The service-oriented technologies are considered as the most promising paradigm over the last few years for delivering functionalities and allowing business cooperation. In those paradigms, the traditional vision of security aims to keep properties such as availability, authentication, and confidentiality by protecting the web service itself. However, in such an approach, the particularities of the human interaction in regard to the behaviors of the service stakeholders have been until now based only on trust. In this article, justified by the need of having an agreement in the business vocabulary used for expressing controllability policies, we present a model formalizing the semantics of service contracts. The DL formalism is used to model the specific knowledge domain, while OWL 2 is used as concrete syntax. \textcopyright 2017 Lavoisier.