If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
2. Check if there is an active Open Thread before posting a new one. (Immediately before; refresh the list-of-threads page before posting.)
3. Open Threads should be posted in Discussion, and not Main.
4. Open Threads should start on Monday, and end on Sunday.
This page suggests "∨".
(I've only ever seen that symbol meaning "or", but that's a kind of maximum.)
That's one of the two possibilities I've found over the past day. The other is ⊤ from https://en.wikipedia.org/wiki/Greatest_element .
(I wonder if presenting this idea to an actual mathematician would induce any wincing? Off to /r/math to find out...)