dcsubject

dcsubject is the Dublin Core subject element used to record the topic or subject matter of a resource. It is part of the Dublin Core Metadata Initiative (DCMI) metadata element set and is commonly represented as dc:subject in XML or RDF serializations. The element helps describe what a resource is about, rather than who created it or when it was created.

Values for dcsubject can be plain text or references to controlled vocabulary terms. It is typically repeatable, allowing a single resource to be described with multiple subjects. Using controlled terms from vocabularies such as Library of Congress Subject Headings (LCSH), MeSH, or domain-specific thesauri improves interoperability and retrieval accuracy, though free text is still permissible when a controlled term is not available.

In practice, dcsubject supports discovery and indexing across catalogs, repositories, and search interfaces. It can be used to drive facet navigation, topic searches, and cross-domain interoperability, particularly when records from different providers share common subject vocabularies. The element is separate from other Dublin Core elements like title, creator, or date, focusing specifically on the topical content of the resource.

Encoding and mapping: In XML, a subject value appears as a dc:subject element. In RDF, it is represented by the dc:subject property whose objects can be literals or links to subject resources. Crosswalks exist to map dcsubject values to other classification schemes and subject headings, supporting broad interoperability among metadata records.