Examples: URN (NBN) assignment

Version 1.0

1. Introduction

Objective of this document

In The URN strategy of the German National Library general requirements with the intention of an agreement for a URN (NBN) application are formulated. The objective of this document is to facilitate practical URN (NBN) assignment by means of selected examples.

What isNOT the objective of this document?

Plans for the next version 1.1

2. General information

2.1 Who is authorised to assign URNs (NBN)?

An institutional commitment is the basis for a URN (NBN) assignment. Individual authors could assign URNs (NBN) themselfes if the online publications would be archived by an institution e.g. at the German National Library.

2.2 Rules (summary)

By fullfilling the following requirements a URN (NBN) assignment for digital objects is possible:


2.3 URN (NBN) structure

Structure of the URN (NBN) sub-namespace

Institution URN structure Comment
Libraries belonging to a library association urn:nbn:de:[designations of library association]:[official notation of university libraries]-[unique production number][check digit]

Example: urn:nbn:de:gbv:089-3321752945
Institutions from within the area of responsibility of the BSZ use the abbreviation "bsz", NOT "swb" to identify the URN sub-namespace of this library association.
Institutions which are not organised in a library association urn:nbn:de:[four digit number]-[unique production number][check digit]

Example: urn:nbn:de:0001-00016

Structure of the "NISS"

Entire object

Algorithm Example Advantages Disadvantages
Consecutive number with a fixed length urn:nbn:de:0001-00016 Uniform model of a URN structure In order to avoid a duplicate URN assignment a URN counter must be implemented. In case the fixed length is utilised it has to be extended.
Consecutive number with a variable length urn:nbn:de:bvb:706-18 Independent of numbers of URNs which will be expected for assignment. In order to avoid duplicate URN assignment a counter must be implemented.
Unique production number of a data record urn:nbn:de:bvb:355-opus-1983 A URN can be assigned without a URN counter. In case of internal restructuring this approach could cause conflicts.
Structuring the NISS using the following information: [year][month][day]+[consecutive number] urn:nbn:de:1111-200606309 A URN can be assigned according to requirements. A scalable contingent per day could be realized by means of consecutive number. A URN counter based on the current date has to be implemented.

Parts of objects

Algorithm Example Advantages Disadvantages
see entire objects urn:nbn:de:kobv:11 The approaches guarantee a consistent URN structure in the long term. The relation between parts of the object and the entire object could be realised by means of metadata. Alternatively, the relation of parts of objects to the entire object could be performed by the URN resolver of German National Library. To realise that the related information must be stored in the resolver. The XML data transfer format for Persistent Identifiers xepicur supports these information. The URN is structured without any semantic information. Therefore it is not possible to draw conclusions from URN itself to the entire object.
[see entire object]-[counter for individual parts of an object] . The URN structure implies the potential to derive information concerning the entire object and individual parts of the object. In case an complex digital object changes the URN structure implies not the correct semantic information.

Object versions

Algorithm Example Advantages Disadvantages
see entire objects Original: urn:nbn:de:bsz:93-opus-15416
Version: urn:nbn:de:bsz:93-opus-15545
s. of parts of objects. The relation between the original object and a version could be stored within the metadata. Alternatively, the relation between the original object and version could be performed by the URN resolver of the German National Library. To realize that the related information must be stored in the resolver. The XML data transfer format for Persistent Identifiers xepicur supports these information. In case the URN is structure without any semantic information it is not possible to derive information of the new version.

3. URN (NBN) assignment for selected publication types

3.1 Online theses and dissertations / university publications

Online theses and dissertations

  • Structuring the accompanying metadata with METADISS, xMetaDiss

Master of Arts and diploma theses


3.2 Monographs


3.3 Research reports / Reports


3.4 Conference proceedings


3.5 Reports (annual reports)


3.6 Online magazines

  • A URN assignment for online magazines is possible if a separate resource which contains a description of the magazine is available online. The URN assigned for an online magazine must not refer to a resource, which contains information about more than one magazine.

3.7 video and audio sequences


3.8 Digitized objects


3.9 XML Namespaces