Point on Curve

In this case the point is defined by an intersection between a curve and a plane:

The plane can be a principal plane or any of the other plane types. The principal plane element is described in section PrincipalPlane/ByPrincipalPlane Element (however, the "ObjId" attribute is not applicable here). The Plane element is documented in section Plane/ByPlane Element. The curve can be a stored curve or a complete curve definition:

Curve will be explained later in the document, see section Seam Element.