URN Service

An Uniform Resource Name (URN) is a persistent identifier (PI), an unique identifier for digital objects, enabling online resources to be permanently identified and reliable cited. The German National Library assigns and administrates URNs from the namespace "urn:nbn:de" and offers an URN resolving service for Germany, Austria and Switzerland. All online resources, archived by the German National Library, get an URN from the namespace "urn:nbn:de". Compared to URLs, URNs offer a unique and permanent identification of digital objects, independent from their storage location. This is an important factor in maintaining the long term preservation. If the storage location of a publication changes, for example if it is moved from one server to another, the access address (URL), which is combined with an URN, can be adjusted. With this, the URN keeps its validity and still refers to the corresponding publication. This makes the cite of an URN a reliable way of a long term reference for digital objects.

The URN Service of the German National Library offers numerous advantages for scientists, authors, publishers, information brokers and archives

• Identifiers provide reliable references to digital objects
• Durable, consistent, stable links in reference systems by using URNs
• Reduced workload in maintaining the permanent access of a document
• Analogical to an ISBN, an URN can be assigned for a document in advance
• Object consistency can be guaranteed with the use of check digits
• The URN service is a free service of the German National Library

Christa Schöning-Walter: Der Uniform Resource Name  (nestor-Handbuch; available only in German)

URN strategy of the German National Library
URN strategy of the Swiss National Library

URN resolving service of the German National Library 
URN management transfer conditions and interfaces at the German National Library 

Presentation of examples (Bibliothekartag 2009) 

Catalogue of criteria for assessing the trustworthiness of PI systems (nestor)

• Schöning-Walter, Christa: Persistent Identifier für Netzpublikationen
  In: Dialog mit Bibliotheken 20 (2008), H. 1, S. 32-38