9.1.1 Support for the VoID and VANN vocabularies
The [VoID]http://www.w3.org/TR/void/ aims at resolving the same problem as the Manifest files described here. In addition, the [VANN]http://vocab.org/vann/ vocabulary provides the information about preferred namepaces prefixes. The RDF library manager can deal with VoID files. The following relations apply:
- VoID
Dataset
andLinkset
are similar tolib:Ontology
, but a VoID resource is always Virtual. I.e., the VoID URI itself never refers to an RDF document. - The
owl:imports
and its lib specializations are replaced byvoid:subset
(referring to another VoID dataset) andvoid:dataDump
(referring to a concrete document). - A description of the dataset is given using
dcterms:description
rather thanrdfs:comment
- The RDF library recognises
lib:source
,lib:baseURI
andlib:Cloudnode
, which have no equivalent in VoID. - The RDF library recognises
vann:preferredNamespacePrefix
andvann:preferredNamespaceUri
as alternatives to its proprietary way for defining prefixes. The domain of these predicates is unclear. The library recognises them regardless of the domain. Note that the range ofvann:preferredNamespaceUri
is a literal. A disadvantage of that is that the Turtle prefix declaration cannot be reused.
Currently, the RDF metadata is not stored in the RDF database. It is processed by low-level primitives that do not perform RDFS reasoning. In particular, this means that rdfs:supPropertyOf and rdfs:subClassOf cannot be used to specialise the RDF meta vocabulary.