Metadata, namespace, Resource Discovery, digitized resources, electronic resources, RDF, Resource Description Framework, crosswalks, interoperability, metatags, XML, eXtensible Markup Language, DOI, Digital Object Identifier, metadata syntax, Encoded Archival Description, EAD, Dublin Core, DC, Government Information Locator Services, GILS, metadata registries, Metadata Schemes, Text Encoding Initiative Header, TEI Header, Visual Resources Association Visual Document Description Categories, VRA Visual Document Description Categories, Consortium for the Interchange of Museum Information metadata set, CIMI metadata set, Digital Geospatial Metadata, DGM, ontologies, MARC, metadati, reperimento delle risorse, risorse elettroniche, mappature, interoperabilità, ontologie, registri di metadati, schemi di metadati, sintassi di metadati