I just came across detect, a tag with the lovely tag wiki summary:
"Detect meaning goes like either discover or identity of presence."
Looking at the 484 questions currently tagged with it, I see no connection between any of them, except for the obvious one that somebody's trying to detect something. Indeed, it looks just like the stereotypical "half a tag": a new user posts a question about "How to detect foo with bar?", but there's no foo-detection tag, so they tag their question bar detect foo.
There's no way this tag could stand alone as the sole tag of a question, nor does it seem to add any value to the questions tagged with it. I'm also unable to find any sort of useful core (like some language, tool or library named "detect") underneath the garbage. I therefore propose that this tag should simply be nuked. Of course, alternative suggestions are also welcome.
Ps. In a way, the obvious solution for dealing with this tag would be to merge it into detection, which at least has a slightly better tag wiki summary:
"Detection is a general term that describes the action of finding an object, event or state during a process."
However, I don't really see any more consistency among the 700 questions tagged with this tag, either, and I don't think it stands up much better against any of the other arguments made for deletion above (although there is at least one highly-voted question currently tagged only with detection), so I hereby include it in this deletion request.
At least, there doesn't seem to be any detecting tag.