From Hard Drop - Tetris Wiki
180° rotation rotates the piece 180 degrees. In some games, that can be actually done. It grossly depends on games.
In DTET, pressing rotate left and rotate right at the same time will rotate 180° with counter-clockwise wallkicks.
In NullpoMino, a new wallkick table is used.
In Tetris, space button rotates 180° with counter-clockwise wallkicks.
In Tetris Perfect, there are 4 180° buttons (total number of rotation buttons is 16). Like in above, two buttons rotate 180° left or right. This time, it uses left/right wallkicks, because that's what is used in this game, not CCW or CW wallkicks. Two other buttons are same, but piece is moved 1 space down before rotating (force-rotation). In SRS, all 4 buttons do the same thing: rotate 180° with no kick, as force-rotation doesn't affect SRS.