Out of Bounds
Out of Bounds (abbreviated OoB) is a rule applied to Super Metroid categories, typically preventing the use of Out of Bounds (e.g. no OoB) in a run.
Out of Bounds is defined as whenever Samus' hitbox leaves the regular boundaries of the room (via x-Ray Climb or any other glitch) and causes the map to shift into a black area that is not marked in the game and is not tracked. The map on the HUD consequently stops blinking when this occurs. In Out of Bounds Samus completely leaves the existing room and is able to exploit junk data left behind from previous rooms.
This does not cover clipping through walls and platforms, as well as an X-Ray that goes through the wall but doesn't leave the room (such as leaving Draygon without Gravity).