Double-Barrelled Stayman

This is a variation of the Two-Way Stayman after a 1NT opening. 2C is used on all hands that cannot guarantee game, and 2D creates a game force. After 2D Stayman, opener rebids in the following manner:

2H, or 2S shows that four card suit
2NT shows four cards in each minor suit
3C, 3D, 3H, 3S shows a five card suit
3NT shows 4333 shape (four cards in a minor)