I've been reviewing close votes that don't seem to fit any of the available categories for voting to close. The questions are reasonably good, there's enough background, they don't need to go to ELL (although they might have been welcome there in the first place). What has happened is that they've been briefly and pertinently answered (in comments) by one or two (or four or five) people, the OP has said "thanks", and there's really nothing more to say. As closed, they remain re-openable in the event someone wants to pose a more comprehensive answer. But they're complete, helpful, and finished as they stand. What about adding a reason like "Taken care of", "Fully Handled," "You can put a fork in me, I'm done."
Would something like "close because complete" work? Or "We're finished here" or "We Be Done" or "That's All Folks"