In order to improve the management of copyright in the Internet, known as Digital Rights Management, there is the need for a shared language for copyright representation. Current approaches are based on purely syntactic solutions, i.e. a grammar that defines a rights expression language. These languages are difficult to put into practice due to the lack of explicit semantics that facilitate its implementation. Moreover, they are simple from the legal point of view because they are intended just to model the usage licenses granted by content providers to end-users. Thus, they ignore the copyright framework that lies behind and the whole value chain from creators to end-users.

The contribution of this work is to apply a semantic approach based on web ontologies to Digital Rights Management. The main contribution is the development of a copyright ontology that puts this approach into practice. It models the copyright core concepts for creations, rights and the basic kinds of actions that operate on them. Altogether allows building a copyright framework for the complete value chain. The set of actions operating on content are the building blocks that combined cope with the complexity of the copyright domain. At the same time, their simplicity guarantees a high level of interoperability and evolvability. The resulting copyright modelling framework is flexible and complete enough to model many copyright scenarios, not just those related to the economic exploitation of content.

Additionally, the ontology design and the selection of tools result in a straightforward implementation. Rights are modelled as classes of actions, action patterns are modelled also as classes and concrete actions are modelled as instances. Then, to check if some right or license grants an action is reduced to check for class subsumption and instance classification, which are the main functionalities of Description Logic reasoners. These checks are guided by the modal operators implicit in some of the case roles used in the ontology.

An additional contribution is to apply the same approach to the main rights expression languages, which are based on syntactic solutions. For each of these initiatives, a web ontology has been developed that captures the language grammar but also formalises its implicit semantics. Thus, it is easier to develop tools for these languages and they can be integrated in the general framework of the Copyright Ontology. The integration produces benefits in both directions. On one hand, the copyright ontology can benefit from it because new requirements are detected an it can be evaluated against real world needs. On the other hand, the copyright ontology can contribute its formal semantics to these syntax-based initiatives.