HTML microdata is an extension to HTML used to embed machine-readable data into HTML documents. Whereas the microdata specification describes a means of markup, the output format is JSON. This specification describes processing rules that may be used to extract RDF from an HTML document containing microdata.
This update adds support for vocabulary expansion, for example to support features such as
schema:additionalType. Microdata vocabulary expansion is a tiny subset of the RDFa vocabulary expansion but follows the same principle: the graph extracted from a microdata document is passed through a specific processor that adds additional triples to the graph (e.g., in the
schema:additionalType case, it adds corresponding