Updates the location of the layouts and drawing (DWG) files referenced by the sheets in the current sheet set.
SHEETSET (Command)
Menu:

List of Options
The following options are available.
Status
Current status of the sheet in the sheet set: missing or resolved.
Sheet
Name of each missing sheet in the current sheet set.
Project Drawing
Drawing (DWG) file name in which the sheet is contained in.
Drawing Name
List of all the drawing (DWG) files that are referenced in the sheet set or added to the dialog box using the Add Drawing (+) button.
Drawing Layout
Lists all the layouts in the drawing selected from the Drawing Name list.
Add Drawing (+)
Adds a drawing to the Drawing Name list.
Remove Drawing (-)
Removes a drawing currently not referenced by the sheet set.