FEN

The Forsyth-Edwards Notation is a standard for describing chess positions using the ASCII (American Standard Code for Information Interchange) character set.  It is intended as a standard position notation for chess programmers, for page layout programs and for confirming position status for e-mail competition.  Six FEN fields specify the piece placement, the active colour, the castling availability, the en passant target square, the half-move clock and the full-move number.  The first four fields of the FEN specification are the same as the first four fields of the closely related EPD specification.  Like FEN, EPD can also be used for general position description.  However, unlike EPD, FEN is not as expandable.  FEN provides no means to add new operations that provide new functionality as needs arise.  A text file composed exclusively of FEN data records should have a file name with “.fen” as the suffix.