What are people playing here, when an opponent preempts and partner overcalls 3NT? I get the impression that the majority method is 4♣ range enquiry, 4♦ flint - in which case, how do you continue over the range enquiry - for example, what does this show? (3♦) 3NT (Pass) 4♣ (Pass)4♦ (Pass) 4♥?