The descriptive metadata registered with a PID provider at the time of identifier minting, and updated thereafter, that describes the identified entity — its title, creators, dates, types, related identifiers, and so on — and that is exposed by the provider's APIs alongside the identifier itself.

ByCASRAI Editorial Board

· Last updated 10 Jul 2026

Examples

Worked examples

Is an instance
The title, authors with ORCID iDs, affiliations with ROR IDs, references, and funder/award data deposited with a Crossref DOI.
Is an instance
The DataCite landing-page URL, creators, contributors, related identifiers, and rights statement on a DataCite DOI.

Counter-examples

Looks similar, but isn't

Not an instance
A landing-page HTML title tag is not PID metadata until it is registered with the PID provider.
Not an instance
Tags added to a paper in a personal reference manager are not PID metadata.

Editorial commentary

Every PID scheme defines a metadata schema that registrants must populate. Crossref uses its own schema (with mandatory and optional fields per content type). DataCite uses the DataCite Metadata Schema (current version 4.x). ORCID uses an XML/JSON record schema. The richer and more accurate the PID metadata, the more useful the identifier is for downstream discovery and graph-building. PID metadata is the substrate of the PID graph.

References

DataCite Metadata Working Group, 'DataCite Metadata Schema 4.x' (schema.datacite.org).
Crossref, 'Schema library' (data.crossref.org/reports/help/schema_doc/index.html).

Also known as

Identifier metadata

Machine-readable encodings

Use in your systems

JATS XML <role> element

xml

<role vocab="credit"
      vocab-identifier="https://casrai.org/dictionary/"
      vocab-term="PID metadata"
      vocab-term-identifier="https://casrai.org/dictionary/term/pid-metadata" />

Schema.org DefinedTerm (JSON-LD)

json

{
  "@context": "https://schema.org",
  "@type": "DefinedTerm",
  "@id": "https://casrai.org/dictionary/term/pid-metadata",
  "name": "PID metadata",
  "identifier": "https://casrai.org/dictionary/term/pid-metadata",
  "description": "The descriptive metadata registered with a PID provider at the time of identifier minting, and updated thereafter, that describes the identified entity — its title, creators, dates, types, related identifiers, and so on — and that is exposed by the provider's APIs alongside the identifier itself.",
  "inDefinedTermSet": "https://casrai.org/dictionary/domain/persistent-identifiers#set",
  "url": "https://casrai.org/dictionary/term/pid-metadata",
  "sameAs": [
    "Identifier metadata"
  ],
  "license": "https://creativecommons.org/licenses/by/4.0/",
  "publisher": {
    "@id": "https://casrai.org/#organization"
  },
  "dateModified": "2026-07-10T02:06:20",
  "inLanguage": "en"
}

Referenced across the research world

View CASRAI adoption →