Cappelletti is a method to describe various kinds of hands over a 1NT opener.
Double is for penalties.
2C is a 1-suited hand. 2D = majors.
2H = hearts plus a minor.
2S= spades plus a minor.
2N = minors.
S: AQxx H: x D: xxx C: AJ9xx S: xx S: xxxx H: AJTxx H: Kxxx D: KJxxx D: x C: x C: KQxx S: KJx H: Qxx D: AQxx C: xxx W N E S 1N 2H P 3H P 4H X P/O