RDFS(FA) "...is a Semantics Web schema language introducing a UML-like metamodeling architecture to RDFS...RDFS(FA) introduces a Fixed layered metamodeling Architecture to RDFS, based on a relatively standard model-theoretic semantics. Therefore, first order languages, like DAML+OIL and OWL, can be built on top of both the syntax and semantics of RDFS(FA). On the other hand, all RDFS(FA) statements are still valid RDFS statements."