2D/H/S openings show either a two suiter (at least 5+,5+) or a single suiter (6 card suit). The hand is 7 - 9 loser (NVul) or 7 - 8 loser (Vul) and 6 - 11 hcp.

1. 2D opening shows either a weak 2H, or C and D, or C and S (at least 5-5)

2. 2H opening shows either a weak 2S, or H and C, or H and D (at least 5-5)
3. 2S opening shows either a weak 2C (3C opening with at least 2/3 top honours), or S and D, or S and H (at least 5-5).
It is important to have most of the hcp in the suit or suits shown by the bid. All suit responses are correctable and the only forcing response is 2NT.
The response structure is: any suit bid is pass or correct, and 2NT being a one round force.
1. 2D - 2NT
a) 3C=C and D or C and S.(Now 3D/S is NF, 3H is a relay:opener bids 3S to show C and S, and 3NT to show C and D).
b) 3D=max. Weak 2H. (Now responders 3H is GF and asks for singleton: 3NT=good trumps, no singleton;4H=bad trumps, no singleton).
c) 3H=min. Weak 2H:
2. 2H - 2NT
a) 3C shows H and C
b) 3D shows H and D
c) 3H = max. Weak 2S (now responders 3S is GF: ditto above).
d) 3S = min. Weak 2S
3. 2S - 2NT
a) 3C shows Clubs
b) 3D shows S and D
c) 3H shows S and H
If the opening two bid is doubled by LHO responder bids as follows:
Pass shows 3 cards in suit bid. Redouble shows *no* 3 card support for suit bid, but implies support in second suit. A bid of two of possible single suit shows values to compete to three level if opener has a single suited hand. If 4th hand bids, opener *must* compete to the three level with that hand. A pass by opener then shows two suited hand.
If doubled in 4th position such as:
Opener LHO Responder RHO
2 Suit P Bid X
Opener bids as follows:
2NT = max. with 2 suiter, lower ranked suits.
XX = max. with 2 suiter, higher ranked suits.
Suit = min. with 2 suiter.