UMLR — UML2: Unclear how to indicate what events a classifier might send

UML2 has Receptions which can be included in realized/provided Interfaces to indicate what Signal events a Classifier is able to receive. But it isn't clear how a Classifier would indicate in its interfaces what events it might send/generate, and therefore what events a collaborating Classifier connected to this Classifier in some way would need to be prepared to handle.

UML2 Reception semantics should be updated to indicate Receptions can appear in either Realized/provided or Usage/required Interfaces. A Reception in a required interface would indicate a signal event the owning classifier might send through a SendSignalAction or BroadcastSignalAction. This would provide all the interface information needed on both sides of a connector to know what SignalEvents might be sent and/or received