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Referent (rft)

The Referent is what an OpenURL is about: the resource being requested. It is the only required entity in a ContextObject.

The Referent is the resource being referenced — the article, book, chapter, dissertation, or patent that the user is trying to reach. Every ContextObject contains exactly one Referent; the rest of the entities supply context around it. In KEV form, the Referent's descriptors are prefixed rft.

Three ways to describe a Referent

A Referent may be described in any combination of three ways:

By metadata (By-Value)

Descriptive bibliographic metadata is sent inline. The format used is named by rft_val_fmt:

rft_val_fmt=info:ofi/fmt:kev:mtx:journal
&rft.atitle=An+Article+Title
&rft.jtitle=A+Journal+Title
&rft.date=2020
&rft.volume=10
&rft.spage=1

Which descriptors are valid depends on the named format. See the format reference pages: journal, book, dissertation, patent.

By identifier

A URI identifier for the Referent is sent in rft_id:

rft_id=info:doi/10.1103/PhysRev.47.777

The identifier may appear without any descriptive metadata, provided the resolver knows the namespace. See Identifiers for the registered forms.

By reference

The metadata describing the Referent is stored elsewhere; the OpenURL points to it:

rft_ref_fmt=info:ofi/fmt:xml:xsd:journal
&rft_ref=https://source.example.com/contextobjects/12345.xml

The resolver fetches the referenced document and parses it. By-Reference is most often used with XML ContextObjects. See Transports.

Combining methods

The three methods can be combined. It is common to include both a DOI and a complete set of descriptive metadata, so that a resolver can use the DOI when its knowledge base recognises it and fall back to metadata when it does not:

rft_val_fmt=info:ofi/fmt:kev:mtx:journal
&rft_id=info:doi/10.1103/PhysRev.47.777
&rft.atitle=Can+Quantum-Mechanical+Description+of+Physical+Reality+Be+Considered+Complete%3F
&rft.jtitle=Physical+Review
&rft.aulast=Einstein
&rft.date=1935
&rft.volume=47
&rft.spage=777

The genre descriptor

Every metadata format defines a rft.genre descriptor that names the specific sub-type of the resource: article, journal, book, bookitem, proceeding, dissertation, and so on. The set of legal values is given by the format. Including rft.genre lets the resolver disambiguate cases where the rest of the metadata is incomplete.

Sources