rfc3044.txt

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   persistence is not ensured.  As a consequence the URLs which are
   stored for resolution have to be checked and updated to ensure
   relevant mapping with the corresponding URNs.

   The URLs which are stored in the database must be checked regularly
   for accuracy and if changes occur they have to be reported in the
   ISSN-URN resolver database.

   The browser has to include the URN facility which allows to express
   the location of a given resource in form of an ISSN, this means that
   if the standard browsers do not include the URN option a "plug-in" is
   to be developed.

   Thus, four types of developments have been considered:

   Design and implementation of a resolver:

   -  In a first step a global centralised resolution system has been
      developed and implemented on one resolution server located at the
      ISSN International Centre.

   It ensures effective mapping between a given ISSN and one or several
   URL(s) which implies that "multiple resolution" is performed by
   design and implementation of an ISSN-URL mapping file.



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   -  Today, the principal method to map ISSN with URLs is to extract
      them from ISSN registered records and to store them in a separate
      file structured specially for the resolution process.  Besides,
      other ways to get URLs for bibliographic resources identified by
      ISSN are tested.  Management data as well as attributes are linked
      to URLs in order to recognise objects handled by the resolver.

   Design and implementation of an URL checker:

   -  In order to control the persistence and the accessibility to
      ISSN-URN a robot called the "URL Watcher" has been written to
      control the status of all URLs stored in the ISSN-URL mapping
      file.  Broken or redirected URLs are detected and stored to permit
      efficient resolution.

   Design and implementation of a browser plug-in:

   -  The existing browsers do not include today the URN "protocol"
      functionality.  One expect to have it implemented in a near
      future.  A plug-in for Netscape communicator and MS-Explorer has
      been developed and is available.

   This enables to enter directly the ISSN preceded by the string
   "urn:ISSN:" in the browsers address box instead of typing the URL and
   as result to get displayed the bibliographic record or/and the online
   resource.  Clicking on an ISSN on an HTML page gives the same result.

      example: urn:ISSN:1560-1560

4.2 Global resolution

   Since the ISSN system is not addressing a local environment (like a
   given Library) and is expected to be linked to other URNs (or other
   identification services) for identification of serial related
   resources having other levels of granularity, we have to consider an
   evolution of the present resolution implementation to a global
   resolution system.

   Resolution and especially global resolution is considered as a major
   issue for becoming an ISSN URN Namespace.

   This is expressed in the following statement (from RFC 2611, "URN
   Namespace Definition Mechanisms"):








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   Process for identifier resolution:

      If a namespace is intended to be accessible for global resolution,
      it must be registered in an RDS (Resolution Discovery System, see
      [RFC2276]) such as NAPTR.  Resolution then proceeds according to
      standard URI resolution processes, and the mechanisms of the RDS.

   Our present views and evaluations to be integrated in such RDS System
   for global resolution for an ISSN URN Namespace are mainly based on
   concepts and proposals from the following RFCs:

   RFC 2276 for RDS architecture for global resolution,
   RFC 2168 for the NAPTR DNS extension,

   From a technical point of view our present resolution system is
   flexible enough to take place in a RDS/NAPTR resolution framework.

5. Namespace registration

   Namespace ID:

      ISSN

   Registration Information:

      Version 1
      Date: 2000-08-28

   Declared registrant of the namespace:

      Name:         S. ROZENFELD (Mr.)

      E-mail:       [e-mail]

      Affiliation:  ISSN International Centre

      Address: 20, rue Bachaumont
                      75002 PARIS
                           FRANCE

   Declaration of syntactic structure:

   In accordance with the ISO standard 3297 - Information and
   documentation International Standard Serial Number(ISSN)-(1998)







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   The ISSN consists of eight digits in Arabic numerals 0 to 9, except
   the last digit which is a check digit and can sometimes be an X.  The
   ISSN has no internal meaningful elements to identify language,
   country, publisher.

   The check digit is always located in the extreme right position and
   is calculated on a modulus 11 basis with weights 8 to 2, using X in
   lieu of 10 where 10 would occur as a check digit.

   Each ISSN is inseparably linked to the serials title "the key title"
   which is a constructed form of the title in order to avoid duplicates
   so that each key title is unique within the ISSN Data base.  ISSN and
   key titles are equivalent, they both identify without ambiguity a
   same serial.

   When printed or displayed the ISSN is preceded by the ISSN prefix and
   a space, and shall appear as two groups of four digits separated by a
   hyphen

      Therefore the ISSN structure is as follows:

         NNNN-NNNC

          where N is a Digit character [0..9]
                C is either a Digit character or letter "X" [0..9,X]
                C is the check character

      An ISSN URN Namespace structure is conformant to URN syntax
      requirements (RFC 2141).

         examples urn:ISSN:0259-000X
                  urn:ISSN:1560-1560

      Relevant ancillary documentation:

         ISO 3279 Information and documentation - International
         Standard Serial Number (ISSN)

         The ISSN: an identifier for serials in digital form.
         Compatibility with the URN framework.
         (ISSN International Centre -  January 1999)

         The ISSN-URN project.
         (ISSN International Centre -  October 1999)

   Identifier uniqueness considerations:

      Uniqueness is guaranteed by ISSN definition.



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      As defined in the ISO 3279 each ISSN is a "unique" identifier for
      a specific serial publication.

      A different ISSN is assigned to each publication issued on
      different media.

      An ISSN is never re-assigned.

   Identifier persistence considerations:

      Persistence of ISSN is guaranteed by the maintenance and update of
      the ISSN Register by the ISSN Centres.
      Even records for "ceased" publications still remain in the ISSN
      database, and links between serials belonging to a same "family"
      are expressed with related ISSN within the records.  This linking
      mechanism extends the current Identifier persistence concept.

   Process of identifier assignment:

      The ISSN network consisting in 68 National Centres and the
      International Centre:

      -  collects the material to be identified
      -  checks for identification all types of serials including
         electronic serial resources.
      -  assigns an ISSN to each different periodical.
      -  establish the bibliographic record.
      -  makes available the data.

      The data consisting in bibliographic records is centralised at the
      ISSN International Centre for global uniqueness checking.
      A given ISSN refers to one and only one form of the title, he
      key-title which is a key element of the bibliographic record as
      well as the ISSN.

      Today, the ISSN database contains more than 950 000 bibliographic
      records and a special attention is given to electronic publication
      resources and related metadata, and the way to access them.

   Process for identifier resolution:

      As a first step the ISSN International Centre has developed a
      centralised ISSN-URN resolver with multiple resolution
      capabilities which runs as a demonstrator.

      In a second step we expect the ISSN Namespace to be accessible for
      global resolution and to provide a set of resolution services
      compliant with the RDS/NAPTR proposals.



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   Rules for Lexical Equivalence:

      The check digit if 'X' is case-sensitive.
      Thus, if "x" is found it must be translated in upper case.

      The hyphen between the 4th and the 5th digit can be omitted

   Conformance with URN Syntax:

      There are no characters reserved.

Security Considerations

   Because this namespace defines no additional reserved characters it
   does not add any security consideration.

   Validation mechanism:

      None specified today.

   Scope:

      Global.

6. Security Considerations

   Security issues are discussed in section 5.

7. References

   [1] ISO 3279 Information and documentation - International Standard
       Serial Number (ISSN)

   [2] The ISDS Manual - ISSN International Centre (Paris, 1983) (under
       revision)

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

   [4] Sollins, K. and L. Masinter, "Functional Requirements for Uniform
       Resource Names", RFC 1737, December 1994.

   [5] Lynch, C., Preston, C. and R. Daniel, "Using Existing
       Bibliographic Identifiers as Uniform Resource Names", RFC 2288,
       February 1998.

   [6] Daniel, R. and M. Mealling, "Resolution of Uniform Resource
       Identifiers using the Domain Name System", RFC 2168, June 1997.




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   [7] Sollins, D., "Architectural Principles of Uniform Resource Name
       Resolution", RFC 2276, January 1998.

8. Contact Information and useful links

   Slawek Rozenfeld (Mr.)
   Head, Computer Section
   ISSN International Centre
     20, rue Bachaumont
           750002 PARIS
                 FRANCE

   EMail: [e-mail]
          [e-mail]

   ISSN Web site  http://www.issn.org
   ISSN-URN links http://www.issn.org/urn/


































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9. Full Copyright Statement

   Copyright (C) The Internet Society (2001).  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.  However, this
   document itself may not be modified in any way, such as by removing
   the copyright notice or references to the Internet Society or other
   Internet organizations, except as needed for the purpose of
   developing Internet standards in which case the procedures for
   copyrights defined in the Internet Standards process must be
   followed, or as required to translate it into languages other than
   English.

   The limited permissions granted above are perpetual and will not be
   revoked by the Internet Society or its successors or assigns.

   This document and the information contained herein is provided on an
   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Acknowledgement

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



















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