BACM12 — The Owl ontology does not record abstract=True from the XMI

Abstract elements are not allowed to be instantiated. The MOF metamodel for BACM marks such elements as "abstract" but this information is not carried over to the Owl ontology, leading users to think that it is proper to "instance" (specialize) elements that should not be specialized directly; instead one of the concrete subclasses of the element should be used.