5♥ or 5♠ bid slam proposal. After the opponents' overcall
When one of the opponents has overcalled, a jump to level 5 in the major is a slam proposal. It's asking for a stopper in the opponent's suit.
Partner's response :
- With 2 low cards in the opponent's suit : Pass
- With a 2nd rank control (singleton or K) : 6 in the agreed major
- With a 1st rank control (void or Ace) : the partner names the Il nomme la couleur adverse (5 ♠ ou 5 ♥) : the partner will then decide to go to small or grand slam