sailor one-piece swimsuit
Generic tag for any one-piece swimsuit design that features a sailor collar.
Note that the sailor collar should be attached to the swimsuit itself; don't use this tag if there is a serafuku shirt over the swimsuit. For instance in Danbooru post #482820, the middle character has a proper sailor one-piece, while the other two don't. Use the serafuku and swimsuit under clothes tags instead.
For the Idolmaster costume, see sailor swimsuit (idolmaster).
See also
This tag implicates one-piece_swimsuit and sailor_collar (learn more).