Latest blog posts
Michelle Cancel
2026 August 26

What does it mean to be a global remote team

We’ve had a year full of growth and reached a milestone of 60+ team members; let’s take a moment to digest what that means for people operations. Hiring staff in 19+ countries is no easy task, but we are up for it, and I can honestly say it is the main reason why our culture is so great. That might sound biased coming from Crossref’s first Head of Human Resources, but hear me out.

...Find out more
Lena Stoll
2026 August 20

Registering rich metadata for books, chapters, reports, dissertations, and updates just got easier

You can now register rich metadata for a variety of record types in Metadata Manager using simple, guided workflows. The tool is used by many in our community to register grant and journal article records, and it has now been expanded to support books and chapters, reports, dissertations, and post-publication updates for journal content.

Metadata Manager makes it easier to capture identifiers for contributors and their affiliations, funding information, references, and more. Thanks to automated reference matching by Crossref, this offers greater visibility for the works, while the affiliations and funding information can serve as important trust signals for the community.

...Find out more
RocĂ­o Gaudioso Pedraza
2026 August 19

To go far, go together: reflections from FORCE2026

This year’s edition of the FORCE11 conference was hosted in June by Singapore Management University. Its title, “To Go Far, Go Together: Advancing Scholarly Communication Across Boundaries and Disruptions” truly resonates with Crossref’s truths; it takes a village! Crossref only works as long as the scholarly research community wants to work together globally, across all disciplines, for integrity and openness of the scientific record. The conversations were influenced by a genuinely diverse mix of librarians, researchers, open infrastructures, and service providers, and that mix shaped almost every interaction we had at the conference.

...Find out more
Lucy Ofiesh
2026 August 13

Fee update: lowering and removing DOI registration fees in January 2027

We have some rather unusual news to share: Crossref fees are going down again. At its meeting in Paris earlier this month, the Crossref Board approved two further recommendations from the Resourcing Crossref for Future Sustainability (RCFS) project: effective 1st January 2027, we will reduce the majority of Content Registration fees for all 25,000 members, and remove fees for back-year records altogether.

Content Registration fees haven’t increased in around 20 years, and this is the first significant change to them in that time—downwards. Since these fees account for the largest share of Crossref’s revenue (around 60%), and since every member registers DOI records, these changes reach further than anything we’ve announced under the RCFS project so far.

...Find out more
  • Menu
search

Documentation

Schema deprecation guide

We periodically deprecate older versions of our metadata deposit schema. This guide explains which schema versions are supported going forward and what you need to do to migrate.

Crossref currently supports schema versions 4.3.0 through 5.5.0. As announced in late 2025, all schema versions prior to 5.3.1 will be deprecated by 2028.

Schema to be deprecated

The following versions are scheduled to be deprecated by the end of 2026:

  • crossref4.3.1.xsd
  • crossref4.3.2.xsd
  • crossref4.8.1.xsd
  • doi_resources4.3.2.xsd
  • doi_resources4.3.4.xsd
  • doi_resources4.3.5.xsd
  • doi_resources4.4.2.xsd

These moderately used version will be deprecated by the end of 2027:

  • crossref4.3.3.xsd
  • crossref4.3.4.xsd
  • crossref4.3.5.xsd

ALL remaining pre-5.3.1 versions will be deprecated by the end of 2028:

  • crossref4.3.0.xsd
  • crossref4.3.6.xsd
  • crossref4.3.7.xsd
  • crossref4.4.0.xsd
  • crossref4.4.1.xsd
  • crossref4.4.2.xsd
  • doi_resources4.3.0.xsd
  • doi_resources4.3.6.xsd

For the full, current list of supported schema versions, see Schema versions.

How to migrate

For versions earlier than 5.3.1

Version 5.3.1 introduced a breaking change to affiliations metadata to add support for organisation identifiers (ROR, Wikidata, and ISNI). If you are including affiliations in your metadata you will need to update how affiliations are marked up in your deposits so they validate against the new schema. See the Affiliations and ROR markup guide for details.

Once your affiliations markup is updated, update the schema declaration in your XML to reference the latest supported version crossref5.5.0.xsd.

For 5.3.1 or later

No migration is currently needed, but versions 5.4.0 and 5.5.0 each add new optional metadata that you may want to consider including in your records. Migrating from 5.3.1 to a later supported version requires only a change to your schema declaration and version number in the XML. No changes to your existing markup are needed.

What’s new in each version:

  • 5.4.0: adds a type attribute for citations, support for version numbering, and status support for posted content/preprints. For more details visit the 5.4.0 migration guide.
  • 5.5.0 (current, recommended): adds support for multiple contributor roles per person and the CRediT vocabulary; adds blog and poster as posted content subtypes (and removes report, working paper, and dissertation as posted content subtypes); adds archive locations for posted content. For more details visit the 5.5.0 migration guide.

Page maintainer: Patricia Feeney
Last updated: 2026-August-21