Person identifiers compared

At a glance

Wikidata QID

Every Wikidata item has a QID. Items about people are instances of human (Q5) and collect statements from many sources, including the other identifiers on this page as external-identifier properties. That makes Wikidata a hub: from one QID you can reach a person's ORCID iD, ISNI, VIAF and Library of Congress records. Coverage is limited to people notable enough to have an item, and anyone can edit it, so statements carry references and ranks. Wikidata's data is released under CC0.

ORCID iD

ORCID (Open Researcher and Contributor ID) gives each researcher a free identifier that they register and control themselves. It is written as a URI,https://orcid.org/0000-0002-1825-0097 (ORCID's documented example, for a fictional researcher). The 16 characters come from a block of the ISNI number space reserved for ORCID, and the last character is an ISO/IEC 7064 MOD 11-2 check character, which may be X. Publishers and funders collect ORCID iDs with submissions, and ORCID can sign a person in with OAuth, which proves they control the record.

// ISO/IEC 7064 MOD 11-2, the check character of ORCID iDs and ISNIs.
function checkCharacter(first15Digits) {
  let total = 0;
  for (const d of first15Digits) total = (total + Number(d)) * 2;
  const result = (12 - (total % 11)) % 11;
  return result === 10 ? "X" : String(result);
}
checkCharacter("000000021825009"); // "7", as in 0000-0002-1825-0097

ISNI

The International Standard Name Identifier is an ISO standard (ISO 27729, first published in 2012) for the public identities of people and organizations involved in creative work: books, music, film, broadcasting and research. It is administered by the ISNI International Agency and assigned through registration agencies, often from library and rights-management data. One person may have more than one public identity, such as a pen name, and each can carry its own ISNI.

VIAF

The Virtual International Authority File, hosted by OCLC, matches the name authority records of national and regional libraries and groups those about the same entity into a cluster with one VIAF ID. A VIAF cluster connects, for example, a person's Library of Congress record with their records in other national libraries, under different spellings and scripts. VIAF data is available under the Open Data Commons Attribution License.

Library of Congress Name Authority File

The LC Name Authority File (LCNAF) holds the authorized forms of names used in library catalogs, maintained by the Library of Congress and libraries in the NACO program. Each record has an identifier such as n followed by digits, and is published as linked data at id.loc.gov. It covers people who have authored or are the subject of cataloged works.

Crunchbase

Crunchbase is a commercial database of companies, investors and the people who run them. A person's page address carries a slug that acts as an identifier. Its data is proprietary and licensed under Crunchbase's terms, so it is useful as a link that identifies someone, not as an open data source.

Others worth knowing

• OpenAlex author IDs identify authors in the open OpenAlex catalog; they are assigned by OpenAlex's own author matching and can change when records are merged. See Open data sources about people.
• Scopus Author ID and Web of Science ResearcherID are the author identifiers of two commercial citation databases.
• GND is the integrated authority file of the German National Library, part of VIAF.
• SEC CIK numbers identify filers with the U.S. Securities and Exchange Commission, including company insiders.

In schema.org markup

List identifiers in identifier as PropertyValue nodes, with the scheme in propertyID, and the resolvable URL in sameAs. The Wikidata QID below is a placeholder.

"identifier": [
  { "@type": "PropertyValue", "propertyID": "ORCID", "value": "0000-0002-1825-0097", "url": "https://orcid.org/0000-0002-1825-0097" },
  { "@type": "PropertyValue", "propertyID": "Wikidata", "value": "Q00000000", "url": "https://www.wikidata.org/wiki/Q00000000" }
],
"sameAs": ["https://orcid.org/0000-0002-1825-0097", "https://www.wikidata.org/wiki/Q00000000"]

How SelfBadge uses identifiers

• Accepted on a profile: Wikidata, ORCID, ISNI, Crunchbase and SEC CIK, each checked against its format before it is saved, and published as identifier and in sameAs.
• ORCID can be verified: connecting the ORCID record through ORCID's own sign-in proves the iD belongs to the person.
• Seeding: profiles created from public Wikidata information keep the Wikidata QID as their source, and take the ORCID iD, Crunchbase person ID and SEC CIK from the item when present.
• Lookup: an agent can use the SelfBadge id (https://selfbadge.com/<handle>#person) as the identifier of a person in its own records. See Reading a SelfBadge profile.