Basically, tropes that have one purpose: how much skin can clothing show before it's considered indecent.
Of course the amount
will vary among cultures, yet any degree is still often a way of
Getting Crap Past the Radar, which is one of the main reasons these tropes are so often used.
And since since a lot of people find partial nudity
more sexy than full nudity, this also makes many of these tropes
Fanservice and
Fetish Fuel, as well as mildly
Not Safe for Work.
Related:
Tropes
