Machine-readable metadata

Declaring [[project.citations]] also makes the site’s citation machine-readable: every page’s <head> carries the self citation as Highwire and Dublin Core meta tags, along with a schema.org JSON-LD description of the site. Each citation’s type decides the schema.org type it is described under there, so type = "dataset" is what makes a data release indexable by Google Dataset Search. A citation’s version reaches the two types that define a property for one — softwareVersion on a SoftwareSourceCode and version on a Dataset — and no other node states it.

Highwire meta tags are what Google Scholar’s inclusion guidelines specify and what Zotero’s embedded-metadata translator reads, so a reader on a page that carries them gets a one-click “Save to Zotero” with the right title, creators, date, and DOI. These are the tags emitted, in this order:

Tag	Value
citation_title	title
citation_author	one per author, family name first; an organization’s name whole
citation_author_institution	that author’s affiliation, when set
citation_author_orcid	that author’s orcid as a resolvable https://orcid.org/ URL, when set
citation_publication_date	date as YYYY/MM/DD, or as YYYY when the entry dates the work to the year or the month
citation_doi	doi, bare
citation_publisher	publisher
citation_fulltext_html_url	the site’s root URL for the self entry, which is the URL that DOI is registered against; the claimed page’s own URL — with the claim’s fragment, when it names one — for an entry that sets page. Either needs base_url, and neither is emitted without one
DC.identifier	the DOI as a resolvable https://doi.org/ URL, the Dublin Core complement DataCite’s landing-page guidance asks for

A field the entry does not state emits no tag, so an entry located by url rather than by a DOI carries no citation_doi and no DC.identifier. Every value is HTML-escaped, so a title containing quotes or angle brackets reaches the tag intact.

Note

Documenteer writes the date tag as citation_publication_date, the spelling Google Scholar documents. A Rubin technote built with technote 0.11.0 or later writes the same tag; earlier releases spelled it citation_date, and a consumer reads either.

Google Scholar’s inclusion guidelines describe only two forms for the value — a full date, or a year alone — so an entry dated to the month states its year in this tag rather than a 2025/06 no guideline covers, which Scholar may not parse at all. The month is not lost: the schema.org datePublished in the page’s JSON-LD block carries the entry’s date at the precision it states, 2025-06 included.

That JSON-LD block is about the self entry, and states every other entry as a relation of it rather than repeating the whole record:

• An entry that names a page is a part of the site’s own work — a data product of a release, say, not something the site cites. The site-wide block names it under hasPart by reference alone: its schema.org type, its DOI, and its title, and nothing more. The full record lives on the page the entry claims, whose own block points back at the site with an isPartOf reference of the same shape.

• An entry with no page is a work the site cites, and reaches the site-wide block in full. The preferred entry always does: it is the citation the site asks readers to use, which is exactly what schema.org citation states, whether or not the footer repeats it. Any other entry reaches the block only when the site displays it, which is to say when in_footer is true.

• An entry that is neither a part, nor preferred, nor shown in the footer appears in no site-wide block at all, because no page of the site presents it. It still renders wherever a citation-card names it.

So in_footer decides a visual surface, and — for the additional entries alone — whether the metadata carries them. A site that writes in_footer = false on its preferred citation keeps the whole of this block; see Sites with a large API reference.

A site that marks no entry self is no DOI’s landing page, so it emits none of the meta tags above on any page — not the title and authors either, since stating them would tell a harvester that this site is the full text of a work published somewhere else. Marking an entry preferred does not change that: preferred says which citation the site asks readers to use, which is a question for the visible surfaces, and only self claims that this site is where a DOI resolves. Its JSON-LD block still has a subject — the site itself, a schema.org WebSite carrying the site’s title and URL and no identifier — and the same entries reach it under the same two relations, in the same shapes. Such a site can still be the landing page of someone else’s DOI on a page of its own, and that page’s block names this WebSite node under isPartOf, so both ends of the relation are stated there too; the reference carries the site’s title and URL in place of a DOI, since that is what identifies a site with no DOI to give. Only the subject differs, so a consumer reads the block the same way whether or not the site publishes a DOI.

This site is one of those. It declares two citations and marks neither self, so viewing the source of this page finds no citation_title or DC.identifier tag in its <head>. It does find one application/ld+json block, whose subject is a WebSite named Documenteer, with the Software entry, the preferred citation, described in full under citation as a SoftwareSourceCode. The Paper entry is in neither: it is not preferred and not shown in the footer, so no page of the site presents it except the ones that render it on a card.

Keeping the parts to references is what lets a site publish a DOI per data product without paying for it on every page: a release with forty product DOIs states forty short references, not forty full records, and each product’s own landing page carries the record that describes it.

See [[project.citations]] for the full field reference.