Domain-specific knowledge representation languages

Z39.50 is an international standard client–server, application layer communications protocol for searching and retrieving information from a database over a TCP/IP computer network, developed and maintained by the Library of Congress. It is covered by ANSI/NISO standard Z39.50, and ISO standard 23950.

RDFa or Resource Description Framework in Attributes is a W3C Recommendation that adds a set of attribute-level extensions to HTML, XHTML and various XML-based document types for embedding rich metadata within web documents. The Resource Description Framework (RDF) data-model mapping enables the use of RDFs for embedding RDF subject-predicate-object expressions within XHTML documents. RDFa also enables the extraction of RDF model triples by compliant user agents.

HTML used to reinforce meaning of documents or webpages

predictive model interchange format