rfc3188.txt

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   1999.

   Declared registrant of the namespace:

   Name: Juha Hakala
   E-mail: [e-mail]
   Affiliation: Helsinki University Library - The National Library of
   Finland, Conference of European National Librarians (CENL) and
   Conference of Directors of National Libraries (CDNL)
   Address: P.O.Box 26, 00014 Helsinki University, Finland

   Both CENL and CDNL made decisions to foster the usage of URNs during
   1998.  The latter organisation has set up a working group for this
   purpose.  One item in the common work plan is utilisation of national
   bibliography numbers as URNs for identification of grey literature
   published in the Internet.  The NBN namespace will be available for
   free for all national libraries in the world.

   Declaration of syntactic structure:








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   The namespace specific string will consist of three parts:

   prefix, consisting of either a two-letter ISO 3166 country code or
   other registered string and sub-namespace codes,

   delimiting characters (colon (:), or hyphen (-), and

   NBN string assigned by the national library.

   Colon is used as a delimiting character only within the prefix,
   between ISO 3166 country code and sub-namespace code, which splits
   the national namespace into smaller parts.  This technique can be
   used when there are several national libraries, which all need their
   own namespaces, or when the national library allows trusted partners
   to set up their own sub-namespaces within the national NBN namespace.

   Dividing non-ISO 3166-based namespaces further with sub-namespace
   codes is not allowed.

   Hyphen is used as a delimiting character between the prefix and the
   NBN string.  Within the NBN string, hyphen can be used for separating
   different sections of the code from one another.

   Non-ISO prefixes used instead of the ISO country code must be
   registered.  A global registry, maintained by the Library of
   Congress, will be created and made available via the Web.  Contact
   information: [e-mail].

   All two-letter codes are reserved for existing and possible future
   ISO country codes and may not be used as non-ISO prefixes.

   Sub-namespace codes must be registered on the national level by the
   national library which assigned the code.  The register must be
   available via the Web, and it should be accessible via the global
   registry set up by the Library of Congress.

   Models:

   URN:NBN:<ISO 3166 country code>-<assigned NBN string>
   URN:NBN:<ISO 3166 country code:sub-namespace code>-<assigned NBN
   string>
   URN:NBN:<non-ISO 3166 prefix>-<assigned NBN string>

   Example:

   A country code-based URN: URN:NBN:fi-fe19981001 (A URN assigned by
   the National Library of Finland).




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   Relevant ancillary documentation:

   National Bibliography Number (NBN) is a generic name referring to a
   group of identifier systems used by the national libraries for
   identification of deposited publications which lack an identifier, or
   to descriptive metadata (cataloguing) that describes the resources.
   Each national library uses its own NBN system independently of other
   national libraries; there is no global authority which controls
   syntax of these identifier systems.

   Each national library can decide freely which resources will receive
   NBNs.  These identifiers have traditionally been assigned to
   documents that do not have a publisher-assigned identifier, but are
   nevertheless catalogued to the national bibliography.  Typically
   identification of grey publications have largely been dependent on
   NBNs.

   Some national libraries (Finland, Norway, Sweden) have established
   Web-based URN generators, which enable authors and publishers to
   fetch NBN-based URNs for their network documents.

   Both syntax and scope of NBNs is decided by each national library
   independently.  Typically, a NBN consist of one or more letters and a
   number.

   Identifier uniqueness considerations:

   NBN strings assigned by two national libraries may be identical.  For
   this reason usage of a controlled prefix in the namespace specific
   string is obligatory in order to guarantee global uniqueness of NBN-
   based URNs.

   In the national level, libraries utilise different policies for
   guaranteeing uniqueness.  A national library may automate the
   delivery of NBN-based URNs.  In this case, the NBNs are assigned
   sequentially by a program (URN generator).

   Identifier persistence considerations:

   Persistence of the NBNs as identifiers is guaranteed by the
   persistence of national libraries and information systems, such as
   national bibliographies, maintained by them.  NBNs have been used for
   several centuries for printed materials.  NBN-based identification of
   electronic documents is a recent practice, but it is likely to
   continue for a very long time.






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   Process of identifier assignment:

   Assignment of NBN-based URNs is always controlled on national level
   by the national library / national libraries.  The Conference of
   Directors of National Librarians (CDNL) has established in 1999 a
   task force, which will co-ordinate the URN usage in all national
   libraries.

   National libraries may choose different strategies in assigning NBN-
   based URNs.  One option is assignment by the library personnel only.
   This is done when the document is catalogued into the national
   bibliography.  Thus in this case the national bibliography database
   will serve as the URN resolution service.

   A national library may also set up a URN generator (generators), and
   allow publishers and authors to retrieve NBN-based URNs from there.
   In this case there is no guarantee that the identified resource will
   ever be catalogued into the national bibliography, and URN resolution
   is dependent on Web index/archive.

   Process for identifier resolution:

   URNs based on NBNs will be primarily resolved via the national
   bibliography databases.  In one model these databases contain
   detailed resource descriptions including URLs, which will point both
   to the copy of the document in the Internet and to the copy in the
   national library's (legal) deposit collection.  Due to the
   limitations in the usage of legal deposit documents it is possible
   that the deposited materials can not be delivered outside the
   premises of the national library.

   For those documents not catalogued into the national bibliography
   database URN resolution may take place via national or international
   Web indexes and/or archives.  Nordic national libraries have
   established in autumn 2000 a joint initiative called Nordic Web
   Archive (NWA), which aims at creating a national Web archive into all
   Nordic countries. Indexes to these archive systems will be able to
   act as URN resolution services of any document which a) is or has
   been available via the Web, and b) had an URN embedded into it.

   Country code and additional sub-namespace information will provide a
   guide to where to find appropriate resolution services.  For
   instance, if the country code is "fi", the primary resolution service
   is the national bibliography database.  Secondary resolution service
   is the Web archive.






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   Generally, there will be one or more resolution services specified
   for each country, depending on the assignment policy and services of
   the national library.  If NBN assignment is limited to the national
   bibliography database, then all NBN-based URNs for that country will
   be resolved there.  If the authors and publishers have been allowed
   to retrieve NBNs to their Web resources, URN resolution services
   require a national Web archive.  If other organisations have been
   allowed to assign NBNs, they may also set up their own URN resolution
   services.

   Rules for Lexical Equivalence:

   None in the global level.  Any national library may provide its own
   rules, on the basis of its NBN syntax.

   Conformance with URN Syntax:

   All NBNs we know of are ASCII strings consisting of letters (a-z) and
   numbers (0-9).  If NBN contains characters that are reserved in the
   URN syntax, this data must be presented in hex encoded form as
   defined in RFC 2141.  A national library may limit the full scope of
   its NBN strings in URN usage in such a way that there are no reserved
   characters in the URN namespace specific strings.

   Validation mechanism:

   None specified on the global level.  A national library may use NBNs,
   which contain a checksum and can therefore be validated, but this is
   for the time being not a common practice.

   Scope:

   Global.

6. References

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

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

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







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7. Author's Address

   Juha Hakala
   Helsinki University Library - The National Library of Finland
   P.O. Box 26
   FIN-00014 Helsinki University
   FINLAND

   EMail: [e-mail]










































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8. Full Copyright Statement

   Copyright (C) The Internet Society (2001).  All Rights Reserved.

   This document and translations of it may be copied and furnished to
   others, and derivative works that comment on or otherwise explain it
   or assist in its implementation may be prepared, copied, published
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   kind, provided that the above copyright notice and this paragraph are
   included on all such copies and derivative works.  However, this
   document itself may not be modified in any way, such as by removing
   the copyright notice or references to the Internet Society or other
   Internet organizations, except as needed for the purpose of
   developing Internet standards in which case the procedures for
   copyrights defined in the Internet Standards process must be
   followed, or as required to translate it into languages other than
   English.

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

   This document and the information contained herein is provided on an
   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
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Acknowledgement

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



















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