You can view and manipulate DGN underlays and change paths to underlays from the External References palette.
You can view file-specific information about the DGN underlays that are attached to a drawing. You can also load and unload underlays and perform other operations from the External References palette.
You can change the file path to a referenced DGN file or search for a DGN underlay when it is reported as not found.
Drawing files that have DGN underlay attachments can be plotted or published as DGN files and DGN underlays are tracked and managed when you eTransmit. Furthermore, DGN underlays are not lost when you save to previous drawing formats.
The Reference Manager application allows you to view file references that are attached to a DWG file and to edit the paths of the attachments.