2C shows a normal Acol two bid: 8+ playing tricks, good suit, four or more defensive tricks, and forcing for one round.

2D is the artificial negative.

Over a suit re-bid, 2NT is the negative.

Responder may pass if opener re-bids their original suit.

2D opening shows a balanced 23+ hand or a game-forcing hand.

2H is the artificial negative.

2H and 2S are weak two bids.