Betza's funny notation ones. The notation is based on dividing moves that can be made on a board of squares into groups of symmetry-equivalent moves, the moves within a group differing only in the direction in which the step is taken. Each such group (referred to as "atom") is indicated by a capital, such as N for the 8 moves of the knight. The letter that represents the atom is usually the first letter of the simplest piece from current or historic chess variants that has this move, such as A and F for the alfil and ferz of shatranj (ancient Arabic/Persian 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