Checkback occurs in sequence: 1m–1M-1NT–2♣ and guarantees the five and 11+ HCP or four and 14+ HCP.

Responder bids:

• • 2♦ -no support 12- HCP;

  • 2 in partner's suit - support 12-  HCP,;

  • 2 in the second major - support 13-14 HCP;

  • 2BA - 13-14 HCP no support.

After a suit or NT intervention, checkback convention is off.