[patroclo]

NORD
Norby Bocchi
♠A Q 10 9 5 4 2
♥J 9 6 4
♦- - -
♣K 5
SUD
Agus Madala
♠K
♥A 10 4
♦A K Q 5
♣A 9 4 3 2

SUD OVEST NORD EST
1♣ passo 1♥* passo * reply on undercolor for ♠
2♥° ! 2SA passo ° not 3 spade but rever in an hand with D or H ---- 2nt 4 cards in D or H with stop in other color
3♠ passo 4♣ passo Cue bid
4♦ passo 4♥ passo cue bid
5♣passo 5♦ passo cue bid
6♦ passo 7♠ Ω the end

And the flood of notes flooded the enraptured audience .
FornaroBridge

The correct bid

[Cyberyeti]

How does N know he's not facing say Jx, Ax, AKQx, AQxxx ? or is 3♠ a cue rather than suit agreement ?

This one fits very nicely into my system:

1♣(4+)-1♠
2N(GF unbal)-3♠(there is a semi forced 3♣ bid here, so this shows 7+♠, red suit would be 5-5)
4N(KC)-5♦(1/4)
5♥(Q♠?)-6♣(yes +K♣)
7♠(teams, possibly 7N at pairs, big loser when K♣ is stiff)

[Zelandakh]

patroclo, on 2013-October-01, 16:33, said:

And the flood of notes flooded the enraptured audience .

Perhaps they would be equally entralled by:

1♣ = 15+ nat/bal or 18+ any
... - 1♥ = 4+ spades, GF, not 3-suited, if balanced then also 4 hearts)
1♠ = relay, usually 18+
... - 1NT = 4+ hearts
2♣ = relay
... - 3NT = 4 hearts, 7+ spades, side void, min
4♣ = relay
... - 4♦ = diamond void
4♥ = relay
... - 5♣ = 3 controls (A=2, K=1)

followed by either

5♦ = relay
... - 5♠ = spade control, no heart control
5NT = relay
... - 6♥ = club control, 2 of top 3 spades, no ♥Q
7♠

or simply

5NT = Q ask
... - 6♣ = no ♣Q
6♠ = non-forcing ♠Q ask
... - 7♣ = yes
7♠

Note that a Pairs gamble on 7NT would be a better bet here than in Cyberyeti's auction as North will have an 8th spade if the club king is stiff.

Incidentally, the notes in the OP must surely be wrong if Responder's 2NT bid showed a 4 card red suit and a stopper in the other. That would be a strange description for a hand with a diamond void. It would also be miraculous for Opener to agree spades at this point facing what could presumably be only a 4 card suit. Any chance of our getting the correct descriptions so that we can be just as enraptured as the kibbers? I suspect a line of the bidding has been missed out.

Edit: I was thinking about this auction a little more in a bathroom break and I think it is actually best to go to 7NT on either sequence. If partner had a singleton ♣K they would not have included it within the control count and will also have the ♥K. In the first auction this is explicitly ruled out but it actually makes no difference in practise. So there is always a side entry to North's spades after clearing ♠K.