A Uniform Resource Name (URN) Namespace for the Liberty Alliance Project
RFC 3622

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Network Working Group                                        M. Mealling
Request for Comments: 3622                                VeriSign, Inc.
Category: Informational                                    February 2004

              A Uniform Resource Name (URN) Namespace for
                     the Liberty Alliance Project

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 (2004).  All Rights Reserved.

Abstract

   This document describes a Uniform Resource Name (URN) namespace that
   will identify various objects within the Liberty Architecture for
   federated network identity.

1.  Introduction

   The Liberty Architecture seeks to provide federated network identity
   in such a way that enhances security, privacy and trust; thus
   creating a networked world across which individuals and businesses
   can engage in virtually any transaction without compromising the
   privacy and security of vital identity information.

   One fundamental component of this architecture is its use of XML [5],
   and specifically, XML Schema [7] and Namespaces [6].  These
   components require identifiers that will live far beyond the lifetime
   of the organization that produced them.  As such, a URN namespace for
   those components that adheres to the assumptions and policies of the
   Liberty specification is required.

   This namespace specification is for a formal namespace.

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RFC 3622               The Liberty URN Namespace           February 2004

2.  Specification Template

   Namespace ID:

      "liberty" requested.

   Registration Information:

      Registration Version Number: 1

      Registration Date: 2003-04-01

   Declared registrant of the namespace:

      Liberty Alliance Project

      c/o IEEE-ISTO

      445 Hoes Lane

      Piscataway, NJ 08855-1331, USA

      info@projectliberty.org

   Declaration of structure:

      The Namespace Specific Strings (NSS) of all URNs assigned by
      Liberty will conform to the syntax defined in section 2.2 of RFC
      2141 [1].  In addition, all Liberty URN NSSs will consist of a
      left-to-right series of tokens delimited by colons.  The left-to-
      right sequence of colon-delimited tokens corresponds to descending
      nodes in a tree.  To the right of the lowest naming authority node
      there may be zero, one or more levels of hierarchical (although
      not in the RFC 2396 [2] sense of 'hierarchy') naming nodes
      terminating in a rightmost leaf node.  See the section entitled
      "Identifier assignment" below for more on the semantics of NSSs.
      This syntax convention is captured in the following normative ABNF
      [4] rules for Liberty NSSs:

      Liberty-NSS        =   1*(subStChar) 0*(":" 1*(subStChar))
      subStChar       =   trans / "%" HEXDIG HEXDIG
      trans           =   ALPHA / DIGIT / other / reserved
      other           =   "(" / ")" / "+" / "," / "-" / "." /
                          "=" / "@" / ";" / "$" /
                          "_" / "!" / "*" / "'"
      reserved        =   "%" / "/" / "?" / "#"

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RFC 3622               The Liberty URN Namespace           February 2004

      The exclusion of the colon from the list of "other" characters
      means that the colon can only occur as a delimiter between string
      tokens.  Note that this ABNF rule set guarantees that any valid
      Liberty NSS is also a valid RFC 2141 NSS.

      For example:

         urn:liberty:schemas:authctx:2002:05
         urn:liberty:schemas:core:2002:12

   Relevant ancillary documentation:

      Liberty Architecture Overview [3]

      Version 1.1

      Liberty Alliance Project

      January 15, 2003

   Identifier uniqueness considerations:

      Identifiers are assigned by the Liberty Project within its various
      standards.  In the process of publishing a specification all newly
      minted names are checked against the record of previously assigned
      names.

   Identifier persistence considerations:

      The assignment process guarantees that names are not reassigned
      and that the binding between the name and its resource is
      permanent, regardless of any standards or organizational changes.

   Process of identifier assignment:

      Names are assigned by the Liberty standards publication process.

   Process of identifier resolution:

      At this time no resolution mechanism is specified.

   Rules for Lexical Equivalence:

      Lexical equivalence of two Liberty namespace specific strings
      (NSSs) is defined as an exact, case-sensitive string match.  The
      Liberty Alliance will assign names of immediately subordinate

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