Implementing Persistent Identifiers

Traditionally, references to web content have been made by using URL hyperlinks. However, as links are ‘broken’ when content is moved to another location, a reference system based on URLs is inherently unstable and poses risks for continued access to web resources. To create a more reliable system for referring to published material on the web, from the mid-1990s a number of schemes have been developed that use name spaces to identify resources, enabling retrieval even if the location on the web is unknown. The report explains the principle of persistent identifiers and helps institutions decide which scheme would best fit their needs. It discusses Handles, Digital Object Identifiers (DOIs), Archival Resource Keys (ARKs), Persistent Uniform Resource Locators (PURLs), Uniform Resource Names (URNs), National Bibliography Numbers (NBNs), and the Open URL, providing examples and extensive references for each. The report was written by the Research and Development Department of the Goettingen State and University Library (Niedersächsische Staats- und Universitätsbibliothek Göttingen) at the request of the Advisory Task Group (ATG) of the Consortium of European Research Libraries. It is co-published by CERL and ECPA.