Minor Stayman is a game forcing convention in response to strong 1NT opening. Minor Stayman is valid even when 1NT is overcalled. The responder or advancer, respectively, is quizzing opening partner if he has a 4 cards MINOR. The alert bid in this case is 2!s. The hand strength is 10+ points.

Many partnerships use 2!s even to game force general hands where Stayman is not possible.

Intention is to reach comfort in a 3NT game.

There are just 3 replies to Minor Stayman call by opener:

2NT /3NT   Comfort with No Trump game. Distribution may be 3343 or 3334 

3!c.    YES 4 CLUBS

3!d      YES 4 DIAMONDS

After opener’s 1NT if opponent interferes with 2!c, Minor Stayman can still be used.

If responder’s next bid is 3 of a new suit, he signals a singleton or void in that suit, but not necessarily slam interest.