The Properties, Classes, Vocabulary Encoding Schemes, and Datatypes declared and maintained by the Dublin Core™ Metadata Initiative are collectively referred to as DCMI Metadata Terms. Property, Class, and Datatype (aka Syntax Encoding Scheme) are defined exactly as in RDF, while a Vocabulary Encoding Scheme is equivalent to the identifier for a SKOS Concept Scheme.
The typology of metadata terms evolved over DCMI's first decade. The original Dublin Core™ workshop of 1995 came up with a set of thirteen Elements. A 1997 workshop produced the Canberra Qualifiers: Language, Scheme, and Type (Sub-Element). By 2000, the Dublin Core™ Qualifiers were called Element Refinements and Encoding Schemes. Although the first, experimental RDF schemas for the Dublin Core™ declared element refinements as RDF properties already in the late 1990s, the Elements only began to be called Properties more widely in the 2000s. The Encoding Scheme came to be differentiated into Vocabulary Encoding Scheme and Syntax Encoding Scheme. Property replaced Element as the designation of choice and was explicitly equated with RDF Property in the revised DCMI Abstract Model of 2007. The term Element Refinement was dropped with the explanation that an Element Refinement was no more than a Property which happened to be a sub-property of another. Syntax Encoding Schemes were declared to be RDF Datatypes.
|The Dublin Core™ (1995)||DCMI Grammatical Principles (2000-2001)||DCMI Abstract Model (2007)||RDF and SKOS (today)|
|element||element||property or element||rdf:Property|
|qualifier||element refinement||property with sub-property-of relation||rdf:Property with rdfs:subPropertyOf relationship|
|encoding scheme||syntax encoding scheme||rdfs:Datatype|
|vocabulary encoding scheme||skos:ConceptScheme, though the equivalence is debatable and has not been formally declared|