Changes

Assuming that event alarms configuration remains global to all of a calendar 's subscribers (not per-user as above), alarm acknowledgment details should probably remain within the client software. User1 should not be able to 'snooze' User2 and User3, just by being the first to respond. Keeping alarm acknowledgment details within the client software has the negative implication of the user having to acknowledge the alarm separately in every client software installation, including past events which the user already acknowledged in another client environment.