Archival Resource Key, a persistent identifier scheme for information objects of any type, in the form ark:/NAAN/Name[Qualifier], where NAAN is a Name Assigning Authority Number and Name is the local identifier; resolvable through any cooperating ARK resolver.

ByCASRAI Editorial Board

· Last updated 10 Jul 2026

Examples

Worked examples

Is an instance
ark:/12148/btv1b8449691v (a manuscript at the Bibliothèque nationale de France).
Is an instance
ark:/13030/kt9c6035s2 (a California Digital Library object).

Counter-examples

Looks similar, but isn't

Not an instance
A DOI such as 10.1038/nature14539 is not an ARK.
Not an instance
A relative URL on a museum website is not an ARK.

Editorial commentary

ARKs were designed by John Kunze at the California Digital Library in 2001 to provide low-cost, distributed persistent identifiers without a central commercial registry. The scheme adds two distinctive features: an Inflection rule (appending ‘?’ yields the object’s metadata, appending ‘??’ yields a ‘persistence policy commitment statement’), and a structural openness that permits qualifiers for sub-parts and variants. Many libraries, archives, and government agencies (notably BnF and the Internet Archive) use ARKs at scale.

References

Kunze J., Rodgers R., 'The ARK Identifier Scheme', IETF Internet-Draft (multiple versions).
ARK Alliance (arks.org).

Also known as

Archival Resource Key

Machine-readable encodings

Use in your systems

JATS XML <role> element

xml

<role vocab="credit"
      vocab-identifier="https://casrai.org/dictionary/"
      vocab-term="ARK"
      vocab-term-identifier="https://casrai.org/dictionary/term/ark" />

Schema.org DefinedTerm (JSON-LD)

json

{
  "@context": "https://schema.org",
  "@type": "DefinedTerm",
  "@id": "https://casrai.org/dictionary/term/ark",
  "name": "ARK",
  "identifier": "https://casrai.org/dictionary/term/ark",
  "description": "Archival Resource Key, a persistent identifier scheme for information objects of any type, in the form ark:/NAAN/Name[Qualifier], where NAAN is a Name Assigning Authority Number and Name is the local identifier; resolvable through any cooperating ARK resolver.",
  "inDefinedTermSet": "https://casrai.org/dictionary/domain/persistent-identifiers#set",
  "url": "https://casrai.org/dictionary/term/ark",
  "sameAs": [
    "Archival Resource Key"
  ],
  "license": "https://creativecommons.org/licenses/by/4.0/",
  "publisher": {
    "@id": "https://casrai.org/#organization"
  },
  "dateModified": "2026-07-10T02:06:19",
  "inLanguage": "en"
}

Referenced across the research world

View CASRAI adoption →