IETF URNbis WG                                               M. Huttunen
Internet-Draft                                                 J. Hakala
Obsoletes: 2288,3187 (if approved)       The National Library of Finland
Intended status: Standards Track                          A. Hoenes, Ed.
Expires: April 20, 2012                                           TR-Sys
                                                        October 18, 2011

  Using International Standard Book Numbers as Uniform Resource Names


   The International Standard Book Number, ISBN, is a widely used
   identifier for monographic publications.  Since 2001, the URN
   (Uniform Resource Name) namespace "ISBN" has been reserved for ISBNs.
   The namespace registration was performed in RFC 3187 and applied only
   to the ISBN as specified in the ISO Standard 2108-1992, now known as
   "ISBN-10".  To allow for further growth in use, the successor ISO
   Standard, ISO 2108:2005, has defined an expanded format for the ISBN,
   known as "ISBN-13".  This document defines how both of these ISBN
   standard versions can be supported within the URN framework.
   Moreover, additional syntax related information required by the RFC
   2141[bis] has been included.  An updated namespace registration is
   provided.  It describes how both the old and the new ISBN format can
   share the same namespace.

   This document replaces RFC 3187; it also obsoletes and moves to
   Historic status the predecessor thereof, RFC 2288.


   This draft is an outcome of work started in 2008 and brought to the
   IETF initially as a private contribution.  When the URNBIS working
   group was launched, revision of the ISBN namespace registration was
   included in its charter.

   Comments are welcome and should be directed to the
   mailing list or the authors.

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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   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at

   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 April 20, 2012.

Copyright Notice

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   document authors.  All rights reserved.

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   Provisions Relating to IETF Documents
   ( in effect on the date of
   publication of this document.  Please review these documents
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   described in the Simplified BSD License.

   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
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   Without obtaining an adequate license from the person(s) controlling
   the copyright in such materials, this document may not be modified
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   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  . . . . . . . . . . . . . .  5
   3.  Fundamental Namespace and Community Considerations . . . . . .  5
     3.1.  The URN:ISBN Namespace . . . . . . . . . . . . . . . . . .  5
     3.2.  Community Considerations for ISBNs . . . . . . . . . . . .  5
   4.  International Standard Book Numbers  . . . . . . . . . . . . .  6
     4.1.  Overview / Namespace Considerations  . . . . . . . . . . .  6
       4.1.1.  ISBN-10 Structure  . . . . . . . . . . . . . . . . . .  6
       4.1.2.  ISBN-13 Structure  . . . . . . . . . . . . . . . . . .  7
       4.1.3.  Relation between ISBN-10 and ISBN-13 . . . . . . . . .  7
     4.2.  Encoding Considerations  . . . . . . . . . . . . . . . . .  8
     4.3.  Resolution of ISBN-based URNs  . . . . . . . . . . . . . .  8
       4.3.1.  General  . . . . . . . . . . . . . . . . . . . . . . .  8
       4.3.2.  Practical Aspects  . . . . . . . . . . . . . . . . . .  9
     4.4.  Additional Considerations  . . . . . . . . . . . . . . . . 12
   5.  URN Namespace Registration and Use . . . . . . . . . . . . . . 13
     5.1.  URN Namespace ID Registration for the International
           Standard Book Number (ISBN)  . . . . . . . . . . . . . . . 13
   6.  Security Considerations  . . . . . . . . . . . . . . . . . . . 17
   7.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 17
   8.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 18
   9.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 18
     9.1.  Normative References . . . . . . . . . . . . . . . . . . . 18
     9.2.  Informative References . . . . . . . . . . . . . . . . . . 18
   Appendix A.  Draft Change Log  . . . . . . . . . . . . . . . . . . 20
     A.1.  draft-hakala-rfc3187bis-isbn-urn-00 to
           draft-ietf-urnbis-*-00 . . . . . . . . . . . . . . . . . . 20
     A.2.  draft-ietf-urnbis-rfc3187bis-isbn-urn-00 to -01  . . . . . 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 ISBN, International Standard Book Number, as specified 2001 in
   RFC 3187 [RFC3187].

   Since 2007, there have been two variants of ISBN in use; an outdated
   one based on ISO 2108-1992 [ISO1] and a new one defined in ISO 2108-
   2005 [ISO2].  These versions shall subsequently be called "ISBN-10"
   and "ISBN-13", respectively, in this document.  If what is said in
   this document applies to both ISBN versions, the generic term "ISBN"
   is used.

   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 [RFC3187] and 3044 [RFC3044],
   respectively, but not for SICI (Serial Item and Contribution
   Identifier), mainly due to the identifier's limited popularity.
   Moreover, URN resolution process for SICIs would be complicated.

   Guidelines for using ISBN-10s (based on ISO 2108:1992) as URNs and
   the original namespace registration have been published in RFC 3187
   [RFC3187].  The RFC at hand replaces RFC 3187; sections related to
   ISBN-13 have been added, all ISBN-10 information has been updated and
   the namespace registration revised to make it compliant with both
   ISBN versions and stipulations of RFC 3406bis
   [I-D.ietf-urnbis-rfc3406bis-urn-ns-reg], the work-in-progress

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   successor of RFC 3406 [RFC3406], which in turn had replaced the
   legacy RFC 2611 [RFC2611] applied in the initial registration.

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].

   "ISBN-10" refers to the original, 10-digit ISBN scheme specified in
   ISO 2108-1992 [ISO1].

   "ISBN-13" refers to the current, 13-digit ISBN scheme specified in
   ISO 2108-2005 [ISO2].

3.  Fundamental Namespace and Community Considerations

3.1.  The URN:ISBN Namespace

   ISBN is a well established standard identifier system for monographic
   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 ISBNs.

3.2.  Community Considerations for ISBNs

   ISBNs are assigned under the auspices of the International ISBN
   Agency [ISBNORG] and national/regional ISBN agencies.  ISBN
   assignment is a well managed and understood process, but as in any
   process administered by humans errors do take place.  If so, there
   are procedures in place for fixing the incorrect ISBNs.

   Books are finite objects, which may consist of component parts such
   as chapters or short stories / novellas.  Such component parts may
   given their own ISBNs if and only if they are available separately.
   The ISBN standard does not allow augmentation of the ISBN of the book
   with (URI) fragments for identification of the book's physical
   component parts.  If a fragment identifier is added to an ISBN, the
   resulting namespace specific string will not be an ISBN; it could be
   another identifier such as a national bibliography number (NBN).

   In late 90s there was an attempt to develop BICI (Book Item and
   Contribution Identifier) but the standard was neither completed nor
   implemented.  BICIs would have been based on ISBNs, and the idea was
   to generate them programmatically for e-books containing structured
   metadata.  The applications needed for this failed to materialize.

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   The materials identified by an ISBN may exist only in printed or
   other physical form, not electronically.  And even if an electronic
   book exists, access rights may be limited.  When the identified
   manifestation of the book cannot be suplied, the URN:ISBN resolver
   SHOULD supply descriptive and rights metadata about the relevant
   manifestation.  The resolver MAY also provide links to other
   manifestations of the same work, or to related works.  ISBN-based URN
   resolution services may support a wide variety of information
   services related to books.

   National libraries are among the key organizations providing URN
   resolution services for books.  Many of them are currently digitizing
   their historical printed books collections.  As a rule, a digitized
   book does not get an ISBN, especially if the original printed book
   did not have one.  Instead, national bibliography numbers are often
   used for identification.  In such cases the digital copy MAY be found
   with the ISBN of the printed original.

   For library users and Internet-based supply chain management for the
   delivery of monographs, URN:ISBN-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; Web browsers are sufficient.

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

4.  International Standard Book Numbers

4.1.  Overview / Namespace Considerations

   An International Standard Book Number (ISBN) identifies a product
   form or edition of a monographic publication.  Each product form
   (e.g. hardcover, paperback, PDF) MUST have its own ISBN.

4.1.1.  ISBN-10 Structure

   The ISBN-10 is defined by the ISO Standard 2108-1992 [ISO1].  It is a
   ten-digit number (the last "digit" can be the letter "X" as well)
   that is divided into four variable length parts usually separated by
   hyphens when printed.  Note that these hyphens can be removed; ISBNs
   with and without the hyphens are lexically equivalent.  The parts are
   as follows (in this order):

   o  a group identifier that specifies a group of publishers, based on
      national, geographic, or some other criteria;

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   o  the publisher identifier;

   o  the title identifier; and

   o  a modulo 11 check digit, using X instead of 10; the details of the
      calculation are specified in [ISO1].

   ISBN-10 was in use from 1970s until ISBN-13 replaced it in January

4.1.2.  ISBN-13 Structure

   ISBN-13 is defined by the ISO Standard 2108-2005 [ISO2].  The ISBN-13
   is a thirteen-digit number that is divided into five parts usually
   separated by hyphens when printed.  The first and the last part have
   a fixed lenght, but the other parts have variable length.  These
   parts are as follows (in this order):

   o  a prefix element of ISBN-13 is a 3 digit prefix specified by the
      International ISBN Agency; at the time of this writing, legal
      values were 978 and 979; future versions of the standard may
      define additional values;

   o  a registration group element that specifies the registration
      group; it identifies the national, geographic, language, or other
      such grouping within which one or more ISBN Agencies operate;

   o  the registrant element;

   o  the publication element; and

   o  a modulo 10 check digit; the details of the calculation are
      specified in [ISO2].

4.1.3.  Relation between ISBN-10 and ISBN-13

   The structural differences between the ISBN-10 and ISBN-13 are the
   prefix element (which does not exist in the ISBN-10) and the check
   digit calculation algorithm, which is modulo 11 in ISBN-10 and modulo
   10 in ISBN-13.

   Terminology in ISBN-10 differs substantially from the terminology
   applied in ISBN-13.  In this document, ISBN-13 terminology shall be
   used from now on; for a reader used to ISBN-10 terminology, the
   following mapping may be useful:

   o  ISBN-10 group identifier <-> ISBN-13 registration group element;

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   o  ISBN-10 publisher identifier <-> ISBN-13 registrant element;

   o  ISBN-10 title identifier <-> ISBN-13 publication element.

   Any ISBN-10 CAN be converted to ISBN-13 form, and retrospective
   conversion is the recommended practice in ISO 2108:2005.  Any
   application that processes ISBN-based URNs MUST be prepared to deal
   with both ISBNs, since ISBN-10 numbers may not be converted to the
   new form.  ISBN-13s using prefix element 979 can not be converted
   back to ISBN-10, since in these ISBNs group identifiers will be re-
   assigned.  New books may still have ISBN-10 alongside ISBN-13 for
   practical reasons, but only as long as the prefix element in ISBN-13
   is 978.

4.2.  Encoding Considerations

   Embedding ISBNs within the URN framework does not present encoding
   problems, since all of the characters that can appear in an ISBN 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, hyphens MAY be used.

      Example 1: URN:ISBN:978-0-395-36341-6

      Example 2: URN:ISBN:951-0-18435-7

      Example 3: URN:ISBN:951-20-6541-X

      Example 3: URN:ISBN:951206541X

4.3.  Resolution of ISBN-based URNs

4.3.1.  General

   For URN resolution purposes, all elements except the check digit (0-9
   for ISBN-13, previously 0-9 or X) must be taken into account.  The
   registration group and registrant element assignments are managed in
   such a way that the hyphens are not needed to parse the ISBN
   unambiguously into its constituent parts.  However, the ISBN is
   normally transmitted and displayed with hyphens to make it easy for
   humans to recognize these elements without having to make reference
   to or have knowledge of the number assignments for registration group
   and registrant elements.  In ISBN-10, registration group element
   codes such as 91 for Sweden were unique.  In ISBN-13, only the
   combination of prefix and registration group elements is guaranteed
   to be unique. 978-951 and 978-952 both mean Finland, but 979-951 and
   979-952 almost certainly will not (once they will be assigned in the

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   future); at the time of this writing, registration group element(s)
   for Finland are not yet known for ISBNs starting with 979.

   The Finnish URN registry is maintained by the national library.  The
   service is capable of resolving ISBN-based URNs.  URNs starting with
   URN:ISBN:978-951 or URN:ISBN:978-952 are mapped into appropriate URL
   addresses in a table maintained within the registry.  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 the
   address is mapped to one or more physical locations.

   ISBN-13 prefix / registration group element combinations (and the
   corresponding ISBN-10 registration group identifiers, if any) usually
   designate a country, but occasionally a single combination / ISBN-10
   group identifier is used to indicate a language area.  For instance,
   "978-3" (or "3" in ISBN-10) is utilised in Germany, Austria, and the
   German speaking parts of Switzerland.  As of this writing, there are
   two regional registration groups: "978-976" is used in the Caribbean
   community and "978-982" in the South Pacific (see [PREFIX]).

   Note that the prefix and registration group element combination
   "979-3" has not yet been assigned.  There is no intention to allocate
   the registration group elements in the same way as was done with

   The registrant element may or may not be used for resolution
   purposes, depending on whether individual publishers have set up
   their resolution services.

   The publication element shall enable targeting the individual

4.3.2.  Practical Aspects

   Due to the lack of URN support in, e.g., web browsers, the URNs are
   usually expressed as URLs when embedded in documents.  The Finnish
   URN registry is located at <>, and URNs are therefore
   expressed in the form<URN>.  For example, the URI
   <> identifies Sami Nurmi's
   doctoral dissertation "Aspects of Inflationary Models at Low Energy

   Any national URN registry can resolve URN:ISBNs with foreign
   registration group element values if a) there is a URN:ISBN
   resolution service for that country, b) the national resolution
   service is aware of the existence of the foreign service and how to
   find it, and c) the two resolution services can communicate with one

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   another.  PERSID project (<>) developed such an
   infrastructure for the URN:NBN namespace.

   Alternatively, instead of linking the national resolvers together, it
   is also possible to build international resolvers which copy
   resolution data from several national services, or to create a way
   station which will enable the resolvers to communicate with one
   another.  We can assume that the network of URN:ISBN resolvers will
   grow, and at the same time the set of services they support will also
   grow and become more diverse.  Such development might make these
   union resolvers and way stations more important.

   If a registration group element does not identify a single country
   but a language area, there are at least two means for locating the
   correct national bibliography.  First, it is possible to define a
   cascade of URN registries - for instance, German, Austrian and Swiss
   national registries, in this order - which should collectively be
   aware of resolution services such as national bibliographies for
   ISBN-13s starting with "978-3".  If the German registry is not able
   to find an authoritative resolution service, the request could be
   passed to the Austrian one, and if there are still no hits, finally
   to the Swiss service.

   Second, the registrant element ranges assigned to the publishers in
   Germany, Austria and Switzerland by the ISBN Agencies could be
   defined directly into the national registries.  This method would be
   more efficient than cascading, since the correct resolution service
   would be known immediately.  The choice between these two and
   possible other options should be made when the establishment of the
   European network of URN registries reaches this level of maturity.

   In some exceptional cases -- notably in the US and in the UK, where
   international companies do a significant portion of publishing -- the
   information provided by the group identifier may not always be fully
   reliable.  For instance, some monographs published in New York by
   international publishing companies may get an ISBN with the
   registration group element "3".  This is technically appropriate when
   the headquarters or one of the offices of the publisher is located in

   Information about such a book may not always be available in the
   German national bibliography, but via the Library of Congress
   systems.  Unfortunately, the German/Austrian/Swiss URN registries
   that should in this case be contacted may not be aware of the
   appropriate resolution service.

   However, the problem posed by the international publishers MAY be
   less severe than it looks.  Some international publishers (Springer,

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   for example) give the whole production to the national library of
   their home country as legal deposit, no matter which country the book
   was published.  Thus everything published by Springer in New York
   with registration group element "3" should be resolvable via the
   German national bibliography.  On the other hand, when these
   companies give their home base also as a place of publication, the
   "home" national library requires the legal deposit.

   A large union catalogue, such as WorldCat maintained by OCLC
   [OCLC-WC] CAN be used to complement the resolution services provided
   in the national level, or as the default service, if no national
   services exist or are known to the registry from which the query

   Due to the semantic structure of ISBN-13, the registrant element CAN
   be used as a "hint".  Technically, it is possible to establish a
   number of URN resolution services maintained by different kinds of
   organizations.  For instance, "978-951-0" is the unique ISBN
   registrant element of the largest publisher in Finland, Sanoma-WSOY.
   Resolution requests for ISBNs starting with "978-951-0" CAN be passed
   to and dealt with the publisher's server, if and when it is made URN-
   aware.  In such a case, resolving the same URN in multiple locations
   MAY provide different services; the national bibliography MAY be able
   to provide bibliographic information only, while the publisher CAN
   provide the book itself, on its own terms.  Resolution services MAY
   co-exist and complement one another.  Same ISBN CAN be resolved both
   as URN and as a Digital Object Identifier (DOI) [DOIHOME].  URN-based
   services hosted by, e.g., a national library, MAY provide only
   bibliographic metadata, whereas a service based on the DOI system
   provided by the publisher MAY supply the book, parts of the book or
   various other services.

   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.

   ISBNs are assigned to manifestations (physical embodiments) of books.
   Printed books tend to be persistent, so even after 500 years, a URN:
   ISBN identifying a printed book CAN resolve to a bibliographic
   description of the book, which MAY contain the location of the book.

   With digital books things get more complicated.  Each product form
   MUST have a separate ISBN, but digital manifestation will not be
   long-lived.  Anyone who tries to use a 100-year old e-book will
   probably be disappointed.  Manifestations of an e-book should be
   interlinked (using, for instance, the work level metadata record) so
   as to make a user aware of the existence of these product forms.

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   This will enable the user to retrieve the form which matches his /
   her interests best.  Some users MAY prefer a modern manifestation
   although it MAY not have the original look and feel, while other
   users want the original manifestation which is authentic but MAY
   require digital archaeology for access.

   Manifestations of e-books, like other e-resources, are not required
   to be persistent per se, but require successive migrations into new
   file formats.  URN:ISBN SHOULD support information architectures
   which enable persistent access to the relevant intellectual content
   (work), independent of its form, although ISBN SHOULD NOT be used to
   identify the works themselves.

   URN resolvers are not static.  The services they'll supply will
   change over time, due to changes in technical infrastructure.  For
   instance, implementation of long term preservation systems will
   enable and necessitate a set of new URN resolution services.

   Persistence of resolvers themselves is mainly an organizational
   issue, related to the persistence of organizations maintaining them.
   As URN:ISBN resolution services will be supplied (among others) by
   the national libraries to enable access to their legal deposit
   collections, we may assume that URN:ISBN resolution services will be

4.4.  Additional Considerations

   The basic guidelines for assigning ISBNs to electronic resources are
   the following:

   o  Product form and the means of delivery are irrelevant to the
      decision whether a product needs an ISBN or not.  If the content
      meets the requirements of the standard, it gets an ISBN, no matter
      what the file format of the delivery system.

   o  Each product form (manifestation) of a digital publication should
      have a separate ISBN.  The definition of a new edition is normally
      based on one of the two criteria:

      *  A change in the kind of packaging involved: the hard cover
         edition, the paperback edition and the library-binding edition
         would each get a separate ISBN.  The same applies to different
         formats of digital files.

      *  A change in the text, excluding packaging or minor changes such
         as correcting a spelling error.  Again, this criterion applies
         regardless of whether the publication is in printed or in
         digital form.

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   Although these rules seem clear, their interpretation may vary.  As
   already RFC 2288 [RFC2288] pointed out,

      The choice of whether to assign a new ISBN or to reuse an existing
      one when publishing a revised printing of an existing edition of a
      work or even a revised edition of a work is somewhat subjective.
      Practice varies from publisher to publisher (indeed, the
      distinction between a revised printing and a new edition is itself
      somewhat subjective).  The use of ISBNs within the URN framework
      simply reflects these existing practices.

   Mistakes can happen.  For instance, an ISBN has sometimes been re-
   used for another book.  These reasonably rare kind of human error do
   not threaten or undermine the value of the ISBN system as a whole.
   Neither do they pose a serious threat to the URN resolution service
   based on ISBNs.  The error described above SHOULD only lead into the
   retrieval of two bibliographic records describing two different
   monographic publications.  Based on the information in the records, a
   user can choose the correct record from the result set.

   Libraries routinely correct ISBN mistakes.  Their catalogs provide
   cross references ("incorrect ISBN -> correct ISBN").  This MUST be
   taken into account in the URN resolution process.  Further details on
   the process of assigning ISBNs can be found in section 5 (Namespace
   registration) below.

5.  URN Namespace Registration and Use

   The formal URN Namespace Identifier Registration for the pre-2005
   version of the International Standard Book Number (ISBN) was done in
   RFC 3187 [RFC3187].

   The new ISBN standard does not require a new namespace, but the
   registration is renewed here.  The registrant organization has moved
   from Staatsbibliothek zu Berlin - Preussischer Kulturbesitz to The
   International ISBN Agency, London, U.K. Moreover, the description of
   the NSS and resolution details have been amended.

5.1.  URN Namespace ID Registration for the International Standard Book
      Number (ISBN)

   This registration describes how International Standard Book Numbers
   (ISBN) 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. ]

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   Namespace ID:  ISBN

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

   Registration Information:

      Version: 2
      Date: 2011-09-08

   Declared registrant of the namespace:

      Registering Organization: The International ISBN Agency

      Designated Contact Person:
      Name: Ms. Stella Griffiths
      Affiliation: Executive Director, The International ISBN Agency
      Postal: EDItEUR, 39-41 North Road, London, N7 9DP, U.K.
      Web URL: <>

   Declaration of syntactic structure of NSS part:

      The namspace-specific string of 'ISBN' URNs is either an ISBN-13
      (see Section 4.1.2 of RFC XXXX) or an ISBN-10 (see Section 4.1.1
      of RFC XXXX); the former is preferred.

      Example 1: URN:ISBN:978-0-395-36341-6
      Example 2: URN:ISBN:951-0-18435-7
      Example 3: URN:ISBN:951-20-6541-X
      Example 4: URN:ISBN:951206541X

   Relevant ancillary documentation:

      The ISBN (International Standard Book Number) is a unique machine-
      readable identification number, which marks any edition of a book
      unambiguously.  This number is defined in ISO Standard 2108:2005.
      ISBNs has been in use for more than 30 years and they have
      revolutionised the international book-trade. 170 countries and
      territories are officially ISBN members.

      The administration of the ISBN system is carried out on three
         International agency,
         Group agencies,

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      The International ISBN agency is located in London.  The main
      functions of the Agency are:

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

      *  To approve the definition and structure of group agencies.

      *  To allocate group identifiers to group agencies.

      *  To advise on the establishment and functioning of group

      *  To advise group agencies on the allocation of international
         publisher identifiers.

      *  To publish the assigned group numbers and publisher prefixes in
         up-to-date form.

      Detailed information about ISBN usage can be found from the ISBN
      Users' Manual.  The manual is available at <
      standards/home/isbn/international/isbnmanual.asp>.  A shorter
      introduction to ISBN usage can be found from the ISBN FAQ,
      available at <>.  There
      are also guidelines for the assignment of ISBNs to e-books,
      available at <

   Conformance with URN Syntax:

      Legal ISBN characters are 0-9 and hyphen for ISBN-13 and 0-9,
      hyphen, and X for ISBN-10.  No percent-encoding is needed.  Hyphen
      carries no semantic content and MAY be dropped from the NSS.

      [[ Editorial Note: Need to discuss new specification requirements
      from the RFC 2141bis draft! ]]

   Rules for Lexical Equivalence of NSS part:

      ISBN numbers are usually printed with the letters 'ISBN' and a
      single blank preceding the ISBN proper (for instance: ISBN 951-
      746-795-8).  The data preceding the ISBN MUST NOT be included in
      the NSS.  No percent encoding is needed.

      Prior to comparing the NSS of two ISBN-based URNs for equivalence,
      all hyphens, if present, MUST be removed and letter 'X'
      capitalized.  Prior to comparing a URN based on ISBN-10 with a URN

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      based on ISBN-13, the ISBN-10 MUST be converted to the ISBN-13
      form.  This step is necessary since the ISBN-10s may or may not be
      already converted to the new form; libraries SHOULD keep the old
      ISBN since it is the one printed in books published prior to 2007,
      while publishers may convert the old identifiers originally
      assigned in ISBN-10 form and use the equivalent ISBN-13s in
      unchanged reprints of the books, which according to the ISBN
      assignment rules should not receive a new ISBN.

      Note that, according to RFC 2141bis, the prefix "URN:ISBN:" 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.

   Identifier uniqueness and persistence considerations:

      ISBN is a unique and persistent identifier.  An ISBN, once it has
      been assigned, MUST NOT be re-used for another book or another
      product form of the same book.  A single product form
      (manifestation) of a book MUST NOT get a new ISBN.  'ISBN' URNs
      inherit the uniqueness and persistence properties from ISBNs.
      Please note that the same ISBN CAN be used as in another
      persistent identifier system, such as DOI or Handle.  The
      resulting persistent identifier SHALL NOT render the URN:ISBN non-
      unique; however, it might provide different resolution services
      than URN:ISBN.

      If there are multiple manifestations of a single literary work
      such as a novel, each one MUST receive a different ISBN.  ISO has
      developed a new standard, ISTC (International Standard Text Code,
      ISO 21047-2009) that enables identification of textual works.  See
      <> for more information.  In the
      standard itself, annex E describes the relations between ISBN and
      other publication identifiers and ISTC.

   Process of identifier assignment:

      Assignment of ISBNs is controlled, and 'ISBN' URNs immediately
      inherit this property.  There are three levels of control: the
      international agency, group agencies that typically operate in the
      national level, and finally each publisher is responsible of using
      the ISBN system correctly.  Small publishers may demand ISBN
      numbers one at a time by contacting the ISBN group agency.  Large
      publishers receive ISBN blocks from which they allocate ISBNs to
      the books according to the ISBN assignment rules.

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   Process for identifier resolution:

      See Section 4.3 of RFC XXXX.

   Validation mechanism:

      The check digit helps to assure the correctness of an ISBN number
      assigned for a book when it has been entered or processed.
      Applications processing bibliographic data such as integrated
      library systems MAY check the correctness of both ISBN-10 and
      ISBN-13 (and make conversions between the two).  If the number is
      wrong due to, e.g., a typing error made by a publisher, a correct
      ISBN SHOULD be assigned afterwards.  Although the book will only
      contain the wrong number, national bibliography and system used by
      the book trade often will contain both the wrong and new, correct
      ISBN number.


      ISBN is a global identifier system used for identification of
      monographic publications.  It is very widely used and supported by
      the publishing industry.

6.  Security Considerations

   This document proposes means of encoding ISBNs within the URN
   framework.  An ISBN-based URN resolution service is depicted here
   both for ISBN-10 and ISBN-13, but only in a fairly generic level;
   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 ISBNs.
   Issues regarding intellectual property rights associated with objects
   identified by the ISBNs are also beyond the scope of this document,
   as are questions about rights to the databases that might be used to
   construct resolvers.

7.  IANA Considerations

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

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8.  Acknowledgements

   This draft version is the outcome of work started in 2008 and brought
   to the IETF in 2010 to launch a much larger 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 participants of project PERSID
   (<>) contributed significantly to the standards

   Leslie Daigle has provided valuable guidance in the initial draft
   stage of this memo.

   Your name could go here ...

9.  References

9.1.  Normative References

              Hoenes, A., "Uniform Resource Name (URN) Syntax",
              draft-ietf-urnbis-rfc2141bis-urn-00 (work in progress),
              November 2010.

              Hoenes, A., "Uniform Resource Name (URN) Namespace
              Definition Mechanisms",
              draft-ietf-urnbis-rfc3406bis-urn-ns-reg-00 (work in
              progress), December 2010.

   [ISO1]     ISO, "Information and documentation - The International
              Standard Book Number (ISBN)", ISO 2108-1992, 1992.

   [ISO2]     ISO, "Information and documentation - The International
              Standard Book Number (ISBN)", ISO 2108-2005, 2005.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

9.2.  Informative References

   [DOIHOME]  International DOI Foundation, "The Digital Object
              Identifier System", <>.

              IANA, "URI Schemes Registry",

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              IANA, "URN Namespace Registry",

   [ISBNORG]  International ISBN Agency, "",

   [OCLC-WC]  OCLC WorldCat, " The World's Largest Library
              Catalog", <>.

   [PREFIX]   International ISBN Agency, "ISBN Prefix Ranges",

   [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.

   [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.

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

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Appendix A.  Draft Change Log

   [[ RFC-Editor: Whole section to be deleted before RFC publication. ]]

A.1.  draft-hakala-rfc3187bis-isbn-urn-00 to draft-ietf-urnbis-*-00

   - formal updates for a WG draft;
   - RFC 2288 now obsoleted and made Historic;
   - added references to rfc2141bis and rfc3406bis;
   - Sect.3 reorganized and amended: Namespace/Community Considerations;
   - registration template adapted to rfc3406bis [-00];
   - numerous editorial fixes and improvements.

A.2.  draft-ietf-urnbis-rfc3187bis-isbn-urn-00 to -01

   - discussion on persistence altered, based on list discussion;
   - changes and amendments to discussion of URN resolution services;
   - discussion of fragment part usage added;
   - broken link to ISBN manual fixed based on feedback from [ISBNORG];
   - various editorial fixes and enhancements.

Authors' Addresses

   Maarit Huttunen
   The National Library of Finland
   P.O. Box 26
   Helsinki, Helsinki University  FIN-00014


   Juha Hakala
   The National Library of Finland
   P.O. Box 15
   Helsinki, Helsinki University  FIN-00014


   Alfred Hoenes (editor)
   Gerlinger Str. 12
   Ditzingen  D-71254


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