Yes, you have the opener's rebids right. Additionally opener can agree hearts by rebidding 2♠ Over 1NT (used on balanced hands and 4-1-4-4 hands) responder rebids as follows: 2♣ = 3 controls 2♦ = 4 controls 2♥ = 5+ controls 2♠ = 0-2 controls Opener then uses the next step to ask about suit distribution Over the suit rebids, responder shows support and strength using steps. The basic scheme is: 1st step = 0-2 card support, extra values 2nd step = 0-2 card support, minimum hand 3rd step = 3 card support 4th step = 4 card support However, these can vary depending on the level. All bids above 2S show 3+ card support. If room, 3/4 card fits can be split between minimum and extra values.