Thanks to Lazeez, who has accepted my suggestion and added a new genre code to the list:
ENF
which stands for "embarrassed nude female." I've added it to several of my Danielle stories. It would also be appropriate for most Naked in School stories.
It may be defined thus: "A woman (or girl) embarrassed because she has to, has been persuaded to, or is forced to strip, or because she is suddenly caught naked, or because she has somehow lost her clothes and cannot avoid embarrassing encounters."
I suggested it because the closest things on the list were "nudism" and "exhibitionism," neither of which quite gets at the concept. I just hope it catches on.
ENF is down at the bottom of list of sexual activities, under "other."