One No Trump (3)

Dealer South, All Vulnerable

South	West	North	East
Bidding
1NT	No	2♣⁽¹⁾	No
2♦⁽²⁾	No	2NT⁽³⁾	No
No⁽⁴⁾	No

Explanations

⁽¹⁾ North's good intermediates mean he is just about worth a mild invitation.

⁽²⁾ South denies a 4-card Major.

⁽³⁾ 2NT now shows interest in 3NT only if South is maximum.

⁽⁴⁾ South has a fairly average mid-range hand, and so passes.