Target was sued by Dyfan LLC for infringement of patents describing improved systems for delivering messages to users based on their locations. The claims of the patents recited “code” or an “application,” when executed, configured to perform certain functions. Other claims recited a “system” with “code.” Target convinced a district court that the terms should be treated as “means-plus-function” limitations under 35 U.S.C. § 112, ¶ 6 (or, equivalently 35 U.S.C. ¶ 112(f)). The Federal Circuit reversed, finding that the claims did not recite “means-plus-function” limitations.

The Federal Circuit began by summarizing the law pertaining to the analysis, noting a rebuttable presumption that a claim limitation is not drafted in means-plus-function format in the absence of the term “means.” The presumption can be overcome if a challenger demonstrates that the claim term “fails to recite sufficiently definite structure.” “[T]he essential inquiry is not merely the presence or absence of the word ‘means,’ but whether the words of the claim are understood by persons of ordinary skill in the art to have a sufficiently definite meaning as the name for structure.”

The Federal Circuit noted that claim terms “need not connote a single, specific structure,” and may instead “describe a class of structures” and still recite “sufficiently definite structure” to not invoke § 112 ¶ 6. And, in cases where it is clear that a claim term itself connotes some structure to a person of ordinary skill in the art, “the presumption that § 112, ¶ 6 does not apply is determinative” in the absence of “more compelling evidence of the understanding of one of ordinary skill in the art.”

Importantly in this case, the Federal Circuit noted that evidence, from the patent and elsewhere, can be used to determine whether the disputed claim language recites sufficiently definite structure or was intended to invoke § 112 ¶ 6, stating that the Court often looks to “extrinsic evidence when determining whether a disputed limitation would have connoted structure to a person of ordinary skill.”

In this regard, Target’s own expert testified that the term “application” would have been commonly understood to mean a “computer program intended to provide some service to a user,” and that developers could have, at the relevant time, selected existing “off-the-shelf software” to perform specific services and functions. Additionally, the expert testified that persons of ordinary skill would have understood that the word “code,” when coupled with language describing its operation, here connotes structure, explaining that a person of ordinary skill would understand that “code” is “a bunch of software instructions” and a person of ordinary skill would have known that the claimed function of displaying information could be implemented using “off-the-shelf” code or applications.

In view of that evidence, the Federal Circuit felt it was demonstrated that the claim limitations do not recite “purely functional language” and, instead, demonstrated that the “code”/“application” limitations here connote a class of structures to a person of ordinary skill, avoiding treatment as “means-plus-function” recitations. The “system” recitation also avoided “means-plus-function” treatment. The Federal Circuit agreed that, in a vacuum, the term “system” may well be a nonce term like “means.” But it held that the claim language itself defined the “system” to include specified structure, pointing to limitations recited in the claims providing are structural components of the “system,” including the “code” it had found to be structural.