This occurs with partnerships playing weak NoTump. The problem occurs when opponents' double partner's weak notrump opening. Typically, responder passses with a weak hand, and opener redoubles for a rescue bid if the second opps passes. To allow responder more accurately to find a suit to run.
1NT-DBL- 2X to play almost always a five card suit 3X premptive RDBL they have made a mistake, I want to play 1NT**, if they run you can double with appropriate hands PASS expresses doubt (the opponents always laugh at this point) Responder denies a five card suit. Opener should bid a five card suit. With no five card suit opener redoubles with a 4-3-3-3 minimum or any 4-4-3-2 hand and we bid four card suits up the line until we find a 4-3 fit, or pass with nothing better to do)i 2NT shows an unbalanced invitational or better hand and opener rebids the cheapest suit in which he would reject a game try, but this has never come up).