Cappelletti Over NT
Over An Opening 1N Bid:Dbl shows any 16+ HCPs
2 shows a one-suited hand
An exception to the above is that with a strong two-suiter which includes a major, you can bid 2N (supposedly showing minors) and after partner picks a minor, bid the major.
Responses To 2C:
Pass shows a good 6+ card Club suit.
2 is an artificial bid to allow partner to bid his suit. The Cappelletti bidder will then rebid:
2 if his suit is Hearts
2 if his suit is Spades
3 if his suit is Clubs
2N with 4 Diamonds and 6 Clubs
Responses to 2D (Majors):
Pass shows a good 6+ card Diamond suit.
2 shows responder's better major, which could be short since without one of the hands above, responder is forced to choose a major.
Responses to 2H or 2S:
2N denies support for the major; asks for the minor
Pass shows support for the major and <8 HCPs.
Jump-raise to 3 level shows a fit and 8-10 HCPs.
In Pass-Out position, Dbl shows a four-card major and a longer minor.
Cappelletti can also be used over 2N or 3N opening bids.
It can also be used after a 1N overcall of partner's opening bid of 1 or 1, where it shows <8 HCPs, since with 8+ HCPs, a penalty double should be made instead.