client-error-not-found', is
  returned indicating that the referenced Job cannot be found.  This
  error status-code is also used when a Client supplies a URI as a
  reference to the Document data in either a Print-URI or Send-URI
  operation but the Document cannot be found.

  In practice, an IPP application should avoid a "not found" situation
  by first querying and presenting a list of valid Printer URIs and Job
  URIs to the End User.

B.1.4.8.  client-error-gone (0x0407)

  The requested object is no longer available, and no forwarding
  address is known.  This condition should be considered permanent.
  Clients with link-editing capabilities should delete references to
  the request URI after user approval.  If the IPP object does not know
  or has no facility to determine whether or not the condition is
  permanent, the status-code 'client-error-not-found' should be used
  instead.

  This response is primarily intended to assist the task of maintenance
  by notifying the recipient that the resource is intentionally
  unavailable and that the IPP object Administrator desires that remote
  links to that resource be removed.  It is not necessary to mark all
  permanently unavailable resources as "gone" or to keep the mark for
  any length of time -- that is left to the discretion of the IPP
  object Administrator and/or Printer implementation.





Sweet & McDonald             Standards Track                  [Page 204]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


B.1.4.9.  client-error-request-entity-too-large (0x0408)

  The IPP object is refusing to process a request because the request
  entity is larger than the IPP object is willing or able to process.
  An IPP Printer returns this status-code when it limits the size of
  Print Jobs and it receives a Print Job that exceeds that limit or
  when the attributes are so many that their encoding causes the
  request entity to exceed IPP object capacity.

B.1.4.10.  client-error-request-value-too-long (0x0409)

  The IPP object is refusing to service the request because one or more
  of the Client-supplied attributes have a variable-length value that
  is longer than the maximum length specified for that attribute.  The
  IPP object might not have sufficient resources (memory, buffers,
  etc.) to process (even temporarily), interpret, and/or ignore a value
  larger than the maximum length.  Another use of this error code is
  when the IPP object supports the processing of a large value that is
  less than the maximum length, but during the processing of the
  request as a whole, the object can pass the value onto some other
  system component that is not able to accept the large value.  For
  more details, see the Implementor's Guides [RFC3196] [PWG5100.19].

  Note: For attribute values that are URIs, this rare condition is only
  likely to occur when a Client has improperly submitted a request with
  long query information (e.g., an IPP application allows an End User
  to enter an invalid URI), when the Client has descended into a URI
  "black hole" of redirection (e.g., a redirected URI prefix that
  points to a suffix of itself), or when the IPP object is under attack
  by a Client attempting to exploit security holes present in some IPP
  objects using fixed-length buffers for reading or manipulating the
  request URI.

B.1.4.11.  client-error-document-format-not-supported (0x040a)

  The IPP object is refusing to service the request because the
  Document data is in a format, as specified in the "document-format"
  operation attribute, that is not supported by the Printer.  This
  error is returned independent of the Client-supplied
  "ipp-attribute-fidelity" attribute.  The Printer MUST return this
  status-code, even if there are other Job Template attributes that are
  not supported as well, since this error is a bigger problem than with
  Job Template attributes.  See Sections 4.1.6.1, 4.1.7, and 4.2.1.1.








Sweet & McDonald             Standards Track                  [Page 205]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


B.1.4.12.  client-error-attributes-or-values-not-supported (0x040b)

  In a Job Creation request, if the Printer does not support one or
  more attributes, attribute syntaxes, or attribute values supplied in
  the request and the Client supplied the "ipp-attribute-fidelity"
  operation attribute with the 'true' value, the Printer MUST return
  this status-code.  The Printer MUST also return in the Unsupported
  Attributes group all the attributes and/or values supplied by the
  Client that are not supported.  See Section 4.1.7.  Examples would be
  if the request indicates 'iso-a4' media but that media type is not
  supported by the Printer, or if the Client supplies a Job Template
  attribute and the attribute itself is not even supported by the
  Printer.  If the "ipp-attribute-fidelity" attribute is 'false', the
  Printer MUST ignore or substitute values for unsupported Job Template
  attributes and values rather than reject the request and return this
  status-code.

  For any operation where a Client requests attributes (such as a
  Get-Jobs, Get-Printer-Attributes, or Get-Job-Attributes operation),
  if the IPP object does not support one or more of the requested
  attributes, the IPP object simply ignores the unsupported requested
  attributes and processes the request as if they had not been
  supplied, rather than returning this status-code.  In this case,
  the IPP object MUST return the
  'successful-ok-ignored-or-substituted-attributes' status-code and
  SHOULD return the unsupported attributes as values of the
  "requested-attributes" operation attribute in the Unsupported
  Attributes group (see Appendix B.1.2.2).

B.1.4.13.  client-error-uri-scheme-not-supported (0x040c)

  The scheme of the Client-supplied URI in a Print-URI or a Send-URI
  operation is not supported.  See Sections 4.1.6.1 and 4.1.7.

B.1.4.14.  client-error-charset-not-supported (0x040d)

  For any operation, if the IPP Printer does not support the charset
  supplied by the Client in the "attributes-charset" operation
  attribute, the Printer MUST reject the operation and return this
  status-code, and any 'text' or 'name' attributes using the 'utf-8'
  charset (Section 4.1.4.1).  See Sections 4.1.6.1 and 4.1.7.










Sweet & McDonald             Standards Track                  [Page 206]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


B.1.4.15.  client-error-conflicting-attributes (0x040e)

  The request is rejected because some attribute values conflicted with
  the values of other attributes that this document does not permit to
  be substituted or ignored.  The Printer MUST also return in the
  Unsupported Attributes group the conflicting attributes supplied by
  the Client.  See Sections 4.1.7 and 4.2.1.2.

B.1.4.16.  client-error-compression-not-supported (0x040f)

  The IPP object is refusing to service the request because the
  Document data, as specified in the "compression" operation attribute,
  is compressed in a way that is not supported by the Printer.  This
  error is returned independent of the Client-supplied
  "ipp-attribute-fidelity" attribute.  The Printer MUST return this
  status-code, even if there are other Job Template attributes that are
  not supported as well, since this error is a bigger problem than with
  Job Template attributes.  See Sections 4.1.6.1, 4.1.7, and 4.2.1.1.

B.1.4.17.  client-error-compression-error (0x0410)

  The IPP object is refusing to service the request because the
  Document data cannot be decompressed when using the algorithm
  specified by the "compression" operation attribute.  This error is
  returned independent of the Client-supplied "ipp-attribute-fidelity"
  attribute.  The Printer MUST return this status-code, even if there
  are Job Template attributes that are not supported as well, since
  this error is a bigger problem than with Job Template attributes.
  See Sections 4.1.7 and 4.2.1.1.

B.1.4.18.  client-error-document-format-error (0x0411)

  The IPP object is refusing to service the request because the Printer
  encountered an error in the Document data while interpreting it.
  This error is returned independent of the Client-supplied
  "ipp-attribute-fidelity" attribute.  The Printer MUST return this
  status-code, even if there are Job Template attributes that are not
  supported as well, since this error is a bigger problem than with Job
  Template attributes.  See Sections 4.1.7 and 4.2.1.1.

B.1.4.19.  client-error-document-access-error (0x0412)

  The IPP object is refusing to service the Print-URI or Send-URI
  request because the Printer encountered an access error while
  attempting to validate the accessibility of, or access to, the
  Document data specified in the "document-uri" operation attribute.
  The Printer MAY also return a specific Document access error code
  using the "document-access-error" operation attribute (see



Sweet & McDonald             Standards Track                  [Page 207]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  Section 4.1.6.4).  This error is returned independent of the
  Client-supplied "ipp-attribute-fidelity" attribute.  The Printer MUST
  return this status-code, even if there are Job Template attributes
  that are not supported as well, since this error is a bigger problem
  than with Job Template attributes.  See Sections 4.1.6.1 and 4.1.7.

B.1.5.  Server Error Status-Code Values

  This class of status-code values indicates cases in which the IPP
  object is aware that it has erred or is incapable of performing the
  request.  The IPP object SHOULD include a message containing an
  explanation of the error situation, and whether it is a temporary or
  permanent condition.

B.1.5.1.  server-error-internal-error (0x0500)

  The IPP object encountered an unexpected condition that prevented it
  from fulfilling the request.  This error status-code differs from
  'server-error-temporary-error' in that it implies a more permanent
  type of internal error.  It also differs from
  'server-error-device-error' in that it implies an unexpected
  condition (unlike a paper-jam or out-of-toner problem, which is
  undesirable but expected).  This error status-code indicates that
  intervention by a knowledgeable human is probably required.

B.1.5.2.  server-error-operation-not-supported (0x0501)

  The IPP object does not support the functionality required to fulfill
  the request.  This is the appropriate response when the IPP object
  does not recognize an operation or is not capable of supporting it.
  See Sections 4.1.6.1 and 4.1.7.

B.1.5.3.  server-error-service-unavailable (0x0502)

  The IPP object is currently unable to handle the request due to
  temporary overloading or due to maintenance of the IPP object.  The
  implication is that this is a temporary condition that will be
  alleviated after some delay.  If known, the length of the delay can
  be indicated in the message.  If no delay is given, the IPP
  application should handle the response as it would for a
  'server-error-temporary-error' response.  If the condition is more
  permanent, the 'client-error-gone' or 'client-error-not-found' error
  status-code could be used.








Sweet & McDonald             Standards Track                  [Page 208]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


B.1.5.4.  server-error-version-not-supported (0x0503)

  The IPP object does not support or refuses to support the IPP version
  that was supplied as the value of the "version-number" operation
  parameter in the request.  The IPP object is indicating that it is
  unable or unwilling to complete the request using the same major and
  minor version number as supplied in the request, other than with this
  error message.  The error response SHOULD contain a "status-message"
  attribute (see Section 4.1.6.2) describing why that version is not
  supported and what other versions are supported by that IPP object.
  See Sections 4.1.6.1, 4.1.7, and 4.1.8.

  The error response MUST identify in the "version-number" operation
  parameter the closest version number that the IPP object does
  support.  For example, if a Client supplies version '1.0' and an
  IPP/1.1 object supports version '1.0', then it responds with
  version '1.0' in all responses to such a request.  If the IPP/1.1
  object does not support version '1.0', then it should accept the
  request and respond with version '1.1' or can reject the request and
  respond with this error code and version '1.1'.  If a Client supplies
  version '1.2', the IPP/1.1 object should accept the request and
  return version '1.1' or can reject the request and respond with this
  error code and version '1.1'.  See Sections 4.1.8 and 5.3.14.

B.1.5.5.  server-error-device-error (0x0504)

  A Printer error, such as a paper jam, occurs while the IPP object
  processes a Print or send operation.  The response contains the true
  Job status (the values of the "job-state" and "job-state-reasons"
  attributes).  Additional information can be returned in the OPTIONAL
  "job-state-message" attribute value or in the OPTIONAL status message
  that describes the error in more detail.  This error status-code is
  only returned in situations where the Printer is unable to accept the
  Job Creation request because of such a device error.  For example, if
  the Printer is unable to spool and can only accept one Job at a time,
  the reason it might reject a Job Creation request is that the Printer
  currently has a paper jam.  In many cases, however, where the Printer
  can accept the request even though the Printer has some error
  condition, the 'successful-ok' status-code will be returned.  In such
  a case, the Client would look at the returned Job object attributes
  or later query the Printer to determine its state and state reasons.










Sweet & McDonald             Standards Track                  [Page 209]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


B.1.5.6.  server-error-temporary-error (0x0505)

  A temporary error such as a buffer-full write error, a memory
  overflow (i.e., the Document data exceeds the memory of the Printer),
  or a disk-full condition, occurs while the IPP Printer processes an
  operation.  The Client MAY try the unmodified request again at some
  later point in time with an expectation that the temporary internal
  error condition has been cleared.  Alternatively, as an
  implementation option, a Printer MAY delay the response until the
  temporary condition is cleared so that no error is returned.

B.1.5.7.  server-error-not-accepting-jobs (0x0506)

  This is a temporary error indicating that the Printer is not
  currently accepting Jobs because the Administrator has set the value
  of the Printer's "printer-is-accepting-jobs" attribute to 'false' (by
  means outside the scope of this IPP/1.1 document).

B.1.5.8.  server-error-busy (0x0507)

  This is a temporary error indicating that the Printer is too busy
  processing Jobs and/or other requests.  The Client SHOULD try the
  unmodified request again at some later point in time with an
  expectation that the temporary busy condition will have been cleared.

B.1.5.9.  server-error-job-canceled (0x0508)

  This is an error indicating that the Job has been canceled by an
  Operator or the system while the Client was transmitting the data to
  the IPP Printer.  If a "job-id" attribute and a "job-uri" attribute
  had been created, then they are returned in the Print-Job,
  Send-Document, or Send-URI response as usual; otherwise, no "job-id"
  and "job-uri" attributes are returned in the response.

B.1.5.10.  server-error-multiple-document-jobs-not-supported (0x0509)

  The IPP object does not support multiple Documents per Job, and a
  Client attempted to supply Document data with a second Send-Document
  or Send-URI operation.












Sweet & McDonald             Standards Track                  [Page 210]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


B.2.  Status-Code Values for IPP Operations

  PJ = Print-Job, PU = Print-URI, CJ = Create-Job, SD = Send-Document,
  SU = Send-URI, V = Validate-Job, GA = Get-Job-Attributes and
  Get-Printer-Attributes, GJ = Get-Jobs, C = Cancel-Job

                                                 IPP Operations
  IPP Status Keyword                       PJ PU CJ SD SU V GA GJ C
  ------------------                       -- -- -- -- -- - -- -- -
  successful-ok                            x  x  x  x  x  x x  x  x
  successful-ok-ignored-or-substituted-    x  x  x  x  x  x x  x  x
       attributes
  successful-ok-conflicting-attributes     x  x  x  x  x  x x  x  x
  client-error-bad-request                 x  x  x  x  x  x x  x  x
  client-error-forbidden                   x  x  x  x  x  x x  x  x
  client-error-not-authenticated           x  x  x  x  x  x x  x  x
  client-error-not-authorized              x  x  x  x  x  x x  x  x
  client-error-not-possible                x  x  x  x  x  x x  x  x
  client-error-timeout                              x  x
  client-error-not-found                   x  x  x  x  x  x x  x  x
  client-error-gone                        x  x  x  x  x  x x  x  x
  client-error-request-entity-too-large    x  x  x  x  x  x x  x  x
  client-error-request-value-too-long      x  x  x  x  x  x x  x  x
  client-error-document-format-not-        x  x     x  x  x x
       supported
  client-error-attributes-or-values-not-   x  x  x  x  x  x x  x  x
       supported
  client-error-uri-scheme-not-supported       x        x
  client-error-charset-not-supported       x  x  x  x  x  x x  x  x
  client-error-conflicting-attributes      x  x  x  x  x  x x  x  x
  client-error-compression-not-supported   x  x     x  x  x
  client-error-compression-error           x  x     x  x
  client-error-document-format-error       x  x     x  x
  client-error-document-access-error          x        x
  server-error-internal-error              x  x  x  x  x  x x  x  x
  server-error-operation-not-supported        x  x  x  x
  server-error-service-unavailable         x  x  x  x  x  x x  x  x
  server-error-version-not-supported       x  x  x  x  x  x x  x  x
  server-error-device-error                x  x  x  x  x
  server-error-temporary-error             x  x  x  x  x
  server-error-not-accepting-jobs          x  x  x        x
  server-error-busy                        x  x  x  x  x  x x  x  x
  server-error-job-canceled                x        x  x
  server-error-multiple-document-jobs-              x  x
         not-supported






Sweet & McDonald             Standards Track                  [Page 211]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  HJ = Hold-Job, RJ = Release-Job, RS = Restart-Job,
  PP = Pause-Printer, RP = Resume-Printer, PJ = Purge-Jobs

                                           IPP Operations (cont.)
  IPP Status Keyword                       HJ RJ RS PP RP PJ
  ------------------                       -- -- -- -- -- --
  successful-ok                            x  x  x  x  x  x
  successful-ok-ignored-or-substituted-    x  x  x  x  x  x
       attributes
  successful-ok-conflicting-attributes     x  x  x  x  x  x
  client-error-bad-request                 x  x  x  x  x  x
  client-error-forbidden                   x  x  x  x  x  x
  client-error-not-authenticated           x  x  x  x  x  x
  client-error-not-authorized              x  x  x  x  x  x
  client-error-not-possible                x  x  x  x  x  x
  client-error-timeout
  client-error-not-found                   x  x  x  x  x  x
  client-error-gone                        x  x  x  x  x  x
  client-error-request-entity-too-large    x  x  x  x  x  x
  client-error-request-value-too-long      x  x  x  x  x  x
  client-error-document-format-not-
       supported
  client-error-attributes-or-values-not-   x  x  x  x  x  x
       supported
  client-error-uri-scheme-not-supported
  client-error-charset-not-supported       x  x  x  x  x  x
  client-error-conflicting-attributes      x  x  x  x  x  x
  client-error-compression-not-supported
  client-error-compression-error
  client-error-document-format-error
  client-error-document-access-error
  server-error-internal-error              x  x  x  x  x  x
  server-error-operation-not-supported     x  x  x  x  x  x
  server-error-service-unavailable         x  x  x  x  x  x
  server-error-version-not-supported       x  x  x  x  x  x
  server-error-device-error
  server-error-temporary-error             x  x  x  x  x  x
  server-error-not-accepting-jobs
  server-error-busy                        x  x  x  x  x  x
  server-error-job-canceled
  server-error-multiple-document-jobs-
         not-supported









Sweet & McDonald             Standards Track                  [Page 212]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


Appendix C.  Processing IPP Attributes

  When submitting a Print Job to a Printer, the IPP Model allows a
  Client to supply operation and Job Template attributes along with the
  Document data.  These Job Template attributes in the Job Creation
  request affect the rendering, production, and finishing of the
  Documents in the Job.  Similar types of instructions can also be
  contained in the Document data itself.  In addition, the Printer has
  a set of attributes that describe what rendering and finishing
  processes are supported by that Printer.  This model, which allows
  for flexibility and power, also introduces the potential that
  Client-supplied attributes can conflict with either:

  o  what the implementation is capable of realizing (i.e., what the
     Printer supports), or

  o  the instructions embedded within the Document data itself.

  The following sections describe how these two types of conflicts are
  handled in the IPP Model.

C.1.  Fidelity

  If there is a conflict between what the Client requests and what a
  Printer supports, the Client can request one of two possible
  conflict-handling mechanisms:

  1)  either reject the Job, since the Job cannot be processed exactly
      as specified, or

  2)  allow the Printer to make any changes necessary to proceed with
      processing the Job the best it can.

  In the first case, the Client is indicating the following to the
  Printer: "Print the Job exactly as specified with no exceptions, and
  if that can't be done, don't even bother printing the Job at all."
  In the second case, the Client is indicating the following to the
  Printer: "It is more important to make sure the Job is printed rather
  than be processed exactly as specified; just make sure the Job is
  printed even if some Client-supplied attributes need to be changed or
  ignored."

  The IPP Model accounts for this situation by introducing an
  "ipp-attribute-fidelity" attribute.







Sweet & McDonald             Standards Track                  [Page 213]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  In a Job Creation request, "ipp-attribute-fidelity" is a boolean
  operation attribute that MAY be supplied by the Client.  The value
  'true' indicates that total fidelity to Client-supplied Job Template
  attributes and values is required.  The Client is requesting that the
  Job be printed exactly as specified, and if that is not possible,
  then the Job MUST be rejected rather than processed incorrectly.  The
  value 'false' indicates that a reasonable attempt to print the Job is
  acceptable.  If a Printer does not support some of the
  Client-supplied Job Template attributes or values, the Printer MUST
  ignore or replace them with supported values.  The Printer can choose
  to substitute the default value associated with that attribute or use
  some other supported value that is similar to the unsupported
  requested value.  For example, if a Client supplies a "media" value
  of 'na_letter_8.5x11in', the Printer can choose to substitute
  'iso_a4_210x297mm' rather than a default value of
  'na_personal_3.625x6.5in'.  If the Client does not supply the
  "ipp-attribute-fidelity" attribute, the Printer assumes a value of
  'false'.

  Each Printer implementation MUST support both types of "fidelity"
  printing (that is, whether the Client supplies a value of 'true' or
  'false'):

  o  If the Client supplies 'false' or does not supply the attribute,
     the Printer MUST always accept the request by ignoring unsupported
     Job Template attributes and by substituting unsupported values of
     supported Job Template attributes with supported values.

  o  If the Client supplies 'true', the Printer MUST reject the request
     if the Client supplies unsupported Job Template attributes.

  Since a Client can always query a Printer to find out exactly what is
  and is not supported, "ipp-attribute-fidelity" set to 'false' is
  useful when:

  1)  The End User uses a command line interface to request attributes
      that might not be supported.

  2)  In a GUI context, if the End User expects the Job might be moved
      to another Printer and prefers a suboptimal result to nothing
      at all.

  3)  The End User just wants something reasonable in lieu of nothing
      at all.







Sweet & McDonald             Standards Track                  [Page 214]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


C.2.  Page Description Language (PDL) Override

  If there is a conflict between the value of an IPP Job Template
  attribute and a corresponding instruction in the Document data, the
  value of the IPP attribute SHOULD take precedence over the Document
  instruction.  Consider the case where a previously formatted file of
  Document data is sent to an IPP Printer.  In this case, if the Client
  supplies any attributes at Job submission time, the Client desires
  that those attributes override the embedded instructions.  Consider
  the case where a previously formatted Document has embedded in it
  commands to load 'iso-a4' media.  However, the Document is passed to
  an End User that only has access to a Printer with 'na-letter' media
  loaded.  That End User most likely wants to submit that Document to
  an IPP Printer with the "media" Job Template attribute set to
  'na-letter'.  Attributes supplied at Job submission time should take
  precedence over the embedded PDL instructions.  However, until
  companies that supply Document data interpreters allow a way for
  external IPP attributes to take precedence over embedded Job
  production instructions, a Printer might not be able to support the
  semantics that IPP attributes override the embedded instructions.

  The IPP Model accounts for this situation by introducing a
  "pdl-override-supported" attribute that describes the Printer's
  capabilities to override instructions embedded in the PDL data
  stream.  The value of the "pdl-override-supported" attribute is
  configured by means outside the scope of this IPP/1.1 document.

  This REQUIRED Printer attribute takes on the following values:

  o  'attempted': This value indicates that the Printer attempts to
     make the IPP attribute values take precedence over embedded
     instructions in the Document data; however, there is no guarantee.

  o  'not-attempted': This value indicates that the Printer makes no
     attempt to make the IPP attribute values take precedence over
     embedded instructions in the Document data.

  At Job processing time, an implementation that supports the value of
  'attempted' might do one of several different actions:

  1)  Generate an Output-Device-specific command sequence to realize
      the feature represented by the IPP attribute value.

  2)  Parse the Document data itself and replace the conflicting
      embedded instruction with a new embedded instruction that matches
      the intent of the IPP attribute value.





Sweet & McDonald             Standards Track                  [Page 215]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  3)  Indicate to the Printer that external supplied attributes take
      precedence over embedded instructions and then pass the external
      IPP attribute values to the Document data interpreter.

  4)  Anything else that allows for the semantics that IPP attributes
      override embedded Document data instructions.

  Since 'attempted' does not offer any type of guarantee, even though a
  given Printer might not do a very "good" job of attempting to ensure
  that IPP attributes take a higher precedence over instructions
  embedded in the Document data, it would still be a conforming
  implementation.

  At Job processing time, an implementation that supports the value of
  'not-attempted' might do one of the following actions:

  1)  Simply prepend the Document data with the PDL instruction that
      corresponds to the Client-supplied PDL attribute, such that if
      the Document data also has the same PDL instruction it will
      override what the Printer prepended.  In other words, this
      implementation is using the same implementation semantics for the
      Client-supplied IPP attributes as for the Printer defaults.

  2)  Parse the Document data and replace the conflicting embedded
      instruction with a new embedded instruction that approximates,
      but does not match, the semantic intent of the IPP attribute
      value.

  Note: The "ipp-attribute-fidelity" attribute applies to the Printer's
  ability to either accept or reject other unsupported Job Template
  attributes.  In other words, if "ipp-attribute-fidelity" is set to
  'true', a Job is accepted if and only if the Client-supplied Job
  Template attributes and values are supported by the Printer.  Whether
  these attributes actually affect the processing of the Job when the
  Document data contains embedded instructions depends on the ability
  of the Printer to override the instructions embedded in the Document
  data with the semantics of the IPP attributes.  If the Document data
  attributes can be overridden ("pdl-override-supported" set to
  'attempted'), the Printer makes an attempt to use the IPP attributes
  when processing the Job.  If the Document data attributes cannot be
  overridden ("pdl-override-supported" set to 'not-attempted'), the
  Printer makes no attempt to override the embedded Document data
  instructions with the IPP attributes when processing the Job, and
  hence, the IPP attributes can fail to affect the Job processing and
  output when the corresponding instruction is embedded in the
  Document data.





Sweet & McDonald             Standards Track                  [Page 216]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


C.3.  Using Job Template Attributes during Document Processing

  The Printer uses some of the Job's Job Template attributes during the
  processing of the Document data associated with that Job.  These
  include, but are not limited to, "orientation-requested",
  "number-up", "sides", "media", and "copies".  The processing of each
  Document in a Job object MUST follow the steps below.  These steps
  are intended only to identify when and how attributes are to be used
  in processing Document data; any alternative steps that accomplish
  the same effect can be used to implement this specification document.

  1.  Using the Client-supplied "document-format" attribute or some
      form of Document format detection algorithm (if the value of
      "document-format" is not specific enough), determine whether the
      Document data has already been formatted for printing.  If the
      Document data has been formatted, then go to step 2.  Otherwise,
      the Document data MUST be formatted.  The formatting detection
      algorithm is implementation defined and is not specified by this
      document.  The formatting of the Document data uses the
      "orientation-requested" attribute to determine how the formatted
      print data should be placed on an Input Page; see Section 5.2.10
      for details.

  2.  The Document data is a set of Input Pages in a known media type.
      The "page-ranges" attribute is used to select, as specified in
      Section 5.2.7, a sub-sequence of the pages in the print-stream
      that are to be processed and imaged.

  3.  The input for this step is a sequence of Input Pages.  This step
      is controlled by the "number-up" attribute.  If the value of
      "number-up" is N, then during the processing of the Input Pages
      each N Input Pages are positioned, as specified in Section 5.2.9,
      to create a single Impression.  If a given Document does not have
      N more Input Pages, then the completion of the Impression is
      controlled by the "multiple-document-handling" attribute as
      described in Section 5.2.4; when the value of this attribute is
      'single-document' or 'single-document-new-sheet', the Input Pages
      of Document data from subsequent Documents are used to complete
      the Impression.

  The size (scaling), position (translation), and rotation of the Input
  Pages on the Impression are implementation defined.  Note that during
  this process the Input Pages can be rendered to a form suitable for
  placing on the Impression; this rendering is controlled by the values
  of the "printer-resolution" and "print-quality" attributes as
  described in Sections 5.2.12 and 5.2.13.  In the case where N = 1,
  the Impression is nearly the same as the Input Page; the differences




Sweet & McDonald             Standards Track                  [Page 217]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  would only be in the size, position, and rotation of the Input Page
  and/or any decoration, such as a frame for the page, that is added by
  the implementation.

  1.  The collection of Impressions is placed, in sequence, onto sides
      of the Media Sheets.  This placement is controlled by the "sides"
      attribute and the orientation of the Input Page, as described in
      Section 5.2.8.  The orientation of the Input Pages affects the
      orientation of the Impression; for example, if "number-up" equals
      2, then, typically, two portrait Input Pages become one landscape
      Impression.  Note that the placement of Impressions onto Media
      Sheets is also controlled by the "multiple-document-handling"
      attribute as described in Section 5.2.4.

  2.  The "copies" and "multiple-document-handling" attributes are used
      to determine how many copies of each Media Sheet are printed and
      in what order.  See Sections 5.2.4 and 5.2.5 for details.

  3.  When the correct number of copies are created, the Media Sheets
      are finished according to the values of the "finishings"
      attribute as described in Section 5.2.6.  Note that sometimes
      finishing processes can require manual intervention to perform
      the finishing processes on the copies, especially uncollated
      copies.  This document allows any or all of the processing steps
      to be performed automatically or manually, at the discretion of
      the Printer.

Appendix D.  Generic Directory Schema

  This section defines a generic schema for an entry in a directory
  service.  Implementations of this schema are defined by "Lightweight
  Directory Access Protocol (LDAP): Schema for Printer Services"
  [RFC7612] and "IPP Everywhere" [PWG5100.14].  A directory service is
  a means by which service users can locate service providers.  In IPP
  environments, this means that IPP Printers can be registered (either
  automatically or with the help of an Administrator) as entries of
  type Printer in the directory using an implementation-specific
  mechanism such as entry attributes, entry type fields, specific
  branches, etc.  Directory Clients can search or browse for entries of
  type Printer.  Clients use the directory service to find entries
  based on naming, organizational contexts, or filtered searches on
  attribute values of entries.  For example, a Client can find all
  Printers in the "Local Department" context.  Authentication and
  authorization are also often part of a directory service so that an
  Administrator can place limits on End Users so that they are only
  allowed to find entries to which they have certain access rights.
  IPP itself does not require any specific directory service protocol
  or provider.



Sweet & McDonald             Standards Track                  [Page 218]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  Note: Some directory implementations allow for the notion of
  "aliasing".  That is, one directory entry object can appear as
  multiple directory entry objects with different names for each
  object.  In each case, each alias refers to the same directory entry
  object, which refers to a single IPP Printer.

  The generic schema is a subset of IPP Printer Job Template and
  Printer Description attributes (Sections 5.2 and 5.4).  These
  attributes are identified as either RECOMMENDED or OPTIONAL for the
  directory entry itself.  This conformance labeling is NOT the same
  conformance labeling applied to the attributes of IPP Printer
  objects.  The conformance labeling in this appendix is intended to
  apply to directory templates and to IPP Printer implementations that
  subscribe by adding one or more entries to a directory.  RECOMMENDED
  attributes SHOULD be associated with each directory entry.  OPTIONAL
  attributes MAY be associated with the directory entry (if known or
  supported).  In addition, all directory entry attributes SHOULD
  reflect the current attribute values for the corresponding Printer.

  As much as possible, the names of attributes in directory schema and
  entries SHOULD be the same as the IPP Printer attribute names as
  shown.

  In order to bridge between the directory service and the IPP Printer,
  one of the RECOMMENDED directory entry attributes is the Printer's
  "printer-uri-supported" attribute.  The directory Client queries the
  "printer-uri-supported" attribute (or its equivalent) in the
  directory entry, and then the IPP Client addresses the IPP Printer
  using one of its URIs.  The "uri-security-supported" attribute
  identifies the protocol (if any) used to secure a channel.

  The attributes in Table 23 define the generic schema for directory
  entries of type Printer.

  +------------------------------------+-------------+----------------+
  | Attribute                          | Conformance | Section        |
  +------------------------------------+-------------+----------------+
  | charset-supported                  | OPTIONAL    | Section 5.4.18 |
  +------------------------------------+-------------+----------------+
  | color-supported                    | RECOMMENDED | Section 5.4.26 |
  +------------------------------------+-------------+----------------+
  | compression-supported              | RECOMMENDED | Section 5.4.32 |
  +------------------------------------+-------------+----------------+
  | document-format-supported          | RECOMMENDED | Section 5.4.22 |
  +------------------------------------+-------------+----------------+
  | finishings-supported               | OPTIONAL    | Section 5.2.6  |





Sweet & McDonald             Standards Track                  [Page 219]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


  +------------------------------------+-------------+----------------+
  | generated-natural-language-        | OPTIONAL    | Section 5.4.20 |
  | supported                          |             |                |
  +------------------------------------+-------------+----------------+
  | ipp-versions-supported             | RECOMMENDED | Section 5.4.14 |
  +------------------------------------+-------------+----------------+
  | media-supported                    | RECOMMENDED | Section 5.2.11 |
  +------------------------------------+-------------+----------------+
  | multiple-document-jobs-supported   | OPTIONAL    | Section 5.4.16 |
  +------------------------------------+-------------+----------------+
  | number-up-supported                | OPTIONAL    | Section 5.2.9  |
  +------------------------------------+-------------+----------------+
  | pages-per-minute-color             | OPTIONAL    | Section 5.4.37 |
  +------------------------------------+-------------+----------------+
  | pages-per-minute                   | OPTIONAL    | Section 5.4.36 |
  +------------------------------------+-------------+----------------+
  | print-quality-supported            | OPTIONAL    | Section 5.2.13 |
  +------------------------------------+-------------+----------------+
  | printer-info                       | OPTIONAL    | Section 5.4.6  |
  +------------------------------------+-------------+----------------+
  | printer-location                   | RECOMMENDED | Section 5.4.5  |
  +------------------------------------+-------------+----------------+
  | printer-make-and-model             | RECOMMENDED | Section 5.4.9  |
  +------------------------------------+-------------+----------------+
  | printer-more-info                  | OPTIONAL    | Section 5.4.7  |
  +------------------------------------+-------------+----------------+
  | printer-name                       | RECOMMENDED | Section 5.4.4  |
  +------------------------------------+-------------+----------------+
  | printer-resolution-supported       | OPTIONAL    | Section 5.2.12 |
  +------------------------------------+-------------+----------------+
  | printer-uri-supported              | RECOMMENDED | Section 5.4.1  |
  +------------------------------------+-------------+----------------+
  | sides-supported                    | RECOMMENDED | Section 5.2.8  |
  +------------------------------------+-------------+----------------+
  | uri-authentication-supported       | RECOMMENDED | Section 5.4.2  |
  +------------------------------------+-------------+----------------+
  | uri-security-supported             | RECOMMENDED | Section 5.4.3  |
  +------------------------------------+-------------+----------------+

                Table 23: Attributes in Directory Entries











Sweet & McDonald             Standards Track                  [Page 220]

RFC 8011              IPP/1.1: Model and Semantics          January 2017


Acknowledgements

  The authors would like to acknowledge the following individuals for
  their contributions to the original IPP/1.1 specifications:

  Roger deBry, Tom Hastings (original RFC 2911 editor), Robert Herriot,
  Scott A. Isaacson, Kirk Ocke, Patrick Powell, and Peter Zehler

Authors' Addresses

  Michael Sweet
  Apple Inc.
  1 Infinite Loop
  MS 111-HOMC
  Cupertino, CA  95014
  United States of America

  Email: [email protected]


  Ira McDonald
  High North, Inc.
  PO Box 221
  Grand Marais, MI  49839
  United States of America

  Phone: +1 906-494-2434
  Email: [email protected]























Sweet & McDonald             Standards Track                  [Page 221]