create alias underskirt -> petticoat
Currently, all post under this tag seem to some kind petticoats.
Underskirt was probably used because pettocoat is a rather specific term maybe?
EDIT: This tag alias has been rejected because it was not approved within 60 days.
EDIT: The tag alias underskirt -> petticoat (forum #142335) has been rejected by @DanbooruBot.
Updated by DanbooruBot