'nurs' <name(char9)|!> ['DEFINE' <u.deg> <v.deg> <u.npnt> -> <v.npnt> <u.nknt> <v.nknt>]| ['CONTROL' <u.index> <v.index> <pnt> <weight>]| ['KNOT' <U>|<V> <index> <value>]| ['END']This keyword is used to define a nurbs shape. Surfaces can use nurbs to define the interior geometry. But this functionallity is not used by the mesher so far. It is used only for rendering purposes. CAD-interfaces might use this functionality.