FEN (Forsyth-Edwards Notation)
A compact single-line text format that fully describes a chess position.
FEN encodes piece placement, side to move, castling rights, en passant target square, and move counters in one string. It is the standard way chess software and databases store and exchange a snapshot of a position without needing the moves that led to it.
Etymology
FEN is an acronym naming its two contributors rather than a word with linguistic roots. The base system, Forsyth notation, was developed in 1883 by the Scottish newspaper journalist David Forsyth and was first proposed in the Glasgow Weekly Herald of 2 February 1883, using Kt for knight, an underline for Black pieces and 0 for an empty square. A revised one-line form using commas and lowercase letters for Black appeared in the 1897 book The Chess Bouquet. In 1993 the American programmer Steven J. Edwards extended Forsyth's scheme for computer use, adding the side to move, castling rights, en passant target square and the halfmove and fullmove counters, and first implemented it in his SAN Kit. The extended format was named Forsyth-Edwards Notation and was published as part of the Portable Game Notation specification, whose commonly cited date is 12 March 1994.
First documented: 1883 — David Forsyth, Glasgow Weekly Herald, 2 February 1883 (base Forsyth notation); extended form by Steven J. Edwards, 1993, published in the PGN specification (12 March 1994)
Translations
Translations for this term haven't been added yet.