You're definitely right about that. Most people think of UML as a notation for relationships between components, and it's useful to have a syntax that people ca

You're definitely right about that. Most people think of UML as a notation for relationships between components, and it's useful to have a syntax that people can agree on so it's clear what you're drawing on the whiteboard. But you don't need a 750 page (really) standard creating a formal specification of this syntax. Just in case people don't know just how formal the specification is, here's part of the explanation of event dispatching: As discussed in sub clause 13.2.3, a Behavior execution always has an associated context object (which may be the execution itself). A context object mediates the handling of Event occurrences for all of its associated Behavior executions. When an Event occurrence is recognized by a context object, it may have an immediate effect or it may be saved for later triggered effect. An immediate effect is manifested by direct invocation of a Behavior as determined by the Event, such as the invocation of the method of a BehavioralFeature (see sub clause 13.2.3). A triggered effect is manifested by the storage of the occurrence in the event pool of the object and the later consumption of the occurrence by an ongoing Behavior execution that reaches a Trigger that matches the Event corresponding to the occurrence in the pool