Model mate
In chess, a model mate is a type of pure mate checkmating position in which: the checkmated king and all vacant squares in its field are attacked only once; squares in the king's field occupied by friendly units are not also attacked by the mating side (unless such a unit is necessarily pinned to the king); and all units of the mating side (with the possible exception of the king and pawns) participate actively in forming the mating net. Model mates are extremely rare in practical play, but they add value to chess problems as they are considered artistic.