  The conceptual knowledge framework OML/CKML needs several components for a
successful design. One important, but previously overlooked, component is the
central core of OML/CKML. The central core provides a theoretical link between
the ontological specification in OML and the conceptual knowledge
representation in CKML. This paper discusses the formal semantics and syntactic
styles of the central core, and also the important role it plays in defining
interoperability between OML/CKML, RDF/S and Ontolingua.
