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Network Working Group                                           A. WalshRequest for Comments: 3541                              Web3D ConsortiumCategory: Informational                                         May 2003A Uniform Resource Name (URN) Namespacefor 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.  Seehttp://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.Walsh                        Informational                      [Page 1]

RFC 3541         URN Namespace for the Web3D Consortium         May 20032. 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: <contact@web3d.org>      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      : <aaron@mantiscorp.com>      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.Walsh                        Informational                      [Page 2]

RFC 3541         URN Namespace for the Web3D Consortium         May 2003   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.Walsh                        Informational                      [Page 3]

RFC 3541         URN Namespace for the Web3D Consortium         May 2003   Scope:      Global3. 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:grass4. 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 openWalsh                        Informational                      [Page 4]

RFC 3541         URN Namespace for the Web3D Consortium         May 2003   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: aaron@mantiscorp.com   Web  : <http://mantiscorp.com/people/aew/>Walsh                        Informational                      [Page 5]

RFC 3541         URN Namespace for the Web3D Consortium         May 2003Full 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   included on all such copies and derivative works.  However, this   document itself may not be modified in any way, such as by removing   the copyright notice or references to the Internet Society or other   Internet organizations, except as needed for the purpose of   developing Internet standards in which case the procedures for   copyrights defined in the Internet Standards process must be   followed, or as required to translate it into languages other than   English.   The limited permissions granted above are perpetual and will not be   revoked by the Internet Society or its successors or assignees.   This document and the information contained herein is provided on an   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.Acknowledgement   Funding for the RFC Editor function is currently provided by the   Internet Society.Walsh                        Informational                      [Page 6]