Puppet Stayman.

Although there are several versions, here are the four most common:

2N - 3C - ?

3D = 1 or 2 4-card majors
3H = 5 card Hearts
3S = 5 card Spades
3N = denial

Responder continues: 2N-3C; 3D- 3H SHOWS spades
4C Minor suit checkback
4D CLUBS, slammish
4H DIAMONDS, slammish
4S GOOD quantitative.
4N Bad quantitative raise.

2N-3C; 3D-3H; 3S DENIES spades, SHOWS hearts.

b) 2N - 3C -
3D = denial
3H = 5 card Hearts
3S = 5 card Spades
3NT= unspecified 5 card minor

c) Same as (a), but with the following continuations

Over 3D show 4 card suits up the line.
Over 3NT, 4C is an enquiry with 4D showing diamonds
5C clubs and min
4H,S is a cue bid with clubs and not min.

d) Romex Puppet Stayman

2N-3C; 3D none of the below:
3H 4 or 5 hearts, not 4 spades.
3S 5 spades. => 4H agrees spades, 4m NAT.
3N 4-4 majors. => 4D/H are transfers.

2N-3C; 3D- 3H asks for 4 spades
3S 5S 4H (to plug the hole)
. 4H 6S 4H (!).

2N-3C; 3H-3S asks for length of suit.