I've just noticed the tag activity which is rather infrequently used and seems to cover a variety of concepts.
About half of the questions seem to be concerning the Android user interface concept, and most of the rest are about UML diagrams. The remainder don't seem to be particularly helpfully tagged at all.
Should these questions be retagged in a less ambiguous fashion (e.g. android-activity and uml-activity, and just detag the rest)?