In X2Y Attenuators, LLC v. ITC,  2013-1340 (Fed. Cir. 2014), the Federal Circuit affirmed the ITC’s construction of U.S. Patent Nos. 7,609,500, 7,916,444, and 8,023,241. Intel argued that the claims should be limited to a sandwich configuration, while X2Y contended that the electrode terms require no construction and should be given their plain and ordinary meanings, and the ITX agreed with Intel.  The Federal Circuit agreed that the “exacting” standard of disavowall was:

The patents’ statements that the presence of a common conductive pathway electrode positioned between paired electromagnetically opposite conductors is “universal to all the embodiments” and is “an essential element among all embodiments or connotations of the invention” constitute clear and unmistakable disavowal of claim scope.

Labeling an element of embodiment “essential” has been found to be a disavowal, and further labelling it “universal to all embodiments” reinforced the conclusion.

One of the patents contained the “essential” disavowal, and the other patents incorporated the “essential” disavowal by reference.  All of the patents incorporated the “universal” disavowal.  The Federal Circuit said that the incorporated patents are “effectively part of the host patents as if they were explicitly contained therein.”  The Federal Circuit conceded that it was possible that a clear and unmistakable disavowal in an incorporated patent is no longer so when placed in the context of the disclosure of the host patent, but that was not the case with the patents in suit.

The lesson of this case is to be careful what its described as “essential” or “universal,” both in the current specification, and in anything incorporated by reference