Network Working Group                                            K. Best
Request for Comments: 3120                                   OASIS, Inc.
Category: Informational                                         N. Walsh
                                                  Sun Microsystems, Inc.
                                                               June 2001


                      A URN Namespace for XML.org

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 (2001).  All Rights Reserved.

Abstract

   This document describes a URN (Uniform Resource Name) namespace that
   is engineered by the Organization for the Advancement of Structured
   Information Standards (OASIS) for naming persistent resources stored
   in the XML.org repository (such as XML (Extensible Markup Language)
   Document Type Definitions, XML Schemas, Namespaces, Stylesheets, and
   other documents).

1. Introduction

   The XML.org Registry is provided by XML.org as a public service where
   XML schemas, DTDs, stylesheets, and other documents can be shared.
   Documents are submitted to a repository then retrieved by others who
   may want to use them.  These documents require unique identifiers.

   Motivated by these observations, XML.org would like to assign URNs to
   some resources in order to retain unique, permanent location-
   independent names for them.

   This namespace specification is for a formal namespace.

2. Specification Template

   Namespace ID:

      "xmlorg" requested.

   Registration Information:

      Registration Version Number: 3
      Registration Date: 2001-02-05

   Declared registrant of the namespace:

      Karl Best
      OASIS - Organization for the Advancement of Structured
      Information Standards
      Post Office Box 455
      Billerica, MA USA 01821

      Phone: +1 (978) 667 5115

   Declaration of structure:

      The Namespace Specific String (NSS) of all URNs assigned by
      XML.org will have the following hierarchical structure:

      There is one branch at the top of the hierarchy: "objects".

      The Objects Hierarchy

         The general structure of the NSS in the names hierarchy has the
         form:

            urn:xmlorg:objects:{type}{:subtype}?:{object-id}

         where "type" identifies the document type (document, schema,
         stylesheet, entity, xmlns, etc.), the optional "subtype"
         provides additional information about the document type (for
         example, stylesheet or schema language), and "object-id" is a
         unique identifier for the document.

         The Director of Technical Operations at OASIS assigns document
         types, subtypes, and all unique identifiers.

   Relevant ancillary documentation:

      None

   Identifier uniqueness considerations:

      Identifier uniqueness will be enforced by the Director of
      Technical Operations who assigns unique identifiers to all
      documents identified by URN.

   Identifier persistence considerations:

      OASIS is committed to maintaining the accessibility and
      persistence of all the resources that are assigned URNs.

   Process of identifier assignment:

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

   Process of identifier resolution:

      The owner will distribute catalogs (OASIS TR9401 Catalogs) that
      map the assigned URNs to resource identifiers (e.g., URLs).  A
      more interactive, online resolution system will also be deployed
      in the near future.

      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 publish OASIS TR9401 Catalogs.
      The presence of a URN in a catalog indicates that it is valid.

   Scope:

      Global

3. Examples

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

         urn:xmlorg:objects:schema:xmlschema:xcatalog
         urn:xmlorg:objects:dtd:xml:docbook:v4.1.2

4. Security Considerations

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

References

   [1] Goldfarb, C. F., "ISO (International Organization for
       Standardization) ISO 8879:1986(E) Information Processing -- Text
       and Office Systems -- Standard Generalized Markup Language
       (SGML)", 1986.

   [2] W3C, XML WG, "Extensible Markup Language (XML) 1.0", February
       1998, <http://www.w3.org/TR/REC-xml>.

   [3] W3C, Namespaces WG, "Namespaces in XML", January 1999,
       <http://www.w3.org/TR/REC-xml-names>.

   [4] OASIS, Entity Mgmt. TC, "Entity Management: OASIS Technical
       Resolution 9401:1997 (Amendment 2 to TR 9401)", January 1994,
       <http://www.oasis-open.org/html/a401.htm>.

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

   [6] Mealling, M. and R. Daniel, "URI Resolution Services Necessary
       for URN Resolution", RFC 2483, January 1999.

Authors' Addresses

   Karl Best
   OASIS, Inc.
   P.O. Box 455
   Billerica, MA  01821
   US

   EMail: karl.best@oasis-open.org


   Norman Walsh
   Sun Microsystems, Inc.
   One Network Drive
   MS UBUR02-201
   Burlington, MA  01803-0902
   US

   EMail: Norman.Walsh@East.Sun.COM

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