Globally Unique Identifier, a generic term for an identifier that is intended to be unique across all systems and time, most commonly implemented as a 128-bit UUID but used informally for any opaque, globally scoped identifier.

ByCASRAI Editorial Board

· Last updated 10 Jul 2026

Examples

Worked examples

Is an instance
{E8E2C0A0-D6BA-11D1-9CDD-0080C7E7B6D8} (a Microsoft-style GUID literal).
Is an instance
A repository internally minting GUIDs for objects and later assigning DOIs as the public-facing PID.

Counter-examples

Looks similar, but isn't

Not an instance
A monotonically-increasing integer primary key in one database is not a GUID.
Not an instance
A short user-chosen URL slug is not a GUID.

Editorial commentary

GUID is a term originating in Microsoft software platforms but widely used as a synonym for UUID. In research-information contexts ‘GUID’ also occurs informally for any opaque global identifier including handles, DOIs, ORCID iDs, and proprietary identifiers issued by repositories. Unlike a UUID (which has a defined ISO/IETF specification), ‘GUID’ has no single normative definition; the literal Microsoft GUID is structurally identical to a Variant-2 UUID.

References

Leach P., Mealling M., Salz R., RFC 4122, 'A Universally Unique IDentifier (UUID) URN Namespace', IETF, 2005.
Microsoft, 'GUID Structure' (Win32 documentation).

Also known as

Globally Unique Identifier

Machine-readable encodings

Use in your systems

JATS XML <role> element

xml

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

Schema.org DefinedTerm (JSON-LD)

json

{
  "@context": "https://schema.org",
  "@type": "DefinedTerm",
  "@id": "https://casrai.org/dictionary/term/guid",
  "name": "GUID",
  "identifier": "https://casrai.org/dictionary/term/guid",
  "description": "Globally Unique Identifier, a generic term for an identifier that is intended to be unique across all systems and time, most commonly implemented as a 128-bit UUID but used informally for any opaque, globally scoped identifier.",
  "inDefinedTermSet": "https://casrai.org/dictionary/domain/persistent-identifiers#set",
  "url": "https://casrai.org/dictionary/term/guid",
  "sameAs": [
    "Globally Unique Identifier"
  ],
  "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

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