Curve-Curve – Select two curves to create a surface between them. When each curve is selected, a match point will appear showing the connection point between each curve.  If the match points are not at the desired location, click the curve again to deselect and click the curve near the opposite end to change its match point location. An arrow will appear indicating the direction of the curve, click the arrow to reverse the curves direction so that both curves are pointed the same direction.

Curve-Point – Select a Curve and a Point to define the Surface.

Curve-Face – Select a Curve, an Edge for the Direction, and a surface to extend to. In addition, user can select the taper angle for the generated surface.

Normal To Face - Select a Curve and a surface that will define the surface to be generated normal to the surface from the curve path