Bridge convention after opponent opens 1NT -- specific question about D.O.N.T
That is something that you must agree with your partner. By default D.O.N.T is off in this situation, but you can agree that it is on. If you use this, it must be alerted. You must also consider how to show hands where the normal bid is impossible. Suppose, for example, your hand is clubs and spades, but the opponent bids diamonds. Obviously 2C is insufficient.