2C Non Forcing Stayman

Playing Forcing Stayman (2-Way Stayman), 2C is non-forcing, and 2D is game-forcing. Since 2D is forcing stayman, 2C is used to show a hand under GF strength. 
 
Responses to 2C:

• 2D with no 4 card major. If responder bid a major it shows 5 card and invitational strength.
• 2H with 4 hearts or both 4 hearts and 4 spades. 
• 2S with 4 spades.

Further bids from responder shows invitational strength. This convention is frequently used in the precision system.