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).
Fairy chess piece So for example, if white moves a bishop, black can follow by moving the joker as a bishop. A royal piece is one which must not be allowed to be captured. If a royal piece is threatened with capture and cannot avoid capture the next move, then the game is lost (a generalization of checkmate). In orthodox chess, the kings are royal. In fairy chess any other piece may instead be royal, and there may be more than one, or none at all (in which case the winning condition must be some other goal, such as capturing all of the