Prosecution History Disclaimer after Top Brand v. Cozy Comfort

Episode 1 of Prosecuting Design Patents for Enforcement, a series on what design patent litigation teaches about prosecution.

This episode discusses how the Federal Circuit applied prosecution history disclaimer to a design patent in Top Brand v. Cozy Comfort, 143 F.4th 1349 (Fed. Cir. 2025), and what that means for how you draft and argue responses to office actions so the patent holds its scope when it is later enforced. It also covers the related doctrine of prosecution history estoppel.

Scope can be surrendered by argument alone

A design patent is more valuable when prosecution arguments win allowance without unnecessarily narrowing the design’s enforceable scope. The drawings define the claim, but so may the title, the written description, the line conventions, and the prosecution history. In July 2025, the Federal Circuit confirmed that a design patent applicant can surrender scope through argument alone.

This episode addresses argument-based surrender of claim scope, prosecution history disclaimer, and the related doctrine of estoppel. Other doctrines may limit design patent scope for different reasons.

What happened in Top Brand

The design in Top Brand LLC v. Cozy Comfort Company LLC was an oversized hooded overgarment with a front pocket. The examiner rejected the claim under 35 U.S.C. § 102 over the White reference.

In response, the applicant distinguished the prior art feature by feature, using annotated side-by-side figures that called out each difference: the shape and width of the marsupial pocket, its position relative to the armholes, and the slope of the bottom hem. The response then said of the pocket, “for this alone, the claimed design is allowable.”

One difference, presented as sufficient by itself.

The Federal Circuit held that these representations clearly and unmistakably surrendered claim scope. Because the accused products shared the pocket width, pocket shape, pocket placement, and hem direction that Cozy Comfort had used to distinguish White, those similarities could not support infringement. On that record, no other non-surrendered similarities supported a finding of infringement.

The related doctrine of estoppel

Nike, Inc. v. Skechers U.S.A., Inc., 2019 U.S. Dist. LEXIS 239086 (C.D. Cal., Mar. 28, 2019), illustrates prosecution history estoppel in this setting. In inter partes review proceedings, Nike distinguished its designs by relying on discrete arrays of converging and truncated lines of substantially the same width. The same characterization appeared across multiple filings, against multiple references, supported by annotated images.

The district court applied prosecution history estoppel, holding that these repeated patentability-focused statements clearly and unmistakably placed certain line arrangements outside the scope of the asserted designs.

Statements made in PTAB proceedings may be considered in determining the scope of an asserted design and in any resulting surrender.

Where the line actually falls

The difference is not simply whether the applicant discussed features. It is whether the prosecution record, read as a whole, clearly tells the public that a feature or visual relationship falls outside the claimed design.

Overall impression framing can reduce the risk of unnecessary narrowing, but merely reciting the words “overall visual impression” is not enough. You have to actually argue the design as a whole.

Note also that Top Brand involved anticipation and Design Ideas involved obviousness. Anticipation arguments can carry particular risk, because they often require a direct one-reference comparison under a standard that, like infringement, turns on the ordinary observer’s visual impression. That does not make obviousness arguments risk-free. A prosecution statement can narrow scope whenever the record clearly and unmistakably conveys a surrender.

Five ways to reduce the risk

First, frame arguments around the overall visual impression. Present individual features as context, not as standalone requirements for patentability.

Second, avoid absolute language. Phrases like “for this alone,” “essential,” and “critical” are the ones that get quoted back to you.

Third, be careful with geometric precision. A statement that the design requires a constant half-inch radius may later be invoked as a narrowing representation.

Fourth, use annotated figures carefully. They can clarify an overall impression, but repeated call-outs and feature-by-feature measurements make a later narrowing argument easier.

Fifth, treat an examiner interview as potentially record-forming. Where a written summary is required or advisable, make sure it captures the discussion accurately and frames any distinctions in terms of the design as a whole.

An argument can be strong enough to overcome a rejection without being narrow enough to unnecessarily limit the claim.

The examiner reads the response during prosecution. A court may read it years later, asking what the record told the public.