Roman Keycard Blackwood (RKC0314):

4NT= ace-asking.

King of trump suit counts as an ace.

If there is no explicit trump suit, the last bid suit is assumed.

    5§=0 or 3 aces

    5¨=1 or 4 aces

    5©=2 aces, no queen of trumps

    5ª=2 aces with queen of trumps

        next non-trump bid= asking for number of kings

          5NT=asking for specific kings

          after kings next non-trump suit asks for queen of trumps 

          other bids - grand slam invitation seeking queen or dubleton

§ ¨ © ª