Functional language may also be employed to limit the claims without using the means-plus-function format. See, e.g., K-2 Corp. v. Salomon S.A., 191 F.3d 1356, 1363 (Fed. Cir. 1999). Unlike means-plus-function claim language that applies only to purely functional limitations,… functional claiming often involves the recitation of some structure followed by its function.