In the dialogue for entering a position (Setup Position) the user can enter positions for analysis.

 

Whilst using this feature the current board position will appear in the board window.

 

 

W 0-0, 0-0-0, B 0-0, 0-0-0: Displays whether it is still possible to castle in the position. Perhaps the king or the rooks have already been moved so that castling rights have already been forfeited.