We'd like to use analytics cookies to understand which symbols people look up, so we know what to research next. They are not used for advertising and we set none of them unless you say yes. What we store.
Everything written on a scoresheet, grouped because the notation is a closed system that only works whole: a piece letter needs a square, a square needs the capture or check mark that says what happened there, and castling needs a form of its own because it names no destination at all. The group also holds the annotation scale — ! through ?? — which is the one part FIDE does not define. Those marks are opinion, and knowing which half of a scoresheet is rule and which is convention is the useful thing to learn here.
A plus sign after a move, recording that the move attacks the enemy king.
A hash after a move, recording that the move ends the game.
A lower-case x between piece and square, recording that a piece was taken.
Two letter O separated by a hyphen, recording the short castle.
Three letter O separated by hyphens, recording the long castle.
An equals sign followed by a piece letter, recording what a pawn became.
An abbreviation marking the capture of a pawn that has just passed.
An exclamation mark marking a move the annotator judges strong.
A double exclamation mark marking an exceptional move.
An exclamation mark followed by a question mark, marking a move worth attention.
A question mark followed by an exclamation mark, marking a doubtful move.
A question mark marking a move the annotator judges weak.
A double question mark marking a serious error.
A crowned figure topped with a cross, standing for the king.
A coronet of points, standing for the queen.
A castellated tower, standing for the rook.
A mitre with a diagonal slit, standing for the bishop.
A horse's head, standing for the knight.
A small ball on a collar, standing for the pawn.