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v2026.1714 entries · CC-BY 4.0
Dictionary termTrack BStablev2026.2

w3id.org PURL

A persistent URL hosted on the w3id.org domain by the W3C Permanent Identifier Community Group, providing a community-maintained redirect under https://w3id.org/<namespace> to ontologies, vocabularies, and standards documents that may move between hosting providers over time.

ByCASRAI Editorial Board
· Last updated 21 May 2026

Examples

Worked examples

  • Is an instance

    https://w3id.org/dpv for the Data Privacy Vocabulary.

  • Is an instance

    https://w3id.org/fair/principles for the FAIR Guiding Principles statement.

Counter-examples

Looks similar, but isn't

  • Not an instance

    A vocabulary served directly from a researcher's personal website is not a w3id.org PURL.

  • Not an instance

    An identifier under purl.archive.org is a different PURL service, not w3id.org.

Editorial commentary

w3id.org is a free, community-run PURL service intended for Web vocabularies, ontologies, and standards. Each namespace is administered through pull requests to a public GitHub repository; redirect rules are expressed in Apache rewrite syntax and reviewed by the community group. The service deliberately stays out of content hosting — it only redirects — and is widely used by the linked-data and FAIR-data communities to provide stable identifiers for ontologies that may be hosted on personal or institutional servers today and elsewhere tomorrow.

References

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Also known as

w3id

Machine-readable encodings

Use in your systems

JATS XML <role> element
xml
<role vocab="credit"
      vocab-identifier="https://casrai.org/dictionary/"
      vocab-term="w3id.org PURL"
      vocab-term-identifier="https://casrai.org/dictionary/term/w3id-purl" />
Schema.org DefinedTerm (JSON-LD)
json
{
  "@context": "https://schema.org",
  "@type": "DefinedTerm",
  "name": "w3id.org PURL",
  "identifier": "https://casrai.org/dictionary/term/w3id-purl",
  "description": "A persistent URL hosted on the w3id.org domain by the W3C Permanent Identifier Community Group, providing a community-maintained redirect under https://w3id.org/<namespace> to ontologies, vocabularies, and standards documents that may move between hosting providers over time.",
  "inDefinedTermSet": "https://casrai.org/dictionary/domain/the-persistent-identifier-ecosystem/",
  "url": "https://casrai.org/dictionary/term/w3id-purl",
  "sameAs": [
    "w3id"
  ],
  "license": "https://creativecommons.org/licenses/by/4.0/"
}

Adopted by research universities worldwide

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