A conventional defence to a 1NT opener whereby 2♣ shows at least 5-4 in the majors. In reply, partner usually shows preference between the majors or, with equal length, bids an artificial 2♦, asking for the overcaller’s longer major.
For example:

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A conventional defence to a 1NT opener whereby 2♣ shows at least 5-4 in the majors. In reply, partner usually shows preference between the majors or, with equal length, bids an artificial 2♦, asking for the overcaller’s longer major.
For example:
