Introduction to Persistent Identifiers

A Persistent Identifier (PID) is a unique identification code attached to a digital object and registered at an agreed location. It is guaranteed to remain functional even if an organisation’s web address changes. Using a PID, you can ensure that a link to a digital object (a scan, audiovisual file, metadata record etc.) keeps working, even when the object’s location or web address has changed.

Various options

There are multiple PID systems. But which system is most suited to your situation: Archival Resource Keys (ARKs), Digital Object Identifiers (DOIs), Handle, OpenURL, Persistent Uniform Resource Locators (PURLs) or Uniform Resource Names (URNs)? Each system has its own particular properties, strengths and weaknesses. The PID Guide from the Digital Heritage Network’s Persistent Identifier project helps you learn and think about important PID subjects, and guides your first steps towards selecting a PID system.

The PID Guide

The PID Guide application guides you through 25 statements, helps you learn and think about important PID subjects, and guides your first steps towards selecting a PID system. Other things than the 25 subjects from the PID Guide may affect your final decision. You may be part of a community that has a strong preference for a particular PID system. Also, where the PID Guide does not rule out any PID system, your organisation could have no-go criteria for selecting a PID system, such as cost, level of support or formal standardisation. The entire process of filling out the PID Guide takes approximately 20 minutes, and you can save your results at any time.

National perspective

The PID Guide was developed for the systems which are most common in the Netherlands: Archival Resource Keys (ARK, ARK Alliance), DataCite DOI (through DataCite Netherlands, Delft University of Technology Library), the Handle System (through SURF in cooperation with EPIC) and URN:NBN (through the KB, National Library of the Netherlands). The international offer of PID systems is larger and more complex than that. DOI e.g. has domain specific (DataCite for datasets, CrossRef for publications, EIDR for audio visual objects) and local language support Registration Agencies (e.g. in Japan, China and Italy). Handle System services are offered by a number of organisations, and you could also host a Handle server yourself. Several national libraries in Europe have a URN:NBN service, and there are other URN namespaces, e.g.: URN:ISBN, URN:ISSN, URN:IETF en URN:LEX. Several other PID systems are listed in this overview document: Overview of PID Systems December 2022 (PDF).

Different perspectives

Your organisation may manage different kinds of objects: physical museum pieces as well as digital art, for example, or scientific articles along with the corresponding datasets. Members of different departments within your organisation may have different ideas regarding the best application of PIDs. The PID Guide can help you gain insight into these differences. It is recommended to have your colleagues and various departments go through the PID Guide separately. Discuss the results among each other, and/or fill out the PID Guide together. Their results may then be saved and compared.

Hybrid solutions

It may be the case that the diversity of objects and/or target audiences in your situation calls for a hybrid solution. If so, the PID Guide will indicate that. It is perfectly possible to use two PID systems simultaneously. DANS, for instance, KNAW’s and NOW’s institute for Data Archiving and Networked Services, uses DOI alongside URN:NBN. 

Persistent Identifiers on video

The Persistent Identifiers project team has produced three short videos on Persistent Identifiers and how best to use them. They are in Dutch. You can watch them on YouTube:

  1. What are Persistent Identifiers?
  2. Choosing the most suitable Persistent Identifier
  3. Implementing Persistent Identifiers

Feel free to use or share these videos within your own organisation as well.

More information

Read more about the following subjects on the following websites:

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