The U.S. Court of Appeals for the Federal Circuit offered more guidance on willful patent infringement in a recently revised panel ruling in i4i Limited Partnership v. Microsoft Corp.

The court’s ruling Wednesday replaced its Dec. 22, 2009, ruling in the closely watched case. Like its predecessor, the Wednesday ruling upheld a lower court’s $290 million patent judgment against Microsoft and ruled that Microsoft must stop selling an infringing version of Microsoft Word 2007 as of Jan. 11. The patent at issue, owned by Canadian software company i4i, concerns “a method for processing and storing information about the structure of electronic documents.”