voiD (from "Vocabulary of Interlinked Datasets") is an RDF based schema to describe linked datasets. With voiD the discovery and usage of linked datasets can be performed both effectively and efficiently.
ISWC2009 Tutorial on Legal and Social Frameworks for Sharing Data on the Web http://www.opendatacommons.org/events/iswc-2009-legal-social-sharing-data-web/