Roles as argument places in a positionalist account of relations are pervasive in conceptual data modelling and linguistics, known also as components of a relationship and as semantic, thematic, or deep roles as parts of a verb or verb class, respectively. They are also planned to be used in Abstract Wikipedia that seeks to combine them. There is, however, no insight in systematic or ontologically sound usage of such roles, in contradistinction to the ample attention given to aligning classes to nouns and relationships to verbs. Roles, as identifiable argument places, may benefit from similar efforts toward an ontology of roles. We aim to take a first step in that direction in a two-pronged approach. First, we conducted an analysis of a set of 101 conceptual data models on their use of roles. Second, we analysed VerbNet, an authoritative linguistic knowledge base on thematic roles. The results show promise for improvements of naming roles in conceptual data models. VerbNet’s roles are challenging to align to an ontology due to its mixing of the ontological and linguistic layers and flexibility of natural language. The insights obtained also indicate ample avenues for further research.