2NT opening or NT style
2N-3C Pupet Stayman
Minor Suit Stayman after 2NT
Minor Suit Transfers after 2NT
Minor Suit Slam Try after 2NT
Niemeijer
2N-3N shows 5 Spades + 4 Hearts. Non forcing.
R E F E R E N C E S
Bridgebum
BridgeHands
Wikipedia