I recall mentioning to my partner in the not too distant past we should play Lebensohl opposite a reverse, so I thought her direct diamond support showed a better than minimum hand, and me with a four loser and source of tricks in clubs went slam investigating. When she bid 4♦ after my cue, I wanted to sign off in 4NT, but was worried she would interpret that as Blackwood (it shouldn't be), so I settled for 5♦. Once I started cue bidding, we have lost the board, because 3NT only makes nine tricks, and 5♦ is one down.
There is a way to use something else to ask for key cards when a minor suit has been agreed, something like minorwood? It wouldn't have mattered here, but is it something like bidding the other minor at the four level or bidding hearts when a minor has been agreed asks for key cards?
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IMO, North-South were unlucky. We play Lebensohl over reverses. IMO North has a reverse but South's 3♦ is a slight overbid. In context, South has useful ♦s and a reasonable hand but the singleton ♣ is a worry, especially as North could have what some call a technical reverse i.e. the ♦s need not be a real suit
e.g. ♠ K x ♥ x ♦ A K x ♣ A K J x x x x
In hindsight, perhaps North should try 3NT over 3♦