Maritha Pottenger

When partner jumps in a suit and you bid a new suit at the 4 level or above, that is assumed to be a cue bid, showing control and exploring for slam. For example, 1 by partner; 1 by opponent; negative double by you; 3 by partner; 4 by you. That is assumed to be a control bid in diamonds, supporting hearts. If you had long, good diamonds, you should have been bidding them in the first place over the 1 overcall.

Ditto, when partner bids over a preempt (showing a good hand and usually a 6-card or longer suit), a new suit by you is assumed to be a control bid, looking for slam. For example, 3 by opponent, 3 by partner, 4 or 4 by you. You are not fighting it out this high on a misfit hand. You are showing a control in a minor suit, having agreed to support partner's spades.