Dublin Core

The Dublin Core vocab defines common metadata terms that can be used to describe either digital or physical resources. It is overseen by the Dublin Core Metadata Initiative (DCMI). The titular "Dublin" in this case refers to Dublin, Ohio, where the schema was first conceived in 1995, meaning that the Dublin core vocab pre-dates the creation of RDF.

Originally, the vocab consisted of just 15 terms which these days is referred to as the "elements 1.1" namespace. This included things like title, description, language and creator. Later, this list was expanded to include many more elements, but these additions were added to a new namespace (the so called "Dublin core terms") to retain compatibility with any older existing implementations (the 15 original elements are mirrored in the new namespace). The DCMI have stated officially that while they will indefinitely support the older namespace, they encourage people to use the new one.

In addition to those two namespaces, DCMI also looks after two more: one consisting of "types" which define the classes that can be used in association with the metadata definition (for example, Text or StillImage for use with the type property). A fourth namespace is also curated by DCMI called DCAM, which allows authors to write metadata about DC metadata using a vocab that mirrors a subset of the elements from RDFS quite closely (but not exactly). The total number of namespaces being maintained by DCMI is therefore four:

• The elements 1.1 namespace - The original 15 items, still supported but not recommended for new projects.
• The terms namespace - The original 15 items plus numerous extensions.
• The types namespace - An extended class list which they maintain seperately to the terms.
• The DCAM namespace - for defining metadata about the metadata.

In all likelihood, most users will only need items from the terms namespace.

Example

This example uses the Dublin Core vocab to describe details about the book "Frankenstein". Note that this uses the /dc/terms namespace instead of the original /elements/1.1 namespace, firstly because that is what DCMI recommends but also because it is making use of the expanded terms that the newer namespace provides, such as alternative.

@prefix : <http://www.example.com/> .
@prefix dcterms : <http://purl.org/dc/terms/> .  # The DC Terms namespace (the original 15 terms + more)
@prefix dcmit : <http://purl.org/dc/dcmitype/> . # The DCMI Types namespace

:MaryShelley a dcterms:Agent ;
    dcterms:title "Mary Shelley" .

:Frankenstein
    dcterms:type dcmit:Text ;
    dcterms:title "Frankenstein" ;
    dcterms:alternative "The Modern Prometheus" ;
    dcterms:language "en" ;
    dcterms:format "Print" ;
    dcterms:creator :MaryShelley ;
    dcterms:created "1818"^^<http://www.w3.org/2001/XMLSchema#gYear> .