This variation of regular Stayman is used by the partner of a notrump bidder to locate not only a 4-card major with the notrumper, but also a 5-card major.
I like to use 1NT-3 as Puppet. So, I use it only with enough values for game (10+ points for responder). The Puppet Stayman user is looking for a 5-3 major-suit fit. So, he will either have a 3-car