Service-Oriented Architectures (SOA) provide a flexible and dynamic platform to implement distributed enterprise systems and open environments. Such systems support automated service publication and run-time discovery thanks to their dynamism and loose coupling. In an SOA, services are self-described [1]. Such descriptions are kept in a component called “service discovery” or “service registry”. Service requesters, depending on their requirements, find a service in the service registry then bind to the service for execution.