Occurs after opening a 1NT partner with a hand of 5431.

Responder bids 3M having singleton or void in major, exactly 3 cards in the OM, at least 54 in minors and 9+ HCP (if 1NT 15-17 HCP).

Examples:

W      N      E      S      

        P      1N     P

3♥*1   P      3N     P

P      P

*1 5431 after 1NT

W      N      E      S      

        P      1N     P

3♠*1   P      3N     P

P      P

*1 5431 after 1NT

Default setting is off.