[Hanoi5]

Playing 2/1 what would the meaning of the following action be:

1♥ 1NT
2NT ???
3NT ???

[awm]

1♥ - 1NT (forcing)
2NT (natural invite, typically 17-18 or something like this)

If 1NT bidder now names a suit, without agreement I would assume this is natural and forcing to game. Even "bad" hands with 5-6 hcp and a six-card suit probably want to be in 3NT on this sequence, so it is more useful to be able to make a slam try rather than offer to play in 3-suit. Note that this is forcing to game now that opener showed 17-18; it presumably was not forcing to game initially.

It is popular to play transfers here though, so 3♣=♦ and so forth; this does help with the rare "I want to get out" hand while still letting you have slam tries.

I would assume that:

1♥ - 1NT(F)
2NT - 3m (forcing natural)
3NT would be intending to play there, not a good hand for slam in the minor.

Pulling this to 4m would be quite rare (I guess a real distributional freak).

1♥ - 1NT(F)
2NT - 3♥ (natural)
3NT would again suggest a contract, pulling to 4♥ just says "I'd rather play in the suit"

If opener likes slam in the suit responder named he can cuebid of course.

[peachy]

For me, 1H-1NT-2NT by opener shows the "jump to 2NT" hand = balanced/semibalanced 18-19. All bids by responder are forcing; if he does not want to go to game, he will pass 2NT.