There was a query about this hand from Wednesday, so the answer is going to the whole list.
Hand #6 from November 28, 2018 at Adventures in Bridge.
North: ♠AQ107 ♥10652 ♦— ♣KQ1097
South: ♠K3 ♥AKQJ ♦Q1096 ♣A64
South opens 1♦. With a void in partner's suit, I would not count the North hand as an opening hand, so would merely bid 1♥ (up the line with majors). However with a card or two in diamonds, I would bid 2♣ (game-force and shape showing) before either 4-card major. After North bids 1♥, South should jump to 4♥. South has 19 HCP and a 5-loser hand. Partner rates to cover two of your losers, so go to game.
Even with a diamond void, North's hand is excellent opposite a partner who is showing the equivalent of 19 HCP. However, it is NOT correct to bid Key Card Blackwood with a void. North should settle for bidding 4♠. This MUST be a cue bid (first or second round control of spades) because you are going past game. Partner can take over from there. South also should NOT bid Key Card because she has two quick losers in a side suit (diamonds). Her proper call is 5♣ (showing slam interest and a club control), and by inference a concern about diamonds, having avoid Key Card, and very good hearts—or she would not be looking for slam. Now North can bid 5♦, showing a diamond control and South will bid 6♥.
Ironically, if N/S mis-bid and South ends up bidding 6NT based on power, they will make 12 tricks on any lead except a diamond, and a diamond lead is HIGHLY unlikely from the West holding when South has opened 1♦. The sane contract, however, is 6♥, making seven.