I counted the number of seats in a theatre and I assume I should use either capacity or capacity:seats but I’m not sure which of those or if I should use another one.
I would go for capacity.
Is it possible to have standing places?
There’s standing space that’s why I assumed I should use capacity:seats over just capacity.
if there is standing space then I would use capacity for capacity and capacity:seats or similar for capacity of seats.
With a park bench, amenity=bench, you can have seats=3 (or whatever, 17 teenagers can fit on one park bench). So, seats=576 maybe?
Stadiums use capacity=, without differentiation between standing and seated. From the pattern in the table at Key:capacity - OpenStreetMap Wiki it suggests that capacity:seats= would be the number of seats (not people or seated people) that would fit in the theatre.
Some event spaces are set up so that they can change an audience area from standing to seating and vice versa.
& in the case of stadiums, is it capacity of people watching a football game from the grandstands, or a rock concert, where they’re also seated on the playing field?