...
If vocabulary is fulfilling the criteria, metadata coordinator checks which RDF/XML data profile the vocabulary content negotiates to - we make a request to URI with the Accept header “application/rdf+xml.” xml” - and creates a crosswalk between the format and EDM. It is possible that the vocabulary supports more than one data profile (preferably, vocabulary is based on standard data models, like, for example, SKOS). Library of Congress Subject Headings (LCSH), for example, supports SKOS as well as MADS, as is evident from this response. It is under the discretion of the Metadata Coordinator to select the data format that is most suitable for transformation.
...