Baron

Baron is an ACOL convention used in response to opening 1NT or 2NT.

After 1NT: 2S This is either a raise to 2NT without a four-card major, which will pass a 2NT response, Or game forcing with slam interest with usually no five card suit

Opener bids 2NT with a minimum hand, or lowest four card suit with a maximum

After 2NT: 3S Game forcing with slam interest, usually no five-card suit

Opener bids 3NT with a minimum hand, or lowest four-card suit with a maximum