We are experimenting with the representation of a DTD and associated documents (i.e., documents conformant to the DTD) in a knowledge representation (KR) system, in order to provide more sophisticated query and retrieval from TEI documents than current systems provide. We are using CLASSIC, a frame-based representation system developed at AT&T Bell Laboratories. Like many KR systems, CLASSIC enables the definition of structured concepts/frames, their organization into taxonomies, the creation and manipulation of individual instances of such concepts, and inference such as inheritance, relation transitivity, inverses, etc. In addition, CLASSIC provides for the key inferences of subsumption and classification. By representing a document as an individual instance of a hierarchy of concepts derived from the DTD, and by allowing the creation of additional user-defined concepts and relations, sophisticated query and retrieval operations can be performed. This paper describes CLASSIC and the formalism of description logic that underlies it, and demonstrates how it can be used for enhanced retrieval from richly encoded documents.