The “Hakim Statement” – Avoiding Estoppel During Prosecution

Parallel, divisional, or continuation applications can be strategically filed to pursue additional or broader claims. Yet, claim scope across related applications can be constrained by the judicially created doctrine of file-wrapper estoppel (also referred to as prosecution history estoppel). 

The doctrine is rooted in equitable principles of fair notice and public reliance on official records. It is intended to limit a patent owner from recapturing subject matter that has been clearly and unmistakably surrendered during prosecution of a patent application.[1] The presumption is that an applicant who narrows claim scope to overcome prior-art rejections (e.g., by way of an amendment) cannot later reclaim the surrendered territory. To rebut the presumption, an applicant must create a prosecution record that is “sufficiently clear” to notify the Patent Office (USPTO) that prior disclaimers are being rescinded and that the previously excluded scope is at issue.[2]

In Hakim,[3] the underlying dispute involved a drinking-cup closure design. In an earlier-filed parent application, the applicant had amended the claims to include a slit-type diaphragm structure to overcome cited prior art. In the continuation application, the applicant sought broader claims that no longer included the slit limitation.  The Patent Office allowed the broader claims, but in a subsequent infringement litigation, the district court—and ultimately the Federal Circuit—held the continuation claims were subject to the estoppel created in the earlier application:

 “[A]n applicant cannot recapture claim scope that was surrendered or disclaimed … Although a disclaimer made during prosecution can be rescinded, permitting recapture of the disclaimed scope, the prosecution history must be sufficiently clear to inform the examiner that the previous disclaimer, and the prior art that it was made to avoid, may need to be re-visited.”[4]

To mitigate the risk of estoppel, an option is to include in the prosecution record of an application (and any continuations or divisionals therefrom) a formal statement expressly rescinding and retracting any and all earlier narrowing assertions, characterizations, or disclaimers. The formal retraction statement may, and optionally should, be filed in both:

• The Remarks section of a Transmittal, an Information Disclosure Statement, or a Preliminary Amendment filed at the time of filing a continuation application.[5]

• Comments on Statement of Reasons for Allowance upon receipt of a Notice of Allowance in any application, particularly if filing a continuation application is anticipated.[6]

A patent practitioner may opt to file the retraction statement in the remarks section of a voluntary information disclosure statement filed with a patent application,[7] whether or not a related application is anticipated at the time of filing, to make sure the retraction is on record.  Best practice would be to include or repeat the retraction at the time of filing the later-filed related application.

Example Broad Retraction:

Any admissions, amendments, characterizations, or other assertions made, previously or going forward, in this application or any related patent applications or patents (including any continuation or continuation-in-part applications or any parent, sibling, or child applications) with respect to any cited reference or art, prior or otherwise, should not be construed as a disclaimer of any subject matter supported by the disclosure made in the present application. 

Applicant hereby rescinds and retracts any disclaimers or admissions whatsoever made in this or any related applications or patents during prosecution or otherwise.  Applicant also respectfully submits that any prior art considered in this or any related patent applications or patents may need to be re-visited and reconsidered by the Office and the Examiner as to relevance and applicability to the subject matter disclosed and claimed herein. 

[Any Examiner statements as to allowance or otherwise (in Application Serial No. xx/xxx,xxx) were not prepared by Applicant and only contain the Examiner’s possible positions in one or more reasons for allowability.  Thus, any interpretation with respect to the Examiner’s statements or reasons for allowance should not be imputed to the Applicant.][8]

In addition to the above, a practitioner may want to provide a specific retraction in a later-filed related application by specifically identifying a prior amendment or argument of concern that is being rescinded. A specific retraction may be critical when the applicant’s arguments narrowly characterize the claimed invention to overcome the prior art.  Best practice includes addressing the prior assertion or disclaimer early during the prosecution of the later-filed related application.

Example Specific Retraction:

To the extent any amendments, characterizations, or other assertions previously made in [Application No. xx/xxx,xxx] with respect to [specifically identify the limiting statement or claim element] could be construed as a disclaimer of any subject matter supported by the present disclosure, Applicant hereby rescinds and retracts such disclaimer. Applicant further requests that the examiner re-evaluate the art previously considered in light of the presently pending claims.

The practitioner would also want to explain why the earlier narrowing amendment or argument was not intrinsic to overcoming the prior art. This extra step would be important because vague or implied rescissions may be deemed ineffective.  Following the above approach should allow an applicant to successfully rebut the presumption of estoppel. However, ultimately it will be up to the examiner, and possibly an appeal panel or a court, to determine whether the rescission was sufficiently clear.

It is noteworthy that while most “prosecution-stage” disclaimers may be retractable through explicit Hakim statements, “specification-based” disclaimers (e.g., language that limits the claimed subject matter in the disclosure itself) generally cannot be retracted.[9] Furthermore, broadening claim scope in a reissue application is distinguishable from the above discussion and is subject to specific recapture rules.  Generally speaking, in a reissue, if a proposed reissue claim is broader, in one respect, then the claim should be materially narrowed, in other respects, to avoid recapture.[10]

Hakim underscores that prosecution history estoppel in one application extends to the entire patent family, unless affirmatively and clearly retracted. This imposes an obligation on applicants to make any recission explicit by filing a written retraction on the record. Failure to do so risks a narrowed claim construction during a future dispute or litigation, even if the Patent Office allows broader claims in a continuation application. 

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