Modified Inverted Minors

A directly support of a minor suit denies 4 cards in either Major suit and shows:

2 of the minor - 4+card support, 10-12 HCP (exactly invitational) or 16+ HCP (slam interest):
After 2 m opener and responder shows values in the other suits to look for a
NT-contract. 2 NT or 3 m from both player are sign off. A direct jump to 3
NT shows good 14 HCP and a jump in a new suit = SPLI (gameforcing).

3 of the minor-1 step (i.e, 1C - 2NT or 1D - 3C): 4+ card support, 4-7 HCP (preemptiv) or 12-16 HCP (game forcing).
Opener asks with a very good hand with a bid in a new suit for a stopper or sign off with 3 of the minor. Therafter responder bid o n with the better hand. A new suit shows values.

3 m: 4+m 7-9 HCP (more unbalanced than 1 NT response, which also may include 4 cards in a minor).
Opener shows with a good hand values in spite of playing 3

3 of any other suit: 4+m shortness (Singleton or void) gameforcing

In a system with a weak NT (12-14 HCP) you can use the jump to the other minor to show a hand with 8-9 HCP. In this case 2 m = 10+ HCP unlimited and 3 m = 4-7 HCP (no game vs a strong NT like 15-18 HCP).

I would like to thank Claus GŁnther,, for submitting this convention.