Over 1NT: 2C is Stayman, 2D/2H = transfers, 2S = clubs (3C shows a fit and 2NT denies one), 2NT = diamonds (3D shows a fit, 3C denies one). After a minor-suit transfer, a new suit by responder shows a shortage. 3C is 5-card Stayman, 3D = 5+C/5+D without a 3-card major FG; 3H = 0-3/1-3 in majors FG, 3S = 3-0/3-1 in majors FG. 4C is Gerber, 4D is 5+H/5+S game only values, 4M is natural and to play. A transfer at the 2-level and a jump to game is non-invitational.
Opener will freely raise responder’s suit with three-card support. After 1m-1M-2M, 2NT is game invitational with only a four-card major, 3NT game values with only a four-card major. New suits are help wanted game tries except for 1m-1H-2H-2S which promises four spades, catering for responder 4-4 in the majors and opener 4-3.
A 1NT rebid is 11-14 and will usually have 1-2 cards in partner’s major. It does NOT deny four-cards in a bypassed major. 2C is a puppet to 2D, which responder will either pass or signoff elsewhere, 2D is any game force, all other bids are invitational, including jumps at 3-level, higher bids are auto-splinters.
A 2NT rebid is 18-19. 3C is a puppet to 3D, over which responder can pass, bid a non-forcing 3M or bid 3NT to show a weak hand with 6+ clubs (4C is then nf), 3D is Staymanic, 3H is a slam try in opener’s suit, 3S is a slam try in responder’s suit.
After 2/1 response, 2NT is 11-14 balanced or 18-19. 3NT is 15-17 with a reason not to have opened 1NT.
A 3NT rebid after a one-level response shows a hand too strong to make a non-forcing jump-rebid in opener’s first suit.
A 2NT opening is 20-22. 3C is Puppet Stayman, 3D/3H are transfers, 3S is a slam try with both minors. Jumps to 4-level are two-up transfers and at least mild slam tries: 4C = hearts, 4D = spades, 4H = clubs, 4S = diamonds. When responder has shown a major, completing the transfer shows a lack of interest and 4NT is RKCB. When responder has shown a minor, 4NT is the weakest action and 5m shows some interest.
KOKISH after a 2C opening: 2C-2D-2NT is 23-24 and non-forcing, 2C-2D-2H-2S-2N is 25+ and all system over 2NT openings apply.