Uniform Resource Names (URN) Namespace Definition Mechanisms
RFC 3406

Network Working Group                                          L. Daigle
Request for Comments: 3406                      Thinking Cat Enterprises
BCP: 66                                                   D.W. van Gulik
Obsoletes: 2611                                               WebWeaving
Category: Best Current Practice                              R. Iannella
                                                             IPR Systems
                                                            P. Faltstrom
                                                                   Cisco
                                                            October 2002

      Uniform Resource Names (URN) Namespace Definition Mechanisms

Status of this Memo

   This document specifies an Internet Best Current Practices for the
   Internet Community, and requests discussion and suggestions for
   improvements.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2002).  All Rights Reserved.

Abstract

   This document lays out general definitions of and mechanisms for
   establishing Uniform Resource Names (URN) "namespaces".  The URN WG
   has defined a syntax for URNs in RFC 2141, as well as some proposed
   mechanisms for their resolution and use in Internet applications in
   RFC 3401 and RFC 3405.  The whole rests on the concept of individual
   "namespaces" within the URN structure.  Apart from proof-of-concept
   namespaces, the use of existing identifiers in URNs has been
   discussed in RFC 2288.

Table of Contents

   1.0 Introduction ................................................. 2
   2.0 What is a URN Namespace? ..................................... 3
   3.0 URN Namespace (Registration) Types ........................... 3
   3.1 Experimental Namespaces .....................................  4
   3.2 Informal Namespaces .........................................  4
   3.3 Formal Namespaces ...........................................  4
   4.0 URN Namespace Registration, Update, and NID Assignment
       Process .....................................................  6
   4.1 Experimental ................................................  6
   4.2 Informal ....................................................  6
   4.3 Formal ......................................................  7
   5.0 Security Considerations .....................................  9

Daigle, et. al.          Best Current Practice                  [Page 1]
RFC 3406          URN Namespace Definition Mechanisms       October 2002

   6.0 IANA Considerations .........................................  9
   7.0 References ..................................................  9
   Appendix A -- URN Namespace Definition Template ................. 11
   Appendix B -- Illustration ...................................... 15
   B.1 Example Template ............................................ 15
   B.2 Registration steps in practice .............................. 17
   Appendix C -- Changes from RFC 2611 ............................. 18
   C.1 Detailed Document Changes ................................... 19
   Authors' Addresses .............................................. 21
   Full Copyright Statement ........................................ 22

1.0 Introduction

   Uniform Resource Names (URNs) are resource identifiers with the
   specific requirements for enabling location independent
   identification of a resource, as well as longevity of reference.
   URNs are part of the larger Uniform Resource Identifier (URI) family
   [RFC3305] with the specific goal of providing persistent naming of
   resources.

   There are 2 assumptions that are key to this document:

   Assumption #1:

      Assignment of a URN is a managed process.

      I.e., not all strings that conform to URN syntax are necessarily
      valid URNs.  A URN is assigned according to the rules of a
      particular namespace (in terms of syntax, semantics, and process).

   Assumption #2:

      The space of URN namespaces is managed.

      I.e., not all syntactically correct URN namespaces (per the URN
      syntax definition) are valid URN namespaces.  A URN namespace must
      have a recognized definition in order to be valid.

   The purpose of this document is to outline a mechanism and provide a
   template for explicit namespace definition, as well as provide the
   mechanism for associating an identifier (called a "Namespace ID", or
   NID) which is registered with the Internet Assigned Numbers Authority
   (IANA).

   Note that this document restricts itself to the description of
   processes for the creation of URN namespaces.  If "resolution" of any
   so-created URN identifiers is desired, a separate process of
   registration in a global NID directory, such as that provided by the