~Minor Suit Stayman and Minor Suit Transfers

With a long, weak minor, a weak 5-5 in the minors, or with a strong 5/5 in the minors, bid 2S over partner’s 1NT opener. After the 2S bid, opener responds with
~2NT with longer diamonds than clubs or, if equal in length, better diamonds.
~3C with longer or better clubs than diamonds or that both minors are equal.

Rebids over 2NT (better fit in diamonds than clubs):
~3C: to play. Responder will have a weak one-suiter in clubs.
~3D: to play. Responder will have a weak one-suiter in diamonds or a weak 5-5 in the minors.
~3H: shows both minors, a singleton or void in hearts, and game values or better.
~3S: shows both minors, a singleton or void in spades, and game values or better.
~3NT: shows 5-4 in the minors and low doubletons in the majors, not forcing.
~4NT is natural and invitational with 2-2-5-4 or 2-2-4-5 shape.

Rebids over 3C (better fit in clubs than diamonds or an equal fit):
~Pass: shows a weak one-suiter in clubs or a weak 5-5 in the minors.
~ 3D: is to play. Responder will have a weak one-suiter in diamonds.
~3H: shows both minors, a singleton or void in hearts, and game values or better.
~3S: shows both minors, a singleton or void in spades, and game values or better.
~3NT: shows 5-4 in the minors and low doubletons in the majors, not forcing.
~4NT is natural and invitational with 2-2-5-4 or 2-2-4-5 shape.

Implies that with game values and 5-4 in the minors and 3-1 in the majors, you just bid 3NT instead of 2S.  After 1NT-2S, a NT bid by responder following opener’s 2NT or 3C bid shows exactly 4-5-2-2 or 5-4-2-2 shape.

This system works when responder has
~a weak hand (0-7 HCP) and 6+ cards in either minor
~a weak hand (0-7 HCP) and 5/5 shape in the minors
~4-5-2-2 or 5-4-2-2 shape (the long suits are the minors) and game strength
~5/5 shape in the minors with slam interest. Responder gets to show shape, which major is the splinter, and slam interest—all below the 3NT level.