Face Curve
Extract isoparametric curves from a surface in the U or V direction. This is useful for creating trim curves that run along a surface but are not attached to it.
Isoparametric curves can also be used to recreate a given surface with different parameterization. Extract several isoparms and use the Loft tool to create a surface through them. An isoparametric curve extracted from a surface can be used as a snappable location when you need to place an object on such a surface.