The vCard Ontology is a W3C specification that expresses vCard contact information — names, phone numbers, email addresses, and postal addresses — as RDF, so that people and organizations can be described and linked as structured, machine-readable data on the web.
vCard Ontology
The vCard Ontology is a W3C specification that maps the familiar vCard contact model into RDF, giving names, addresses, phone numbers, and emails a formal vocabulary that can be published and linked as structured data on the web. Where a vCard file is a self-contained business card, the vCard Ontology lets the same information become a first-class node in a graph, describable, queryable, and joinable with other linked data.
- RDF vocabulary - Defines classes and properties (like
vcard:Individual,vcard:hasEmail,vcard:hasAddress) for describing people and organizations. - Web-native contacts - Contact data becomes addressable by URI and embeddable in pages, rather than trapped in a downloadable file.
- Interoperable with vCard 4.0 - It mirrors the concepts of RFC 6350 so the RDF form and the file form stay aligned.
- Linkable and queryable - As linked data it can be traversed and queried with SPARQL and combined with vocabularies like Schema.org.
In API and data practice, the vCard Ontology is how contact information stops being an opaque attachment and becomes part of a knowledge graph. Publishing people and organizations with a shared vocabulary lets APIs, catalogs, and semantic-web tooling reason over “who” data consistently, and it gives structured, machine-readable identity to the contacts an agent might need to resolve or act on. It sits alongside the file-format vCard as the semantic-web expression of the same standard.
