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Versions: 00 01 02 RFC 3613

Network Working Group                                          R. Morgan
Internet-Draft                                       Univ. of Washington
Expires: May 20, 2003                                        K. Hazelton
                                              Univ. of Wisconsin-Madison
                                                       November 19, 2002


                        A URN Namespace for MACE
                  draft-hazelton-mace-urn-namespace-02

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
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   This Internet-Draft will expire on May 20, 2003.

Copyright Notice

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

Abstract

   This document describes a proposed URN (Uniform Resource Name)
   namespace that would be managed by the Internet2 Middleware
   Architecture Committee for Education (MACE) for naming persistent
   resources defined by MACE, its working groups and other designated
   subordinates.








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1. Introduction and community considerations

   The Internet2 Middleware Architecture Committee for Education (MACE)
   produces many kinds of documents: specifications, working drafts,
   object classes, schemas, stylesheets, etc.  It also defines directory
   attributes and controlled vocabularies for the values of some of
   those attributes.

   MACE wishes to provide global, distributed, persistent, location-
   independent names for these resources.  The Uniform Resource Name
   (URN) variant of URIs meets these requirements.

   MACE working groups and other MACE-affiliated groups would benefit
   from the MACE URN proposal by having an easy, efficient way to assign
   globally unique, persistent identifiers to resources that they
   create.  The nature of MACE work is that it is carried out to serve
   the needs of one or more communities of interest.  A namespace
   managed so as to facilitate the creation, registration and resolution
   of unique, persistent identifiers would be of great value for MACE,
   its affiliates and the higher education community generally.

   The proposed URN namespace specification is for a formal namespace.





























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2. Specification Template

   Namespace ID:

         "mace" requested.

   Registration Information:

         Registration Version Number 1

         Registration Date: 2002-xx-yy

   Registrant of the namespace:

         Middleware Architecture Committee for Education (MACE)
         ATTN: Lisa Hogeboom
         Internet2
         3025 Boardwalk  Suite 200
         Ann Arbor, MI 48108

         Phone: +1 734 913 4250



         Contact: Keith Hazelton

         Affiliation: Univ.  of Wisconsin-Madison
         1210 W.  Dayton St.
         Madison, WI  53706
         Phone: +1 608 262 0771

         hazelton@doit.wisc.edu

   Syntactic structure:

         The Namespace Specific Strings (NSS) of all URNs assigned by
         MACE will conform to the syntax defined in section 2.2 of
         RFC2141, "URN Syntax." [1] In addition, all MACE 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



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         lowest naming authority node there may be zero, one or more
         levels of hierarchical 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 rules
         for MACE NSSs (see RFC2234): [2]



         MACE-NSS        =   1*(subStChar) 0*(":" 1*(subStChar))



         subStChar       =   trans / "%" HEXDIG HEXDIG



         trans           =   ALPHA / DIGIT / other / reserved



         other           =   "(" / ")" / "+" / "," / "-" / "." /

                              "=" / "@" / ";" / "$" /

                              "_" / "!" / "*" / "'"



         reserved        =   "%" / "/" / "?" / "#"

         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 MACE NSS is also a valid RFC2141 NSS.

   Relevant ancillary documentation:

         None.

   Identifier uniqueness:

         It is the responsibility of MACE directors to guarantee
         uniqueness of the names of immediately subordinate naming
         authorities.  Each lower-level naming authority in turn
         inherits the responsibility of guaranteeing uniqueness of names
         in their branch of the naming tree.




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   Identifier persistence:

         MACE directors bear ultimate responsibility for maintaining the
         usability of MACE URNs over time.  This responsibility may be
         delegated to subordinate naming authorities per the discussion
         in the section below on identifier assignment.  That section
         provides a mechanism for the delegation to be revoked in case a
         subordinate naming authority ceases to function.

   Identifier assignment:

         MACE directors will create an initial series of  immediately
         subordinate naming authorities, and will define a process for
         adding to that list of authorities.  Each top-level working
         group of MACE will be invited to designate a naming authority
         and to suggest one or more candidate names for that authority.
         The MACE-Shibboleth group, for example, might propose creating
         a naming authority under "urn:mace:shib," "urn:mace:shibboleth"
         or some other name.

         Institutions and communities affiliated with MACE may request,
         through their designated MACE liaison, that they be granted
         MACE-subordinate naming authority status.  They may propose
         candidate names for that authority.  One way for such entities
         to guarantee uniqueness of their proposed name is to base it on
         a DNS name.  That is, if Georgetown University wished to be
         designated a subordinate naming authority under MACE, the
         institutional MACE liaison could propose to MACE directors that
         they be delegated control over names beginning with
         "urn:mace:georgetown.edu."  Institutions seeking affiliation
         with MACE should send email to mace-submit@internet2.edu,
         nominating an institutional liaison and providing contact
         information for that person.

         On at least an annual basis, MACE directors will contact the
         liaisons or directors of each immediately subordinate naming
         authority.  If there is no response, or if the respondent
         indicates that they wish to relinquish naming authority, the
         authority over that branch of the tree reverts to MACE.  This
         process will be enforced recursively by each naming authority
         on its subordinates.  This process guarantees that
         responsibility for each branch of the tree will lapse for less
         than one year at worst before being reclaimed by a superior
         authority.

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



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         naming authorities in lower case only.  This forestalls the
         registration of two MACE-subordinate naming authorities whose
         names differ only in case.

   Identifier resolution:

         MACE directors will maintain an index of all MACE and MACE
         workgroup assigned URNs on its web site, http://
         middleware.internet2.edu/MACE.  That index will map URNs to
         resource identifiers, usually URLs.  MACE-affiliated naming
         authorities will specify how to resolve the URNs they assign if
         they are resolvable.

   Lexical equivalence:

         Lexical equivalence of two MACE namespace specific strings
         (NSSs) is defined as an exact, case-sensitive string match.

   Conformance with URN syntax:

         All MACE NSSs fully conform to RFC2141 syntax rules for NSSs.

   Validation mechanism:

         As specified in the "Identifier resolution" section above, MACE
         directors will maintain an index of all MACE and MACE workgroup
         assigned URNs on its web site, http://middleware.internet2.edu/
         MACE.  Presence in that index implies that a given URN is
         valid.  MACE-affiliated naming authorities will specify how to
         validate the URNs they assign.

   Scope:

         Global.

















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3. Security Considerations

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















































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4. Namespace Considerations

   Registration of an NID specific to MACE is reasonable given the
   following considerations:

   1.  MACE would like to assign URNs to some very fine-grained objects
   (such as specific controlled vocabulary values of an attribute in
   MACE-defined LDAP object classes).  This does not seem to be the
   primary intended use of the XMLORG namespace (RFC3120) [3], let alone
   the more tightly controlled OASIS namespace (RFC3121) [4].

   2.  MACE seeks naming autonomy.  We understand that the XMLORG
   registrants left the door open to subordinate naming authorities,
   "OASIS may assign portions of its [XMLORG] namespace for assignment
   by other parties" (RFC3120), but there is no specified process for
   such assignment.  That would in any case mean having a fixed XMLORG-
   assigned prefix on every single object to which we assign a URN.
   MACE has a number of active work groups that may well generate a
   growing number of subordinate naming authorities.  Moreover, MACE is
   not a member of OASIS, so becoming a subordinate naming authority
   under the OASIS URN space is currently not an option.

   3.  MACE will want to assign URNs to non-XML objects as well.  That
   is another reason that XMLORG may not be an appropriate higher-level
   naming authority for MACE.

   Some MACE-developed schema and namespaces may be good candidates for
   inclusion in the XMLORG registry.  The fact that such an object might
   already have a MACE-assigned URN shouldn't be a hindrance.  Work in
   progress to update RFC2611 [5] includes an explicit statement that
   two or more URNs may point to the same resource.  A resource with a
   MACE-assigned namespace-specific-string would, of course, be given an
   XMLORG namespace-specific-string at the time it enters the XMLORG
   registry.

















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5. IANA Considerations

   This document is intended as a formal request to IANA for the
   registration of a "MACE" NID within the IANA registry of URN NIDs.















































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References

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

   [2]  Crocker, D. and P. Overell, "Augmented BNF for Syntax
        Specifications: ABNF", RFC 2234, November 1997.

   [3]  Best, K. and N. Walsh, "A URN Namespace for XML.org", RFC 3120,
        June 2001.

   [4]  Best, K. and N. Walsh, "A URN Namespace for OASIS", RFC 3121,
        June 2001.

   [5]  Daigle, L., van Gulik, D., Iannella, R. and P. Faltstrom, "URN
        Namespace Definition Mechanisms", BCP 33, RFC 2611, June 1999.


Authors' Addresses

   RL "Bob" Morgan
   4545 15th Ave. NE
   Seattle, WA  98105
   U.S.A.

   EMail: rlmorgan@washington.edu


   Keith D. Hazelton
   University of Wisconsin-Madison
   1210 W. Dayton St.
   Madison, WI  53706
   U.S.A.

   EMail: hazelton@doit.wisc.edu

















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Full Copyright Statement

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

   This document and translations of it may be copied and furnished to
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Acknowledgement

   Funding for the RFC Editor function is currently provided by the
   Internet Society.



















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