Rebids by 2C opener with unbalanced hands.
New suit bid (2♥, 2♠, 3♣, 3♦) is natural, forcing, and promises at least 5 cards in the suit. With no 5-card suit, bid notrump. The third round of bidding allows both partners to bid 4-card suits. However, if a fit has been located, it's better to confirm that fit. A player who knows the right contract is notrump can bid notrump. New suit bids by both partners are still forcing.