 Someone who understands the Algebraic notation must be able to follow descriptions of particular chess games in it and someone who can do that must be able to tell which move is represented by particular lines within such a description. Nonetheless, it is clear that when someone sees the line \(\b{Bb5}\) in the middle of such a description, knowing what \(\bB, \bb\), and \(\b{5}\) mean will not be enough to figure out what this move is supposed to be. It must be a move to \(\b{b5}\) made by a bishop, but we don’t know which bishop (not even whether it is white or black) and we don’t know which square it is coming from. All this can be determined by following the description of the game from the beginning, assuming that one knows what the initial configurations of figures are on the chessboard, that white moves first, and that afterwards black and white move one after the other. But staring at \(\b{Bb5}\) itself will not help.