2NT major/minor

This opening promise 5-5 in majors or minors. In Norway this convention is only allowed in 1st and 2nd division, and in the national team finals. The reason is that the rules in Norway state that you have to  define at least one suit if the opening bid is weaker then 16 HCP. Personally I love this convention, and think it's great.

3C: Preference
        - Pass: Minors.
        - 3D: Majors.

3D: Preference
        - Pass: Minors.
        - 3H: Majors.

3H : Invitation in heart, asks for 3NT if minors.
        - Pass : Majors and minimum.
        - 3NT : Minors.
        - 4C : Void and majors.
        - 4D : Void and majors.
        - 4H : Majors and maximum.

3S : Invitation in spade, asks for 3NT if minors.
        - Pass : Majors and minimum.
        - 3NT : Minors.
        - 4C : Void and majors.
        - 4D : Void and majors. 
        - 4S : Majors and maximum.

3NT : To play if minors.
        - 4C : Void and majors.
        - 4D : Void and majors.
        - 4H : Majors and no void.

4C : Forcing.
        - 4D : Majors.
        - 4H : Minors and minimum
        - 4S : Minors and maximum.