e.p.

e.p. abbreviates en passant, French for in passing. The capture can occur when a pawn advances two squares from its starting position and lands beside an opposing pawn. That opposing pawn may capture it only on the immediately following move, as though it had advanced just one square, provided the capture is otherwise legal.

The capturing pawn moves diagonally to the square the other pawn crossed, while the captured pawn is removed from the square where it landed. In exd6 e.p., the pawn from the e-file, the vertical column labeled e, moves to d6 and captures the pawn that has just passed through d6.

Rules of the International Chess Federation (FIDE) allow e.p. to be appended to the notation. In Portable Game Notation (PGN), the plain-text format for exchanging games, the standard form of algebraic notation adds no special mark at the end: the same move is stored simply as exd6. The x already marks the capture, and the position determines that it was en passant.