In Comcast Cable Communications, LLC v. Promptu Systems Corp., 1 the Federal Circuit held that the plain meaning of the claim phrase “command function” was limited to functions that command an action to be taken. The meaning of this claim phrase turned out to be a focal point, and Comcast lost its invalidity challenge to the claims as a result of this interpretation. Comcast filed a petition for inter partes review (IPR) of U.S. Patent No. 7,260,538 (the ’538 patent) on the grounds that the contested claims would have been obvious in view of two prior art references—U.S. Patent No. 6,513,063 (Julia) or U.S. Patent No. 7,013,283 (Murdock)—alone or in combination with U.S. Patent No. 5,774,859 (Houser). The Patent Trial and Appeal Board (Board) instituted review and issued a final-written decision in each IPR. The Board rejected Comcast’s interpretation of the claim language “command function” as unreasonably broad. Since Comcast’s contentions were based on its rejected claim interpretation, the Board held that Comcast failed to prove obviousness, including motivation to combine Houser with either prior art reference.