The portion of a DOI after the first forward slash, assigned by the registrant within their issued DOI prefix, identifying the specific object; can contain any Unicode characters with the case-insensitivity rule applied during comparison.

ByCASRAI Editorial Board

· Last updated 10 Jul 2026

Examples

Worked examples

Is an instance
nature14539 in the DOI 10.1038/nature14539.
Is an instance
zenodo.4317001 in the DOI 10.5281/zenodo.4317001.

Counter-examples

Looks similar, but isn't

Not an instance
A query string '?ref=abc' on a DOI URL is not part of the suffix.
Not an instance
A URI fragment '#section-3' on a DOI URL is not part of the suffix.

Editorial commentary

The DOI suffix is the registrant’s degree of freedom. It can be a human-meaningful string (e.g. 10.1234/journal.2024.01.005 reflecting journal/year/issue/page), an opaque sequence (e.g. 10.5281/zenodo.4317001), or a UUID. DOI suffix syntax restrictions are minimal (any printable Unicode, subject to URL-percent-encoding rules and case-insensitivity); registrants are encouraged to keep suffixes opaque, short, and free of embedded semantics that may become misleading over time.

References

International DOI Foundation, 'DOI Handbook'.

Machine-readable encodings

Use in your systems

JATS XML <role> element

xml

<role vocab="credit"
      vocab-identifier="https://casrai.org/dictionary/"
      vocab-term="DOI suffix"
      vocab-term-identifier="https://casrai.org/dictionary/term/doi-suffix" />

Schema.org DefinedTerm (JSON-LD)

json

{
  "@context": "https://schema.org",
  "@type": "DefinedTerm",
  "@id": "https://casrai.org/dictionary/term/doi-suffix",
  "name": "DOI suffix",
  "identifier": "https://casrai.org/dictionary/term/doi-suffix",
  "description": "The portion of a DOI after the first forward slash, assigned by the registrant within their issued DOI prefix, identifying the specific object; can contain any Unicode characters with the case-insensitivity rule applied during comparison.",
  "inDefinedTermSet": "https://casrai.org/dictionary/domain/persistent-identifiers#set",
  "url": "https://casrai.org/dictionary/term/doi-suffix",
  "sameAs": [],
  "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

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