Algebraic notation (chess) board. Thus each square has a unique identification of file letter followed by rank number. (For example, White's king starts the game on square e1; Black's knight on b8 can move to open squares a6 or c6.) Each piece type (other than pawns) is identified by an uppercase letter. English-speaking players use the letters "K" for king, "Q" for queen, "R" for rook, "B" for bishop, and "N" for knight (since K is already used). "S" (from the German "Springer") was also used for the knight in the early days of algebraic notation and is still used in some chess
Algebraic notation (chess) of chess is ICCF numeric notation. In recent years, the majority of correspondence games have been played on on-line servers rather than by email or post, leading to a decline in the use of ICCF numeric notation. Chess games are often stored in computer files using Portable Game Notation (PGN), which uses algebraic chess notation as well as additional markings to codify a game. As mentioned, PGN requires uppercase letter "O" to represent castling (e.g. O-O), while the FIDE Handbook uses digit zero (0-0). Though not technically a part of algebraic notation, the following are some common symbols frequently used