Archival Resource Key

California Digital Library Persistent identifier National Library of Medicine

An Archival Resource Key (ARK) is a Uniform Resource Identifier (URI)[1] that is a multi-purpose persistent identifier for information objects of any type. An ARK contains the label ark: after the URL's hostname, which sets the expectation that, when submitted to a web browser, the URL terminated by '?' returns a brief metadata record, and the URL terminated by '??' returns metadata that includes a commitment statement from the current service provider. The ARK and its inflections ('?' and '??') provide access to three facets of a provider's ability to provide persistence.

Implicit in the design of the ARK scheme is that persistence is purely a matter of service and not a property of a naming syntax. Moreover, that a "persistent identifier" cannot be born persistent, but an identifier from any scheme may only be proved persistent over time. The inflections provide information with which to judge an identifier's likelihood of persistence.

ARKs can be maintained and resolved locally using open source software such as Noid (Nice Opaque Identifiers) or via services such as EZID and the central N2T (Name-to-Thing) resolver.

Structure

[http://NMAH/]ark:/NAAN/Name[Qualifier]

Name Assigning Authority Numbers (NAANs)

A complete NAAN registry[4] is maintained by the California Digital Library and replicated at the Bibliothèque Nationale de France and the US National Library of Medicine. In June of 2018 it contained over 530 entries and in July 2020 this has increased to 633.

Example entries:

Generic Services

Three generic ARK services have been defined. They are described below in protocol-independent terms. Delivering these services may be implemented through many possible methods given available technology (today's or future).

Access Service (access, location)

Policy Service (permanence, naming, etc.)

Description Service

See also

Notes and references

  1. ^ "Uniform Resource Identifier (URI) Schemes".
  2. ^ Hierarchy qualifiers begin with a slash character.
  3. ^ Variant qualifiers begin with a dot character.
  4. ^ Name Assigning Authority Number registry