Network Working Group P. Stickler Internet-Draft Nokia Research Center Expires: September 5, 2002 March 7, 2002 The 'xmlns:' URI Scheme for XML Namespace Reification and Namespace Prefix Declaration draft-pstickler-xmlns-01 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 September 5, 2002. Copyright Notice Copyright (C) The Internet Society (2002). All Rights Reserved. Abstract This document describes the 'xmlns:' Uniform Resource Identifier (URI) scheme for the reification of XML namespaces and namespace prefix declarations. Stickler Expires September 5, 2002 [Page 1] Internet-Draft The 'xmlns:' URI Scheme March 2002 Table of Contents 1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. BNF for the 'xmlns:' URI Scheme . . . . . . . . . . . . . . . . 3 3. Security Considerations . . . . . . . . . . . . . . . . . . . . 4 References . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 4 Full Copyright Statement . . . . . . . . . . . . . . . . . . . . 5 Stickler Expires September 5, 2002 [Page 2] Internet-Draft The 'xmlns:' URI Scheme March 2002 1. Overview The 'xmlns:' URI scheme is intended to provide a simple but consistent means by which XML Namespaces [1] can be reified, and which also provides for the association of a namespace prefix with a given namespace. Examples: xmlns:rdf:http://www.w3.org/1999/02/22-rdf-syntax-ns%23 xmlns:rdfs:http://www.w3.org/2000/01/rdf-schema%23 xmlns:xsd:http://www.w3.org/2001/XMLSchema%23 xmlns:jdoe:mailto:john.doe@abc.com xmlns:*:http://www.w3.org/1999/02/22-rdf-syntax-ns%23 These examples are provided for illustrative purposes only and do not necessarily constitute actual URIs. See the BNF definition below for an explicit definition of 'xmlns:' URI syntax. 2. BNF for the 'xmlns:' URI Scheme This is a BNF-like description of the 'xmlns:' Uniform Resource Identifier syntax, using the conventions of RFC 822[2], except that "|" is used to designate alternatives, and brackets [] are used around optional or repeated elements. Briefly, literals are quoted with "", optional elements are enclosed in [brackets], and elements may be preceded with * to designate n or more repetitions of the following element; n defaults to 0. This BNF description adopts sub-definitions defined in RFC 2396 "Uniform Resource Identifiers (URI): Generic Syntax" [3] and the W3C Recommendation REC-xml-names "Namespaces in XML" [1] which are not repeated here. xmlns-URI = "xmlns:" prefix ":" namespace prefix = "*" | NCName namespace = absoluteURI [ "%23" fragment ] NCName = absoluteURI = fragment = An asterisk "*" in the prefix field of an 'xmlns:' URI indicates that no specific prefix is specified and the 'xmlns:' URI reifies the namespace alone. Stickler Expires September 5, 2002 [Page 3] Internet-Draft The 'xmlns:' URI Scheme March 2002 Note that the URI scheme prefix "xmlns:" is considered to be a valid URI denoting this URI scheme, though it is not itself a valid URI according to this URI scheme. 3. Security Considerations This document raises no known security issues. References [1] World Wide Web Consortium, "REC-xml-names: Namespaces in XML", January 1999, . [2] Crocker, D., "STANDARD FOR THE FORMAT OF ARPA INTERNET TEXT MESSAGES", RFC 822, August 1982. [3] Berners-Lee, T., Fielding, R. and L. Masinter, "Uniform Resource Identifiers (URI): Generic Syntax", RFC 2396, August 1998. Author's Address Patrick Stickler Nokia Research Center Visiokatu 1 Tampere 33720 FI EMail: patrick.stickler@nokia.com Stickler Expires September 5, 2002 [Page 4] Internet-Draft The 'xmlns:' URI Scheme March 2002 Full Copyright Statement Copyright (C) The Internet Society (2002). 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. 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Acknowledgement Funding for the RFC Editor function is currently provided by the Internet Society. Stickler Expires September 5, 2002 [Page 5]