Recent research has led to proposals for the model-driven configuration of Enterprise Systems (ES) by the help of configurable reference models. While the proposed on gura le P s (C-EPCs) provide adequate conceptual support towards reference model configuration, the issue of translating the configured models towards executable process specifications has not been approached yet. A first step in this direction is the definition of a machine-readable format for C-EPCs that can be used as an interchange format and as an input format for transformations. This paper proposes a C-EPC representation in XML based on the P Mar up anguage (EPML) format. We take the formal C-EPC syntax definition as a starting point to define the requirements for a respective extension to EPML and introduce a C-EPC representation in EPML. Furthermore, we introduce the - P alidator, a program that generates validity reports for C-EPCs represented in EPML. The C-EPC Validator can be used to validate both configurable and configured C-EPCs. Finally, we highlight future application areas of the C-EPC schema.