Amid failing revenues and internal cost cutting, Autodesk asked its external law firm Wilson Sonsini Goodrich & Rosati to revive its appeal to the US Patent and Trademark Office over Autodesk's fantasy that in the USA a file extension can be registered as a trademark; it can't.
During seven years of attempts by Autodesk to turn .dwg into DWG, the USPTO told Autodesk -- repeatedly -- that it is not possible, because .dwg (a) is a file extension, not a name, and (b) even as a file extension, it is not unique. I can imagine the sighs of trademark judges Zervas, Wellington, and Greenbaum as John Slafsky (representing Autodesk) last Wednesday came before the three to tell them that Autodesk is right and that everyone else is wrong.
To avoid further unwanted lawsuits, Open Design Alliance and other firms have been using .dwg instead of DWG in their literature: Autodesk can't sue you for writing about a file extension. I suppose the multi-billion-dollar CAD software giant still harbours a flicker of hope, still not quite extinguished, that its external law firm can use the USPTO's extensive appeals system to bypass the Office's own rulings and those made by the American justice system. It'll fail.