FICS Style 12

FICS stands for Free Internet Chess Server. Style 12 is output designed for programs rather than ordinary reading. When the server sends it, a client, the program a person uses to connect, can reconstruct the displayed position, clocks, and other information needed to show or follow a game.

The line begins with <12>, and the historical specification defines 31 non-empty fields separated by spaces. They include eight fields for the board's horizontal ranks, the side to move, information about the previous double pawn push, four castling indicators, player names, the time control, meaning the starting time and increment after each move, remaining times, move number, previous move, and board orientation.

Understanding the purpose does not require memorizing all 31 fields. Their fixed order gives them meaning. The document also warns that future fields may be appended, so software should parse from left to right rather than assume that the line must end after the last field it knows.

Style 12 is an operational server snapshot. It does not replace a PGN export file, where PGN means Portable Game Notation and records a game for exchange or archiving. It also does not replace the DGT protocol, from Digital Game Technology, which connects a physical board to a computer.