UCS-Router (E. Bertino et al.) is a policy engine developed for message dispatching in a Universal Communication System. A user of the system has a unique identifier, named Universal Communication Identifier (UCI), independent from the actual communication devices the user owns. It is a task of the UCS-Router to properly route messages or phone calls arriving at the UCI to the proper user devices. The routing process is performed according to policies the user specifies on the type of message, on the device capabilities and states, on the sender characteristics, and on the message sending time. We present a declarative policy language developed for UCS-Router. Users of UCS-Router can use this language for specifying message filtering and routing policies. Moreover, we present issues that can arise in the evaluation process of the policies. Such issues are primarily due to the high expressiveness of the language and to the possibility to handle a great variety of message media format. Finally, we present how the UCS-Router addresses such issues.