Wednesday 22nd October 2025—Crossref, the open scholarly infrastructure nonprofit, today releases an enhanced dashboard showing metadata coverage and individual organisations’ contributions to documenting the process and outputs of scientific research in the open. The tool helps research-performing, funding, and publishing organisations identify gaps in open research information, and provides supporting evidence for movements like the Barcelona Declaration for Open Research Information, which encourages more substantial commitment to stewarding and enriching the scholarly record through open metadata.
Welcome back to our series of case studies of research funders using the Grant Linking System. In this interview, I talk with Cátia Laranjeira, PTCRIS Program Manager at FCCN|FCT, Portugal’s main public funding agency, about the agency’s approach to metadata, persistent identifiers, Open Science and Open Infrastructure.
With a holistic approach to the management, production and access to information on science, FCCN|FCT’s decision to implement the Grant Linking System within their processes was not simply a technical upgrade, but a coordinated effort to continue building a strong culture of openness. With the mantra “register once, reuse always”, FCCN|FCT efforts to embrace open funding metadata was only logical.
Repositories are home to a wide range of scholarly content; they often archive theses, dissertations, preprints, datasets, and other valuable outputs. These records are an important part of the research ecosystem and should be connected to the broader scholarly record. But to truly serve their purpose, repository records need to be connected to each other, to the broader research ecosystem, and to the people behind the research. Metadata is what makes that possible. Enhancing metadata is a way to tell a fuller, more accurate story of research. It helps surface relationships between works, people, funders, and institutions, and allows us as a community to build and use a more connected, more useful network of knowledge - what Crossref calls the ‘Research Nexus’.
The Crossref Grant Linking System (GLS) has been facilitating the registration, sharing and re-use of open funding metadata for six years now, and we have reached some important milestones recently! What started as an interest in identifying funders through the Open Funder Registry evolved to a more nuanced and comprehensive way to share and re-use open funding data systematically. That’s how, in collaboration with the funding community, the Crossref Grant Linking System was developed. Open funding metadata is fundamental for the transparency and integrity of the research endeavour, so we are happy to see them included in the Research Nexus.
A DOI may refer to a journal or book (a title-level DOI), or to a specific article or chapter.
Journals and DOIs
Like a set of nesting dolls, a journal may be made up of volumes, each containing a number of issues, each containing a number of articles. You can assign a DOI at each level, for example:
journal-level-DOI (sometimes called the title-level-DOI) 10.5555/QYPF2031. Like an ISSN, it refers to the whole journal
volume-level-DOI 10.5555/FFFU4804
issue-level-DOI 10.5555/QKLE5634
article-level-DOI 10.5555/CNBT7653
The role of the journal-level-DOI, volume-level-DOI, and issue-level-DOI is to link persistently to a point in the journal structure. These DOIs do not have any associated content, and it does not cost anything to register these DOIs.
However, article-level-DOIs do have associated content, and therefore a fee applies to register these DOIs.
Books and DOIs
Like a set of nesting dolls, a book may be made up of chapters. Again, you can assign a DOI at each level, for example:
book-level-DOI (sometimes called the title-level-DOI) 10.5555/ZAAR1365. Just like an ISBN, it refers to the whole book.
chapter-level-DOI 10.5555/TFWD2627
Both book-level-DOIs and chapter-level-DOIs have associated content, and therefore a fee applies to register these DOIs.
