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Versions: 00 01                                                         
IETF URNbis WG                                               P. Godefroy
Internet-Draft                                 ISSN International Centre
Obsoletes: 3044 (if approved)                           November 7, 2012
Intended status: Standards Track
Expires: May 5, 2013

 Using International Standard Serial Numbers as Uniform Resource Names


   The International Standard Serial Number, ISSN, has been the
   authoritative identifier for continuing resources (which include
   serials) for more than three decades.  Since 2001, the URN (Uniform
   Resource Name) namespace "ISSN" has been reserved for ISSNs.  The
   namespace registration was performed in RFC 3044.  This document
   redefines -- in a backwards compatible manner -- how the revised ISSN
   standard can be supported within the URN framework, taking into
   account in particular the latest revision of the ISSN standard in the
   ISO framework (ISO 3297:2007).  Moreover, additional syntax related
   information required by the RFC 2141[bis] has been included.  An
   updated namespace registration is provided.  This document replaces
   RFC 3044.

Status of this Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
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   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on May 5, 2013.

Copyright Notice

   Copyright (c) 2012 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal

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   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
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   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
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   This document may contain material from IETF Documents or IETF
   Contributions published or made publicly available before November
   10, 2008.  The person(s) controlling the copyright in some of this
   material may not have granted the IETF Trust the right to allow
   modifications of such material outside the IETF Standards Process.
   Without obtaining an adequate license from the person(s) controlling
   the copyright in such materials, this document may not be modified
   outside the IETF Standards Process, and derivative works of it may
   not be created outside the IETF Standards Process, except to format
   it for publication as an RFC or to translate it into languages other
   than English.

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Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  4
   2.  Conventions Used in This Document  . . . . . . . . . . . . . .  4
   3.  Fundamental Namespace and Community Considerations . . . . . .  5
     3.1.  The URN:ISSN Namespace . . . . . . . . . . . . . . . . . .  5
     3.2.  Community Considerations for ISSNs . . . . . . . . . . . .  5
   4.  International Standard Serial Numbers  . . . . . . . . . . . .  6
     4.1.  Overview / Namespace Considerations  . . . . . . . . . . .  6
       4.1.1.  Allocation of Blocks of ISSNs  . . . . . . . . . . . .  7
     4.2.  ISSN Structure . . . . . . . . . . . . . . . . . . . . . .  8
     4.3.  Encoding Considerations  . . . . . . . . . . . . . . . . .  8
     4.4.  Resolution of ISSN-based URNs  . . . . . . . . . . . . . .  9
       4.4.1.  General  . . . . . . . . . . . . . . . . . . . . . . .  9
       4.4.2.  Practical Aspects  . . . . . . . . . . . . . . . . . .  9
     4.5.  Additional Considerations  . . . . . . . . . . . . . . . . 10
       4.5.1.  ISSN-L (or "Linking ISSN") . . . . . . . . . . . . . . 10
       4.5.2.  Updating and Management of URLs Corresponding to
               Resources Identified by URN:ISSN . . . . . . . . . . . 12
   5.  URN Namespace Registration and Use . . . . . . . . . . . . . . 14
     5.1.  URN Namespace ID Registration for the International
           Standard Serial Number (ISSN)  . . . . . . . . . . . . . . 14
   6.  Security Considerations  . . . . . . . . . . . . . . . . . . . 18
   7.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 18
   8.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 18
   9.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 18
     9.1.  Normative References . . . . . . . . . . . . . . . . . . . 18
     9.2.  Informative References . . . . . . . . . . . . . . . . . . 19
   Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 20

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1.  Introduction

   One of the basic permanent URI schemes (cf. RFC 3986 [RFC3986],
   [IANA-URI]) is 'URN' (Uniform Resource Name) as originally defined in
   RFC 2141 [RFC2141] and now being formally specified in RFC 2141bis
   [I-D.ietf-urnbis-rfc2141bis-urn].  Any identifier, when used within
   the URN system, needs its own namespace.  In August 2011 there were
   44 registered URN namespaces (see [IANA-URN]), one of which belongs
   to ISSN, International Standard Serial Number, as specified 2001 in
   RFC 3044 [RFC3044].

   As part of the validation process for the development of URNs, the
   IETF URN working group agreed that it is important to demonstrate
   that a URN syntax proposal can accommodate existing identifiers from
   well established namespaces.  One such infrastructure for assigning
   and managing names comes from the bibliographic community.
   Bibliographic identifiers function as names for objects that exist
   both in print and, increasingly, in electronic formats.  RFC 2288
   [RFC2288] investigated the feasibility of using three identifiers
   (ISBN, ISSN and SICI, see below) as URNs, with positive results;
   however, it did not formally register corresponding URN namespaces.
   This was in part due to the still evolving process to formalize
   criteria for namespace definition documents and registration,
   consolidated later in the IETF into RFC 3406 [RFC3406].  That RFC, in
   turn, is now being updated as well into RFC 3406bis

   URN Namespaces have subsequently been registered for both ISBN
   (International Standard Book Number) and ISSN (International Serial
   Standard Number) in RFCs 3187 and 3044 ([RFC3187], [RFC3044]),

   The RFC at hand replaces RFC 3044; all ISSN information has been
   updated and the namespace registration revised to make it compliant
   with stipulations of RFC 3406bis
   [I-D.ietf-urnbis-rfc3406bis-urn-ns-reg], the work-in-progress
   successor of RFC 3406 [RFC3406], which in turn had replaced the
   legacy RFC 2611 [RFC2611] applied in the initial registration.  This
   version of the URN:ISSN registration is fully backwards compatible
   with the original one, in the sense that all ISSN URNs assigned under
   RFC 3044 remain valid and semantically unchanged.

2.  Conventions Used in This Document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   document are to be interpreted as described in RFC 2119 [RFC2119].

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3.  Fundamental Namespace and Community Considerations

3.1.  The URN:ISSN Namespace

   ISSN is an authoritative standard identifier system for continuing
   resources and in particular serial publications.  Therefore, any
   useful and deployable method for identifying these entities for
   network-wide reference and making their metadata available on the
   Internet needs to be based on ISSNs.  ISSNs are authoritatively
   referenced in a centrally managed database called the "ISSN
   Register", which can be used as the basis for URN:ISSN resolution

3.2.  Community Considerations for ISSNs

   ISSNs are assigned under the auspices of the ISSN International
   Centre and national ISSN Centres.  ISSN assignment is a well managed
   and understood process, but as in any process administered by humans
   errors do take place.  While some errors may happen in the ISSN
   Register itself and are readily corrected, most errors happen in the
   outside world through the use of inappropriate ISSN in external
   references or the resources themselves.

   Continuing resources, including serials, most often consist of
   component parts such as volumes, issues, articles.  The ISSN standard
   does not allow the identification of component parts of the serial
   designated by the ISSN, and the URN:ISSN Namespace equally does not
   support such augmentation -- neither by an added NSS component nor by
   use of URI fragment identifiers.

   For all the communities interested in the identification of
   continuing resources and their contents, URN:ISSN-based
   identification and resolution services offer efficient, reliable and
   persistent access to resources and/or resource-related services.  The
   users will not need special tools for this as Web browsers are
   sufficient to display bibliographic information or when appropriate,
   an access point to the resources themselves.

   The next chapter presents an overview of the application of the URN:
   ISSN namespace and the principles, and systems used, for the
   resolution of ISSN-based URNs.

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4.  International Standard Serial Numbers

4.1.  Overview / Namespace Considerations

   Each ISSN is a unique identifier for a specific serial or other
   continuing resource in a defined medium.

   ISSNs are applicable to serials and other continuing resources,
   whether past, present, or to be produced in the foreseeable future,
   whatever the medium of production.  Continuing resources are issued
   over time with no predetermined conclusion, they include serials and
   ongoing integrating resources.  ISSNs are assigned to the entire
   population of serials and to ongoing integrating resources.

   Serials are resources for which additional information is supplied
   indefinitely in a succession of discrete parts.  All serials are
   eligible for an ISSN.  Also eligible for ISSN assignment are those
   bibliographic resources issued in successive issues or parts that
   bear numbering and that also bear other characteristics of a serial
   (e.g. frequency in the title), but whose duration is limited (e.g.
   the newsletter of an event).

   Ongoing integrating resources are resources that are updated over
   time and with no predetermined conclusion, for which the updates are
   integrated into the resources and do not remain discrete.  Those
   ongoing integrating resources that are eligible for an ISSN must be
   updated indefinitely, and/or have an update statement.  Advertising
   and individual home pages, online diaries, personal weblogs, and web
   sites consisting exclusively of links are not eligible for an ISSN.

   Individual monographs, technical reports, sound and video recordings,
   printed music publications, audiovisual works and musical works have
   their own identifier systems.  Such items may carry an ISSN in
   addition to their own standard numbers when they are part of a
   continuing resource.

   Only one ISSN is assigned to a continuing resource in a defined
   medium.  This ISSN is permanently linked to the so called key title,
   a standardized form of title derived from information appearing on
   the continuing resource.  A key title is unique to a particular
   continuing resource.  Titles that would otherwise not be unique are
   made unique by the addition of qualifying elements.  In cases where
   the title changes sufficiently (as per specific rules defined in the
   ISSN Manual) to warrant creating a new key title, a new ISSN is
   assigned.  In cases where the medium of the continuing resource
   changes, a new ISSN and a new key title are assigned.

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   Changes in publisher, country, language, frequency, subject scope or
   any other characteristic of a given continuing resource do not
   warrant the assignment of a new ISSN.  Title changes that are deemed
   minor are registered in the ISSN metadata as "variant titles".

   When a new ISSN is assigned to a continuing resource (because of a
   significant title change or of a media change), both the "former" and
   "new" ISSN are deemed valid and identify two distinct entities: each
   of them identifies the continuing resource in its incarnation in a
   given time interval, under a particular key title and/or physical
   medium.  "Dead" continuing resources are dead in the sense that they
   are no longer updated, but they continue to be accessible in library
   shelves or as archives on servers and their continuing identification
   is an obvious need for the whole chain of stakeholders.

   In such cases, ISSNs, through the metadata stored in the ISSN records
   of the ISSN Register are reciprocally linked.  In fact, one of the
   major aspects of the ISSN Register is its linking structure through
   which various incarnations of continuing resources are reciprocally
   linked using the ISSN as pointer.  There are different categories of
   such links (for former and successor titles, other media editions,
   other language editions, supplements etc.).  A given ISSN may thus be
   linked directly to a number of other ISSN, which in turn may be
   linked to other ISSNs, etc.  We can thus define the concepts of
   directly and indirectly linked ISSNs.

4.1.1.  Allocation of Blocks of ISSNs

   The ISSN International Centre is responsible for the allocation of
   blocks of ISSN to National Centres.  Each Centre receives limited
   blocks of numbers.  In using blocks of ISSNs, National ISSN Centres
   adhere to the following procedures:

   I. Report all ISSNs assigned by their centre to the ISSN Register;

   II.  Assign the ISSNs within their allocated block consecutively and
   use up one block completely before starting another block;

   III.  Ensure that ISSN assignments made in advance of publication or
   production of a continuing resource are recorded in the ISSN Register
   by determining if publication or production of the resource has
   occurred and creating the appropriate ISSN records.

   Although it is possible, on the basis of internal management
   procedures of the ISSN Register, to determine in a majority of cases
   that a given ISSN is part of a given block of ISSNs allocated to a
   given ISSN National Centre, this feature cannot be used for ISSN
   resolution mechanisms for the following reasons:

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   -  The country of publication of a continuing resource may change
      over time (which implies that the responsibility of a given ISSN
      may be switched from one ISSN National Centre to another and that
      the ISSN block from which the given ISSN was used may not
      correspond to the actual country of publication).

   -  A significant number of ISSNs were initially assigned in a
      "multinational" framework where the block of ISSNs was not
      attached to a given country.

   -  There exists a significant number of "multinational" publications
      where "national" responsibility for ISSN assignment and management
      has necessarily to be defined on somewhat arbitrary basis, which
      may vary over time.

   For similar or identical reasons, although metadata attached to an
   ISSN in the framework of the ISSN Register defines the current
   National ISSN Centre responsible for the management of the ISSN and
   its corresponding ISSN record, this information cannot and should not
   be used to infer a resolution path.

4.2.  ISSN Structure

   An ISSN consists of eight digits.  These are the Arabic numerals 0 to
   9, except that an upper case X can sometimes occur in the final
   position as a check digit (when representing the number "10").  Since
   ISSNs are likely to be used in the same context as codes designed for
   other purposes, a distinction must be preserved in the form of
   presentation.  An ISSN therefore appears as two groups of four
   digits, separated by a hyphen:

      ISSN 0317-8471

      ISSN 1050-124X

   The check digit is always located in the extreme right (low order)
   position, and is calculated on a modulus 11 basis using weights 8 to

4.3.  Encoding Considerations

   Embedding ISSNs within the URN framework does not present encoding
   problems, since all of the characters that can appear in an ISSN (the
   10 digits (0 to 9), the hyphen and capital letter X) are valid in the
   namespace-specific string (NSS) part of the URN.  Percent-encoding,
   as described in RFC 2141bis [I-D.ietf-urnbis-rfc2141bis-urn], is
   never needed.  In order to improve readability of the NSS, central
   hyphens SHOULD always be used.

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   Example: URN:ISSN:1234-1231

4.4.  Resolution of ISSN-based URNs

4.4.1.  General

   For URN resolution purposes, all elements, including the check digit
   and the central hyphen, must be taken into account.

   If a local resource stores and manages ISSNs without a central
   hyphen, it SHOULD be programmatically inserted for the constitution
   of URN:ISSN.

   Applications, such as the national bibliography or the open archive
   of a university, can use the URN as the persistent address of the
   resource.  There is just one place (the URN registry) where the
   address is mapped to one or more physical locations.

4.4.2.  Practical Aspects

   Persistence is one of the key features for any persistent identifier
   system.  There are three inter-related aspects of persistence that
   need to be discussed: persistence of the resource itself, persistence
   of the identifier, and persistence of the URN-based resolvers.

   Persistence of the resources: continuing resources are complex
   objects that evolve over time.  In their (mostly) paper incarnations,
   they have been stored on library shelves sometimes for centuries.
   Bibliographic records mediate identification and access.  If a
   continuing resource is available on print only, its URN:ISSN will
   resolve to the bibliographic record in the ISSN register.

   The ISSN Register has identified (at the beginning of 2012) almost
   100,000 online continuing resources that may or may not have print
   equivalents.  Furthermore, vast digitization efforts are now
   undertaken over the world to create electronic archives of printed
   continuing resources (these initiatives have often a dual aim of long
   term preservation and economies in shelving space); efforts are also
   under way to manage the long term preservation of online continuing

   All these efforts that have as a goal the persistence of the
   continuing resources will be all the more successful if they benefit
   from a standardized identification layer.  This obviously also has an
   impact on the management of contents (volumes, issues, and first and
   foremost articles) where linking frameworks that appeared during the
   last ten years (CROSSREF or Open URL) make heavy use of the ISSN.

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   Persistence of the identifier: The ISSN as an identifier is
   persistent in the sense that once assigned, an ISSN will never be re-
   assigned to a different continuing resource.

   Persistence of the resolvers: URN resolvers are not static.  The
   services they'll supply will change over time, due to changes in
   technical infrastructure.  For instance, new URN resolution services
   may be added or modified over time.  Persistence of the resolvers
   themselves is mainly an organizational issue, related to the
   persistence of organizations maintaining them.  As URN:ISSN
   resolution services will be based on the ISSN Register, which is
   itself a persistent resource that has been maintained for almost 35
   years, we may thus assume that URN:ISSN resolution services will be

   The ISSN Register will initially support four resolution services
   specified in RFC 2483 [RFC2483], namely I2L, I2Ls, I2C and I2Cs.
   Only I2C and I2Cs (URI to URC(s); delivery of descriptive metadata
   related to the resource) are valid for non-networked resources.
   Descriptive metadata can only be supplied in the MARC21 format.  The
   resolutions service will be conformant with the syntax defined for
   the query instruction for URN service selection specified in
   RFC 2141bis [I-D.ietf-urnbis-rfc2141bis-urn].

   Due to the structure of the ISSN, it is assumed that URN:ISSN
   resolution can only be reliably achieved through a central service,
   based on the ISSN Register that in turn can benefit from automated
   linking with other local resources using the ISSN as an identifier.
   Only a combination of the authority of the centralized ISSN Register
   and of local data can guarantee both reliability and persistence.

4.5.  Additional Considerations

4.5.1.  ISSN-L (or "Linking ISSN")

   In the framework of URN:ISSN resolution, the ISSN-L is a very
   important new feature.

   The ISSN-L (or "linking ISSN") is an important modification
   introduced in the latest revision of the ISSN standard in the ISO

   The ISSN-L has been defined to meet the need for a collocation, or
   grouping mechanism that brings together the various media versions of
   a continuing resource, and thus facilitate content management.

   The ISSN-L is an ISSN designated by the ISSN Network to group the
   different media versions of a continuing resource.

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   Only one ISSN-L is designated regardless of how many different media
   versions of a continuing resource exist.  A continuing resource will
   be associated with only one ISSN-L.  Designation of the ISSN-L

   The designation of the ISSN-L is carried out either by a centre of
   the ISSN Network or is performed automatically as records are added
   to the ISSN Register.  It is done either by those ISSN National
   Centres that are able to undertake this responsibility, or by the
   International Centre.  The records produced by these National Centres
   include the ISSN-L in the ISSN records under their responsibility.  Rules for the Designation of the ISSN-L

   The first ISSN assigned, in the ISSN Register, to any media version
   of a continuing resource is designated by default to function also as
   the ISSN-L and applies to all other media versions of that resource
   identified in the ISSN Register.  An ISSN-L is designated for each
   continuing resource identified in the ISSN Register, even if the
   continuing resource is issued in only one medium.  Only one ISSN-L is
   designated regardless of how many different media versions of a
   continuing resource exist.

   In the framework of URN:ISSN resolution, whether an ISSN is submitted
   as an ISSN-L or as an ISSN should be considered as having no
   practical impact as the response should always include by default
   basic resolution data for all ISSNs that may be linked through a
   common ISSN-L.

   For efficient practical resolution purposes, it should not be assumed
   that the requesting service has an unambiguous knowledge of either:

   o  the media version associated to a given ISSN; or

   o  the ISSN which is designated to function as the ISSN-L that links
      the different media versions.

   The URN:ISSN resolution service should make no such assumption
   concerning the knowledge of the requesting service.  The URN:ISSN
   resolution should make available sufficient authoritative metadata so
   as to allow the requesting service to obtain the expected response,
   even if the ISSN submitted is not used fully adequately by the
   requestor.  URN:ISSN resolution metadata should allow the requesting
   service to check and correct if necessary its potentially incorrect
   assumptions, so as to avoid the following situations:

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   o  an ISSN would be left unresolved (for instance because a "print"
      ISSN was sent instead of the "online" ISSN and I2L service is

   o  the requesting service would be left unaware of the existence of
      other ISSN linked through a common linking ISSN-L, because it
      would have submitted for resolution an ISSN not designated as

   o  the requesting service would have to perform several successive
      URN:ISSN resolution requests for all ISSN linked through a common


      URN:ISSN:1234-1231 identifies the current print edition of
      "Medical News".

      URN:ISSN:1560-1560 identifies the current online edition of
      "Medical News".

   The ISSN-L linking both media versions of "Medical News" happens to
   be ISSN-L 1234-1231 (i.e based on the ISSN 1234-1231, designated as
   such in the framework of the management of the ISSN Register).

   The resolution of URN:ISSN:1234-1231 should be equivalent to the
   resolution of URN:ISSN 1560-1560; i.e., in both cases one should find
   a reference to the other media version.

4.5.2.  Updating and Management of URLs Corresponding to Resources
        Identified by URN:ISSN

   As already indicated, continuing resources are complex objects or
   sets of objects that evolve over time and can be partly or fully
   duplicated, published, archived, remixed.  Various entities
   (publishers, issuing bodies, libraries, content aggregators,
   archiving institutions, subscription services, ...) may be partly or
   fully responsible over time for the online management of these

   Their stewardship may be ambiguously implemented for various reasons:

   o  It may extend over a restricted sub-set of the resource (only from
      a given year for instance).

   o  It may express itself over time through various technical
      implementations, which may translate into server name and URL

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   o  It may or may not be associated with an adequate stewardship over
      the appropriate identification of the objects (inadequate ISSN
      being used for media versions, title changes not taken into
      account, ...).

   o  The ISSN assigned may or may not be used in a consistent and
      standardized machine processable form in the objects themselves or
      in external reference lists.  Even if an appropriate ISSN is used
      in the stored metadata, it may be duplicated at the level of all
      the sub-objects (volumes, issues, articles, ...) making it
      impractical to ascertain the adequate entry point of the
      continuing resource itself as a whole.

   In some cases, continuing resources are not processed or managed as
   such and only their constituent parts (for instance, volumes, issues,
   articles, ...) are made directly accessible as evolving sets.

   Last but not least, commercial publications may restrict access to
   authenticated users only.

   This practically means that "resolution" (in the sense of
   localization) of continuing resources can best be achieved in the
   framework of long term coordinated efforts, but cannot be guaranteed
   in all cases.  The best results will of course be obtained with
   "preservation silos" or big entities.  Concerning the "long tail" of
   small publications, preservation initiatives are best equipped to
   handle the link between identification and access to the resources

   This means that URN:ISSN resolution will not be able to offer "full
   resolution" (i.e. reliable access to the resource itself) in all
   cases, even if the resource is "online".

   On the other hand, URN:ISSN extended resolution services could be
   offered on a systematic basis thanks to the metadata stored in the
   ISSN Register and its potential linking with external resources, such

   o  basic metadata stored in the ISSN Register identifying or
      describing the resource, including, as stated above, metadata from
      the ISSN records linked through a common ISSN-L; in particular,
      the minimum set of data should include the category of the ISSN as
      defined above, so as to allow for instance an adequate processing
      of "cancelled ISSNs";

   o  access to the direct or indirect linking structure associating the
      ISSN with other continuing resources;

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   o  linking to administrative metadata such as archiving and
      preservation information about the resource or in a more general
      and wider way, to any kind of relevant ancillary information:
      publisher, issuing body, availability through third party outfits,
      such as union catalogues etc., external evaluation and
      authentication data, in fact to any other party or service
      offering relevant ISSN based metadata.

   URN:ISSN resolution services can be both human readable and machine
   processable so as to support semantic web compatible services.

   It should finally be noted that as the ISSN Register is a
   subscription based resource, URN:ISSN resolution cannot be a fully
   open service.

5.  URN Namespace Registration and Use

   The formal URN Namespace Identifier Registration for the pre-2007
   version of the International Standard Serial Number (ISSN) standard
   was done in RFC 3044 [RFC3044].

   The revised ISSN standard does not require a new namespace, but the
   registration is updated here.  The registrant organization has moved
   from a former address to a new one in Paris.  Moreover, the
   description of the NSS and resolution details have been amended.

5.1.  URN Namespace ID Registration for the International Standard
      Serial Number (ISSN)

   This registration describes how the International Standard Serial
   Number (ISSN) can be supported within the URN framework.

   [ RFC Editor: please replace "XXXX" in all instances of "RFC XXXX"
   below by the RFC number assigned to this document. ]

   Namespace ID:  ISSN

      This Namespace ID has already been assigned to the International
      Standard Serial Number in January 2001 when the namespace was
      initially registered.

   Kind of named resources:

      Continuing (serial) publications.

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   Registration Information:

      Version: 2
      Date: 2012-10-31

   Declared registrant of the namespace:

      Registering Organization: Centre international d'Enregistrement
      des Publications en Serie - CIEPS-ISSN - ISSN International Centre

      Designated Contact Person:
      Name: Ms. Francoise Pelle
      Affiliation: Director, ISSN International Centre
      Email: issnic@issn.org
      Postal: 45 rue de Turbigo, 75003 PARIS, FRANCE
      Web URL: <http://www.issn.org/>

   Declaration of syntactic structure of NSS part:

      The ISSN syntax (used literally as the NSS) is as follows:


      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

      Example 1: URN:ISSN:1234-1231
      Example 2: URN:ISSN: 0259-000X

   Relevant ancillary documentation:

      The ISSN (International Standard Serial Number) is a unique
      machine-readable identification number, which identifies
      unambiguously any continuing resource.  This number is defined in
      ISO Standard 3297:2007.  ISSNs have been in use for more than 30
      years and they have deeply affected the handling of continuing
      resources and their contents. 88 countries are officially ISSN
      members (at the beginning of 2012).

      The administration of the ISSN system is carried out at two
      levels: International Centre and National Centres.

      The ISSN International Centre is located in Paris (France).
      The main functions of the Centre are:

      *  To promote, co-ordinate and supervise the world-wide use of the
         ISSN system.

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      *  To maintain and publish the ISSN Register.

      *  To allocate blocks of ISSNs to ISSN National Centres.

      *  to assign ISSN to international publications and to serials
         issued in countries with no National Centre.

      Detailed information about ISSN usage can be found from the ISSN
      Users' Manual.  The manual is available at

   Conformance with URN Syntax:

      Legal ISSN characters are 0-9 and hyphen and X. No percent-
      encoding is needed.  Hyphen carries no semantic content but SHOULD
      NOT be dropped from the NSS.

   Rules for Lexical Equivalence of NSS part:

      ISSN numbers are usually printed with the letters 'ISSN' and a
      single blank preceding the ISSN proper (for instance: ISSN 1234-
      1231).  Any data preceding the ISSN MUST NOT be included in the
      NSS.  No percent encoding is needed.

      Prior to comparing the NSS of two ISSN-based URNs for equivalence,
      all hyphens, if present, MUST be removed and letter 'X'

      Note that, according to RFC 2141bis
      [I-D.ietf-urnbis-rfc2141bis-urn], the prefix "URN:ISSN:" is case-
      insensitive; generic URI parsing and comparison software
      frequently uses lower case as the canonical (normalized) form.

      The URNs are equivalent if the normalized forms obtained this way
      compare equal.

   Usage of query instructions:

      'ISSN' URN resolvers initially support four of the resolution
      services specified in RFC 2483 [RFC2483], namely I2L, I2Ls, I2C
      and I2Cs.  Only I2C and I2Cs (URI to URC(s); delivery of
      descriptive metadata related to the resource) are valid for non-
      networked resources, and hence I2C is the default service.

      'ISSN' URN resolution by the ISSN International Centre will ignore
      query keywords other than "s".

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   Usage of fragment part:

      There are no provisions for support of the fragment part in URI
      references to 'ISSN' URNs.
      However, the MARC21 format used to return metadata for 'ISSN' URNs
      can be interpreted by cognizant resolution clients.

   Identifier uniqueness and persistence considerations:

      ISBN is a unique identifier.  ISSN is a unique and persistent
      identifier.  An ISSN, once it has been assigned, MUST NOT be re-
      used for another continuing resource.  'ISSN' URNs inherit the
      uniqueness and persistence properties from ISSNs.

   Process of identifier assignment:

      Assignment of ISSNs is controlled, and 'ISSN' URNs immediately
      inherit this property.  There are three levels of control: the
      ISSN International Centre, national ISSN Centres, and finally all
      the stakeholders responsible for a correct use of the ISSN system.

   Process for identifier resolution:

      See Section 4.4 of RFC XXXX.

   Validation mechanism:

      The check digit helps to assure the correctness of an ISSN number
      assigned for a continuing resource when it has been entered or
      processed.  Applications processing bibliographic data such as
      integrated library systems MAY use the check digit to check the
      correctness of the ISSN string.  If the number is found to be
      wrong due to, e.g., a typing error made by a publisher, the
      correct ISSN SHOULD nevertheless be used while the wrong number
      may be stored alongside for reference.  Although the resource
      itself may only contain the wrong number, national bibliographies
      and systems used by relevant communities often will contain both
      the wrong and correct ISSN number.


      ISSN is a global identifier system used for identification of
      continuing resources.  It is very widely used and supported by the
      publishing and scholarly publication communities.

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6.  Security Considerations

   This document proposes means of encoding ISSNs within the URN
   framework.  An ISSN-based URN resolution service is depicted here,
   but in a generic level only; thus questions of secure or
   authenticated resolution mechanisms are excluded.  It does not deal
   with means of validating the integrity or authenticating the source
   or provenance of URNs that contain ISSNs.  Issues regarding
   intellectual property rights associated with objects identified by
   the ISSNs are also beyond the scope of this document.

   Access control mechanisms may be implemented to limit access to some
   or all URN resolution services available in the URN Register.  Such
   mechanisms, if any, will be discussed separately.

7.  IANA Considerations

   IANA is asked to update the existing registration of the Formal URN
   Namespace 'ISSN' using the template given above in Section 5.1, which
   follows the outline specified in RFC 3406bis

8.  Acknowledgements

   This draft is part of the URNBIS effort to revise the basic URN RFCs.
   The aim in the IETF is to bring these RFCs in alignment with the
   current URI Standard (STD 63, RFC 3986), ABNF, and IANA guidelines.
   The PERSID project <http://www.persid.org/> is a significant impulse
   to this work.

9.  References

9.1.  Normative References

              Hoenes, A., "Uniform Resource Name (URN) Syntax",
              draft-ietf-urnbis-rfc2141bis-urn-03 (work in progress),
              October 2012.

              Hoenes, A., "Defining Uniform Resource Name (URN)
              Namespaces", draft-ietf-urnbis-rfc3406bis-urn-ns-reg-03
              (work in progress), October 2012.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate

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              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC3986]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
              Resource Identifier (URI): Generic Syntax", STD 66,
              RFC 3986, January 2005.

9.2.  Informative References

              Huttunen, M., Hakala, J., and A. Hoenes, "Using
              International Standard Book Numbers as Uniform Resource
              Names", draft-ietf-urnbis-rfc3187bis-isbn-urn-03 (work in
              progress), October 2012.

              IANA, "URI Schemes Registry",

              IANA, "URN Namespace Registry",

   [RFC2141]  Moats, R., "URN Syntax", RFC 2141, May 1997.

   [RFC2288]  Lynch, C., Preston, C., and R. Jr, "Using Existing
              Bibliographic Identifiers as Uniform Resource Names",
              RFC 2288, February 1998.

   [RFC2483]  Mealling, M. and R. Daniel, "URI Resolution Services
              Necessary for URN Resolution", RFC 2483, January 1999.

   [RFC2611]  Daigle, L., van Gulik, D., Iannella, R., and P. Faltstrom,
              "URN Namespace Definition Mechanisms", BCP 33, RFC 2611,
              June 1999.

   [RFC3044]  Rozenfeld, S., "Using The ISSN (International Serial
              Standard Number) as URN (Uniform Resource Names) within an
              ISSN-URN Namespace", RFC 3044, January 2001.

   [RFC3187]  Hakala, J. and H. Walravens, "Using International Standard
              Book Numbers as Uniform Resource Names", RFC 3187,
              October 2001.

   [RFC3406]  Daigle, L., van Gulik, D., Iannella, R., and P. Faltstrom,
              "Uniform Resource Names (URN) Namespace Definition
              Mechanisms", BCP 66, RFC 3406, October 2002.

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Author's Address

   Pierre Godefroy
   ISSN International Centre
   45 rue de Turbigo
   Paris,   75003

   Phone: +33-1-44-88-22-18
   Email: godefroy@issn.org

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