Law360, New York ( September 25, 2015, 10:44 AM EDT) -- In a recent case, Williamson v. Citrix Online, LLC, --- F.3d ---, (Fed. Cir. June 16, 2015) ("Williamson II"), the en banc Federal Circuit overruled several prior opinions and lowered the standard used to determine whether a claim term is subject to Section 112(f).[1] As a result, the original panel reversed itself and found that a patent claim limitation using the word "module," but not the term "means," was subject to Section 112(f), and invalidated the claims. A subsequent panel held that a term in a different patent using the word "mechanism" was subject to Section 112(f), and invalidated the claims. These decisions mark a change in Federal Circuit jurisprudence regarding attempts by patentees to avoid articulating the structures covered by their patents....