Uniform Resource Names, Revised (URNbis) -- Draft Proposed WG Charter
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Administrivia
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  Last Modified:  2010-05-20  [AH]

  Chair(s):
    o   N.N.

  Applications Area Director(s):
    o   Alexey Melnikov  <alexey.melnikov@isode.com>
    o   Peter Saint-Andre  <stpeter@stpeter.im>

  Applications Area Advisor:
    o   N.N.

  Mailing Lists:
    o  General Discussion: urn@ietf.org
       To Subscribe:
         https://www.ietf.org/mailman/listinfo/urn
       Archive:
         http://www.ietf.org/mail-archive/web/urn/current/maillist.html

    o  Related lists (used for IANA registration procedures (BCP 35/66):
         urn-nid@ietf.org, uri-review@ietf.org

  Additional information will be available at:
    http://tools.ietf.org/wg/___


Description of Working Group
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  * * *  Problem Statement  * * *

  Uniform Resource Names (URNs) are location-independent, persistent
  identifiers for information resources.

  The RFCs defining URNs and services based on them were published
  in 1997-2001, based on old (or even provisional) basic documents
  on the concepts of URI, URL, and URN, and with almost no
  implementation experience.
  Since then, the URN system has gained significant popularity, and
  many URN Namespaces have been defined and registered with IANA.
  Among the more traditional parties with deep interest in persistent
  identifiers and making heavy use of URNs are national libraries;
  solely within this area, tens of millions of resources have been
  assigned URNs; this enables efficient searching of and persistent
  linking to these documents.  However, the evolving distributed,
  interlinked URN resolution system being built lacks a fundament
  that is consistent in terminology and formal description with
  present (Full) Internet Standards.

  The core URN RFCs -- RFC 2141 (URN Syntax) and RFC 4306 (Namespace
  Definition Mechanisms) -- were based on outdated framework documents.
  For instance, all References in RFC 2141 point to "work in progress"
  or documents that have been superseded at least once.
  Most importantly, since RFC 2141 was published before even the
  now-obsolete RFC 2396 was published, it is based on pre-2396 drafts
  and should be updated for consistency with the contemporary URI
  syntax and terminology reflected in STD 66, RFC 3986.  Additionally,
  since RFC 2141 predates RFC 2234, it uses for its syntax definitions
  an early form of BNF, not the ABNF commonly used in the IETF (first
  specified in RFC 2234, later evolved to the current STD 68, RFC 5234).
  All IANA considerations and procedures should now be based on the
  terminology and rules laid down in BCP 26, RFC 5226.

  The lack of a formal registration of the 'urn' URI scheme fosters
  recurring discussions on what URNs are.  Such formal registration
  is needed to clarify that URNs are specific URIs (namely those using
  the 'urn' URI scheme) and hence all general rules for URIs apply to
  URNs, in addition to the common rules for all URNs and particular
  scheme-specific rules.

  Key bibliographic identifier standards are ISBN and ISSN, which are
  based on ISO standards and cover books and serials, respectively.
  These ISO standards were revised in 2007 to clarify and extend the
  underlying namespaces; those changes should be reflected in the URN
  definitions so as to enable use of the extended forms of these
  identifiers in URNs.
  For materials not covered by ISBN, ISSN, or other formal standards,
  many national libraries and other institutions apply National
  Bibliography Numbers (NBNs). Their usage has increased a lot since
  a related URN namespace was specified in RFC 3188, and the deployment
  has proven that more flexibility was needed than provided by the RFC
  -- both for NBN syntax and for the distributed management of these
  identifiers.
  Thus, there is a need to revise these namespace registration to
  correctly reflect the current state of the art.

  Other (early) URN namespace definitions should be screened to verify
  their alignment with the existing and updated base identifier
  standards and updated RFCs, and to give advice to registrants
  in case mismatches/deficiencies were detected.

  The elaborations on URN resolution in early RFCs predate large-scale
  experience with URIs in general and URNs in particular, and they do
  predate the consolidation of terms achieved in a joint W3C / IETF
  collaboration (published for the IETF as RFC 3305).  Hence there is
  a need to revisit these Informational documents as well and provide
  updates, if necessary.  It also needs to be determined whether the
  implementation experiences from project PersID (and other existing
  URN resolution systems) deserve consolidation towards standardization
  to further interoperability of services and service user applications.


  * * *  Objectives for the Working Group  * * *

  This working group is chartered to update the key RFCs describing the
  URN system, including RFC 2141 (URN Syntax) and RFC 4306 (Namespace
  Definition Mechanisms), update selected URN namespace specifications
  including those for ISBN, NBN and ISSN, and to screen and update RFCs
  describing URN resolution principles and practices.
  For all document revisions, the stability of existing identifiers and
  backward compatibility with previous specifications (as far as possible
  with respect to existing Full Standards) are of foremost importance.

  Thus, in support of the current international efforts to establish a
  distributed, linked system of URN resolution systems for bibliographic
  identifiers, the primary aim of the WG is an updated set of documents,
  all on the Standards-Track.  These updates are needed to provide a
  normative foundation and assure uniformity and interoperability of the
  URN assignment and resolution concepts and procedures at the abstract
  level.

  Details and tasks (the WG will approach these tasks in roughly this
  order):

  a)  Core URN specifications

  For RFC 2141, this revision will include in particular:
  - an update of the formal syntax specification in the light of the
    URI Standard (STD 66, RFC 3986) using the ABNF from STD 68
    (RFC 5234);
  - a formal IANA registration for the 'urn' URI scheme using the
    current template from BCP 35 (RFC 4395);
  - a revised set of URN examples (the WG will determine whether the
    granted persistence of URNs allows usage of concrete, real-life
    URN examples -- as desired by implementers -- or whether a URN
    "example" namespace should be created for this purpose);
  - and an update of the sections describing how URNs are resolved
    in the Internet.

  RFC 4306 (BCP 66) needs a less pervasive update, mostly to align it
  with the current IANA procedures and terminology as defined in BCP 26
  (RFC 5226).

  b) URN Namespace specifications

  The WG will focus on updates for the definitions of URNs based on
  bibliographic identifier systems, in particular
  - RFC 3187 (URN Namespace for International Standard Book Numbers),
  - RFC 3188 (URN Namespace for National Bibliography Numbers), and
  - RFC 3044 (URN Namespace for International Serial Standard Number).

  In all these cases, the respective identifier system and/or the
  institutions and roles involved in their assignment and resolution
  have evolved since these RFCs have been published (see below for a
  sketch).
  The global importance of these identifier systems makes it highly
  desirable to have Standards-Track namespace definition documents.

  In particular, the URN:ISBN namespace needs to be extended according
  to the revision of the international ISBN standard, ISO 2108: A new
  version of the ISBN standard was approved in 2007.  Changes to the
  standard were non-trivial, and a thorough revision of RFC 3187 was
  needed.
    The version -00 of the RFC 3187bis I-D has already been submitted,
    and the staff of the ISBN International Centre has been informed
    about the revision, supports this work, and already has approved
    the technical changes contained in it.

  The ISSN (International Standard Serial Name) system (ISO 3297)
  underwent a thorough revision a few years ago. The new version of the
  standard (2007) introduces ISSN-L (linking ISSN), which makes it
  necessary to rethink the way in which URN:ISSNs are resolved, and to
  update RFC 3044 accordingly.  This work to revise RFC 3044 is being
  performed in co-operation with the ISSN International Centre.

  The NBN (National Bibliography Number) URN namespace was registered
  (by RFC 3188) before the national libraries or other users were
  actually using the URN system. Now that millions of URN:NBNs have
  been assigned mainly to resources the national libraries have stored
  in their digital archives, the WG will provide a revised namespace
  definition RFC that accurately catches the ways in which URN:NBNs are
  assigned and resolved in practice, and that is aligned with the basic
  standards and the revised core URN specifications.

  c)  URN resolution and resolution mechanisms

  Alongside the modernization of these core RFCs for URNs and specific
  URN namespaces, the working group will also consider a revision of
  earlier RFCs related to the principles of URNs and URN resolution,
  such as RFC 2483 (URI Resolution services necessary for URN
  resolution), RFC 2276 (Architectural principles of Uniform Resource
  Name Resolution), RFC 1737 (Functional requirements for Uniform
  Resource Names) and RFC 2169 (A trivial convention for using HTTP in
  URN resolution).  All these must be checked; if the document is still
  deemed relevant, it will be modernized as required to align it with
  contemporary IETF terminology and the state-of-the-art of URN
  resolution services.

  The working group will also consider the possibility of publishing
  Best Current Practices on how to resolve the URNs utilizing the
  existing Internet protocols such as HTTP.  Such BCP will be based on
  experience from large-scale URN resolution projects, in particular
  the European URN resolution infrastructure under construction in the
  project PersID.

  Since the revised specifications will be based on existing production
  systems and provide important guidelines for future implementers,
  the WG aims at publishing the RFCs on the Standards Track and will try
  to advance the core document at least to Draft Standard status as fast
  as possible.

  d) Further work

  The WG will offer advice to previous and new registrants of URN
  namespaces.  It will screen the legacy URN namespace definition
  documents and will provide advice to their registrants regarding
  necessary steps to bring these registrations in line with the
  existing standards and the revised URN core specifications, and
  regarding other issues, if such are found.

  The WG can take on work to update well-established URN namespace
  definitions other than the aforementioned cases of bibliographic
  identifier based URN namespaces, upon a case-by-case decision, and
  in collaboration with the respective original registrating party
  (or its legitimate successor); doing so will require an update to
  this charter.


WG Input / Output
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Input documents:

  RFC 2141
  RFC 3406

  RFC 3187
  RFC 3188
  RFC 3044

  RFC 2483
  RFC 2276
  RFC 1737
  RFC 2169

Goals and Milestones (rough and preliminary):

  Dec 2010   WG Last Call on "core document set" ( a) + b) above )
  Feb 2011   core document set forwarded to IESG
      2011   work on supporting documents (guidelines, URN resolution)
      2012   implementation report for promoting 2141bis to Draft Std.

Internet-Drafts:

  draft-ah-rfc2141bis-urn          (-00: submitted March 2010)
  draft-hakala-rfc3187bis-isbn-urn (-00: submitted March 2010)
  draft-hakala-rfc3188bis-nbn-urn  (-00: submitted May 2010)

Request For Comments:

  none so far