Network Working Group M. Mealling Internet-Draft VeriSign, Inc. Expires: December 25, 2001 June 26, 2001 The IANA XML Registry draft-mealling-iana-xmlns-registry-01.txt Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on December 25, 2001. Copyright Notice Copyright (C) The Internet Society (2001). All Rights Reserved. Abstract This documenet describes an IANA maintained registry for IETF standards which use XML related items such as Namespaces, DTD, Schemas, and RDF Schemas. 1. Introduction Over the past few years XML [2] has become a widely used method for data markup. There have already been several IETF Working Groups that have produced standards that define XML DTDs, XML Namespaces [3] and XML Schemas [4]. Each one of these technologies uses URIs [1] to identify their respective versions. For example, a given XML document defines its DTD using the DOCTYPE element. This element, Mealling Expires December 25, 2001 [Page 1] Internet-Draft IANA XML Registry June 2001 like SGML, has a PUBLIC and a SYSTEM identifier. It is standard practice within W3C standards to forego the use of the PUBLIC identifier in favor of 'well known' SYSTEM identifiers. There have been several IETF standards that have simply created non-existent URIs in order to simply identify but not resolve the SYSTEM identifier for some given XML document. This document seeks to standardize this practice by creating an IANA maintained registry of XML elements so that document authors and implementors have a well maintained and authoritative location for their XML elements. As part of this standard, the IANA will both house the public representation of the document and assign it a Uniform Resource Name that can be used as the URI in any URI based identification components of XML. 2. Registerable Documents 2.1 The Assigned URIs All elements in this registry will have a URN of the form: urn:iana:xml:: where is the type of the document being registered (see below). is a unique id generated by the IANA based on any means the IANA deems necessary to maintain uniqueness and persistence. The IANA will also maintain a file server available via at least HTTP that contains all of the registered elements in some publicly accessible file space (in the same way that all of the IANAs registered elements are available via http://www.isi.edu/in-notes/iana/assignments/). 2.2 Document Types The list of types of XML documents that can be registered with the IANA are: dtd -- An XML document that contains a DOCTYPE element can identify its DTD via both a PUBLIC identifier and a SYSTEM identifier. The URN assigned by the IANA can be used as the value of the SYSTEM identifier. ns -- XML Namespaces [3] are named by a URI. They have no real, machine-parseable representation other than the specifications that define them. Thus the element registered will be the specification (or a pointer to it). The URN assigned by the IANA Mealling Expires December 25, 2001 [Page 2] Internet-Draft IANA XML Registry June 2001 will be the XML Namespace's name. schema -- XML Schemas [4] are also identified by a URI but their contents are machine parseable. The IANA registered document will be the XML Schema file. The URN the IANA assigns can be used as the URI for the schema. rdfschema -- The Resource Description Format (RDF) [5] is an XML serialization of a connected graph based data model used for metadata expression. RDF makes use of schemas for RDF that express grammars about relationships between URIs. These grammars are identified by URIs. The URN assigned by the IANA can be used as the identifying URI. 3. Registration Procedures Until such time as the IANA requests or implements an automated process for the registration of these elements, any specifications wishing to do so must make that request part of the IANA considerations section of their respective documents. 4. IANA Considerations This documents seeks to create a rather large registry for which the IANA (at the direction of the IESG) will primarily be responsible. The amount of effort required to maintain this registry is not insignificant and the policies and procedures surrounding any approval process are non-trivial. References [1] Berners-Lee, T., Fielding, R. and L. Masinter, "Uniform Resource Identifiers (URI): Generic Syntax", RFC 2396, August 1998. [2] WorldWideWeb Consortium, "Extensible Markup Language (XML) 1.0 (Second Edition)", W3C Recommendation, Available at http://www.w3.org/TR/2000/REC-xml-20001006, October 2000. [3] WorldWideWeb Consortium, "Namespaces in XML", W3C Recommendation, Available at http://www.w3.org/TR/1999/REC-xml- names-19990114/, January 1999. [4] WorldWideWeb Consortium, "XML Schema Part 0: Primer", W3C Recommendation, Available at http://www.w3.org/TR/xmlschema-0/, May 2001. [5] WorldWideWeb Consortium, "Resource Description Framework (RDF) Mealling Expires December 25, 2001 [Page 3] Internet-Draft IANA XML Registry June 2001 Model and Syntax Specification", W3C Recommendation, Available at http://www.w3.org/TR/REC-rdf-syntax/, February 1999. Author's Address Michael Mealling VeriSign, Inc. Mountain View, CA US EMail: michael@research.netsol.com URI: http://www.research.netsol.com Mealling Expires December 25, 2001 [Page 4] Internet-Draft IANA XML Registry June 2001 Full Copyright Statement Copyright (C) The Internet Society (2001). 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 assigns. 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. Mealling Expires December 25, 2001 [Page 5]