Change what kind of continuity a blend curve maintains with an object its constraint is attached to.
Change the continuity at the picked blend points
Change how curvature continuity is calculated at the picked blend point
You can only change the curvature type of a constraint that is attached to an object, and has G2 or greater continuity.
What is the difference between parametric and geometric curvature?
Parametric curvature: align the curvature to the isoparametric direction of the surface. This type of curvature is especially useful to achieve curvature continuity with the corner of a surface.
Geometric curvature: align the curvature to the intersection of the tangent and the normal direction of the surface.