[gnasher]

I'm surprised at all the comments saying, essentially, that 5♦ doesn't exist. Do we really have so much space that we can afford to just not use this sequence at all? Obviously 5♦ should be something fairly specific, and should imply that there's no need to investigate major-suit controls. Applying fast-arrival principles, I would expect something like x x KQxxx QJ10xxx, which makes a slam if everything in opener's hand is working, but not otherwise.

I'm even more puzzled by the comments that imply that 5♦ does exist, but it cancels the slam-try message. If 3♦ showed a slam try, responder has a slam try. You can't have slam interest on the first round of the bidding, hear some good news, and then not have slam interest any more.

This assumes, of course, that the original poster's statement that "he's looking for slam" was an agreement rather than merely an opinion. It appears that this assumption wouldn't apply to this partnership.

[kenrexford]

Partner bid 2♠, defined as a slam try, and then 5♦. Presumably he had other tools available, but elected to not use them. Knowing those tools would allow us to decipher what 5♦ shows. Obviously, it seems somewhat important to know what 5♦ shows when deciding whether to bid 6♦ or not, but apparently that is only relevant to a few of us. Everyone else uses general principles, whatever that means.

If I had to guess what makes sense, I would assume the very strange meaning that I would assign to this sequence. 5♣ as a WEAK slam try with short hearts, 5♦ as a WEAK slam try with short spades. "WEAK" meaning not two with the Queen, such that partner is missing one of the key cards we want for slam. "WEAK" probably also means something else bad, whatever that is. Maybe only four trumps, maybe not great in the other minor. Whatever.