I think tagging almost all 350 thousand touhou images with it would just dilute the search results for mob cap. Like how frog is mostly images of kochiya sanae, even when the frog isn't a focus of the image.
Posted under General
So, I reckon mob_cap is the tag for the type of hats remilia_scarlet and a good half of the Touhou cast wear. However there are only ~400 posts tagged with it. Should I tag all the thousands of Touhou images with mob caps? Maybe there is some reason why it hasn't been done yet, I don't know.
MagicalAsparagus said: Well yeah, but still. Someone can always try -touhou query, right?
-touhou is a standard addition to nearly every query I run for just this reason. It can get a bit annoying, but if the tagging is accurate, it's accurate. So yes I suppose the image can/should be tagged on Touhou characters where appropriate.