Determines whether object snaps are available for geometry in DWF, DWFx, PDF, and DGN underlays.
UOSNAP overrides the DWFOSNAP, PDFOSNAP, and DGNOSNAP settings. Conversely, you can override the UOSNAP settings for DWF, DWFx, PDF, and DGN underlays by entering values for DWFOSNAP, PDFOSNAP, or DGNOSNAP system variables.