Background
Dyfan, LLC sued Target Corporation for infringement of patents covering location-based mobile application technology — systems that deliver notifications or content to a user’s phone based on physical proximity to a store or other location. The patents used claim terms like “code” and “application” to describe software components that performed certain functions.
Target moved for summary judgment, arguing that the claim terms were means-plus-function limitations subject to 35 U.S.C. § 112, paragraph 6. Under that statute, a claim element drafted in purely functional terms — without reciting sufficient structure — is limited to the specific structures disclosed in the specification and their equivalents. Because Dyfan’s specification allegedly disclosed no corresponding structure for the functions at issue, Target argued the claims were indefinite and therefore invalid.
The Northern District of Texas agreed with Target, construing the disputed terms as means-plus-function limitations and finding the claims indefinite. Dyfan appealed, arguing that “code” and “application” are understood in the art to connote definite structure — namely, software — and thus should not be treated as mere functional placeholders requiring disclosure of specific algorithms.
The Court’s Holding
The Federal Circuit reversed. Writing for a unanimous panel, Judge Stoll held that the claim terms “code” and “application” are not subject to means-plus-function treatment because they connote sufficiently definite structure to a person of ordinary skill in the art. The court reaffirmed that § 112 ¶ 6 is invoked only when a claim element uses the word “means” or a substitute that fails to recite sufficiently definite structure. The presumption against means-plus-function treatment — which applies when “means” is not used — can be overcome only if the term has no plain meaning in the art or if the plain meaning fails to connote structure.
The court found that both “code” and “application” are well-understood software terms that a skilled artisan would recognize as referring to a defined category of things: software programs or routines. That understanding is itself structural, even if the terms do not describe hardware or a specific algorithm. The court distinguished earlier decisions that had subjected nonce-word substitutes like “mechanism” or “module” to § 112 ¶ 6 treatment, noting that those terms are purely functional placeholders, while “code” and “application” carry specific meaning in the software field.
Because the terms connote structure, the court reversed the indefiniteness finding and remanded for further claim construction and proceedings consistent with a non-means-plus-function treatment.
Key Takeaways
- Software-specific terms like “code,” “application,” and similar expressions can connote sufficient structure to rebut the means-plus-function presumption, even without reciting a specific algorithm in the claim.
- The § 112 ¶ 6 analysis turns on whether a person of ordinary skill in the art would understand the claim term to denote a class of structures — not whether the term describes hardware or a detailed implementation.
- Generic software terms avoid means-plus-function treatment more readily than nonce words like “module,” “mechanism,” or “unit,” which courts have frequently found to be purely functional placeholders.
- Patent drafters using software-related claim language should consider whether their chosen terms are recognized in the field as structural (like “code” or “app”) versus functional placeholders that risk indefiniteness.
Why It Matters
Software patent claims frequently describe functional capabilities without spelling out detailed algorithms in the claim body itself. The Dyfan decision gives patent owners a meaningful tool to defend against means-plus-function attacks on software claims: if the term used is a recognized software concept rather than a generic functional placeholder, it likely carries sufficient structural meaning to avoid § 112 ¶ 6 treatment and the indefiniteness that can result when no corresponding structure is disclosed in the specification.
This matters practically because means-plus-function construction often leads to claim invalidation when the specification lacks a specific algorithm tied to the claimed function. By holding that “code” and “application” connote structure without requiring algorithm disclosure in the spec, the Federal Circuit provided clearer guidance on where the line falls — giving software patent holders more confidence in claims drafted with standard software terminology while signaling that generic terms like “module” remain risky.