If a player has castled illegally, Rook and King must be moved
back, and the King must make another move, if there is a legal
one. If not, any other move can be played. A player who makes an
illegal move with a piece must retract that move, and make
another one if possible with the same piece. If the mistake is
only noticed later on, the game should be restarted from the
position in which the error occurred.


II. NOTATION


A special notation has been adopted to make the study of games
and positions possible, and it is necessary for students of the
game to become thoroughly conversant with it. The original and
earliest notation is still in use in English, French, and Spanish
speaking countries. It is derived from the original position in
the game, in that the squares take the names of the pieces which
occupy them. Thus the corner squares are called R 1 (Rook's
square or Rook's first), and to distinguish them from one another
QR1 or KR 1 (Queen's or King's Rook's square). The squares
immediately in front are called QR2 or KR2. A distinction is made
between White and Black, and White's R 1 is Black's R 8, Black's
R 2 is White's R 7, White's K B 3 is Black's KB6, and so on. K
stands for King; Q for Queen; B for Bishop; Kt for Knight; R for
Rook; and P for Pawn. In describing a capture, only the capturing
and the captured pieces are mentioned, and not the squares.

When confusion is possible, it is customary to add whether King's
side or Queen's side pieces are concerned, e.g. KRx Q Kt. In