No, it is not international, it is an extended FEN notation to handle more than 600 pieces : https://musketeerchess.net/docs/boardpainter/board-painter-user-guide.html jerome I am aware of the 2-character piece name in the FEN extended format, what I mean is this one, RNBQKBNR/PPPPPPPP/8/8/8/8/pppp...