I play a raise of the minor by opener after a 2 over 1 as showing either extra values or extra playing strength. On that assumption, I would bid 4C showing a club control while denying a heart control which can be shown by bidding 3H and pulling 3NT to 4m.

The form of scoring is important. My suggested rebid is easy in teams but definitely harder in pairs where consideration would need to be given to bidding 3NT. Also, if playing minorwood or kickback where one can still get out to 4NT, I would take the more aggressive slam exploration bid of 4C.

I think chances for slam in diamonds are reasonable so I would bid 4c as a cue bid. If partner bids 4d I would suspect he has no heart control and would bid 4s which partner can pass as he will know I don’t have a heart control. If he bids 4h over 4d I will continue with 4s and then respect a sign off in 5d.

I play that after 3D, 3 level bids are natural. so 3h would show a heart stopper looking for 3nt, 3s typically shows 3-card spade support and would probably just muddy the waters for slam investigation in diamonds.

3S

This means that I am (at least initially) looking for the best game and that hearts might be a problem. I don't necessarily need a spade support this good, but I must have clubs well stopped if I am planning to pass 3NT (which I am). It would look silly to be anywhere else opposite something like -

    Kxxxx
    AQ
    KJxx
    xx

With better spades and weaker hearts, partner might suggest 4S, and with no heart stopper, he will probably revert to 4D (which I should be allowed to pass). Over 4D, I intend to bid 4S - suggesting a good doubleton.

Partner will know that my honours are outside hearts, so should be excited with a singleton heart.

In standard methods you are stuck for a bid that is entirely truthful. Standard bridge says that in a potential NT probe situation if there are two (or three suits) unbid, then we show a stopper and if there is one suit unbid we ask for a stopper. So here 3H would mean in general “I have a heart stopper – can you bid NT with clubs stopped”. So we cannot really do that. That limits our options to 3S ()which would be forcing with 3 card support (AQ looks nearly like three cards) or just punting 3NT and praying partner can look after hearts. Of the two lies I prefer the former so 3S would be my choice without further agreement.

However, ther was a great article written by Michael Rosenberg a couple of years ago. I think it was called “The trouble with diamonds” and this is a case in point. For instance suppose you have an auction 1D – 1H / 3D now how does responder proceed? He recommended that when we have these auctions or the one that you had, we switch from standard methods to asking methods. So 1D – 1H / 3D – 3S would ask for a spade stopper for NT. An on your auction 3H would ask for a heart stopper for NT. This is a much more sensible agreemenr. If it is the club suit that is involved, we do not need to switch as after 1C – 1M / 3C or similar auctions we have the space to show where we live but not with the diamond suit.

A good question and an area worthy of discussion in any partnership.