A cue bid made when there has been no direct suit agreement. For example in the auction 1NT-Pass-3♠-Pass-4♦, the 4♦ bid is an advance cue bid. You would normally rebid either 3NT (with a doubleton spade) or 4♠, but you can make this cue bid to imply that you have a good spade fit, maximum values for the 1NT opening and that you hold the ♦A. The 4♦ bid cannot be a natural bid, showing a long string of diamonds, since the 1NT opening showed a balanced hand. Here is a possible hand for the sequence:
