Missing isn’t broken
RDFWeb and Friend of a Friend (FOAF): Missing isn't broken: data validation and freedom on the Semantic Web
Developers who come to the Semantic Web effort via XML technology often make an understandable mistake. They assume that missing is broken when it comes to the contents of RDF/XML documents, that if you omit some piece of information from an RDF file, you have in some formal, technical sense 'done something wrong' and should be punished.
RDF doesn't work like that. Missing isn't broken.
Developers who come to the Semantic Web effort via XML technology often make an understandable mistake. They assume that missing is broken when it comes to the contents of RDF/XML documents, that if you omit some piece of information from an RDF file, you have in some formal, technical sense 'done something wrong' and should be punished.
RDF doesn't work like that. Missing isn't broken.