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CASRAI

Editorial · CASRAI · The persistent identifier ecosystem

Crossref and the DOI Registration Agencies

Crossref and DataCite are the two best-known DOI registration agencies, appointed under the DOI system to register identifiers and curate metadata. This explainer covers metadata deposit, reference linking, Cited-by, and how Crossref and DataCite specialise.

ByCASRAI Editorial Board
Published 20 Jun 2026· 4 minute read

Crossref is the principal DOI registration agency for scholarly text content — journal articles, conference papers, books and similar outputs — appointed under the DOI system to register identifiers and curate the metadata that makes them useful. Alongside Crossref, DataCite serves as the registration agency focused on research data and other non-traditional outputs. Together they are the two registration agencies most familiar to researchers, and they sit beneath the International DOI Foundation within the broader DOI ecosystem.

This article explains what a DOI registration agency does, how metadata deposit and reference linking work, what services such as Cited-by provide, and how Crossref and DataCite divide the field between articles and data.

What a registration agency does

The International DOI Foundation governs the DOI system but does not register individual DOIs itself. That role falls to registration agencies, each serving a particular community. A registration agency assigns DOIs on behalf of its members, collects the descriptive metadata that accompanies each identifier, ensures the DOIs resolve correctly through the Handle System, and operates value-added services built on the metadata it holds. In effect, the agency is where a DOI is actually minted and where its metadata lives.

Metadata deposit

When a publisher registers a DOI with Crossref, it does not merely reserve a string — it deposits metadata describing the work: title, authors, publication date, the journal or book it belongs to, the references it cites, funding information, licensing and the target URL. This metadata is the real value of the system. It powers discovery, enables accurate citation, feeds downstream services and research-information systems, and increasingly captures relationships to other identifiers such as ORCID for authors and ROR for institutions. The richer and more complete the deposited metadata, the more useful the DOI becomes across the scholarly infrastructure described in our persistent-identifiers coverage.

Reference linking and Cited-by

Two of Crossref’s most consequential services are built directly on deposited reference metadata. Reference linking turns the reference lists in articles into resolvable DOI links, so a reader can move from a citation straight to the cited work — the connective tissue of the digital literature. Cited-by reverses the direction, surfacing which later works cite a given article, by matching the references that publishers deposit. Together these create a navigable web of citations that complements the citation indexes of platforms such as Web of Science.

Crossref versus DataCite: a division of labour

The clearest way to understand the two agencies is by what they specialise in.

Aspect Crossref DataCite
Primary focus Scholarly text: articles, books, proceedings Research data and other outputs
Typical members Publishers, scholarly societies Data centres, repositories, institutions
Signature services Reference linking, Cited-by Metadata for datasets and versioned outputs
Role in the DOI system DOI registration agency DOI registration agency

The boundary is not absolute — both register DOIs, both curate metadata, and the two organisations collaborate on shared infrastructure — but the rule of thumb is articles to Crossref, data to DataCite. DataCite’s focus on data also makes it central to the versioning practices for evolving outputs, discussed in our article on concept and version DOIs.

The broader DOI ecosystem

Crossref and DataCite are the most visible registration agencies, but the DOI system supports others serving different communities. All operate under the same governance, the same ISO 26324 syntax, and the same Handle-based resolution, which is what gives DOIs their consistency regardless of which agency minted them. DOIs in turn interlock with the wider PID stack — ORCID, ROR, RAiD and more — to connect outputs, people, organisations and projects. Definitions for all of these terms are maintained in the CASRAI dictionary.

Frequently asked questions

Is Crossref the same as the DOI Foundation?

No. The International DOI Foundation governs the overall DOI system. Crossref is a registration agency appointed under that system to register DOIs and curate metadata for scholarly text content; it is one agency among several.

What is the difference between Crossref and DataCite?

Both are DOI registration agencies, but Crossref specialises in scholarly text such as journal articles and books, while DataCite specialises in research data and other non-traditional outputs. The simplest rule is articles to Crossref, data to DataCite.

What is Cited-by?

Cited-by is a Crossref service that shows which later publications cite a given work, derived by matching the reference metadata that publishers deposit when registering their DOIs.

Why does deposited metadata matter so much?

The metadata, not just the identifier string, is what makes a DOI useful: it drives discovery, accurate citation, reference linking and integration with other identifiers and research-information systems. Incomplete metadata limits all of those benefits.

Referenced across the research world

University of Cambridge logoColumbia University logoUniversity of Edinburgh logoHarvard University logoUniversity of Oxford logoPrinceton University logoStanford School of Medicine logoUniversity College London logoORCID logoCrossref logoUniversity of Cambridge logoColumbia University logoUniversity of Edinburgh logoHarvard University logoUniversity of Oxford logoPrinceton University logoStanford School of Medicine logoUniversity College London logoORCID logoCrossref logo
  • University of Cambridge logo
  • Columbia University logo
  • University of Edinburgh logo
  • Harvard University logo
  • University of Oxford logo
  • Princeton University logo
  • Stanford School of Medicine logo
  • University College London logo
  • ORCID logo
  • Crossref logo

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