On Super User, ui is a synonym for user-interface. On Meta Super User, they are two separate tags. That doesn’t make any sense. I recommend making ui a synonym for user-interface on Meta Super User.
I just discovered that this question is a duplicate of
Can the “ui” tag be merged with “user-interface”?,
but that one says that it’s status-completed -- but it isn’t.
(Perhaps it got reverted in the intervening two years.)
