2/3♠ after partner NT style - hand without majors (The Minor Suit Stayman conventions has several variations).

The 2/3♠ response to 1NT/2NT is artificial, denies a 4-card major and showing: 

• minor suit signoff to play with minors 5+5+;

• interest in game or slam with;

Opener's rebid after 2♠ with 15-16* HCP:

• 2NT - denies a 4-card minor;

  • • 3♥/3♠ - splinter;

    • 4♥ - crosswood on default ♣;

    • 4♠ - crosswood on default ♦;

    • others - natural,

• 3♣ - 4+♣;

• 3♦ - 4+♦.

Opener's rebid after 2♠ with 17* HCP:

• 3♥/3♠ - stoper, usually no four minor but allowed 4333;

• 3NT - denies a 4-card minor, stoppers in majors;

• 4♣ - 4+♣;

• 4♦ - 4+♦.

Opener's rebid after 3♠:

• 3NT - denies a 4-card minor;

• 4♣ - 4+♣;

• 4♦ - 4+♦.

*Depending on the NT range.

After suit or NT intervention, the convention is off.