Similar to Jacoby transfers. After partner's opening 1nt, responder bids
a. 2D - transfer to Hearts
b. 2H - transfer to spades
c. 2s - Minor Suit Stayman
d. 2NT - transfer to clubs, after which responder may bid 3D - this hand shows a club or diamond bust.
To invite game in NT, responder bids 2C (Stayman), then rebids 2NT.