I play: 2♣: 20-21 balanced or GF (25+ balanced/suit), this was partner's idea which I've gone on to adapt a bit, but the main reason we play it is to get out opposite 20-21 balanced 2M: 5-card suit to play opposite 20-21 2NT: 6+♣ 0-3 or 8+ 3♣ 6+♦ 0-3 or 8+ Over the transfers into a minor, completion shows 20-21 balanced, obviously any move after the completion would show 8+ 2♣ - 2♦ is any positive or a negative without a 5cM or 6cm 2♣ - 2♦ - 2♥ is 20-21 balanced or hearts 2♣ - 2♦ - 2♥- 2NT is 5-5 minors 0-3 and at most 1 heart 2♣ - 2♦ - 2♥- 3♣ is 5-5 minors 0-3 with 2-3 hearts 2♣ - 2♦ - 2♥ - 2♠ are all the other hands including the balanced negatives that pass the 20-21 2NT rebid Of course, considering the rarity of 2♣/2NT openers I've not had much chance to see where this gains/fails I'd like to play transfer negatives starting at 2♦ not 2NT but I'm not sure if partner would play them with the argument being 2♣ 2♦ 2♥ Pass, but I've not really asked him. You could then use 2♣ - 2♠ as 0-3 5-5 minors or 6-card minor (Ken Rexford) and the transfers into the minors as real positives or something else