Ellipsis

In move numbers, one period introduces a White move and three periods introduce a Black move. Thus, 1. e4 marks White's first move, while 1... e5 marks Black's reply under the same number.

A continuous move record does not repeat the three periods before every reply: 1. e4 e5 already makes the order clear. Portable Game Notation (PGN), the plain-text format for exchanging games, uses the three-period form when a Black move appears without the immediately preceding White move, such as after a comment or when a recorded starting position has Black to move.

The mark also commonly begins a variation whose alternative move belongs to Black. Here the periods do not mean that moves were omitted; they identify which side is moving.