You can view and manipulate underlays and change paths to underlays in the External References palette.
You can view file-specific information about the underlays that are attached to a drawing in the External References palette. You can also load and unload underlays and perform other operations there.
You can change the file path to a referenced DWF, DWFx, PDF, or DGN file or search for an underlay when it is reported as not found.
When you eTransmit a file, DWF, DWFx, PDF, and DGN underlays are tracked and managed.
With the Reference Manager, you can view DWF, DWFx, PDF, and DGN underlays that are attached to a DWG file and edit the paths of the attachments.