Namespace Identifier:  NBN
   This namespace ID was formally assigned to the National
   Bibliography Number in October 2001, when the namespace was
   registered officially [RFC3188].  Utilization of URN:NBNs had
   started in demo systems already in 1998.  Since 2001, tens of
   millions of URN:NBNs have been assigned.  The number of users of
   the namespace has grown in two ways: new national libraries have
   started using NBNs, and many national libraries using the system
   have formed new liaisons.

Version:  5

Date:  2018-04-09

Registrant:
   National Library of Finland
   Role: URN Service Desk
   Email: kk-urn&helsinki.fi
   Postal: P.O. Box 15, 00014 University of Helsinki, Finland
   Web URL: http://www.nationallibrary.fi/

   The National Library of Finland registered the namespace on behalf
   of the Conference of the European National Librarians (CENL) and
   Conference of Directors of National Libraries (CDNL).  The NBN
   namespace is available for free for the national libraries.  They
   can allow other organizations to assign URN:NBNs and use the
   resolution services established by the library for free or for a
   fee.  The fees, if collected, can be based on, e.g., the
   maintenance costs of the system.

Purpose:  See Section 3 of RFC 8458

Syntax:  See Section 4.2 of RFC 8458

Assignment:  See Section 4.1 of RFC 8458

Security and Privacy:  See Section 7 of RFC 8458


Interoperability:
   National libraries and their partners usually apply URN:NBNs if a
   standard identifier such as ISBN is not applicable for the
   resource to be identified.  Some overlap with other URN namespaces
   is possible.

   URN:NBNs may contain characters which must be percent-encoded, but
   usually they consist of printable ASCII characters only.

Resolution:  See Section 4.4 of RFC 8458

Documentation:  RFC 8458

Revision Information:
   This version of the URN:NBN namespace registration has been
   updated to use the revised definition of URN syntax from RFC 8141,
   although usage of r-components is not specified yet.  In addition,
   non-ISO 3166 (country code) based NBNs have been deleted due to
   lack of deployment.  The entire NBN prefix is now specified to be
   case insensitive in accordance with established practice.  This
   version also includes numerous clarifications based on actual
   usage of URN:NBNs.