Digital contents distributed over the internet are regulated by law and by technical management systems. The latter include a semantic component that describes licenses, i.e. rights of use which are granted to the user. These elements of Digital Rights Management (DRM) systems are called Rights Expression Languages (REL), they gather terms and relations needed to build licenses. Some are based on an ontology of online licenses, not necessarily related to applicable law and various legal systems, and cannot interoperate. As a consequence, there is a need for a more generic way to express licenses. Here, generic means that rightholders should only need to express the license they need once, and semi-automatic tools should then translate this license so it can be browsed by any specific system. Hence it implies the necessity to be able to model concept semantics in order to translate a license expressed in generic terms into more specific terms that are compliant with the specific standards used by distribution systems. This work comes as part of larger studies on legal ontologies, legal systems and RELs.