This article reflects an ongoing effort to systematize the use of terms applied by philosophers and computer scientists in the context of ontology and ontological engineering. We show that a common reference terminology is needed to connect terms in representational artifacts to what they mean ontologically. Without such a reference, statements in and about knowledge representation languages will be ambiguous, both as between various languages and within a single language. We identify problems common to a number of knowledge representation languages used to formalize ontologies. We show that a reference terminology can be used to disambiguate the meanings of some, and to reveal ontological problems in other, evidently confused, statements in and about different representation languages. Our final conclusion is not that our proposed terminology is the ultimate one to serve as a common reference; rather, we argue that it is necessary to have such a standard with well-defined terms linked...