Network Working Group                                      S. Hollenbeck
Request for Comments: 5730                                VeriSign, Inc.
STD: 69                                                      August 2009
Obsoletes: 4930
Category: Standards Track


                Extensible Provisioning Protocol (EPP)

Abstract

  This document describes an application-layer client-server protocol
  for the provisioning and management of objects stored in a shared
  central repository.  Specified in XML, the protocol defines generic
  object management operations and an extensible framework that maps
  protocol operations to objects.  This document includes a protocol
  specification, an object mapping template, and an XML media type
  registration.  This document obsoletes RFC 4930.

Status of This Memo

  This document specifies an Internet standards track protocol for the
  Internet community, and requests discussion and suggestions for
  improvements.  Please refer to the current edition of the "Internet
  Official Protocol Standards" (STD 1) for the standardization state
  and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

  Copyright (c) 2009 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 in effect on the date of
  publication of this document (http://trustee.ietf.org/license-info).
  Please review these documents carefully, as they describe your rights
  and restrictions with respect to this document.














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Table of Contents

  1. Introduction ....................................................3
     1.1. Conventions Used in This Document ..........................3
  2. Protocol Description ............................................4
     2.1. Transport Mapping Considerations ...........................7
     2.2. Protocol Identification ....................................8
     2.3. Hello Format ...............................................8
     2.4. Greeting Format ............................................8
     2.5. Command Format ............................................12
     2.6. Response Format ...........................................13
     2.7. Protocol Extension Framework ..............................16
          2.7.1. Protocol Extension .................................16
          2.7.2. Object Extension ...................................17
          2.7.3. Command-Response Extension .........................18
     2.8. Object Identification .....................................18
     2.9. Protocol Commands .........................................19
          2.9.1. Session Management Commands ........................19
                 2.9.1.1. EPP <login> Command .......................20
                 2.9.1.2. EPP <logout> Command ......................22
          2.9.2. Query Commands .....................................23
                 2.9.2.1. EPP <check> Command .......................23
                 2.9.2.2. EPP <info> Command ........................25
                 2.9.2.3. EPP <poll> Command ........................26
                 2.9.2.4. EPP <transfer> Query Command ..............30
          2.9.3. Object Transform Commands ..........................31
                 2.9.3.1. EPP <create> Command ......................32
                 2.9.3.2. EPP <delete> Command ......................33
                 2.9.3.3. EPP <renew> Command .......................34
                 2.9.3.4. EPP <transfer> Command ....................35
                 2.9.3.5. EPP <update> Command ......................38
  3. Result Codes ...................................................39
  4. Formal Syntax ..................................................45
     4.1. Base Schema ...............................................45
     4.2. Shared Structure Schema ...................................56
  5. Internationalization Considerations ............................59
  6. IANA Considerations ............................................59
  7. Security Considerations ........................................60
  8. Acknowledgements ...............................................61
  9. References .....................................................62
     9.1. Normative References ......................................62
     9.2. Informative References ....................................62
  Appendix A.  Object Mapping Template ..............................64
  Appendix B.  Media Type Registration: application/epp+xml .........66
  Appendix C.  Changes from RFC 4930 ................................67






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1.  Introduction

  This document describes specifications for the Extensible
  Provisioning Protocol (EPP) version 1.0, an XML text protocol that
  permits multiple service providers to perform object-provisioning
  operations using a shared central object repository.  EPP is
  specified using the Extensible Markup Language (XML) 1.0 as described
  in [W3C.REC-xml-20040204] and XML Schema notation as described in
  [W3C.REC-xmlschema-1-20041028] and [W3C.REC-xmlschema-2-20041028].
  EPP meets and exceeds the requirements for a generic registry
  registrar protocol as described in [RFC3375].  This document
  obsoletes RFC 4930 [RFC4930].

  EPP content is identified by MIME media type application/epp+xml.
  Registration information for this media type is included in an
  appendix to this document.

  EPP is intended for use in diverse operating environments where
  transport and security requirements vary greatly.  It is unlikely
  that a single transport or security specification will meet the needs
  of all anticipated operators, so EPP was designed for use in a
  layered protocol environment.  Bindings to specific transport and
  security protocols are outside the scope of this specification.

  The original motivation for this protocol was to provide a standard
  Internet domain name registration protocol for use between domain
  name registrars and domain name registries.  This protocol provides a
  means of interaction between a registrar's applications and registry
  applications.  It is expected that this protocol will have additional
  uses beyond domain name registration.

  XML is case sensitive.  Unless stated otherwise, XML specifications
  and examples provided in this document MUST be interpreted in the
  character case presented to develop a conforming implementation.

1.1.  Conventions Used in This Document

  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].

  In examples, "C:" represents lines sent by a protocol client and "S:"
  represents lines returned by a protocol server.  Indentation and
  white space in examples are provided only to illustrate element
  relationships and are not REQUIRED features of this protocol.  A
  protocol client that is authorized to manage an existing object is
  described as a "sponsoring" client throughout this document.




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2.  Protocol Description

  EPP is a stateful XML protocol that can be layered over multiple
  transport protocols.  Protected using lower-layer security protocols,
  clients exchange identification, authentication, and option
  information, and then engage in a series of client-initiated command-
  response exchanges.  All EPP commands are atomic (there is no partial
  success or partial failure) and designed so that they can be made
  idempotent (executing a command more than once has the same net
  effect on system state as successfully executing the command once).

  EPP provides four basic service elements: service discovery,
  commands, responses, and an extension framework that supports
  definition of managed objects and the relationship of protocol
  requests and responses to those objects.

  An EPP server MUST respond to client-initiated communication (which
  can be either a lower-layer connection request or an EPP service
  discovery message) by returning a greeting to a client.  A server
  MUST promptly respond to each EPP command with a coordinated response
  that describes the results of processing the command.  The following
  server state machine diagram illustrates the message exchange process
  in detail:




























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             |
             V
     +-----------------+                  +-----------------+
     |   Waiting for   |     Connected    |     Prepare     |
     |      Client     |----------------->|     Greeting    |
     +-----------------+    or <hello>    +-----------------+
        ^                                           |
        | Close Connection                     Send |
        |     or Idle                      Greeting |
     +-----------------+                            V
     |       End       |     Timeout      +-----------------+
     |     Session     |<-----------------|   Waiting for   |
     +-----------------+                  |      Client     |
        ^    ^    ^        Send +-------->|  Authentication |
        |    |    |    Response |         +-----------------+
        |    |    |     +--------------+            |
        |    |    |     | Prepare Fail |            | <login>
        |    |    +-----|   Response   |            | Received
        |    |    Send  +--------------+            V
        |    |    2501          ^         +-----------------+
        |    |   Response       |         |   Processing    |
        |    |                  +---------|     <login>     |
        |    |                  Auth Fail +-----------------+
        |    |       Timeout                         |
        |    +-------------------------------+       | Auth OK
        |                                    |       V
        |   +-----------------+  <hello>  +-----------------+
        |   |     Prepare     |<----------|   Waiting for   |
        |   |     Greeting    |---------->|   Command or    |
        |   +-----------------+   Send    |     <hello>     |
        | Send x5xx             Greeting  +-----------------+
        | Response  +-----------------+  Send    ^  |
        +-----------|     Prepare     | Response |  | Command
                    |     Response    |----------+  | Received
                    +-----------------+             V
                               ^          +-----------------+
                       Command |          |   Processing    |
                     Processed +----------|     Command     |
                                          +-----------------+

  Figure 1: EPP Server State Machine

  EPP commands fall into three categories: session management commands,
  query commands, and object transform commands.  Session management
  commands are used to establish and end persistent sessions with an
  EPP server.  Query commands are used to perform read-only object
  information retrieval operations.  Transform commands are used to
  perform read-write object management operations.



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  Commands are processed by a server in the order they are received
  from a client.  Though an immediate response confirming receipt and
  processing of the command is produced by the server, the protocol
  includes features that allow for offline review of transform commands
  before the requested action is actually completed.  In such
  situations, the response from the server MUST clearly note that the
  command has been received and processed but that the requested action
  is pending.  The state of the corresponding object MUST clearly
  reflect processing of the pending action.  The server MUST also
  notify the client when offline processing of the action has been
  completed.  Object mappings SHOULD describe standard formats for
  notices that describe completion of offline processing.

  EPP uses XML namespaces to provide an extensible object management
  framework and to identify schemas required for XML instance parsing
  and validation.  These namespaces and schema definitions are used to
  identify both the base protocol schema and the schemas for managed
  objects.  The XML namespace prefixes used in examples (such as the
  string "foo" in "xmlns:foo") are solely for illustrative purposes.  A
  conforming implementation MUST NOT require the use of these or any
  other specific namespace prefixes.

  All XML instances SHOULD begin with an <?xml?> declaration to
  identify the version of XML that is being used, optionally identify
  use of the character encoding used, and optionally provide a hint to
  an XML parser that an external schema file is needed to validate the
  XML instance.  Conformant XML parsers recognize both UTF-8 (defined
  in RFC 3629 [RFC3629]) and UTF-16 (defined in RFC 2781 [RFC2781]);
  per RFC 2277 [RFC2277], UTF-8 is the RECOMMENDED character encoding
  for use with EPP.

  Character encodings other than UTF-8 and UTF-16 are allowed by XML.
  UTF-8 is the default encoding assumed by XML in the absence of an
  "encoding" attribute or a byte order mark (BOM); thus, the "encoding"
  attribute in the XML declaration is OPTIONAL if UTF-8 encoding is
  used.  EPP clients and servers MUST accept a UTF-8 BOM if present,
  though emitting a UTF-8 BOM is NOT RECOMMENDED.

  Example XML declarations:

  <?xml version="1.0" encoding="UTF-8" standalone="no"?>

  <?xml version="1.0" standalone="no"?>

  <?xml version="1.0" encoding="UTF-8"?>

  <?xml version="1.0"?>




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2.1.  Transport Mapping Considerations

  As described previously, EPP can be layered over multiple transport
  protocols.  There are, however, a common set of considerations that
  MUST be addressed by any transport mapping defined for EPP.  These
  include:

  -  The transport mapping MUST preserve command order.

  -  The transport mapping MUST address the relationship between
     sessions and the client-server connection concept.

  -  The transport mapping MUST preserve the stateful nature of the
     protocol.

  -  The transport mapping MUST frame data units.

  -  The transport mapping MUST be onto a transport, such as TCP
     [RFC0793] or Stream Control Transmission Protocol (SCTP)
     [RFC4960], that provides congestion avoidance that follows RFC
     2914 [RFC2914]; or, if it maps onto a protocol such as SMTP
     [RFC5321] or Blocks Extensible Exchange Protocol (BEEP) [RFC3080],
     then the performance issues need to take into account issues of
     overload, server availability, and so forth.

  -  The transport mapping MUST ensure reliability.

  -  The transport mapping MUST explicitly allow or prohibit
     pipelining.

  Pipelining, also known as command streaming, is when a client sends
  multiple commands to a server without waiting for each corresponding
  response.  After sending the commands, the client waits for the
  responses to arrive in the order corresponding to the completed
  commands.  Performance gains can sometimes be realized with
  pipelining, especially with high-latency transports, but there are
  additional considerations associated with defining a transport
  mapping that supports pipelining:

  -  Commands MUST be processed independent of each other.

  -  Depending on the transport, pipelining MAY be possible in the form
     of sending a complete session in a well-defined "batch".

  -  The transport mapping MUST describe how an error in processing a
     command affects continued operation of the session.





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  A transport mapping MUST explain how all of these requirements are
  met, given the transport protocol being used to exchange data.

2.2.  Protocol Identification

  All EPP XML instances MUST begin with an <epp> element.  This element
  identifies the start of an EPP protocol element and the namespace
  used within the protocol.  The <epp> start element and the associated
  </epp> ending element MUST be applied to all structures sent by both
  clients and servers.

  Example "start" and "end" EPP elements:

  <epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  </epp>

2.3.  Hello Format

  EPP MAY be carried over both connection-oriented and connection-less
  transport protocols.  An EPP client MAY request a <greeting> from an
  EPP server at any time between a successful <login> command and a
  <logout> command by sending a <hello> to a server.  Use of this
  element is essential in a connection-less environment where a server
  cannot return a <greeting> in response to a client-initiated
  connection.  An EPP <hello> MUST be an empty element with no child
  elements.

  Example <hello>:

  C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  C:  <hello/>
  C:</epp>

2.4.  Greeting Format

  An EPP server responds to a successful connection and <hello> element
  by returning a <greeting> element to the client.  An EPP greeting
  contains the following elements:

  -  An <svID> element that contains the name of the server.

  -  An <svDate> element that contains the server's current date and
     time in Universal Coordinated Time (UTC).

  -  An <svcMenu> element that identifies the services supported by the
     server, including:




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     o  One or more <version> elements that identify the protocol
        versions supported by the server.

     o  One or more <lang> elements that contain the identifiers of the
        text response languages known by the server.  Language
        identifiers MUST be structured as documented in [RFC4646].

     o  One or more <objURI> elements that contain namespace URIs
        representing the objects that the server is capable of
        managing.  A server MAY limit object management privileges on a
        per-client basis.

     o  An OPTIONAL <svcExtension> element that contains one or more
        <extURI> elements that contain namespace URIs representing
        object extensions supported by the server.

     o  A <dcp> (data collection policy) element that contains child
        elements used to describe the server's privacy policy for data
        collection and management.  Policy implications usually extend
        beyond the client-server relationship.  Both clients and
        servers can have relationships with other entities that need to
        know the server operator's data collection policy to make
        informed provisioning decisions.  Policy information MUST be
        disclosed to provisioning entities, though the method of
        disclosing policy data outside of direct protocol interaction
        is beyond the scope of this specification.  Child elements
        include the following:

        *  An <access> element that describes the access provided by
           the server to the client on behalf of the originating data
           source.  The <access> element MUST contain one of the
           following child elements:

           +  <all/>: Access is given to all identified data.

           +  <none/>: No access is provided to identified data.

           +  <null/>: Data is not persistent, so no access is
              possible.

           +  <personal/>: Access is given to identified data relating
              to individuals and organizational entities.

           +  <personalAndOther/>: Access is given to identified data
              relating to individuals, organizational entities, and
              other data of a non-personal nature.





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           +  <other/>: Access is given to other identified data of a
              non-personal nature.

        *  One or more <statement> elements that describe data
           collection purposes, data recipients, and data retention.
           Each <statement> element MUST contain a <purpose> element, a
           <recipient> element, and a <retention> element.  The
           <purpose> element MUST contain one or more of the following
           child elements that describe the purposes for which data is
           collected:

           +  <admin/>: Administrative purposes.  Information can be
              used for administrative and technical support of the
              provisioning system.

           +  <contact/>: Contact for marketing purposes.  Information
              can be used to contact individuals, through a
              communications channel other than the protocol, for the
              promotion of a product or service.

           +  <prov/>: Object-provisioning purposes.  Information can
              be used to identify objects and inter-object
              relationships.

           +  <other/>: Other purposes.  Information may be used in
              other ways not captured by the above definitions.

        *  The <recipient> element MUST contain one or more of the
           following child elements that describes the recipients of
           collected data:

           +  <other/>: Other entities following unknown practices.

           +  <ours>: Server operator and/or entities acting as agents
              or entities for whom the server operator is acting as an
              agent.  An agent in this instance is defined as a third
              party that processes data only on behalf of the service
              provider for the completion of the stated purposes.  The
              <ours> element contains an OPTIONAL <recDesc> element
              that can be used to describe the recipient.

           +  <public/>: Public forums.

           +  <same/>: Other entities following server practices.

           +  <unrelated/>: Unrelated third parties.





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        *  The <retention> element MUST contain one of the following
           child elements that describes data retention practices:

           +  <business/>: Data persists per business practices.

           +  <indefinite/>: Data persists indefinitely.

           +  <legal/>: Data persists per legal requirements.

           +  <none/>: Data is not persistent and is not retained for
              more than a brief period of time necessary to make use of
              it during the course of a single online interaction.

           +  <stated/>: Data persists to meet the stated purpose.

        *  An OPTIONAL <expiry> element that describes the lifetime of
           the policy.  The <expiry> element MUST contain one of the
           following child elements:

           +  <absolute/>: The policy is valid from the current date
              and time until it expires on the specified date and time.

           +  <relative/>: The policy is valid from the current date
              and time until the end of the specified duration.

  Data collection policy elements are based on work described in the
  World Wide Web Consortium's Platform for Privacy Preferences
  [W3C.REC-P3P-20020416] specification.

  Example greeting:

  S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  S:  <greeting>
  S:    <svID>Example EPP server epp.example.com</svID>
  S:    <svDate>2000-06-08T22:00:00.0Z</svDate>
  S:    <svcMenu>
  S:      <version>1.0</version>
  S:      <lang>en</lang>
  S:      <lang>fr</lang>
  S:      <objURI>urn:ietf:params:xml:ns:obj1</objURI>
  S:      <objURI>urn:ietf:params:xml:ns:obj2</objURI>
  S:      <objURI>urn:ietf:params:xml:ns:obj3</objURI>
  S:      <svcExtension>
  S:        <extURI>http://custom/obj1ext-1.0</extURI>
  S:      </svcExtension>
  S:    </svcMenu>
  S:    <dcp>



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  S:      <access><all/></access>
  S:      <statement>
  S:        <purpose><admin/><prov/></purpose>
  S:        <recipient><ours/><public/></recipient>
  S:        <retention><stated/></retention>
  S:      </statement>
  S:    </dcp>
  S:  </greeting>
  S:</epp>

2.5.  Command Format

  An EPP client interacts with an EPP server by sending a command to
  the server and receiving a response from the server.  In addition to
  the standard EPP elements, an EPP command contains the following
  elements:

  -  A command element whose tag corresponds to one of the valid EPP
     commands described in this document.  The command element MAY
     contain either protocol-specified or object-specified child
     elements.

  -  An OPTIONAL <extension> element that MAY be used for server-
     defined command extensions.

  -  An OPTIONAL <clTRID> (client transaction identifier) element that
     MAY be used to uniquely identify the command to the client.
     Clients are responsible for maintaining their own transaction
     identifier space to ensure uniqueness.

  Example command with object-specified child elements:

  C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  C:  <command>
  C:    <info>
  C:      <obj:info xmlns:obj="urn:ietf:params:xml:ns:obj">
  C:        <obj:name>example</obj:name>
  C:      </obj:info>
  C:    </info>
  C:    <clTRID>ABC-12345</clTRID>
  C:  </command>
  C:</epp>








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2.6.  Response Format

  An EPP server responds to a client command by returning a response to
  the client.  EPP commands are atomic, so a command will either
  succeed completely or fail completely.  Success and failure results
  MUST NOT be mixed.  In addition to the standard EPP elements, an EPP
  response contains the following elements:

  -  One or more <result> elements that document the success or failure
     of command execution.  If the command was processed successfully,
     only one <result> element MUST be returned.  If the command was
     not processed successfully, multiple <result> elements MAY be
     returned to document failure conditions.  Each <result> element
     contains the following attribute and child elements:

     o  A "code" attribute whose value is a four-digit, decimal number
        that describes the success or failure of the command.

     o  A <msg> element containing a human-readable description of the
        response code.  The language of the response is identified via
        an OPTIONAL "lang" attribute.  If not specified, the default
        attribute value MUST be "en" (English).

     o  Zero or more OPTIONAL <value> elements that identify a client-
        provided element (including XML tag and value) or other
        information that caused a server error condition.

     o  Zero or more OPTIONAL <extValue> elements that can be used to
        provide additional error diagnostic information, including:

        *  A <value> element that identifies a client-provided element
           (including XML tag and value) that caused a server error
           condition.

        *  A <reason> element containing a human-readable message that
           describes the reason for the error.  The language of the
           response is identified via an OPTIONAL "lang" attribute.  If
           not specified, the default attribute value MUST be "en"
           (English).

  -  An OPTIONAL <msgQ> element that describes messages queued for
     client retrieval.  A <msgQ> element MUST NOT be present if there
     are no messages queued for client retrieval.  A <msgQ> element MAY
     be present in responses to EPP commands other than the <poll>
     command if messages are queued for retrieval.  A <msgQ> element
     MUST be present in responses to the EPP <poll> command if messages
     are queued for retrieval.  The <msgQ> element contains the
     following attributes:



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     o  A "count" attribute that describes the number of messages that
        exist in the queue.

     o  An "id" attribute used to uniquely identify the message at the
        head of the queue.

     The <msgQ> element contains the following OPTIONAL child elements
     that MUST be returned in response to a <poll> request command and
     MUST NOT be returned in response to any other command, including a
     <poll> acknowledgement:

     o  A <qDate> element that contains the date and time that the
        message was enqueued.

     o  A <msg> element containing a human-readable message.  The
        language of the response is identified via an OPTIONAL "lang"
        attribute.  If not specified, the default attribute value MUST
        be "en" (English).  This element MAY contain XML content for
        formatting purposes, but the XML content is not specified by
        the protocol and will thus not be processed for validity.

  -  An OPTIONAL <resData> (response data) element that contains child
     elements specific to the command and associated object.

  -  An OPTIONAL <extension> element that MAY be used for server-
     defined response extensions.

  -  A <trID> (transaction identifier) element containing the
     transaction identifier assigned by the server to the command for
     which the response is being returned.  The transaction identifier
     is formed using the <clTRID> associated with the command if
     supplied by the client and a <svTRID> (server transaction
     identifier) that is assigned by and unique to the server.

  Transaction identifiers provide command-response synchronization
  integrity.  They SHOULD be logged, retained, and protected to ensure
  that both the client and the server have consistent temporal and
  state-management records.

  Example response without <value> or <resData>:

  S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  S:  <response>
  S:    <result code="1000">
  S:      <msg lang="en">Command completed successfully</msg>
  S:    </result>
  S:    <trID>



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  S:      <clTRID>ABC-12345</clTRID>
  S:      <svTRID>54321-XYZ</svTRID>
  S:    </trID>
  S:  </response>
  S:</epp>

  Example response with <resData>:

  S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  S:  <response>
  S:    <result code="1000">
  S:      <msg>Command completed successfully</msg>
  S:    </result>
  S:    <resData>
  S:      <obj:creData xmlns:obj="urn:ietf:params:xml:ns:obj">
  S:        <obj:name>example</obj:name>
  S:      </obj:creData>
  S:    </resData>
  S:    <trID>
  S:      <clTRID>ABC-12345</clTRID>
  S:      <svTRID>54321-XYZ</svTRID>
  S:    </trID>
  S:  </response>
  S:</epp>

  Example response with error value elements:

  S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  S:  <response>
  S:    <result code="2004">
  S:      <msg>Parameter value range error</msg>
  S:      <value xmlns:obj="urn:ietf:params:xml:ns:obj">
  S:        <obj:elem1>2525</obj:elem1>
  S:      </value>
  S:    </result>
  S:    <result code="2005">
  S:      <msg>Parameter value syntax error</msg>
  S:      <value xmlns:obj="urn:ietf:params:xml:ns:obj">
  S:        <obj:elem2>ex(ample</obj:elem2>
  S:      </value>
  S:      <extValue>
  S:        <value xmlns:obj="urn:ietf:params:xml:ns:obj">
  S:          <obj:elem3>abc.ex(ample</obj:elem3>
  S:        </value>
  S:        <reason>Invalid character found.</reason>
  S:      </extValue>



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  S:    </result>
  S:    <trID>
  S:      <clTRID>ABC-12345</clTRID>
  S:      <svTRID>54321-XYZ</svTRID>
  S:    </trID>
  S:  </response>
  S:</epp>

  Example response with notice of waiting server messages:

  S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  S:  <response>
  S:    <result code="1000">
  S:      <msg>Command completed successfully</msg>
  S:    </result>
  S:    <msgQ count="5" id="12345"/>
  S:    <trID>
  S:      <clTRID>ABC-12345</clTRID>
  S:      <svTRID>54321-XYZ</svTRID>
  S:    </trID>
  S:  </response>
  S:</epp>

  Command success or failure MUST NOT be assumed if no response is
  returned or if a returned response is malformed.  Protocol
  idempotency ensures the safety of retrying a command in cases of
  response-delivery failure.

2.7.  Protocol Extension Framework

  EPP provides an extension framework that allows features to be added
  at the protocol, object, and command-response levels.

2.7.1.  Protocol Extension

  The EPP extension framework allows for definition of new protocol
  elements identified using XML namespace notation with a reference to
  an XML schema that defines the namespace.  The <epp> element that
  identifies the beginning of a protocol instance includes multiple
  child element choices, one of which is an <extension> element whose
  children define the extension.  For example, a protocol extension
  element would be described in generic terms as follows:

  C:<epp>
  C:  <extension>
  C:    <!-- One or more extension elements. -->
  C:    <ext:foo xmlns:ext="urn:ietf:params:xml:ns:ext">



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  C:      <!-- One or more extension child elements. -->
  C:    </ext:foo>
  C:  </extension>
  C:</epp>

  This document does not define mappings for specific extensions.
  Extension specifications MUST be described in separate documents that
  define the objects and operations subject to the extension.

2.7.2.  Object Extension

  EPP provides an extensible object management framework that defines
  the syntax and semantics of protocol operations applied to a managed
  object.  This framework pushes the definition of each protocol
  operation into the context of a specific object, providing the
  ability to add mappings for new objects without having to modify the
  base protocol.

  Protocol elements that contain data specific to objects are
  identified using XML namespace notation with a reference to an XML
  schema that defines the namespace.  The schema for EPP supports use
  of dynamic object schemas on a per-command and per-response basis.
  For example, the start of an object-specific command element would be
  described in generic terms as follows:

  C:<EPPCommandName>
  C:  <object:command xmlns:object="urn:ietf:params:xml:ns:object">
  C:    <!-- One or more object-specific command elements. -->
  C:  </object:command>
  C:</EPPCommandName>

  An object-specific response element would be described similarly:

  S:<resData>
  S:  <object:resData xmlns:object="urn:ietf:params:xml:ns:object">
  S:    <!-- One or more object-specific response elements. -->
  S:  </object:resData>
  S:</resData>

  This document does not define mappings for specific objects.  The
  mapping of EPP to an object MUST be described in separate documents
  that specifically address each command and response in the context of
  the object.  A suggested object mapping outline is included as an
  appendix to this document.







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2.7.3.  Command-Response Extension

  EPP provides a facility for protocol command and response extensions.
  Protocol commands and responses MAY be extended by an <extension>
  element that contains additional elements whose syntax and semantics
  are not explicitly defined by EPP or an EPP object mapping.  This
  element is OPTIONAL.  Extensions are typically defined by agreement
  between client and server and MAY be used to extend EPP for unique
  operational needs.  A server-extended command element would be
  described in generic terms as follows:

  C:<command>
  C:  <!-- EPPCommandName can be "create", "update", etc. -->
  C:  <EPPCommandName>
  C:    <object:command xmlns:object="urn:ietf:params:xml:ns:object">
  C:      <!-- One or more object-specific command elements. -->
  C:    </object:command>
  C:  </EPPCommandName>
  C:  <extension>
  C:    <!-- One or more server-defined elements. -->
  C:  </extension>
  C:</command>

  A server-extended response element would be described similarly:

  S:<response>
  S:  <result code="1000">
  S:    <msg lang="en">Command completed successfully</msg>
  S:  </result>
  S:  <extension>
  S:    <!-- One or more server-defined elements. -->
  S:  </extension>
  S:  <trID>
  S:    <clTRID>ABC-12345</clTRID>
  S:    <svTRID>54321-XYZ</svTRID>
  S:  </trID>
  S:</response>

  This document does not define any specific server extensions.  The
  mapping of server extensions to EPP MUST be described in separate
  documents that specifically address extended commands and responses
  in the server's operational context.

2.8.  Object Identification

  Some objects, such as name servers and contacts, can have utility in
  multiple repositories.  However, maintaining disjoint copies of
  object information in multiple repositories can lead to



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  inconsistencies that have adverse consequences for the Internet.  For
  example, changing the name of a name server in one repository but not
  in a second repository that refers to the server for domain name
  delegation can produce unexpected DNS query results.

  Globally unique identifiers can help facilitate object-information
  sharing between repositories.  A globally unique identifier MUST be
  assigned to every object when the object is created; the identifier
  MUST be returned to the client as part of any request to retrieve the
  detailed attributes of an object.  Specific identifier values are a
  matter of repository policy, but they SHOULD be constructed according
  to the following algorithm:

  a.  Divide the provisioning repository world into a number of object
      repository classes.

  b.  Each repository within a class is assigned an identifier that is
      maintained by IANA.

  c.  Each repository is responsible for assigning a unique local
      identifier for each object within the repository.

  d.  The globally unique identifier is a concatenation of the local
      identifier, followed by a hyphen ("-", ASCII value 0x002D),
      followed by the repository identifier.

2.9.  Protocol Commands

  EPP provides commands to manage sessions, retrieve object
  information, and perform transformation operations on objects.  All
  EPP commands are atomic and designed so that they can be made
  idempotent, either succeeding completely or failing completely and
  producing predictable results in case of repeated executions.  This
  section describes each EPP command, including examples with
  representative server responses.

2.9.1.  Session Management Commands

  EPP provides two commands for session management: <login> to
  establish a session with a server and <logout> to end a session with
  a server.  The <login> command establishes an ongoing server session
  that preserves client identity and authorization information during
  the duration of the session.








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2.9.1.1.  EPP <login> Command

  The EPP <login> command is used to establish a session with an EPP
  server in response to a greeting issued by the server.  A <login>
  command MUST be sent to a server before any other EPP command to
  establish an ongoing session.  A server operator MAY limit the number
  of failed login attempts N, 1 <= N <= infinity, after which a login
  failure results in the connection to the server (if a connection
  exists) being closed.

  A client identifier and initial password MUST be created on the
  server before a client can successfully complete a <login> command.
  The client identifier and initial password MUST be delivered to the
  client using an out-of-band method that protects the identifier and
  password from inadvertent disclosure.

  In addition to the standard EPP command elements, the <login> command
  contains the following child elements:

  -  A <clID> element that contains the client identifier assigned to
     the client by the server.

  -  A <pw> element that contains the client's plain text password.
     The value of this element is case sensitive.

  -  An OPTIONAL <newPW> element that contains a new plain text
     password to be assigned to the client for use with subsequent
     <login> commands.  The value of this element is case sensitive.

  -  An <options> element that contains the following child elements:

     -  A <version> element that contains the protocol version to be
        used for the command or ongoing server session.

     -  A <lang> element that contains the text response language to be
        used for the command or ongoing server session commands.

     The values of the <version> and <lang> elements MUST exactly match
     one of the values presented in the EPP greeting.

  -  A <svcs> element that contains one or more <objURI> elements that
     contain namespace URIs representing the objects to be managed
     during the session.  The <svcs> element MAY contain an OPTIONAL
     <svcExtension> element that contains one or more <extURI> elements
     that identify object extensions to be used during the session.






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  The PLAIN Simple Authentication and Security Layer (SASL) mechanism
  presented in [RFC4616] describes a format for providing a user
  identifier, an authorization identifier, and a password as part of a
  single plain-text string.  The EPP authentication mechanism is
  similar, though EPP does not require a session-level authorization
  identifier and the user identifier and password are separated into
  distinct XML elements.  Additional identification and authorization
  schemes MUST be provided at other protocol layers to provide more
  robust security services.

  Example <login> command:

  C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  C:  <command>
  C:    <login>
  C:      <clID>ClientX</clID>
  C:      <pw>foo-BAR2</pw>
  C:      <newPW>bar-FOO2</newPW>
  C:      <options>
  C:        <version>1.0</version>
  C:        <lang>en</lang>
  C:      </options>
  C:      <svcs>
  C:        <objURI>urn:ietf:params:xml:ns:obj1</objURI>
  C:        <objURI>urn:ietf:params:xml:ns:obj2</objURI>
  C:        <objURI>urn:ietf:params:xml:ns:obj3</objURI>
  C:        <svcExtension>
  C:          <extURI>http://custom/obj1ext-1.0</extURI>
  C:        </svcExtension>
  C:      </svcs>
  C:    </login>
  C:    <clTRID>ABC-12345</clTRID>
  C:  </command>
  C:</epp>

  When a <login> command has been processed successfully, a server MUST
  respond with an EPP response with no <resData> element.  If
  successful, the server will respond by creating and maintaining a new
  session that SHOULD be terminated by a future <logout> command.

  Example <login> response:

  S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  S:  <response>
  S:    <result code="1000">
  S:      <msg>Command completed successfully</msg>



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  S:    </result>
  S:    <trID>
  S:      <clTRID>ABC-12345</clTRID>
  S:      <svTRID>54321-XYZ</svTRID>
  S:    </trID>
  S:  </response>
  S:</epp>

  The EPP <login> command is used to establish a session with an EPP
  server.  A <login> command MUST be rejected if received within the
  bounds of an existing session.  This command MUST be available to all
  clients.

2.9.1.2.  EPP <logout> Command

  The EPP <logout> command is used to end a session with an EPP server.
  The <logout> command MUST be represented as an empty element with no
  child elements.

  A server MAY end a session due to client inactivity or excessive
  client-session longevity.  The parameters for determining excessive
  client inactivity or session longevity are a matter of server policy
  and are not specified by this protocol.

  Transport mappings MUST explicitly describe any connection-oriented
  processing that takes place after processing a <logout> command and
  ending a session.

  Example <logout> command:

  C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  C:  <command>
  C:    <logout/>
  C:    <clTRID>ABC-12345</clTRID>
  C:  </command>
  C:</epp>

  When a <logout> command has been processed successfully, a server
  MUST respond with an EPP response with no <resData> element.  If
  successful, the server MUST also end the current session.

  Example <logout> response:

  S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  S:  <response>
  S:    <result code="1500">



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  S:      <msg>Command completed successfully; ending session</msg>
  S:    </result>
  S:    <trID>
  S:      <clTRID>ABC-12345</clTRID>
  S:      <svTRID>54321-XYZ</svTRID>
  S:    </trID>
  S:  </response>
  S:</epp>

  The EPP <logout> command is used to end a session with an EPP server.
  A <logout> command MUST be rejected if the command has not been
  preceded by a successful <login> command.  This command MUST be
  available to all clients.

2.9.2.  Query Commands

2.9.2.1.  EPP <check> Command

  The EPP <check> command is used to determine if an object can be
  provisioned within a repository.  It provides a hint that allows a
  client to anticipate the success or failure of provisioning an object
  using the <create> command as object-provisioning requirements are
  ultimately a matter of server policy.

  The elements needed to identify an object are object-specific, so the
  child elements of the <check> command are specified using the EPP
  extension framework.  In addition to the standard EPP command
  elements, the <check> command contains the following child elements:

  -  An object-specific <obj:check> element that identifies the objects
     to be queried.  Multiple objects of the same type MAY be queried
     within a single <check> command.

  Example <check> command:

  C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  C:  <command>
  C:    <check>
  C:      <obj:check xmlns:obj="urn:ietf:params:xml:ns:obj">
  C:        <obj:name>example1</obj:name>
  C:        <obj:name>example2</obj:name>
  C:        <obj:name>example3</obj:name>
  C:      </obj:check>
  C:    </check>
  C:    <clTRID>ABC-12346</clTRID>
  C:  </command>
  C:</epp>



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  When a <check> command has been processed successfully, a server MUST
  respond with an EPP <resData> element that MUST contain a child
  element that identifies the object namespace.  The child elements of
  the <resData> element are object-specific, though the EPP <resData>
  element MUST contain a child <obj:chkData> element that contains one
  or more <obj:cd> (check data) elements.  Each <obj:cd> element
  contains the following child elements:

  -  An object-specific element that identifies the queried object.
     This element MUST contain an "avail" attribute whose value
     indicates object availability (can it be provisioned or not) at
     the moment the <check> command was completed.  A value of "1" or
     "true" means that the object can be provisioned.  A value of "0"
     or "false" means that the object cannot be provisioned.

  -  An OPTIONAL <obj:reason> element that MAY be provided when an
     object cannot be provisioned.  If present, this element contains
     server-specific text to help explain why the object cannot be
     provisioned.  This text MUST be represented in the response
     language previously negotiated with the client; an OPTIONAL "lang"
     attribute MAY be present to identify the language if the
     negotiated value is something other than the default value of "en"
     (English).

  Example <check> response:

  S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  S:  <response>
  S:    <result code="1000">
  S:      <msg>Command completed successfully</msg>
  S:    </result>
  S:    <resData>
  S:      <obj:chkData xmlns:obj="urn:ietf:params:xml:ns:obj">
  S:        <obj:cd>
  S:          <obj:name avail="1">example1</obj:name>
  S:        </obj:cd>
  S:        <obj:cd>
  S:          <obj:name avail="0">example2</obj:name>
  S:          <obj:reason>In use</obj:reason>
  S:        </obj:cd>
  S:        <obj:cd>
  S:          <obj:name avail="1">example3</obj:name>
  S:        </obj:cd>
  S:      </obj:chkData>
  S:    </resData>
  S:    <trID>
  S:      <clTRID>ABC-12346</clTRID>



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  S:      <svTRID>54322-XYZ</svTRID>
  S:    </trID>
  S:  </response>
  S:</epp>

  The EPP <check> command is used to determine if an object can be
  provisioned within a repository.  This action MUST be open to all
  authorized clients.

2.9.2.2.  EPP <info> Command

  The EPP <info> command is used to retrieve information associated
  with an existing object.  The elements needed to identify an object
  and the type of information associated with an object are both
  object-specific, so the child elements of the <info> command are
  specified using the EPP extension framework.  In addition to the
  standard EPP command elements, the <info> command contains the
  following child elements:

  -  An object-specific <obj:info> element that identifies the object
     to be queried.

  Example <info> command:

  C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  C:  <command>
  C:    <info>
  C:      <obj:info xmlns:obj="urn:ietf:params:xml:ns:obj">
  C:        <!-- Object-specific elements. -->
  C:      </obj:info>
  C:    </info>
  C:    <clTRID>ABC-12346</clTRID>
  C:  </command>
  C:</epp>

  When an <info> command has been processed successfully, a server MUST
  respond with an EPP <resData> element that MUST contain a child
  element that identifies the object namespace and the Repository
  Object IDentifier (ROID) that was assigned to the object when the
  object was created.  Other child elements of the <resData> element
  are object-specific.

  Example <info> response:

  S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  S:  <response>



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  S:    <result code="1000">
  S:      <msg>Command completed successfully</msg>
  S:    </result>
  S:    <resData>
  S:      <obj:infData xmlns:obj="urn:ietf:params:xml:ns:obj">
  S:        <obj:roid>EXAMPLE1-REP</obj:roid>
  S:        <!-- Object-specific elements. -->
  S:      </obj:infData>
  S:    </resData>
  S:    <trID>
  S:      <clTRID>ABC-12346</clTRID>
  S:      <svTRID>54322-XYZ</svTRID>
  S:    </trID>
  S:  </response>
  S:</epp>

  The EPP <info> command is used to retrieve information associated
  with an existing object.  This action SHOULD be limited to authorized
  clients; restricting this action to the sponsoring client is
  RECOMMENDED.

2.9.2.3.  EPP <poll> Command

  The EPP <poll> command is used to discover and retrieve service
  messages queued by a server for individual clients.  If the message
  queue is not empty, a successful response to a <poll> command MUST
  return the first message from the message queue.  Each response
  returned from the server includes a server-unique message identifier
  that MUST be provided to acknowledge receipt of the message, and a
  counter that indicates the number of messages in the queue.  After a
  message has been received by the client, the client MUST respond to
  the message with an explicit acknowledgement to confirm that the
  message has been received.  A server MUST dequeue the message and
  decrement the queue counter after receiving acknowledgement from the
  client, making the next message in the queue (if any) available for
  retrieval.

  Servers can occasionally perform actions on objects that are not in
  direct response to a client request, or an action taken by one client
  can indirectly involve a second client.  Examples of such actions
  include deletion upon expiration, automatic renewal upon expiration,
  and transfer coordination; other types of service information MAY be
  defined as a matter of server policy.  Service messages SHOULD be
  created for passive clients affected by an action on an object.
  Service messages MAY also be created for active clients that request
  an action on an object, though such messages MUST NOT replace the
  normal protocol response to the request.  For example, <transfer>
  actions SHOULD be reported to the client that has the authority to



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  approve or reject a transfer request.  Other methods of server-client
  action notification, such as offline reporting, are also possible and
  are beyond the scope of this specification.

  Message queues can consume server resources if clients do not
  retrieve and acknowledge messages on a regular basis.  Servers MAY
  implement other mechanisms to dequeue and deliver messages if queue
  maintenance needs exceed server resource consumption limits.  Server
  operators SHOULD consider time-sensitivity and resource management
  factors when selecting a delivery method for service information
  because some message types can be reasonably delivered using non-
  protocol methods that require fewer server resources.

  Some of the information returned in response to a <poll> command can
  be object-specific, so some child elements of the <poll> response MAY
  be specified using the EPP extension framework.  The <poll> command
  MUST be represented as an empty element with no child elements.  An
  "op" attribute with value "req" is REQUIRED to retrieve the first
  message from the server message queue.  An "op" attribute (with value
  "ack") and a "msgID" attribute (whose value corresponds to the value
  of the "id" attribute copied from the <msg> element in the message
  being acknowledged) are REQUIRED to acknowledge receipt of a message.

  Example <poll> command:

  C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  C:  <command>
  C:    <poll op="req"/>
  C:    <clTRID>ABC-12345</clTRID>
  C:  </command>
  C:</epp>

  The returned result code notes that a message has been dequeued and
  returned in response to a <poll> command.

  Example <poll> response with object-specific information:

  S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  S:  <response>
  S:    <result code="1301">
  S:      <msg>Command completed successfully; ack to dequeue</msg>
  S:    </result>
  S:    <msgQ count="5" id="12345">
  S:      <qDate>2000-06-08T22:00:00.0Z</qDate>
  S:      <msg>Transfer requested.</msg>
  S:    </msgQ>



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  S:    <resData>
  S:      <obj:trnData
  S:       xmlns:obj="urn:ietf:params:xml:ns:obj-1.0">
  S:        <obj:name>example.com</obj:name>
  S:        <obj:trStatus>pending</obj:trStatus>
  S:        <obj:reID>ClientX</obj:reID>
  S:        <obj:reDate>2000-06-08T22:00:00.0Z</obj:reDate>
  S:        <obj:acID>ClientY</obj:acID>
  S:        <obj:acDate>2000-06-13T22:00:00.0Z</obj:acDate>
  S:        <obj:exDate>2002-09-08T22:00:00.0Z</obj:exDate>
  S:      </obj:trnData>
  S:    </resData>
  S:    <trID>
  S:      <clTRID>ABC-12345</clTRID>
  S:      <svTRID>54321-XYZ</svTRID>
  S:    </trID>
  S:  </response>
  S:</epp>

  A client MUST acknowledge each response to dequeue the message and
  make subsequent messages available for retrieval.

  Example <poll> acknowledgement command:

  C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  C:  <command>
  C:    <poll op="ack" msgID="12345"/>
  C:    <clTRID>ABC-12346</clTRID>
  C:  </command>
  C:</epp>

  A <poll> acknowledgement response notes the ID of the message that
  has been acknowledged and the number of messages remaining in the
  queue.

  Example <poll> acknowledgement response:

  S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  S:  <response>
  S:    <result code="1000">
  S:      <msg>Command completed successfully</msg>
  S:    </result>
  S:    <msgQ count="4" id="12345"/>
  S:    <trID>
  S:      <clTRID>ABC-12346</clTRID>
  S:      <svTRID>54322-XYZ</svTRID>



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  S:    </trID>
  S:  </response>
  S:</epp>

  Service messages can also be returned without object information.

  Example <poll> response with mixed message content and without
  object-specific information:

  S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  S:  <response>
  S:    <result code="1301">
  S:      <msg>Command completed successfully; ack to dequeue</msg>
  S:    </result>
  S:    <msgQ count="4" id="12346">
  S:      <qDate>2000-06-08T22:10:00.0Z</qDate>
  S:      <msg lang="en">Credit balance low.
  S:        <limit>100</limit><bal>5</bal>
  S:      </msg>
  S:    </msgQ>
  S:    <trID>
  S:      <clTRID>ABC-12346</clTRID>
  S:      <svTRID>54321-XYZ</svTRID>
  S:    </trID>
  S:  </response>
  S:</epp>

  The returned result code and message is used to note an empty server
  message queue.

  Example <poll> response to note an empty message queue:

     S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
     S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
     S:  <response>
     S:    <result code="1300">
     S:      <msg>Command completed successfully; no messages</msg>
     S:    </result>
     S:    <trID>
     S:      <clTRID>ABC-12346</clTRID>
     S:      <svTRID>54321-XYZ</svTRID>
     S:    </trID>
     S:  </response>
     S:</epp>






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  The EPP <poll> command is used to discover and retrieve client
  service messages from a server.  This action SHOULD be limited to
  authorized clients; queuing service messages and limiting queue
  access on a per-client basis is RECOMMENDED.

2.9.2.4.  EPP <transfer> Query Command

  The EPP <transfer> command provides a query operation that allows a
  client to determine real-time status of pending and completed
  transfer requests.  The elements needed to identify an object that is
  the subject of a transfer request are object-specific, so the child
  elements of the <transfer> query command are specified using the EPP
  extension framework.  In addition to the standard EPP command
  elements, the <transfer> command contains an "op" attribute with
  value "query" and the following child elements:

  -  An object-specific <obj:transfer> element that identifies the
     object whose transfer status is requested.

  Transfer status is typically considered sensitive information by the
  clients involved in the operation.  Object mappings MUST provide
  features to restrict transfer queries to authorized clients, such as
  by requiring authorization information as part of the request.

  Example <transfer> query command:

  C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  C:  <command>
  C:    <transfer op="query">
  C:      <obj:transfer xmlns:obj="urn:ietf:params:xml:ns:obj">
  C:        <!-- Object-specific elements. -->
  C:      </obj:transfer>
  C:    </transfer>
  C:    <clTRID>ABC-12346</clTRID>
  C:  </command>
  C:</epp>

  When a <transfer> query command has been processed successfully, a
  server MUST respond with an EPP <resData> element that MUST contain a
  child element that identifies the object namespace.  The child
  elements of the <resData> element are object-specific, but they MUST
  include elements that identify the object, the status of the
  transfer, the identifier of the client that requested the transfer,
  the date and time that the request was made, the identifier of the
  client that is authorized to act on the request, the date and time by





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  which an action is expected, and an OPTIONAL date and time noting
  changes in the object's validity period (if applicable) that occur as
  a result of the transfer.

  Example <transfer> query response:

  S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  S:  <response>
  S:    <result code="1000">
  S:      <msg>Command completed successfully</msg>
  S:    </result>
  S:    <resData>
  S:      <obj:trnData xmlns:obj="urn:ietf:params:xml:ns:obj">
  S:        <obj:name>example</obj:name>
  S:        <obj:trStatus>pending</obj:trStatus>
  S:        <obj:reID>ClientX</obj:reID>
  S:        <obj:reDate>2000-06-08T22:00:00.0Z</obj:reDate>
  S:        <obj:acID>ClientY</obj:acID>
  S:        <obj:acDate>2000-06-13T22:00:00.0Z</obj:acDate>
  S:        <obj:exDate>2002-09-08T22:00:00.0Z</obj:exDate>
  S:      </obj:trnData>
  S:    </resData>
  S:    <trID>
  S:      <clTRID>ABC-12346</clTRID>
  S:      <svTRID>54322-XYZ</svTRID>
  S:    </trID>
  S:  </response>
  S:</epp>

  The EPP <transfer> command provides a query operation that allows a
  client to determine real-time status of pending and completed
  transfer requests.  This action SHOULD be limited to authorized
  clients; restricting queries to the requesting and responding clients
  is RECOMMENDED.  Object transfer MAY be unavailable or limited by
  object-specific policies.

2.9.3.  Object Transform Commands

  EPP provides five commands to transform objects: <create> to create
  an instance of an object with a server, <delete> to remove an
  instance of an object from a server, <renew> to extend the validity
  period of an object, <transfer> to manage changes in client
  sponsorship of an object, and <update> to change information
  associated with an object.






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2.9.3.1.  EPP <create> Command

  The EPP <create> command is used to create an instance of an object.
  An object can be created for an indefinite period of time, or an
  object can be created for a specific validity period.  The EPP
  mapping for an object MUST describe the status of an object with
  respect to time in order to include expected client and server
  behavior if a validity period is used.

  The elements needed to identify an object and associated attributes
  are object-specific, so the child elements of the <create> command
  are specified using the EPP extension framework.  In addition to the
  standard EPP command elements, the <create> command contains the
  following child elements:

  -  An object-specific <obj:create> element that identifies the object
     to be created and the elements that are required to create the
     object.

  Example <create> command:

  C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  C:  <command>
  C:    <create>
  C:      <obj:create xmlns:obj="urn:ietf:params:xml:ns:obj">
  C:        <!-- Object-specific elements. -->
  C:      </obj:create>
  C:    </create>
  C:    <clTRID>ABC-12345</clTRID>
  C:  </command>
  C:</epp>

  When a <create> command has been processed successfully, a server MAY
  respond with an EPP <resData> element that MUST contain a child
  element that identifies the object namespace.  The child elements of
  the <resData> element are object-specific.

  Example <create> response with <resData>:

  S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  S:  <response>
  S:    <result code="1000">
  S:      <msg>Command completed successfully</msg>
  S:    </result>
  S:    <resData>
  S:      <obj:creData xmlns:obj="urn:ietf:params:xml:ns:obj">



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  S:        <!-- Object-specific elements. -->
  S:      </obj:creData>
  S:    </resData>
  S:    <trID>
  S:      <clTRID>ABC-12345</clTRID>
  S:      <svTRID>54321-XYZ</svTRID>
  S:    </trID>
  S:  </response>
  S:</epp>

  The EPP <create> command is used to create an instance of an object.
  This action SHOULD be limited to authorized clients and MAY be
  restricted on a per-client basis.

2.9.3.2.  EPP <delete> Command

  The EPP <delete> command is used to remove an instance of an existing
  object.  The elements needed to identify an object are object-
  specific, so the child elements of the <delete> command are specified
  using the EPP extension framework.  In addition to the standard EPP
  command elements, the <delete> command contains the following child
  elements:

  -  An object-specific <obj:delete> element that identifies the object
     to be deleted.

  Example <delete> command:

  C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  C:  <command>
  C:    <delete>
  C:      <obj:delete xmlns:obj="urn:ietf:params:xml:ns:obj">
  C:        <!-- Object-specific elements. -->
  C:      </obj:delete>
  C:    </delete>
  C:    <clTRID>ABC-12346</clTRID>
  C:  </command>
  C:</epp>

  When a <delete> command has been processed successfully, a server MAY
  respond with an EPP <resData> element that MUST contain a child
  element that identifies the object namespace.  The child elements of
  the <resData> element are object-specific.







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  Example <delete> response without <resData>:

  S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  S:  <response>
  S:    <result code="1000">
  S:      <msg>Command completed successfully</msg>
  S:    </result>
  S:    <trID>
  S:      <clTRID>ABC-12346</clTRID>
  S:      <svTRID>54322-XYZ</svTRID>
  S:    </trID>
  S:  </response>
  S:</epp>

  The EPP <delete> command is used to remove an instance of an existing
  object.  This action SHOULD be limited to authorized clients;
  restricting this action to the sponsoring client is RECOMMENDED.

2.9.3.3.  EPP <renew> Command

  The EPP <renew> command is used to extend the validity period of an
  existing object.  The elements needed to identify and extend the
  validity period of an object are object-specific, so the child
  elements of the <renew> command are specified using the EPP extension
  framework.  In addition to the standard EPP command elements, the
  <renew> command contains the following child elements:

  -  An object-specific <obj:renew> element that identifies the object
     to be renewed and the elements that are required to extend the
     validity period of the object.

  Example <renew> command:

  C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  C:  <command>
  C:    <renew>
  C:      <obj:renew xmlns:obj="urn:ietf:params:xml:ns:obj">
  C:        <!-- Object-specific elements. -->
  C:      </obj:renew>
  C:    </renew>
  C:    <clTRID>ABC-12346</clTRID>
  C:  </command>
  C:</epp>






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  When a <renew> command has been processed successfully, a server MAY
  respond with an EPP <resData> element that MUST contain a child
  element that identifies the object namespace.  The child elements of
  the <resData> element are object-specific.

  Example <renew> response with <resData>:

  S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  S:  <response>
  S:    <result code="1000">
  S:      <msg>Command completed successfully</msg>
  S:    </result>
  S:    <resData>
  S:      <obj:renData xmlns:obj="urn:ietf:params:xml:ns:obj">
  S:        <!-- Object-specific elements. -->
  S:      </obj:renData>
  S:    </resData>
  S:    <trID>
  S:      <clTRID>ABC-12346</clTRID>
  S:      <svTRID>54322-XYZ</svTRID>
  S:    </trID>
  S:  </response>
  S:</epp>

  The EPP <renew> command is used to extend the validity period of an
  existing object.  This action SHOULD be limited to authorized
  clients; restricting this action to the sponsoring client is
  RECOMMENDED.  Object renewal MAY be unavailable or limited by object-
  specific policies.

2.9.3.4.  EPP <transfer> Command

  The EPP <transfer> command is used to manage changes in client
  sponsorship of an existing object.  Clients can initiate a transfer
  request, cancel a transfer request, approve a transfer request, and
  reject a transfer request using the "op" command attribute.

  A client who wishes to assume sponsorship of a known object from
  another client uses the <transfer> command with the value of the "op"
  attribute set to "request".  Once a transfer has been requested, the
  same client can cancel the request using a <transfer> command with
  the value of the "op" attribute set to "cancel".  A request to cancel
  the transfer MUST be sent to the server before the current sponsoring
  client either approves or rejects the transfer request and before the
  server automatically processes the request due to responding client
  inactivity.




Hollenbeck                  Standards Track                    [Page 35]

RFC 5730                          EPP                        August 2009


  Once a transfer request has been received by the server, the server
  MUST notify the current sponsoring client of the requested transfer
  either by queuing a service message for retrieval via the <poll>
  command or by using an out-of-band mechanism to inform the client of
  the request.  The current status of a pending <transfer> command for
  any object can be found using the <transfer> query command.  Transfer
  service messages MUST include the object-specific elements specified
  for <transfer> command responses.

  The current sponsoring client MAY explicitly approve or reject the
  transfer request.  The client can approve the request using a
  <transfer> command with the value of the "op" attribute set to
  "approve".  The client can reject the request using a <transfer>
  command with the value of the "op" attribute set to "reject".

  A server MAY automatically approve or reject all transfer requests
  that are not explicitly approved or rejected by the current
  sponsoring client within a fixed amount of time.  The amount of time
  to wait for explicit action and the default server behavior are local
  matters not specified by EPP, but they SHOULD be documented in a
  server-specific profile document that describes default server
  behavior for client information.

  Objects eligible for transfer MUST have associated authorization
  information that MUST be provided to complete a <transfer> command.
  The type of authorization information required is object-specific;
  passwords or more complex mechanisms based on public key cryptography
  are typical.

  The elements needed to identify and complete the transfer of an
  object are object-specific, so the child elements of the <transfer>
  command are specified using the EPP extension framework.  In addition
  to the standard EPP command elements, the <transfer> command contains
  the following child elements:

  -  An object-specific <obj:transfer> element that identifies the
     object to be transferred and the elements that are required to
     process the transfer command.

  Example <transfer> command:

  C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  C:  <command>
  C:    <transfer op="request">
  C:      <obj:transfer xmlns:obj="urn:ietf:params:xml:ns:obj">
  C:        <!-- Object-specific elements. -->
  C:      </obj:transfer>



Hollenbeck                  Standards Track                    [Page 36]

RFC 5730                          EPP                        August 2009


  C:    </transfer>
  C:    <clTRID>ABC-12346</clTRID>
  C:  </command>
  C:</epp>

  When a <transfer> command has been processed successfully, a server
  MUST respond with an EPP <resData> element that MUST contain a child
  element that identifies the object namespace.  The child elements of
  the <resData> element are object-specific, but they MUST include
  elements that identify the object, the status of the transfer, the
  identifier of the client that requested the transfer, the date and
  time that the request was made, the identifier of the client that is
  authorized to act on the request, the date and time by which an
  action is expected, and an OPTIONAL date and time noting changes in
  the object's validity period (if applicable) that occur as a result
  of the transfer.

  Example <transfer> response with <resData>:

  S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  S:  <response>
  S:    <result code="1001">
  S:      <msg>Command completed successfully; action pending</msg>
  S:    </result>
  S:    <resData>
  S:      <obj:trnData xmlns:obj="urn:ietf:params:xml:ns:obj">
  S:        <obj:name>example</obj:name>
  S:        <obj:trStatus>pending</obj:trStatus>
  S:        <obj:reID>ClientX</obj:reID>
  S:        <obj:reDate>2000-06-08T22:00:00.0Z</obj:reDate>
  S:        <obj:acID>ClientY</obj:acID>
  S:        <obj:acDate>2000-06-13T22:00:00.0Z</obj:acDate>
  S:        <obj:exDate>2002-09-08T22:00:00.0Z</obj:exDate>
  S:      </obj:trnData>
  S:    </resData>
  S:    <trID>
  S:      <clTRID>ABC-12346</clTRID>
  S:      <svTRID>54322-XYZ</svTRID>
  S:    </trID>
  S:  </response>
  S:</epp>

  The EPP <transfer> command is used to manage changes in client
  sponsorship of an existing object.  This action SHOULD be limited to
  authorized clients; restricting <transfer> requests to a client other
  than the current sponsoring client, <transfer> approval requests to




Hollenbeck                  Standards Track                    [Page 37]

RFC 5730                          EPP                        August 2009


  the current sponsoring client, and <transfer> cancellation requests
  to the original requesting client is RECOMMENDED.  Object transfer
  MAY be unavailable or limited by object-specific policies.

2.9.3.5.  EPP <update> Command

  The EPP <update> command is used to change information associated
  with an existing object.  The elements needed to identify and modify
  an object are object-specific, so the child elements of the <update>
  command are specified using the EPP extension framework.  In addition
  to the standard EPP command elements, the <update> command contains
  the following child elements:

  -  An object-specific <obj:update> element that identifies the object
     to be updated and the elements that are required to modify the
     object.  Object-specific elements MUST identify values to be
     added, values to be removed, or values to be changed.

  Example <update> command:

  C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  C:  <command>
  C:    <update>
  C:      <obj:update xmlns:obj="urn:ietf:params:xml:ns:obj">
  C:        <!-- Object-specific elements. -->
  C:      </obj:update>
  C:    </update>
  C:    <clTRID>ABC-12346</clTRID>
  C:  </command>
  C:</epp>

  When an <update> command has been processed successfully, a server
  MAY respond with an EPP <resData> element that MUST contain a child
  element that identifies the object namespace.  The child elements of
  the <resData> element are object-specific.

  Example <update> response without <resData>:

  S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
  S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
  S:  <response>
  S:    <result code="1000">
  S:      <msg>Command completed successfully</msg>
  S:    </result>
  S:    <trID>
  S:      <clTRID>ABC-12346</clTRID>
  S:      <svTRID>54322-XYZ</svTRID>



Hollenbeck                  Standards Track                    [Page 38]

RFC 5730                          EPP                        August 2009


  S:    </trID>
  S:  </response>
  S:</epp>

  The EPP <update> command is used to change information associated
  with an existing object.  This action SHOULD be limited to authorized
  clients; restricting this action to the sponsoring client is
  RECOMMENDED.

3.  Result Codes

  EPP result codes are based on the theory of reply codes described in
  section 4.2.1 of [RFC5321].  EPP uses four decimal digits to describe
  the success or failure of each EPP command.  Each of the digits of
  the reply have special significance.

  The first digit denotes command success or failure.  The second digit
  denotes the response category, such as command syntax or security.
  The third and fourth digits provide explicit response detail within
  each response category.

  There are two values for the first digit of the reply code:

  1yzz    Positive completion reply.  The command was accepted and
          processed by the system without error.

  2yzz    Negative completion reply.  The command was not accepted, and
          the requested action did not occur.

  The second digit groups responses into one of six specific
  categories:

  x0zz    Protocol Syntax

  x1zz    Implementation-specific Rules

  x2zz    Security

  x3zz    Data Management

  x4zz    Server System

  x5zz    Connection Management

  The third and fourth digits provide response detail within the
  categories defined by the first and second digits.  The complete list
  of valid result codes is enumerated below and in the normative
  schema.



Hollenbeck                  Standards Track                    [Page 39]

RFC 5730                          EPP                        August 2009


  Every EPP response MUST include a result code and a human-readable
  description of the result code.  The language used to represent the
  description MAY be identified using an instance of the "lang"
  attribute within the <msg> element.  If not specified, the default
  language is English, identified as "en".  A description of the
  structure of valid values for the "lang" attribute is described in
  [RFC4646].

  Response text MAY be translated into other languages, though the
  translation MUST preserve the meaning of the code as described here.
  Response code values MUST NOT be changed when translating text.

  Response text in the table below is enclosed in quotes to clearly
  mark the beginning and ending of each response string.  Quotes MUST
  NOT be used to delimit these strings when returning response text via
  the protocol.

  Successful command completion responses:

     Code    Response text in English

     ____    ________________________

     1000    "Command completed successfully"

             This is the usual response code for a successfully
             completed command that is not addressed by any other
             1xxx-series response code.

     1001    "Command completed successfully; action pending"

             This response code MUST be returned when responding to a
             command that requires offline activity before the
             requested action can be completed.  See Section 2 for a
             description of other processing requirements.

     1300    "Command completed successfully; no messages"

             This response code MUST be returned when responding to a
             <poll> request command and the server message queue is
             empty.

     1301    "Command completed successfully; ack to dequeue"

             This response code MUST be returned when responding to a
             <poll> request command and a message has been retrieved
             from the server message queue.




Hollenbeck                  Standards Track                    [Page 40]

RFC 5730                          EPP                        August 2009


     1500    "Command completed successfully; ending session"

             This response code MUST be returned when responding to a
             successful <logout> command.

  Command error responses:

     Code    Response text in English

     ____    ________________________

     2000    "Unknown command"

             This response code MUST be returned when a server receives
             a command element that is not defined by EPP.

     2001    "Command syntax error"

             This response code MUST be returned when a server receives
             an improperly formed command element.

     2002    "Command use error"

             This response code MUST be returned when a server receives
             a properly formed command element but the command cannot
             be executed due to a sequencing or context error.  For
             example, a <logout> command cannot be executed without
             having first completed a <login> command.

     2003    "Required parameter missing"

             This response code MUST be returned when a server receives
             a command for which a required parameter value has not
             been provided.

     2004    "Parameter value range error"

             This response code MUST be returned when a server receives
             a command parameter whose value is outside the range of
             values specified by the protocol.  The error value SHOULD
             be returned via a <value> element in the EPP response.

     2005    "Parameter value syntax error"

             This response code MUST be returned when a server receives
             a command containing a parameter whose value is improperly
             formed.  The error value SHOULD be returned via a <value>
             element in the EPP response.



Hollenbeck                  Standards Track                    [Page 41]

RFC 5730                          EPP                        August 2009


     2100    "Unimplemented protocol version"

             This response code MUST be returned when a server receives
             a command element specifying a protocol version that is
             not implemented by the server.

     2101    "Unimplemented command"

             This response code MUST be returned when a server receives
             a valid EPP command element that is not implemented by the
             server.  For example, a <transfer> command can be
             unimplemented for certain object types.

     2102    "Unimplemented option"

             This response code MUST be returned when a server receives
             a valid EPP command element that contains a protocol
             option that is not implemented by the server.

     2103    "Unimplemented extension"

             This response code MUST be returned when a server receives
             a valid EPP command element that contains a protocol
             command extension that is not implemented by the server.

     2104    "Billing failure"

             This response code MUST be returned when a server attempts
             to execute a billable operation and the command cannot be
             completed due to a client-billing failure.

     2105    "Object is not eligible for renewal"

             This response code MUST be returned when a client attempts
             to <renew> an object that is not eligible for renewal in
             accordance with server policy.

     2106    "Object is not eligible for transfer"

             This response code MUST be returned when a client attempts
             to <transfer> an object that is not eligible for transfer
             in accordance with server policy.

     2200    "Authentication error"

             This response code MUST be returned when a server notes an
             error when validating client credentials.




Hollenbeck                  Standards Track                    [Page 42]

RFC 5730                          EPP                        August 2009


     2201    "Authorization error"

             This response code MUST be returned when a server notes a
             client-authorization error when executing a command.  This
             error is used to note that a client lacks privileges to
             execute the requested command.

     2202    "Invalid authorization information"

             This response code MUST be returned when a server receives
             invalid command authorization information when attempting
             to confirm authorization to execute a command.  This error
             is used to note that a client has the privileges required
             to execute the requested command, but the authorization
             information provided by the client does not match the
             authorization information archived by the server.

     2300    "Object pending transfer"

             This response code MUST be returned when a server receives
             a command to transfer of an object that is pending
             transfer due to an earlier transfer request.

     2301    "Object not pending transfer"

             This response code MUST be returned when a server receives
             a command to confirm, reject, or cancel the transfer of an
             object when no command has been made to transfer the
             object.

     2302    "Object exists"

             This response code MUST be returned when a server receives
             a command to create an object that already exists in the
             repository.

     2303    "Object does not exist"

             This response code MUST be returned when a server receives
             a command to query or transform an object that does not
             exist in the repository.

     2304    "Object status prohibits operation"

             This response code MUST be returned when a server receives
             a command to transform an object that cannot be completed
             due to server policy or business practices.  For example,
             a server can disallow <transfer> commands under terms and



Hollenbeck                  Standards Track                    [Page 43]

RFC 5730                          EPP                        August 2009


             conditions that are matters of local policy, or the server
             might have received a <delete> command for an object whose
             status prohibits deletion.

     2305    "Object association prohibits operation"

             This response code MUST be returned when a server receives
             a command to transform an object that cannot be completed
             due to dependencies on other objects that are associated
             with the target object.  For example, a server can
             disallow <delete> commands while an object has active
             associations with other objects.

     2306    "Parameter value policy error"

             This response code MUST be returned when a server receives
             a command containing a parameter value that is
             syntactically valid but semantically invalid due to local
             policy.  For example, the server can support a subset of a
             range of valid protocol parameter values.  The error value
             SHOULD be returned via a <value> element in the EPP
             response.

     2307    "Unimplemented object service"

             This response code MUST be returned when a server receives
             a command to operate on an object service that is not
             supported by the server.

     2308    "Data management policy violation"

             This response code MUST be returned when a server receives
             a command whose execution results in a violation of server
             data management policies.  For example, removing all
             attribute values or object associations from an object
             might be a violation of a server's data management
             policies.

     2400    "Command failed"

             This response code MUST be returned when a server is
             unable to execute a command due to an internal server
             error that is not related to the protocol.  The failure
             can be transient.  The server MUST keep any ongoing
             session active.






Hollenbeck                  Standards Track                    [Page 44]

RFC 5730                          EPP                        August 2009


     2500    "Command failed; server closing connection"

             This response code MUST be returned when a server receives
             a command that cannot be completed due to an internal
             server error that is not related to the protocol.  The
             failure is not transient and will cause other commands to
             fail as well.  The server MUST end the active session and
             close the existing connection.

     2501    "Authentication error; server closing connection"

             This response code MUST be returned when a server notes an
             error when validating client credentials and a
             server-defined limit on the number of allowable failures
             has been exceeded.  The server MUST close the existing
             connection.

     2502    "Session limit exceeded; server closing connection"

             This response code MUST be returned when a server receives
             a <login> command and the command cannot be completed
             because the client has exceeded a system-defined limit on
             the number of sessions that the client can establish.  It
             might be possible to establish a session by ending
             existing unused sessions and closing inactive connections.

4.  Formal Syntax

  EPP is specified in XML Schema notation.  The formal syntax presented
  here is a complete schema representation of EPP suitable for
  automated validation of EPP XML instances.

  Two schemas are presented here.  The first schema is the base EPP
  schema.  The second schema defines elements and structures that can
  be used by both the base EPP schema and object mapping schema.  The
  BEGIN and END tags are not part of the schema; they are used to note
  the beginning and ending of the schema for URI registration purposes.

4.1.  Base Schema

  Copyright (c) 2009 IETF Trust and the persons identified as authors
  of the code.  All rights reserved.

  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions
  are met:





Hollenbeck                  Standards Track                    [Page 45]

RFC 5730                          EPP                        August 2009


  o  Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.

  o  Redistributions in binary form must reproduce the above copyright
     notice, this list of conditions and the following disclaimer in
     the documentation and/or other materials provided with the
     distribution.

  o  Neither the name of Internet Society, IETF or IETF Trust, nor the
     names of specific contributors, may be used to endorse or promote
     products derived from this software without specific prior written
     permission.

  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

  BEGIN
  <?xml version="1.0" encoding="UTF-8"?>

  <schema targetNamespace="urn:ietf:params:xml:ns:epp-1.0"
          xmlns:epp="urn:ietf:params:xml:ns:epp-1.0"
          xmlns:eppcom="urn:ietf:params:xml:ns:eppcom-1.0"
          xmlns="http://www.w3.org/2001/XMLSchema"
          elementFormDefault="qualified">

  <!--
  Import common element types.
  -->
    <import namespace="urn:ietf:params:xml:ns:eppcom-1.0"/>

    <annotation>
      <documentation>
        Extensible Provisioning Protocol v1.0 schema.
      </documentation>
    </annotation>

  <!--
  Every EPP XML instance must begin with this element.
  -->



Hollenbeck                  Standards Track                    [Page 46]

RFC 5730                          EPP                        August 2009


    <element name="epp" type="epp:eppType"/>

  <!--
  An EPP XML instance must contain a greeting, hello, command,
  response, or extension.
  -->
    <complexType name="eppType">
      <choice>
        <element name="greeting" type="epp:greetingType"/>
        <element name="hello"/>
        <element name="command" type="epp:commandType"/>
        <element name="response" type="epp:responseType"/>
        <element name="extension" type="epp:extAnyType"/>
      </choice>
    </complexType>

  <!--
  A greeting is sent by a server in response to a client connection
  or <hello>.
  -->
    <complexType name="greetingType">
      <sequence>
        <element name="svID" type="epp:sIDType"/>
        <element name="svDate" type="dateTime"/>
        <element name="svcMenu" type="epp:svcMenuType"/>
        <element name="dcp" type="epp:dcpType"/>
      </sequence>
    </complexType>

  <!--
  Server IDs are strings with minimum and maximum length restrictions.
  -->
    <simpleType name="sIDType">
      <restriction base="normalizedString">
        <minLength value="3"/>
        <maxLength value="64"/>
      </restriction>
    </simpleType>

  <!--
  A server greeting identifies available object services.
  -->
    <complexType name="svcMenuType">
      <sequence>
        <element name="version" type="epp:versionType"
         maxOccurs="unbounded"/>
        <element name="lang" type="language"
         maxOccurs="unbounded"/>



Hollenbeck                  Standards Track                    [Page 47]

RFC 5730                          EPP                        August 2009


        <element name="objURI" type="anyURI"
         maxOccurs="unbounded"/>
        <element name="svcExtension" type="epp:extURIType"
         minOccurs="0"/>
      </sequence>
    </complexType>

  <!--
  Data Collection Policy types.
  -->
    <complexType name="dcpType">
      <sequence>
        <element name="access" type="epp:dcpAccessType"/>
        <element name="statement" type="epp:dcpStatementType"
         maxOccurs="unbounded"/>
        <element name="expiry" type="epp:dcpExpiryType"
         minOccurs="0"/>
      </sequence>
    </complexType>

    <complexType name="dcpAccessType">
      <choice>
        <element name="all"/>
        <element name="none"/>
        <element name="null"/>
        <element name="other"/>
        <element name="personal"/>
        <element name="personalAndOther"/>
      </choice>
    </complexType>

    <complexType name="dcpStatementType">
      <sequence>
        <element name="purpose" type="epp:dcpPurposeType"/>
        <element name="recipient" type="epp:dcpRecipientType"/>
        <element name="retention" type="epp:dcpRetentionType"/>
      </sequence>
    </complexType>

    <complexType name="dcpPurposeType">
      <sequence>
        <element name="admin"
         minOccurs="0"/>
        <element name="contact"
         minOccurs="0"/>
        <element name="other"
         minOccurs="0"/>
        <element name="prov"



Hollenbeck                  Standards Track                    [Page 48]

RFC 5730                          EPP                        August 2009


         minOccurs="0"/>
      </sequence>
    </complexType>

    <complexType name="dcpRecipientType">
      <sequence>
        <element name="other"
         minOccurs="0"/>
        <element name="ours" type="epp:dcpOursType"
         minOccurs="0" maxOccurs="unbounded"/>
        <element name="public"
         minOccurs="0"/>
        <element name="same"
         minOccurs="0"/>
        <element name="unrelated"
         minOccurs="0"/>
      </sequence>
    </complexType>

    <complexType name="dcpOursType">
      <sequence>
        <element name="recDesc" type="epp:dcpRecDescType"
         minOccurs="0"/>
      </sequence>
    </complexType>

    <simpleType name="dcpRecDescType">
      <restriction base="token">
        <minLength value="1"/>
        <maxLength value="255"/>
      </restriction>
    </simpleType>

    <complexType name="dcpRetentionType">
      <choice>
        <element name="business"/>
        <element name="indefinite"/>
        <element name="legal"/>
        <element name="none"/>
        <element name="stated"/>
      </choice>
    </complexType>

    <complexType name="dcpExpiryType">
      <choice>
        <element name="absolute" type="dateTime"/>
        <element name="relative" type="duration"/>
      </choice>



Hollenbeck                  Standards Track                    [Page 49]

RFC 5730                          EPP                        August 2009


    </complexType>

  <!--
  Extension framework types.
  -->
    <complexType name="extAnyType">
      <sequence>
        <any namespace="##other"
         maxOccurs="unbounded"/>
      </sequence>
    </complexType>

    <complexType name="extURIType">
      <sequence>
        <element name="extURI" type="anyURI"
         maxOccurs="unbounded"/>
      </sequence>
    </complexType>

  <!--
  An EPP version number is a dotted pair of decimal numbers.
  -->
    <simpleType name="versionType">
      <restriction base="token">
        <pattern value="[1-9]+\.[0-9]+"/>
        <enumeration value="1.0"/>
      </restriction>
    </simpleType>

  <!--
  Command types.
  -->
    <complexType name="commandType">
      <sequence>
        <choice>
          <element name="check" type="epp:readWriteType"/>
          <element name="create" type="epp:readWriteType"/>
          <element name="delete" type="epp:readWriteType"/>
          <element name="info" type="epp:readWriteType"/>
          <element name="login" type="epp:loginType"/>
          <element name="logout"/>
          <element name="poll" type="epp:pollType"/>
          <element name="renew" type="epp:readWriteType"/>
          <element name="transfer" type="epp:transferType"/>
          <element name="update" type="epp:readWriteType"/>
        </choice>
        <element name="extension" type="epp:extAnyType"
         minOccurs="0"/>



Hollenbeck                  Standards Track                    [Page 50]

RFC 5730                          EPP                        August 2009


        <element name="clTRID" type="epp:trIDStringType"
         minOccurs="0"/>
      </sequence>
    </complexType>

  <!--
  The <login> command.
  -->
    <complexType name="loginType">
      <sequence>
        <element name="clID" type="eppcom:clIDType"/>
        <element name="pw" type="epp:pwType"/>
        <element name="newPW" type="epp:pwType"
         minOccurs="0"/>
        <element name="options" type="epp:credsOptionsType"/>
        <element name="svcs" type="epp:loginSvcType"/>
      </sequence>
    </complexType>

    <complexType name="credsOptionsType">
      <sequence>
        <element name="version" type="epp:versionType"/>
        <element name="lang" type="language"/>
      </sequence>
    </complexType>

    <simpleType name="pwType">
      <restriction base="token">
        <minLength value="6"/>
        <maxLength value="16"/>
      </restriction>
    </simpleType>

    <complexType name="loginSvcType">
      <sequence>
        <element name="objURI" type="anyURI"
         maxOccurs="unbounded"/>
        <element name="svcExtension" type="epp:extURIType"
         minOccurs="0"/>
      </sequence>
    </complexType>

  <!--
  The <poll> command.
  -->
    <complexType name="pollType">
      <attribute name="op" type="epp:pollOpType"
       use="required"/>



Hollenbeck                  Standards Track                    [Page 51]

RFC 5730                          EPP                        August 2009


      <attribute name="msgID" type="token"/>
    </complexType>

    <simpleType name="pollOpType">
      <restriction base="token">
        <enumeration value="ack"/>
        <enumeration value="req"/>
      </restriction>
    </simpleType>

  <!--
  The <transfer> command.  This is object-specific, and uses attributes
  to identify the requested operation.
  -->
    <complexType name="transferType">
      <sequence>
        <any namespace="##other"/>
      </sequence>
      <attribute name="op" type="epp:transferOpType"
       use="required"/>
    </complexType>

    <simpleType name="transferOpType">
      <restriction base="token">
        <enumeration value="approve"/>
        <enumeration value="cancel"/>
        <enumeration value="query"/>
        <enumeration value="reject"/>
        <enumeration value="request"/>
      </restriction>
    </simpleType>

  <!--
  All other object-centric commands.  EPP doesn't specify the syntax or
  semantics of object-centric command elements.  The elements MUST be
  described in detail in another schema specific to the object.
  -->
    <complexType name="readWriteType">
      <sequence>
        <any namespace="##other"/>
      </sequence>
    </complexType>

    <complexType name="trIDType">
      <sequence>
        <element name="clTRID" type="epp:trIDStringType"
         minOccurs="0"/>
        <element name="svTRID" type="epp:trIDStringType"/>



Hollenbeck                  Standards Track                    [Page 52]

RFC 5730                          EPP                        August 2009


      </sequence>
    </complexType>

    <simpleType name="trIDStringType">
      <restriction base="token">
        <minLength value="3"/>
        <maxLength value="64"/>
      </restriction>
    </simpleType>

  <!--
  Response types.
  -->
    <complexType name="responseType">
      <sequence>
        <element name="result" type="epp:resultType"
         maxOccurs="unbounded"/>
        <element name="msgQ" type="epp:msgQType"
         minOccurs="0"/>

        <element name="resData" type="epp:extAnyType"
         minOccurs="0"/>
        <element name="extension" type="epp:extAnyType"
         minOccurs="0"/>
        <element name="trID" type="epp:trIDType"/>
      </sequence>
    </complexType>

    <complexType name="resultType">
      <sequence>
        <element name="msg" type="epp:msgType"/>
        <choice minOccurs="0" maxOccurs="unbounded">
          <element name="value" type="epp:errValueType"/>
          <element name="extValue" type="epp:extErrValueType"/>
        </choice>
      </sequence>
      <attribute name="code" type="epp:resultCodeType"
       use="required"/>
    </complexType>

    <complexType name="errValueType" mixed="true">
      <sequence>
        <any namespace="##any" processContents="skip"/>
      </sequence>
      <anyAttribute namespace="##any" processContents="skip"/>
    </complexType>





Hollenbeck                  Standards Track                    [Page 53]

RFC 5730                          EPP                        August 2009


    <complexType name="extErrValueType">
      <sequence>
        <element name="value" type="epp:errValueType"/>
        <element name="reason" type="epp:msgType"/>
      </sequence>
    </complexType>

    <complexType name="msgQType">
      <sequence>
        <element name="qDate" type="dateTime"
         minOccurs="0"/>
        <element name="msg" type="epp:mixedMsgType"
         minOccurs="0"/>
      </sequence>
      <attribute name="count" type="unsignedLong"
       use="required"/>
      <attribute name="id" type="eppcom:minTokenType"
       use="required"/>
    </complexType>

    <complexType name="mixedMsgType" mixed="true">
      <sequence>
        <any processContents="skip"
         minOccurs="0" maxOccurs="unbounded"/>
      </sequence>
      <attribute name="lang" type="language"
       default="en"/>
    </complexType>

  <!--
  Human-readable text may be expressed in languages other than English.
  -->
    <complexType name="msgType">
      <simpleContent>
        <extension base="normalizedString">
          <attribute name="lang" type="language"
           default="en"/>
        </extension>
      </simpleContent>
    </complexType>

  <!--
  EPP result codes.
  -->
    <simpleType name="resultCodeType">
      <restriction base="unsignedShort">
        <enumeration value="1000"/>
        <enumeration value="1001"/>



Hollenbeck                  Standards Track                    [Page 54]

RFC 5730                          EPP                        August 2009


        <enumeration value="1300"/>
        <enumeration value="1301"/>
        <enumeration value="1500"/>
        <enumeration value="2000"/>
        <enumeration value="2001"/>
        <enumeration value="2002"/>
        <enumeration value="2003"/>
        <enumeration value="2004"/>
        <enumeration value="2005"/>
        <enumeration value="2100"/>
        <enumeration value="2101"/>
        <enumeration value="2102"/>
        <enumeration value="2103"/>
        <enumeration value="2104"/>
        <enumeration value="2105"/>
        <enumeration value="2106"/>
        <enumeration value="2200"/>
        <enumeration value="2201"/>
        <enumeration value="2202"/>
        <enumeration value="2300"/>
        <enumeration value="2301"/>
        <enumeration value="2302"/>
        <enumeration value="2303"/>
        <enumeration value="2304"/>
        <enumeration value="2305"/>
        <enumeration value="2306"/>
        <enumeration value="2307"/>
        <enumeration value="2308"/>
        <enumeration value="2400"/>
        <enumeration value="2500"/>
        <enumeration value="2501"/>
        <enumeration value="2502"/>
      </restriction>
    </simpleType>

  <!--
  End of schema.
  -->
  </schema>
  END











Hollenbeck                  Standards Track                    [Page 55]

RFC 5730                          EPP                        August 2009


4.2.  Shared Structure Schema

  Copyright (c) 2009 IETF Trust and the persons identified as authors
  of the code.  All rights reserved.

  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions
  are met:

  o  Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.

  o  Redistributions in binary form must reproduce the above copyright
     notice, this list of conditions and the following disclaimer in
     the documentation and/or other materials provided with the
     distribution.

  o  Neither the name of Internet Society, IETF or IETF Trust, nor the
     names of specific contributors, may be used to endorse or promote
     products derived from this software without specific prior written
     permission.

  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

  BEGIN
  <?xml version="1.0" encoding="UTF-8"?>

  <schema targetNamespace="urn:ietf:params:xml:ns:eppcom-1.0"
          xmlns:eppcom="urn:ietf:params:xml:ns:eppcom-1.0"
          xmlns="http://www.w3.org/2001/XMLSchema"
          elementFormDefault="qualified">

    <annotation>
      <documentation>
        Extensible Provisioning Protocol v1.0
        shared structures schema.
      </documentation>
    </annotation>



Hollenbeck                  Standards Track                    [Page 56]

RFC 5730                          EPP                        August 2009


  <!--
  Object authorization information types.
  -->
    <complexType name="pwAuthInfoType">
      <simpleContent>
        <extension base="normalizedString">
          <attribute name="roid" type="eppcom:roidType"/>
        </extension>
      </simpleContent>
    </complexType>

    <complexType name="extAuthInfoType">
      <sequence>
        <any namespace="##other"/>
      </sequence>
    </complexType>

  <!--
  <check> response types.
  -->
    <complexType name="reasonType">
      <simpleContent>
        <extension base="eppcom:reasonBaseType">
          <attribute name="lang" type="language"/>
        </extension>
      </simpleContent>
    </complexType>

    <simpleType name="reasonBaseType">
      <restriction base="token">
        <minLength value="1"/>
        <maxLength value="32"/>
      </restriction>
    </simpleType>

  <!--
  Abstract client and object identifier type.
  -->
    <simpleType name="clIDType">
      <restriction base="token">
        <minLength value="3"/>
        <maxLength value="16"/>
      </restriction>
    </simpleType>

  <!--
  DNS label type.
  -->



Hollenbeck                  Standards Track                    [Page 57]

RFC 5730                          EPP                        August 2009


    <simpleType name="labelType">
      <restriction base="token">
        <minLength value="1"/>
        <maxLength value="255"/>
      </restriction>
    </simpleType>

  <!--
  Non-empty token type.
  -->
    <simpleType name="minTokenType">
      <restriction base="token">
        <minLength value="1"/>
      </restriction>
    </simpleType>

  <!--
  Repository Object IDentifier type.
  -->
    <simpleType name="roidType">
      <restriction base="token">
        <pattern value="(\w|_){1,80}-\w{1,8}"/>
      </restriction>
    </simpleType>

  <!--
  Transfer status identifiers.
  -->

    <simpleType name="trStatusType">
      <restriction base="token">
        <enumeration value="clientApproved"/>
        <enumeration value="clientCancelled"/>
        <enumeration value="clientRejected"/>
        <enumeration value="pending"/>
        <enumeration value="serverApproved"/>
        <enumeration value="serverCancelled"/>
      </restriction>
    </simpleType>

  <!--
  End of schema.
  -->
  </schema>
  END






Hollenbeck                  Standards Track                    [Page 58]

RFC 5730                          EPP                        August 2009


5.  Internationalization Considerations

  EPP is represented in XML, which provides native support for encoding
  information using the Unicode character set and its more compact
  representations including UTF-8.  Conformant XML processors recognize
  both UTF-8 and UTF-16.  Though XML includes provisions to identify
  and use other character encodings through use of an "encoding"
  attribute in an <?xml?> declaration, use of UTF-8 is RECOMMENDED in
  environments where parser-encoding-support incompatibility exists.

  EPP includes a provision for returning a human-readable message with
  every result code.  This document describes result codes in English,
  but the actual text returned with a result MAY be provided in a
  language negotiated when a session is established.  Languages other
  than English MUST be noted through specification of a "lang"
  attribute for each message.  Valid values for the "lang" attribute
  and "lang" negotiation elements are described in [RFC4646].

  All date-time values presented via EPP MUST be expressed in Universal
  Coordinated Time using the Gregorian calendar.  XML Schema allows use
  of time zone identifiers to indicate offsets from the zero meridian,
  but this option MUST NOT be used with EPP.  The extended date-time
  form using upper case "T" and "Z" characters defined in
  [W3C.REC-xmlschema-2-20041028] MUST be used to represent date-time
  values, as XML Schema does not support truncated date-time forms or
  lower case "T" and "Z" characters.

6.  IANA Considerations

  This document uses URNs to describe XML namespaces and XML schemas
  conforming to a registry mechanism described in [RFC3688].  Four URI
  assignments have been registered by the IANA.

  Registration request for the EPP namespace:

     URI: urn:ietf:params:xml:ns:epp-1.0

     Registrant Contact: See the "Author's Address" section of this
     document.

     XML: None.  Namespace URIs do not represent an XML specification.

  Registration request for the EPP XML schema:

     URI: urn:ietf:params:xml:schema:epp-1.0

     Registrant Contact: See the "Author's Address" section of this
     document.



Hollenbeck                  Standards Track                    [Page 59]

RFC 5730                          EPP                        August 2009


     XML: See the "Base Schema" section of this document.

  Registration request for the EPP shared structure namespace:

     URI: urn:ietf:params:xml:ns:eppcom-1.0

     Registrant Contact: See the "Author's Address" section of this
     document.

     XML: None.  Namespace URIs do not represent an XML specification.

  Registration request for the EPP shared structure XML schema:

     URI: urn:ietf:params:xml:schema:eppcom-1.0

     Registrant Contact: See the "Author's Address" section of this
     document.

     XML: See the "Shared Structure Schema" section of this document.

  A MIME media type registration template is included in Appendix B.

7.  Security Considerations

  EPP provides only simple client-authentication services.  A passive
  attack is sufficient to recover client identifiers and passwords,
  allowing trivial command forgery.  Protection against most common
  attacks and more robust security services MUST be provided by other
  protocol layers.  Specifically, EPP instances MUST be protected using
  a transport mechanism or application protocol that provides
  integrity, confidentiality, and mutual, strong client-server
  authentication.

  EPP uses a variant of the PLAIN SASL mechanism described in [RFC4616]
  to provide a simple application-layer authentication service that
  augments or supplements authentication and identification services
  that might be available at other protocol layers.  Where the PLAIN
  SASL mechanism specifies provision of an authorization identifier,
  authentication identifier, and password as a single string separated
  by ASCII NUL characters, EPP specifies use of a combined
  authorization and authentication identifier and a password provided
  as distinct XML elements.

  Repeated password guessing attempts can be discouraged by limiting
  the number of <login> attempts that can be attempted on an open
  connection.  A server MAY close an open connection if multiple
  <login> attempts are made with either an invalid client identifier,




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  an invalid password, or both an invalid client identifier and an
  invalid password.

  EPP uses authentication information associated with objects to
  confirm object-transfer authority.  Authentication information
  exchanged between EPP clients and third-party entities MUST be
  exchanged using a facility that provides privacy and integrity
  services to protect against unintended disclosure and modification
  while in transit.

  EPP instances SHOULD be protected using a transport mechanism or
  application protocol that provides anti-replay protection.  EPP
  provides some protection against replay attacks through command
  idempotency and client-initiated transaction identification.
  Consecutive command replays will not change the state of an object in
  any way.  There is, however, a chance of unintended or malicious
  consequence if a command is replayed after intervening commands have
  changed the object state and client identifiers are not used to
  detect replays.  For example, a replayed <create> command that
  follows a <delete> command might succeed without additional
  facilities to prevent or detect the replay.

  As described in Section 2, EPP includes features that allow for
  offline review of transform commands before the requested action is
  actually completed.  The server is required to notify the client when
  offline processing of the action has been completed.  Notifications
  can be sent using an out-of-band mechanism that is not protected by
  the mechanism used to provide EPP transport security.  Notifications
  sent without EPP's transport-security services should be protected
  using another mechanism that provides an appropriate level of
  protection for the notification.

8.  Acknowledgements

  RFC 3730 is a product of the PROVREG working group, which suggested
  improvements and provided many invaluable comments.  The author
  wishes to acknowledge the efforts of WG chairs Edward Lewis and Jaap
  Akkerhuis for their process and editorial contributions.  RFC 4930
  and this document are individual submissions, based on the work done
  in RFC 3730.

  Specific suggestions that have been incorporated into this document
  were provided by Chris Bason, Eric Brunner-Williams, Jordyn Buchanan,
  Roger Castillo Cortazar, Dave Crocker, Ayesha Damaraju, Sheer
  El-Showk, Patrik Faltstrom, James Gould, John Immordino, Dan Kohn,
  Hong Liu, Klaus Malorny, Dan Manley, Michael Mealling, Patrick
  Mevzek, Andrew Newton, Budi Rahardjo, Asbjorn Steira, Rick Wesson,
  and Jay Westerdal.



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9.  References

9.1.  Normative References

  [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
             Requirement Levels", BCP 14, RFC 2119, March 1997.

  [RFC2277]  Alvestrand, H., "IETF Policy on Character Sets and
             Languages", BCP 18, RFC 2277, January 1998.

  [RFC2914]  Floyd, S., "Congestion Control Principles", BCP 41,
             RFC 2914, September 2000.

  [RFC3629]  Yergeau, F., "UTF-8, a transformation format of ISO
             10646", STD 63, RFC 3629, November 2003.

  [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
             January 2004.

  [RFC4646]  Phillips, A. and M. Davis, "Tags for Identifying
             Languages", BCP 47, RFC 4646, September 2006.

  [W3C.REC-xml-20040204]
             Sperberg-McQueen, C., Maler, E., Yergeau, F., Paoli, J.,
             and T. Bray, "Extensible Markup Language (XML) 1.0 (Third
             Edition)", World Wide Web Consortium FirstEdition REC-xml-
             20040204, February 2004,
             <http://www.w3.org/TR/2004/REC-xml-20040204>.

  [W3C.REC-xmlschema-1-20041028]
             Maloney, M., Thompson, H., Mendelsohn, N., and D. Beech,
             "XML Schema Part 1: Structures Second Edition", World Wide
             Web Consortium Recommendation REC-xmlschema-1-20041028,
             October 2004,
             <http://www.w3.org/TR/2004/REC-xmlschema-1-20041028>.

  [W3C.REC-xmlschema-2-20041028]
             Malhotra, A. and P. Biron, "XML Schema Part 2: Datatypes
             Second Edition", World Wide Web Consortium
             Recommendation REC-xmlschema-2-20041028, October 2004,
             <http://www.w3.org/TR/2004/REC-xmlschema-2-20041028>.

9.2.  Informative References

  [RFC0793]  Postel, J., "Transmission Control Protocol", STD 7,
             RFC 793, September 1981.





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  [RFC2781]  Hoffman, P. and F. Yergeau, "UTF-16, an encoding of ISO
             10646", RFC 2781, February 2000.

  [RFC3023]  Murata, M., St. Laurent, S., and D. Kohn, "XML Media
             Types", RFC 3023, January 2001.

  [RFC3080]  Rose, M., "The Blocks Extensible Exchange Protocol Core",
             RFC 3080, March 2001.

  [RFC3375]  Hollenbeck, S., "Generic Registry-Registrar Protocol
             Requirements", RFC 3375, September 2002.

  [RFC4616]  Zeilenga, K., "The PLAIN Simple Authentication and
             Security Layer (SASL) Mechanism", RFC 4616, August 2006.

  [RFC4930]  Hollenbeck, S., "Extensible Provisioning Protocol (EPP)",
             RFC 4930, May 2007.

  [RFC4960]  Stewart, R., "Stream Control Transmission Protocol",
             RFC 4960, September 2007.

  [RFC5321]  Klensin, J., "Simple Mail Transfer Protocol", RFC 5321,
             October 2008.

  [W3C.REC-P3P-20020416]
             Marchiori, M., "The Platform for Privacy Preferences 1.0
             (P3P1.0) Specification", World Wide Web Consortium
             Recommendation REC-P3P-20020416, April 2002,
             <http://www.w3.org/TR/2002/REC-P3P-20020416>.






















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Appendix A.  Object Mapping Template

  This appendix describes a recommended outline for documenting the EPP
  mapping of an object.  Documents that describe EPP object mappings
  SHOULD describe the mapping in a format similar to the one used here.
  Additional sections are required if the object mapping is written in
  Internet-Draft or RFC format.

  1. Introduction

     Provide an introduction that describes the object and gives an
     overview of the mapping to EPP.

  2. Object Attributes

     Describe the attributes associated with the object, including
     references to syntax specifications as appropriate.  Examples of
     object attributes include a name or identifier and dates
     associated with modification events.

  3. EPP Command Mapping

  3.1.  EPP Query Commands

  3.1.1.  EPP <check> Command

     Describe the object-specific mappings required to implement the
     EPP <check> command.  Include both sample commands and sample
     responses.

  3.1.2.  EPP <info> Command

     Describe the object-specific mappings required to implement the
     EPP <info> command.  Include both sample commands and sample
     responses.

  3.1.3.  EPP <poll> Command

     Describe the object-specific mappings required to implement the
     EPP <poll> command.  Include both sample commands and sample
     responses.

  3.1.4.  EPP <transfer> Command

     Describe the object-specific mappings required to implement the
     EPP <transfer> query command.  Include both sample commands and
     sample responses.




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  3.2.  EPP Transform Commands

  3.2.1.  EPP <create> Command

     Describe the object-specific mappings required to implement the
     EPP <create> command.  Include both sample commands and sample
     responses.  Describe the status of the object with respect to
     time, including expected client and server behavior if a validity
     period is used.

  3.2.2.  EPP <delete> Command

     Describe the object-specific mappings required to implement the
     EPP <delete> command.  Include both sample commands and sample
     responses.

  3.2.3.  EPP <renew> Command

     Describe the object-specific mappings required to implement the
     EPP <renew> command.  Include both sample commands and sample
     responses.

  3.2.4.  EPP <transfer> Command

     Describe the object-specific mappings required to implement the
     EPP <transfer> command.  Include both sample commands and sample
     responses.

  3.2.4.  EPP <update> Command

     Describe the object-specific mappings required to implement the
     EPP <update> command.  Include both sample commands and sample
     responses.

  4. Formal Syntax

     Provide the XML schema for the object mapping.  An XML DTD MUST
     NOT be used, as DTDs do not provide sufficient support for XML
     namespaces and strong data typing.












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Appendix B.  Media Type Registration: application/epp+xml

  MIME media type name: application

  MIME subtype name: epp+xml

  Required parameters: none

  Optional parameters: Same as the charset parameter of application/xml
  as specified in [RFC3023].

  Encoding considerations: Same as the encoding considerations of
  application/xml as specified in [RFC3023].

  Security considerations: This type has all of the security
  considerations described in [RFC3023] plus the considerations
  specified in the Security Considerations section of this document.

  Interoperability considerations: XML has proven to be interoperable
  across WWW Distributed Authoring and Versioning (WebDAV) clients and
  servers, and for import and export from multiple XML authoring tools.
  For maximum interoperability, validating processors are recommended.
  Although non-validating processors can be more efficient, they are
  not required to handle all features of XML.  For further information,
  see Section 2.9, "Standalone Document Declaration", and Section 5,
  "Conformance", of [W3C.REC-xml-20040204].

  Published specification: This document.

  Applications that use this media type: EPP is device-, platform-, and
  vendor-neutral and is supported by multiple service providers.

  Additional information: If used, magic numbers, fragment identifiers,
  base URIs, and use of the BOM should be as specified in [RFC3023].

  Magic number(s): None.

  File extension(s): .xml

  Macintosh file type code(s): "TEXT"

  Person & email address for further information: See the "Author's
  Address" section of this document.

  Intended usage: COMMON

  Author/Change controller: IETF




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Appendix C.  Changes from RFC 4930

  1.   Changed "This document obsoletes RFC 3730" to "This document
       obsoletes RFC 4930".

  2.   Replaced references to RFC 2595 with references to RFC 4616.

  3.   Replaced references to RFC 2821 with references to RFC 5321.

  4.   Replaced references to RFC 2960 with references to RFC 4960.

  5.   Replaced references to RFC 3066 with references to RFC 4646.

  6.   Replaced references to RFC 3730 with references to RFC 4930.

  7.   Added "A protocol client that is authorized to manage an
       existing object is described as a "sponsoring" client throughout
       this document" in Section 1.1.

  8.   Changed "This action MUST be open to all authorized clients" to
       "This command MUST be available to all clients" in the
       descriptions of the <login> and <logout> commands.

  9.   Changed "Specific result codes are listed in the table below" to
       "The complete list of valid result codes is enumerated below and
       in the normative schema" in Section 3.

  10.  Added new paragraph to Section 7 to give guidance on the need to
       protect offline transaction notices.

  11.  Added reference to Appendix B in the IANA Considerations
       section.

  12.  Added BSD license text to XML schema section.

Author's Address

  Scott Hollenbeck
  VeriSign, Inc.
  21345 Ridgetop Circle
  Dulles, VA  20166-6503
  US

  EMail: [email protected]







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