Yamaha MONTAGE 6 Supplementary Manual page 19

Polarity (Curve Polarity)
Determines the Curve Polarity of the Curve type set in "Curve Type."
Settings: Uni, Bi
Uni:
Unipolar changes only in a positive direction or in a negative direction from a base parameter value according to the Curve shape.
Bi:
Bipolar changes in both of positive and negative directions from a base parameter value.
Ratio (Curve Ratio)
Determines the Curve Ratio.
Settings:
-64 – +63
MONTAGE Supplementary Manual
19