Network Working Group                                           A. Walsh
Request for Comments: 3541                              Web3D Consortium
Category: Informational                                         May 2003


               A Uniform Resource Name (URN) Namespace
                   for the Web3D Consortium (Web3D)

Status of this Memo

  This memo provides information for the Internet community.  It does
  not specify an Internet standard of any kind.  Distribution of this
  memo is unlimited.

Copyright Notice

  Copyright (C) The Internet Society (2003).  All Rights Reserved.

Abstract

  This document describes a Uniform Resource Name (URN) namespace for
  the Web3D Consortium (Web3D) for naming persistent resources such as
  technical documents and specifications, Virtual Reality Modeling
  Language (VRML) and Extensible 3D (X3D) files and resources,
  Extensible Markup Language (XML) Document Type Definitions (DTDs),
  XML Schemas, namespaces, style sheets, media assets, and other
  resources produced or managed by Web3D.

1. Introduction

  Web3D is a non-profit organization with a mandate to develop and
  promote open standards to enable 3D for the Internet, Web and
  broadcast applications.  Web3D is responsible for developing,
  advancing, and maintaining the VRML97 ISO/IEC International Standard
  (ISO/IEC 14772-1:1997), X3D (the forthcoming official successor to
  VRML) and related technologies.

  Web3D maintains and extends its standardization activities through
  the coordinated efforts of dedicated Working Groups, Task Groups, and
  professional Liaisons to related standards bodies such as ISO, W3C,
  and MPEG.  See http://web3d.org/ for details.

  Web3D would like to assign unique, permanent, location-independent
  names based on URNs for some resources it produces or manages.

  This namespace specification is for a formal namespace.





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2. Specification Template

  Namespace ID:

     "web3d"

  Registration Information:

     Registration Version Number: 1
     Registration Date: 2003-05-06

  Declared registrant of the namespace:

     Web3D Consortium, Inc.
     Email: <[email protected]>
     Web: <http://web3d.org>

   c/o
     Name       : Aaron E. Walsh
     Affiliation: Web3D Working Group Chair; Web3D Liaison to MPEG, W3C
     Address    : 18 Haviland Street, Boston, MA USA 02115
     Phone      : +1 (617) 536-3279
     Email      : <[email protected]>
     Web        : <http://mantiscorp.com/people/aew/>

  Declaration of syntactic structure:

     URNs assigned by Web3D will have the following hierarchical
     structure based on the group's organizational structure:

        urn:web3d:{subgroup}:{subgroup-specific string}

     where "subgroup" corresponds to an official Web3D subgroup or
     activity such as the VRML standard ('vrml97'), Extensible 3D
     ('x3d'), Universal Media Working Group ('media'), Geographical
     VRML Working Group ('geovrml'), Humanoid Animation Working Group
     ('hanim') and so forth, and "subgroup-specific string" is a US-
     ASCII string that conforms to URN Syntax requirements ([RFC2141]).

     In cases where ownership or management of a resource is shared by
     multiple Web3D subgroups or activities, a general category may be
     used in place of a specific subgroup.

     Chairs of Web3D subgroups and activities assign all unique
     identifiers that fall within the scope of the subgroup or activity
     that they chair.  Chairs of Web3D subgroups and activities are
     also responsible for publishing the specific structure of URNs
     assigned by their group or activity.



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  Relevant ancillary documentation:

     None

  Identifier uniqueness considerations:

     Identifier uniqueness will be enforced by the Web3D Board of
     Directors (BoD) in cooperation with Chair(s) of corresponding
     Web3D subgroups.

  Identifier persistence considerations:

     Web3D is committed to maintaining the accessibility and
     persistence of all resources that are officially assigned URNs by
     the organization.

  Process of identifier assignment:

     Assignment is limited to the owner and those authorities that are
     specifically designated by the owner.  Web3D may designate
     portions of its namespace for assignment by other parties.

  Process of identifier resolution:

     The owner will develop and maintain "URN catalogs" that map all
     assigned URNs to Uniform Resource Locators (URLs), specifically to
     enable Web-based resolution of named resources.  In the future, an
     interactive online resolution system may be developed to automate
     this process.

     The owner will authorize additional resolution services as
     appropriate.

  Rules for Lexical Equivalence:

     URNs are lexically equivalent if they are lexically identical.

  Conformance with URN Syntax:

     No special considerations.

  Validation mechanism:

     None specified.  The owner will develop and maintain URN catalogs.
     The presence of a URN in a catalog indicates that it is valid.






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  Scope:

     Global

3. Examples

  The following examples are not guaranteed to be real.  They are
  presented for pedagogical reasons only.

     urn:web3d:vrml97:node:GeoCoordinate
     urn:web3d:vrml97:node:NurbsCurve
     urn:web3d:x3d:schemas:2002:compact
     urn:web3d:x3d:schemas:2002:compromise
     urn:web3d:media:textures:nature:grass

4. Security Considerations

  There are no additional security considerations other than those
  normally associated with the use and resolution of URNs in general.

5. Namespace Considerations and Community Considerations

  The Web3D Consortium (formerly "VRML Consortium") long acknowledged
  the value and utility of URNs starting with the VRML International
  Standard issued in 1997 (ISO/IEC 14772-1:1997, commonly known as
  "VRML97").  Annex F.2, "URNs", of that standard outlines non-
  normative use of URNs as a persistent naming mechanism for referenced
  resources such as files, EXTERNPROTOs, textures, and so forth.

  As such numerous VRML players and authoring tools, as well as content
  authoring communities, have adopted Web3D-oriented URNs for this
  purpose despite the fact that no formal "web3d" URN NID has been
  established by the Web3D Consortium.  Consequently, interoperability
  of resources named using these disparate naming conventions is
  difficult, if not impossible, owing to the lack of a single, well
  defined "web3d" URN namespace that is formally registered and
  maintained by the Web3D Consortium.

  In order to promote complete compatibility and interoperability
  across past, current and future Web3D standards, as well as across
  myriad Web3D-related products, tools, and content, the Web3D
  Consortium believes formal registration and management of the "web3d"
  URN namespace is necessary and in the best interest of the larger
  Internet- and Web-based communities it serves.

  The "web3d" URN namespace will be used to name VRML and X3D files and
  resources, XML DTDs and Schemas, namespaces, style sheets, media
  assets, and other resources produced or managed by Web3D.  As an open



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  standards organization, any Web3D Consortium resources that are
  officially named using the "web3d" namespace will be made freely
  available to the public.

  Resources will be named and maintained in accordance with the
  process(es) described in this document.  Any organization or
  individual can utilize the Web3D Consortium's freely available URN
  catalogs to resolve a resource named therein.  Although the Web3D
  Consortium will control the naming and allocation of resources in
  order to maintain compliance with the process(es) described in this
  document, resolution and/or use of these resources is unrestricted
  and without fee in order to promote widespread adoption of open Web3D
  technologies.  To this end, related documentation and open source
  resolvers will be freely provided through the Web3D Consortium's Web
  site.

  Additionally, member organizations or individuals that wish to name
  their own resources using the "web3d" namespace may submit such
  request(s) directly to the corresponding Web3D Working Group
  (subgroup) for subsequent review.

6. IANA Considerations

  This document describes a "web3d" URN NID registration for the Web3D
  Consortium which has been entered into the IANA registry of URN NIDs
  (http://www.iana.org/assignments/urn-namespaces).

References

  [RFC2141] Moats, R., "URN Syntax", RFC 2141, May 1997.

Author's Address

  Aaron E. Walsh
  Mantis Development Corp.
  18 Haviland Street
  Boston, MA USA 02115

  Phone: +1 (617) 536-3279
  EMail: [email protected]
  Web  : <http://mantiscorp.com/people/aew/>










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Full Copyright Statement

  Copyright (C) The Internet Society (2003).  All Rights Reserved.

  This document and translations of it may be copied and furnished to
  others, and derivative works that comment on or otherwise explain it
  or assist in its implementation may be prepared, copied, published
  and distributed, in whole or in part, without restriction of any
  kind, provided that the above copyright notice and this paragraph are
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  the copyright notice or references to the Internet Society or other
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  The limited permissions granted above are perpetual and will not be
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  TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
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Acknowledgement

  Funding for the RFC Editor function is currently provided by the
  Internet Society.



















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