Today, we’re delighted to let you know that Crossref members can now use ROR IDs to identify funders in any place where you currently use Funder IDs in your metadata. Funder IDs remain available, but this change allows publishers, service providers, and funders to streamline workflows and introduce efficiencies by using a single open identifier for both researcher affiliations and funding organizations.
As you probably know, the Research Organization Registry (ROR) is a global, community-led, carefully curated registry of open persistent identifiers for research organisations, including funding organisations.
We began our Global Equitable Membership (GEM) Program to provide greater membership equitability and accessibility to organizations in the world’s least economically advantaged countries. Eligibility for the program is based on a member’s country; our list of countries is predominantly based on the International Development Association (IDA). Eligible members pay no membership or content registration fees. The list undergoes periodic reviews, as countries may be added or removed over time as economic situations change.
Retractions and corrections from Retraction Watch are now available in Crossref’s REST API. Back in September 2023, we announced the acquisition of the Retraction Watch database with an ongoing shared service. Since then, they have sent us regular updates, which are publicly available as a csv file. Our aim has always been to better integrate these retractions with our existing metadata, and today we’ve met that goal.
This is the first time we have supplemented our metadata with a third-party data source.
As a provider of foundational open scholarly infrastructure, Crossref is an adopter of the Principles of Open Scholarly Infrastructure (POSI). In December 2024 we posted our updated POSI self-assessment. POSI provides an invaluable framework for transparency, accountability, susatinability and community alignment. There are 21 other POSI adopters.
Together, we are now undertaking a public consultation on proposed revisions for a version 2.0 release of the principles, which would update the current version 1.
We maintain an expansive set of relationship types to support the various content items that a research object, like a journal article, might link to. For data and software, we ask you to provide the following information:
identifier of the dataset/software
identifier type: DOI, Accession, PURL, ARK, URI, Other (additional identifier types are also accepted beyond those used for data or software, including ARXIV, ECLI, Handle, ISSN, ISBN, PMID, PMCID, and UUID)
relationship type: isSupplementedBy or references (use the former if it was generated as part of the research results)
description of dataset or software
We and DataCite both use this kind of linking. Data repositories which register their content with DataCite follow the same process and apply the same metadata tags. This means that we achieve direct data interoperability with links in the reverse direction (data and software repositories to journal articles).
The possible relationship types between content items can be as varied as the items themselves. We use a controlled vocabulary to define these relationships, in order to construct an orderly mapped network of content.
This is achieved by (i) an implicit approach where the relation type is a function of a specific service and is declared in the structure of the deposited XML, and (ii) in an explicit approach where the relation type is selected as a value within the deposited metadata.
Reference linking and Cited-by: implicitly creates cites and isCitedBy relationships between a content item and the items in its bibliography
Crossmark: explicit creation of update relations between an item and other items that materially affect it (for example, a retraction)
Funding data: implicit creation of isFundedBy and hasAward relationships between an item and the funding source that supported the underlying research
Linked clinical trials: implicit creation of a belongsTo relationship between and item and a registered clinical trial
Components: implicit creation of a isChildOf relationship between an item and its elemental parts that are assigned their own DOI (limited parent relation typing)
General typed relations: explicitly typed relation between an item with a Crossref DOI and an item with one of several possible identifiers.
Relationship types for associated research objects: intra-work (within a work)
Description
Reciprocal relationship types
Expression
isExpressionOf, hasExpression
Format
isFormatOf, hasFormat
Identical
isIdenticalTo
Manifestation
isManifestationOf, hasManifestation
Manuscript
isManuscriptOf, hasManuscript
Preprint
isPreprintOf, hasPreprint
Replacement
isReplacedBy, Replaces
Translation
isTranslationOf, hasTranslation
Variant
isVariantFormOf, isOriginalFormOf
Version
isVersionOf, hasVersion
Relationship types for associated research objects: inter-work (between works)
Description
Reciprocal relationship types
Basis
isBasedOn, isBasisFor
Comment
isCommentOn, hasComment
Continuation
isContinuedBy, Continues
Derivation
isDerivedFrom, hasDerivation
Documentation
isDocumentedBy, Documents
Funding
finances, isFinancedBy
Part
isPartOf, hasPart
Peer review
isReviewOf, hasReview
References
references, isReferencedBy
Related material, such as a protocol
isRelatedMaterial, hasRelatedMaterial
Reply
isReplyTo, hasReply
Requirement
requires, isRequiredBy
Software compilation
isCompiledBy, compiles
Supplement, such as a dataset generated as part of research results
isSupplementTo, isSupplementedBy
General typed relations
This service allows for the creation of a typed relationship between an item with a Crossref DOI and another content item. The other item may be represented by another Crossref DOI, a DOI from some other Registration Agency, or an item not identified with a DOI. When DOIs are used, the deposit process will fail if the DOI does not exist. Non-DOI identifiers are not verified.
When DOIs are used, a bidirectional relation is automatically created by us when a relation is created in the deposit of one item in a pair. The DOI with metadata creating the relation is said to be the claimant, the other item does not need to have its metadata directly contain the relationship.
Example: translated article
A single journal article is published in two languages with each being assigned its own DOI. In this example, both are published in the same journal. The original language instance has metadata that contains no indication of the translation instance. The alternative language instance includes in its metadata a relation to the original language instance. Here is a screenshot of the relevant section in the code. Please refer to the code snippet below to see it in context.
<journal_article publication_type="full_text">
<titles>
<title>Um artigo na lÃngua original, que passa a ser o inglês</title>
<original_language_title language="en">An article in its original language which happens to be English</original_language_title>
</titles>
<contributors>
<person_name sequence="first" contributor_role="author">
<given_name>Daniel</given_name>
<surname>Stepputtis</surname>
<ORCID authenticated="true">http://orcid.org/0000-0003-4824-1631</ORCID>
</person_name>
</contributors>
<publication_date media_type="online">
<month>02</month>
<day>28</day>
<year>2013</year>
</publication_date>
<program xmlns="https://0-www-crossref-org.library.alliant.edu/relations.xsd">
<related_item>
<description>Portuguese translation of an article</description>
<intra_work_relation relationship-type="isTranslationOf" identifier-type="doi">10.5555/original_language</intra_work_relation>
</related_item>
</program>
<doi_data>
<doi>10.5555/translation</doi>
<resource>https://0-www-crossref-org.library.alliant.edu/</resource>
</doi_data>
</journal_article>
Example: book review
This example has a book review published as an article in the journal The Holocene. The article’s title, taken from the publisher’s site is “Book Review: Understanding the Earth system: compartments, processes and interactions” where this book has the DOI https://doi.org/10.1007/978-3-642-56843-5.
A: The current metadata for the review article gives no indication of the actual book being reviewed:
An article with a Crossref DOI identifies that data represented by a DataCite DOI was used in the research and was mentioned in the article’s acknowledgment section.
