Applied-For Patent Claim Indefiniteness Based on PTO Role, Not Court Standard

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By Tony Dutra  

May 6 --The Patent and Trademark Office's review for definiteness is governed by its role “in ensuring that patent claims are clear and unambiguous,” and not subject to the standards used by courts on post-issuance claims, the U.S. Court of Appeals for the Federal Circuit ruled May 6 .  

The court acknowledged that the Supreme Court is currently reviewing the “insolubly ambiguous” standard for indefiniteness, under 35 U.S.C. §112(b), it has defined and developed over the last 13 years, in Nautilus, Inc. v. Biosig Instruments, Inc., No. 13-369 (U.S., argued April 28, 2014).

However, it said that the applicant's failure here to adequately respond to the PTO's “well-grounded” rejections for lack of patent claim clarity is determinative, “without regard to the proper formulation of the judicially-applied indefiniteness standard that may be appropriate for post-issuance assessment of indefiniteness.”

A concurrence supplemented the per curiam opinion of the court with a direct response to the applicant's argument that the pre-issuance and post-issuance standards should be aligned.

Coin Change Holder Patent Application

Thomas G. Packard filed a patent application (No. 12/004,324) on a coin change holder. No attorney or patent agent is listed as prosecuting his application.

After an initial rejection, Packard cancelled the original claims and substituted claims 28 through 37. The examiner rejected the replacement claims as well, and the Patent Trial and Appeal Board affirmed.

The PTO's rejection for indefiniteness cited the Manual of Patent Examining Procedure §2173.05(3), which begins: “A claim is indefinite when it contains words or phrases whose meaning is unclear.” This paragraph gives examples of clear and unclear terms but otherwise offers no further standard for determining word or phrase clarity.

Packard appealed, contending that the PTO must apply the “insolubly ambiguous” indefiniteness standard of the Federal Circuit.

Applicant Responsible for Rejection Response

In a per curiam opinion, with Judges Kathleen M. O'Malley, S. Jay Plager and Richard G. Taranto on the panel, the Federal Circuit laid out the process by which the PTO can reject a claim for indefiniteness:

We conclude that, when the USPTO has initially issued a well-grounded rejection that identifies ways in which language in a claim is ambiguous, vague, incoherent, opaque, or otherwise unclear in describing and defining the claimed invention, and thereafter the applicant fails to provide a satisfactory response, the USPTO can properly reject the claim as failing to meet the statutory requirements of §112(b).  


The court restated that process in a subsequent passage that also said a “well-grounded rejection” for lack of clarity is one “based on the perspective of one of ordinary skill in the art in view of the entire written description and developing prosecution history.”

The applicant can respond with a clarifying modification to the claim or with “persuasive explanation” for why the rejection is in error, the court said, but Packard did neither here.

The court characterized the examiner's “ample grounds” for indefiniteness as indicating that Packard wrote claims that were “imprecise or confusing, sometimes not even understandable, considering them in light of the written description.” The concurrence identified four questionable terms in an appendix. For example, one claim limitation referred to a “front top side.”

The court thus affirmed the rejection for indefiniteness “under the MPEP standard properly applied by the USPTO, the standard which we have here approved.”


Plager's concurring opinion was twice the length of the court's opinion.

“I write separately because I am of the view that a petitioner to this court seeking reversal of a decision is entitled to an explanation of why the arguments on which he relied for his appeal did not prevail,” he said. “I also believe that the significant issues raised by Mr. Packard deserve to be addressed directly.”

Plager identified “policy options” related to the analysis for indefiniteness, with varying weights given to the presumptive validity of a patent and the importance of its function of giving notice to the public of the metes and bounds of the invention. Accordingly, he said that the Federal Circuit has a “complex of standards,” not just one, depending on the policy option applying to different circumstances.

The PTO, Plager said, is driven by the notice requirement and thus applies a “lower threshold” test “that is uniquely applicable to the pre-issuance situation.” He therefore had to agree with Packard that the PTO's standard “differs materially” from the court's complex of standards.

However, Plager then provided a detailed argument--with a host of references to articles generally on post-issuance concerns over ambiguous patent claims--for why the PTO's role should be allowed to apply this lower threshold test.

In conclusion, he said, “there are no legal obstacles to the USPTO's proposed interpretation, and there are compelling reasons why, as a policy matter, this court should not preclude or otherwise interfere with the USPTO carrying out its full responsibilities under the Patent Act.”

Louis W. Tompros of Wilmer Cutler Pickering Hale and Dorr LLP, Boston, represented Packard. PTO Solicitor Nathan K. Kelley represented the office.


To contact the reporter on this story: Tony Dutra in Washington at

To contact the editor responsible for this story: Naresh Sritharan at

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