Romex Stayman
In Romex a 2NT opening or re-bid may contain a five card major. Then, responder may want to find the five card major. Responder bids the cheapest club bid and asks.
Responder's hand could
The re-bids by opener to 3C after 2NT is below:
2NT 3C 3NT four-four in the majors (responder passes or bids one under
the intended major of play)
3S five card spade suit (responder passes, or bids 3NT or 4S)
3H four or five card heart suit (responder passes, bids 3NT or 4H, or bids 3S to
ask:
3NT re-bid shows four hearts
4C 2-5-3-3 these show five plus where doubleton is in S
4D 3-5-2-3 the doubleton is in D
4H 3-5-3-2 ascending order
3D none of the above-- could have four spades (responder then re-
bids 3NT to play 3H shows four spades [opener bids 3S or
3NT] 3S shows five spades (and four hearts).