To print this article, all you need is to be registered or login on Mondaq.com. Functional claim language—which defines an invention by what it does rather than what it is—can be a powerful claim drafting tool when used carefully. For example, functional language may be advantageous for computer-implemented inventions that are characterized with reference to logical components instead of physical hardware. 35 U.S.C. § 112(f) (formerly § 112¶ 6) expressly permits the use of functional claiming and is traditionally invoked by the phrase "means for" followed by a functional modifier. But even when the term "means" is not used, other terms that are not understood