Also known as: 伏臥
When a character lies flat on their stomach with their Feet Up in the air.
This is usually done to show off a character's Breasts, Ass, and Feet all at the same time. The subject can be wearing legwear or Barefoot, but their Feet must be visible as this is a term coined by foot fetish enthusiasts to describe a particular pose that shows off the feet.
For Danbooru purposes, the character can be wearing footwear.