Occasionally I stumble across a collection where there is nothing erotic in them. I mean the set below is probably only a turn on if you're an eskimo in the high arctic and you're going "wow she's down to just three layers of clothing".
So what do you want to do with such sets. I personally find them a complete waste of space. Do you want to leave them, mark them for deletion or tag them as "non-nude" or even "totally fucking useless".
It goes back to previous threads of mine about rating the content of the collection.

Originally the collections were meant to be for personal use. Since they've been introduced they've lost that role, and the same thing is the case with the pinboards. Really the two systems are too similar.
In my mind the collections should be private by default, so that they're more for personal use again. The pinboards should be the public-facing ones I think.
I like porn