I created the wiki page http://wiki.openstreetmap.org/wiki/Key:clothes some time ago, to standardize things like shop=clothes, clothes=costumes.

Now I looked up whether it was being used:
http://taginfo.openstreetmap.org/keys/clothes#values
I was quite surprised that there were six occurences of "clothes=off".

First I thought someone had tagged nude beaches or swinger clubs. :D
Then looked the six nodes up. All of them clothes-off motorcycle shops. Turned out, it was a name clash with:
http://wiki.openstreetmap.org/wiki/Tag:shop=motorcycle

;)