rfc3044.txt

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Network Working Group                                       S. Rozenfeld
Request for Comments: 3044                     ISSN International Centre
Category: Informational                                     January 2001


       Using The ISSN (International Serial Standard Number) as
       URN (Uniform Resource Names) within an ISSN-URN Namespace

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 (2001).  All Rights Reserved.

Abstract

   This document presents how the ISSN - International Standard Serial
   Number - which is a persistent number for unique identification of
   serials widely recognised and used in the bibliographic world, can be
   supported within the Uniform Resource Name (URN) framework as a
   specific URN namespace identifier.

   An ISSN URN resolution system using the ISSN identifier as Uniform
   resource Name within an ISN URN Namespace has been developed by the
   ISSN International Centre (ISSN-IC) and is operating as a
   demonstrator to evaluate all requirements to deploy it in an
   operational environment.

   This proceeds from concepts and proposals developed in several IETF
   RFCs emphasising the way to implement and to use "recognised"
   existing numbering system within the URN framework (RFC 2248, RFC
   2141, RFC 2611).















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Table of Contents

   1. Introduction ..................................................  2
   2. The ISSN system ...............................................  3
     2.1 The ISSN code ..............................................  3
     2.2  Construction of ISSN ......................................  3
     2.3 The ISSN Bibliographic record ..............................  4
     2.4 The ISSN Network ...........................................  4
     2.5 The ISSN Register ..........................................  5
   3. The ISSN and URN ..............................................  5
     3.1 compatibility ..............................................  5
     3.2 identification and access ..................................  7
   4  Resolution ....................................................  7
     4.1 Overview of the ISSN URN Resolution system .................  8
     4.2 Global Resolution ..........................................  9
   5. Registration of an ISSN URN Namespace ......................... 10
   6. Security Considersations ...................................... 13
   7. References .................................................... 13
   8. Contact information and useful links .......................... 14
   9. Full Copyright Statement ...................................... 15

1. Introduction

   The ISSN International Centre has undertaken in 1999-2000 an URN
   implementation taking advantage of the functional compatibility
   between the ISSN and the URN.

   The present implementation at the ISSN-IC Centre based on IETF RFCs
   on URN includes a centralised resolution system which allows direct
   access to electronic resources by using the ISSN identifiers as
   Uniform Resource Names within an ISSN URN Namespace.

   It demonstrates that the URN can integrate existing identifiers from
   well established identification schemes used by the bibliographic
   community.

   Nevertheless, to deploy this demonstrator into a wider operational
   system a responsible body or infrastructure is needed to assign
   namespaces and manage an RDS/NAPTR global resolution framework.  It
   is intended here that serials refer to all forms of serials published
   in printed form as well as in form of electronic resources.  Since
   this document contains a Registration form for an ISSN URN Namespace,
   this form also includes some paragraphs already present in other
   parts of this document.

   All figures and descriptions are dated 13 July 2000.





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2. The ISSN system

   The ISSN system results from a joint UNESCO and ICSU-AB working group
   on bibliographic descriptions set up in 1967 in order to establish a
   world registry of serial titles currently issued, stored or archived.

   Today, the ISSN system which is defined by an International standard
   (ISO 3297), relies on two main data elements:

   The International Standard Serial Number which is a unique identifier
   for a specific serial publication.

   The key-title, which is a unique name assigned to a serial, and is
   inseparably linked with its ISSN.

   And on a well established framework: the ISSN International network.

2.1 The ISSN code

   The ISSN - International Standard Serials Number is defined in the
   ISO standard 3297:1998 as a code for the unique identification of
   serials.

   This standard states that:

   Each ISSN is a unique identifier for a specific serial publication.
   ISSN are applicable to the entire population of serials, whether
   past, present or to be published in the foreseeable future, whatever
   the medium of publication.

   Serials include periodicals, newspapers, annuals (such as reports,
   yearbooks, directories, etc.), and the journals, series, memoirs,
   proceedings, transactions, etc., of societies.

   Today, ISSN are assigned to data bases and electronic serial
   resources.  Further broadening of the scope to continuing resources
   is under discussion.

2.2 Construction of ISSN

   The ISO 3297 standard states that:

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





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   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 a "the key title".  The Key title is
   a form of the title which is constructed in order to avoid duplicates
   so that each key title is unique in the ISSN Data base also named the
   ISSN Register.  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.

   examples  ISSN 0000-0019   ISSN 1560-1560

   ISSN are constructed and distributed by the ISSN International Centre
   to National Centres for assignment.

2.3 The ISSN Bibliographic record

   It contains in addition to the ISSN and key-title some thirty
   bibliographic data elements enabling the unambiguous and secure
   identification of a serial.

   One characteristic of an ISSN bibliographic record is that it
   contains other ISSN in linking fields in order to establish
   relationships between the given serial and a set of other related
   serials already identified.

   To recognise and to allow access to serial resources in digital form,
   the ISSN format has included additional data elements:

   -  A medium code which indicates the medium of the given serial
   -  A linking field to express relations between the different forms
      of "equivalent" serials on different media (from printed version
      to online as well as from online to printed)
   -  The location of an electronic resource: the URLs of a given
      resource.

2.4 The ISSN network

   It is the operational structure, main functions of which are:

   -  collecting the material which needs to be identified
   -  assigning the ISSN and the key title to a serial for unambiguous
      identification
   -  creating and editing bibliographic records in ISSN format



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   -  making available the bibliographic records

   It consists of:

   -  National Centres - 69 centres - responsible for the identification
      of serials published in their respective countries.
      Records created by National Centres are transmitted to the ISSN-IC
      for validation and update of the ISSN Register.

   -  The International Centre which co-ordinates the network and acts
      as a National Centre for serials published by International
      institutions and by countries with no National Centre.
      It collects and checks all bibliographic records to update in a
      consistent way the ISSN Register.

      It maintains the ISSN Register and makes it available.

2.5 The ISSN Register

   It is a data base controlled and maintained by the ISSN-IC.  It
   consists in 970 000 bibliographic records stored in ISSN-MARC format
   (a subset of USMARC format ) which are available on different media
   (CD-ROM, DAT, and on the Internet).

3. THE ISSN AND URN

3.1 ISSN compliance with URN requirements

   The different specifications and requirements on URNs have been
   studied from the following documents:

   URN Syntax
   (RFC 2141, May 1997 - R. Moats)

   Using Existing Bibliographic Identifiers as Uniform Resource Names
   (RFC 2288 February 1998 - C. Lynch, R. Daniel)

   Functional Requirements for Uniform Resource Names
   (RFC 1737, December 1994 - K. Sollins, L. Masinter)

   URN Namespace Definition Mechanisms
   (RFC 2611, June 1999 - L. Daigle, R. Iannella)

   A URN Namespace for IETF Documents
   (RFC 2648, August 1999 - R. Moats)

   Requirements for URNs' functional capabilities (from RFC 1737)




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   Global scope: A URN is a name with global scope which does not imply
   a location.  It has the same meaning everywhere.

   -  Applicable for ISSN.  Accordingly to ISO standard 3297 there is no
      limitations for serial resource identification.

   Global uniqueness: The same URN will never be assigned to two
   different resources.

   -  Applicable for ISSN.  By definition an ISSN is assigned to one and
      only one serial resource.  Once assigned, an ISSN is never re-
      assigned.

   Persistence: The lifetime of a URN is permanent.

   -  Applicable for ISSN.  All ISSN are registered in the ISSN Register
      data base which covers current serial resources as well as ceased.

   Scalability: URNs can be assigned to any resource that might
   conceivably be available on the network, for hundreds of years.

   -  Applicable for ISSN.  More than 98500000 ISSN have yet been
      assigned.

   Legacy support: The scheme must permit the support of existing legacy
   naming systems.

   -  Applicable for ISSN.  By definition the ISSN system is a legacy
      identification system for serial resources.

   Independence: It is solely the responsibility of a name issuing
   authority to determine the conditions under which it will issue a
   name.

   -  Applicable for ISSN.  By definition of the ISSN system.

   Resolution: For URNs that have corresponding URLs, there must be some
   feasible mechanism to translate a URN to a URL.

   -  Applicable for ISSN.  The ISSN-IC has developed an ISSN URN
      resolver which translates one given ISSN into one or several URLs.

   In addition to these basic requirements on the functional elements of
   the URNs, there are other requirements for how they are encoded in a
   string:

   Single encoding, Simple comparison, Simple human transcribability,
   Transport friendliness, Machine consumption, Text recognition.



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   -  Applicable to ISSN.  As defined in the ISO standard the ISSN is a
      very simple and short character string which fully responds to
      those requirements.

   Considering the aim of the ISSN, its framework and new developments
   for electronic serial resources identification, we can state that the
   ISSN fulfills all expressed URN requirements.

   Syntax requirements

   Considering syntax requirements (RFC2141) for an URN namespace and
   the URN syntax, an ISSN based URN namespace is compliant with such
   requirements since it does not use any reserved characters.

   In RFC 2288 (4.2 Encoding Considerations and Lexical Equivalence) it
   is stated that:

   There is no problem representing ISSN in the namespace - specific
   string of URNs since all characters valid in the ISSN are valid in
   the namespace-specific URN string, and %-encoding is never required.

   Example: urn:ISSN:1046-8188

   Supplementary comparison rules are also appropriate for the ISSN
   namespace, hyphens should be dropped prior to comparison and
   occurrences of 'x' normalised to uppercase.

3.2 Identification and access

   The role of an URN is also to provide safe access to the
   characteristics of a resource and to the resource itself.  One may
   view an ISSN bibliographic record as a metadata since it contains
   different data information on the resource which is to be identified,
   described, located and/or accessed.

   The ISSN is widely used as an identification number for serial
   resources.  Since the ISSN Network provides the URLs corresponding to
   the identified resources the ISSN is now also a tool for the location
   and access to resources on the Internet.  This is achieved by an ISSN
   URN resolution system.

4. RESOLUTION

   The different specifications and requirements on URN resolution have
   been studied from the following documents:

   URI Resolution Services Necessary for URN Resolution
   (RFC 2483, January 1999 - M. Mealling)



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   Resolution of Uniform Resource Identifiers using the Domain Name
   System
   (RFC 2168 June 1997 - R. Daniel, M. Mealling )

   Architectural Principles of Uniform Resource Name Resolution
   (RFC 2276, January 1998 - K. Sollins )

4.1. Overview of the ISSN URN Resolution system

   Using ISSN as Uniform Resource Name implies that some mapping
   mechanism is provided to ensure a reliable access to available
   resources when using Internet tools like a standard Web browser.

   From the technical point of view this has led to develop within our
   system the different pieces of software and services required to
   fulfill such aim.

   The resolution software be able to translate a given ISSN-URN into
   electronic locations:

   -  location of the bibliographic description or metadata
   -  location of the periodical itself (if it is in electronic form).

   These electronic locations are expressed in form of URLs for which