Spectra Precision FAST Survey Reference Manual - Manual (Page 326)

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CL to Polyline (CL2P):
This command draws a POLYLINE entity using the data from a centerline file. You can practice this command by
selecting the file Demo.cl, provided with the program. It draws in the current layer set within the View pulldown, Layer
command.
Convert Polylines to 2D (C2D):
Pick any 3D polyline or contour polyline at uniform elevation and convert it to 2D (elevations of vertices are set to 0).
Edit - Polyline (EDP):
Remove vertices, insert vertices and update (alter) the coordinates of any vertex. For example, if we pick the centerline
that was used above, we obtain the edit dialog, with options to add or remove segments or arcs, edit curve information,
etc. Saving changes updates the graphics on the screen.