Can {{tag|historic|city_gate}} be used for a gate in a castle that has only military purposes (not a citywall)?

Hello there.
Do you think {{tag|historic|city_gate}} could also be used for the gate of a fort, a fortress that is used for military purposes only, rather than a city wall surrounding a residence?

  • I’ve refined the title and question a bit.

settlement the tag should not be set. For other walls there is barrier=wall
and there are some proposed fortification tags-