Event covers have been created for all manner of events:
Philatelic ... club meetings, exhibitions, the works
Hobbies ... covers issued by our brethren coin collectors, auto/rail modelers, et al
Postal ... branch post office openings, closings, first days
Terrestrial ... railway/highway first runs, last runs, re-runs
Naval ... launchings, deployments, homecomings, circumnavigations, ports-of-call, polar (anything)
Aviation ... first flights, airfield openings, races, competitions, exhibitions
Space ... (too many micro-categories to count, let alone list)
Olympics ... so many stamps that there must be a zillion covers
Jamborees ... surely the merit badge means that there are plenty of jamboree event covers?
Each of these categories has its own websites, specialty societies, literature, checklists, forum threads.
But what about the singularities?
What about events that folks did not even know were events?
For example: institution anniversaries, civil war re-enactments, demolitions ... do I know?
I'll start with (keywords) cover events Backgammon pmk 19800802 PH Baguio City
Q/ Do you have any Event Covers ... for events that folks did not even know were events?
/s/ ikeyPikey (who is well aware that this is a shameless lemons-into-lemonade post, but what else could I do with that cover?)