Explanation

The pattern is named after epaulettes, an ornamental shoulder decoration used in military uniforms.

In the case with the queen, the queen might not be next to the king, because then the queen would already guard the two escape squares next to the king.

Examples

White can deliver Epaulette mate with Qf7#. The two squares next to the king are blocked by the rook on h8 and the pawn on h6. As the queen is two squares away from the king, the escape squares on g8 and g6 are guarded by the queen.

Black can deliver Epaulette mate with Qd1#. The two squares next to the king are blocked by the rook on e3 and the pawn on c3. The king is not on the edge of the board, but the two escape squares behind the king on e4 and c4 are guarded by the pawn on d5.

White can deliver Epaulette mate with the rook Rxg7#.

Pattern matching

This pattern can happen if the opponent's king is blocked on two sides by own pieces, but has no cover in front.

Related patterns

Related patterns are the dovetail (the queen is diagonally adjacent to the king) and swallow's tail mates (the queen is orthogonally adjacent to the king).