What is Crossref and Why Your Journal Needs DOIs

When researchers cite articles, they need reliable links that won't break over time. When databases index content, they need standardised identifiers that work across systems. When readers click citation links, they expect to reach the right article instantly. DOIs (Digital Object Identifiers) make all this possible, and Crossref is the primary registration agency serving scholarly publishing.

Understanding Digital Object Identifiers #

A DOI is a persistent identifier—a permanent, unique string that identifies a specific digital object and resolves to its current location. Unlike URLs that break when websites restructure, DOIs remain functional indefinitely because they're managed through a resolution system that tracks content locations.

DOIs follow a standard format: a prefix assigned to the registrant, a forward slash, and a suffix chosen by the registrant. For example, "10.1234/example.2024.001" where "10.1234" is the prefix and "example.2024.001" is the suffix the publisher selected.

When someone enters a DOI into a resolver (like doi.org), the system looks up the current URL associated with that identifier and redirects the user there. If the content moves to a new URL, the publisher updates the resolution record, and existing DOI links continue working.

What is Crossref? #

Crossref is a not-for-profit membership organisation that operates as a DOI registration agency for scholarly content. Founded in 2000, Crossref has grown to include thousands of member publishers registering DOIs for journals, books, conference proceedings, datasets, and other scholarly outputs.

Beyond DOI registration, Crossref provides infrastructure services that scholarly publishing depends upon:

Citation Linking: Crossref's Cited-by service tracks citations between DOI-registered works, enabling features like "cited by" counts and forward citation tracking.

Reference Matching: Publishers can match their reference lists against Crossref's database to add DOI links, improving citation connectivity.

Metadata Distribution: Crossref distributes registered metadata to indexing services, discovery platforms, and library systems worldwide.

Funder Registry: A standardised database of research funders enabling proper acknowledgment and tracking of funded research.

Why DOIs Matter for Journals #

Citation Reliability #

Academic work builds on previous research through citations. When citation links break, the scholarly record fragments. DOIs ensure that citations remain functional regardless of website changes, domain migrations, or platform transitions. A citation from 2010 can still resolve correctly in 2030.

Indexing and Discovery #

Major academic databases and discovery services use DOIs as primary identifiers. Google Scholar, Scopus, Web of Science, PubMed, and numerous discipline-specific databases rely on DOIs to identify, link, and track scholarly content. Journals without DOIs may face indexing limitations.

Professional Standards #

DOI registration has become an expected standard for legitimate scholarly journals. Indexing services, funding agencies, and academic institutions increasingly expect DOI presence. Applications for DOAJ, Scopus, and other indexes often ask about DOI registration practices.

Author Expectations #

Researchers expect their published work to have DOIs. Articles without DOIs may appear less credible, receive fewer citations, and integrate poorly with reference management systems and institutional repositories. Authors may prefer journals that provide proper DOIs.

Metrics and Tracking #

DOIs enable various metrics and tracking services. Citation counts, Altmetrics, usage statistics, and other measures often depend on DOI identification. Journals seeking to demonstrate impact benefit from DOI infrastructure.

Crossref Membership #

To register DOIs through Crossref, organisations must become members. Membership involves:

Application Process: Organisations apply through Crossref's website, providing information about their publishing activities and agreeing to membership terms.

Annual Fees: Crossref charges annual membership fees based on organisation type and publishing volume. Fees vary significantly—small publishers pay less than large commercial operations.

Per-DOI Fees: Beyond membership fees, Crossref charges per DOI registered. These fees are modest but accumulate with publication volume.

Metadata Requirements: Members must provide complete, accurate metadata for registered content. Crossref enforces metadata quality standards.

DOI Registration in OJS #

OJS includes plugins for Crossref DOI registration. Properly configured, these plugins can:

Automatically generate DOI suffixes following consistent patterns. Submit registration requests to Crossref when articles publish. Include comprehensive metadata required by Crossref schemas. Update registrations when article information changes.

However, effective DOI registration requires more than plugin activation. Journals need Crossref membership credentials, properly configured plugin settings, complete article metadata, and ongoing attention to registration status. Failed registrations require troubleshooting and resubmission.

Metadata Quality Requirements #

Crossref accepts DOI registrations only with adequate metadata. Required elements include:

Title: Complete article title as published

Authors: All contributor names with proper formatting

Publication Date: When the article became available

Journal Title: Full title and any abbreviated forms

ISSN: Valid ISSN for the journal

URL: Working link to the article

Optional but valuable elements include abstracts, funding information, license details, ORCID iDs, and cited references. Richer metadata improves discoverability and enables additional Crossref services.

Reference Linking #

One of Crossref's most valuable services involves reference linking. When journals deposit reference lists with their DOI registrations, Crossref matches these references against its database and adds DOI links where possible.

This creates bidirectional citation linking: articles link to their references, and Crossref tracks which newer works cite older ones. The "Cited-by" counts visible on many journal websites depend on this reference linking infrastructure.

Alternatives to Crossref #

While Crossref dominates scholarly DOI registration, alternatives exist:

DataCite: Focuses on research data, though it registers DOIs for various content types. Often used for datasets, software, and non-traditional outputs.

mEDRA: A European-based registration agency serving primarily European publishers.

For most academic journals, Crossref remains the appropriate choice due to its comprehensive scholarly infrastructure, widespread recognition, and extensive integration with academic systems.

Common Challenges #

Journals encounter various DOI-related challenges:

Incomplete Metadata: Articles lacking required metadata fields cannot be registered. Journals must ensure complete metadata capture during publication.

Registration Failures: Technical issues, schema errors, or duplicate attempts cause registration failures requiring investigation and correction.

URL Maintenance: DOIs must resolve to working URLs. Website changes require updating DOI resolution records.

Retrospective Registration: Assigning DOIs to previously published content involves significant metadata compilation and registration work.

Cost Management: For high-volume publishers, per-DOI fees accumulate. Budgeting must account for ongoing registration costs.

DOIs and Open Access #

Open access journals particularly benefit from DOI registration. Freely accessible content depends on discoverability—readers can only access what they can find. DOIs ensure open access articles appear properly in academic databases, get credited in citation counts, and remain permanently linkable.

Many funding agencies requiring open access publication also expect DOI assignment. DOIs provide the persistent identifiers necessary for compliance verification and impact tracking.