We have a whole bunch of tags that IMO inexplicably separate panties vs. underwear: panties_down, panties_aside, panties_around_one_leg, panties_on_head, panty_pull, panty_peak. There is no reason whatsoever for this split other than the historical artifact that the panty tags came first and where in most cases promptly implicated to panty, making their uses for, e.g. jockstraps and boxers impossible.
As far as I'm concerner, they should all be merged with a few exceptions (most notably panties aside, where the makle version is poking_out) to a generic underwear_* series of tag to make everyone's life easier.
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