VoID
The Vocabulary of Interlinked Datasets is a vocabulary for providing concise summaries of Resource Description Framework datasets—meaningful collections of semantic triples—using the syntax of RDF Schema. It can be used for general metadata, access metadata, structural metadata, and linking metadata.
A linked dataset is a collection of data, published and maintained by a single provider, available as RDF on the Web, where at least some of the resources in the dataset are identified by dereferencable Uniform Resource Identifiers. VoID is used to provide metadata on RDF datasets to facilitate query processing on a graph of interlinked datasets in the Semantic Web.