Named form
Back Rank Mate
Checkmate on the back rank, where the king cannot step forward because of its own pawns.
A checkmate delivered along the back rank by a rook or queen. The king cannot step forward because at least two of the squares in front of it are blocked by its own pawns.
Boundary
The catalogue records only the delivered mate.
A check delivered on the back rank is not enough. The defining feature is the absence of a viable escape, capture or blocking defence.