Kiri Asking Bid

After partner opens one notrump, responder bids 4D to ask partner about the strength of the hand. Opener rebids

4H = minimum notrump hand
4S = average notrump hand
4NT = maximum notrump hand

Responder's next bid is to play (a pass of opener's rebid of 4H or 4S promises at least 6 cards in that suit).