Defining roles of agents (i.e., people, organisations, etc.) is required in various Semantic Web applications, including access control, knowledge management and skill repository. So far, many theoretical discussions have taken place on the nature of roles and how to represent them. In this paper, we present how we implemented a lightweight OWL-DL ontology that allows to represent roles and their relations to agents. We especially focus on the various steps for choosing a well-founded model that is compatible with the general design principle of creating (and consuming) lightweight and easily re-usable ontology components for the Semantic Web. Our criteria to assess the beauty of an ontology component, in particular, are derived from practical requirements that are typical to Linked Data applications. Hence, our modeling proposal follows an original approach that bridges a gap between the Linked Data philosophy and more theoretical issues of ontology engineering. We also describe a use-case in which this ontology has been used, demonstrating in practice the benefits of our model for maintaining, browsing and querying Linked Data. © 2011-IOS Press and the authors. All rights reserved.