The Implicit Invocation (II) architectural style improves modularity and is promoted by aspect-oriented (AO) languages and design patterns like Observer. However, it makes modular reasoning difficult, especially when reasoning about control effects of the advised code (subject). Our language Ptolemy, which was inspired by II languages, uses translucid contracts for modular reasoning about the control effects; however, this reasoning relies on Ptolemy’s event model, which has explicit event announcement and declared event types. In this paper we investigate how to apply translucid contracts to reasoning about events in other AO languages and even non-AO languages like C#.