This tool works on a selection set of splined polylines. It finds the vertices that were inserted by spline fitting and changes (commits) them to regular vertices. This is useful in situations where other routines may be ignoring the vertices, and especially useful for extruding polylines. The extrude command will not accept a polyline containing spline fit vertices, returning unable to extrude this object.
Keyboard Command: PlnSplCom
It is important to note that after this operation, you will not be able to use the PEDIT Decurve option to remove the spline vertices.