Noun
checkback (uncountable)
(bridge) A play of a designated card as a prompt to one's partner to respond with a play indicating the kinds of card he/she holds.
Checkback Stayman 2 ♣ Checkback Stayman (or simply Checkback) is used after a 1NT rebid by opener rather than a 1NT opening. Source: Internet
In five-card major systems, bidding Checkback implies that the responder has five cards in his major, and may have four in the other. Source: Internet
Non promissory Stayman and 2 ♠ checkback by responder Some partnerships play that 2 ♣ Stayman does not absolutely promise a four-card major (non promissory Stayman). Source: Internet
In Acol, if the opening bid was a major, opener can rebid his major after a Checkback inquiry to show that it has five cards rather than four and find 5-3 fits. Source: Internet
New Minor Forcing is an alternative to Checkback Stayman where either 2 ♣ or 2 ♦ can be used as the checkback bid. Source: Internet