Conditions for the cue bid:

• explicitly agreed suit;

• a bid below game.

Additionally:

• the first cue bid in the opposite side's suit is singleton or void;

• cue bid in the partner's suit cannot be a singleton (without ace and king) or void;

• if the partner's first cue bid misses a suit, the bid to the next suit indicates the skipped suit stopper (artificial cue bid);

• if opponents showed length then 2NT or 3NT are a cue bid of the suit shown;

• the cue bid immediately below the tip in the agreed suit is surplus;

• redouble is surplus or real cue bid if partner's length is above 1.

Using artificial cue bid:

W N E S

1H P 2D P

2H P 3H P

4C P ?

• 4D - cue bid, a spades stopper;

• 4H - denies a spades stopper.