When using the normal stuff, your partner can still ask about a King by bidding that suit. Here 6
♦ would ask to bid 7
♥ with
♦K. The problem with this hand is not if you have or have not the
♦K, but if you
also have the
♦J! And I don't see any immediate sollution to that problem unless starting a full relay system...
You can clearly see the problem if partner needs
♠K. Here it's clear he needs it to be in grand, but if you had answered 6
♦ instead of 6
♣, then you still might miss the grand, since you don't know if partner was searching for
♣K or
♠K.
A sollution is to play Kickback: use 4
♠ as RKC
♥ (when there's no confusion possible) instead of 4NT. Then you can ask for Kings with 5
♠ and you can show what King(s) you have immediatly:
5NT = 0/3 Kings
6m = that King or the 2 other Kings
6
♥ =
♠K or both minor Kings
Usually it should be clear what you have, and otherwise you can still use the next bid to ask if partner has 2 (or 3) Kings.
"It may be rude to leave to go to the bathroom, but it's downright stupid to sit there and piss yourself" - blackshoe