Central to interoperability is a shared conceptualization of the domain or universe of discourse (UoD). A conceptual model (CM) documents this shared understanding between people in a formal language, augmenting prose but neutral of later implementation decisions. Having such an explicit layer has benefits for enhanced interoperability, higher quality implementations, reuse and mapping, and as such is recognized as desirable by many modeling frameworks. In this paper, we describe our motivation and efforts to date, to use the ontologically well founded profile of the Unified Modeling Language (UML) proposed in Guizzardi-2005 to create such models. Relevant subsets of a CM form the basis for physical data models (PDM) targeting specific technologies, in this case the generation of Extensible Markup Language (XML) schemata represented in the World Wide Web Consortium (W3C) Schema Language (XSD). These physical data models are annotated by a developer, with a set of encoding directives. These encoding directives and the custom developed software that interprets them to map concepts in the CM to their expression in an XSD, are our principle contribution. The CM language, the XSD encoding annotations, and the software are briefly described.