Words to Avoid in U.S. Patent Prosecution

Michael Kondoudis
September 25, 2008 — 2,018 views  
Become a Bronze Member for monthly eNewsletter, articles, and white papers.

I often see terms used in responses to Office Actions that needlessly create estoppel, complicate litigation, and thus lessen the value of a resulting patent. I submit that patent prosecutors should always carefully consider the language that they select, and should very carefully (re)consider any use of the following terms/phrases in particular.

The Invention/Embodiments of the Invention

The focus of examination is on the claims of an application. It is axiomatic then that an Applicant's focus should also be on the claims. Accordingly, patentability arguments should always focus on why claims, not "the invention," patentably define over the cited art. (See for example Section 714.04 of the Manual of Patent Examining Procedure). Statements/characterizations about the invention are inapposite, are often ignored by examiners who are focusing on the claims, and can result in significant, needless argument estoppel.

Take the example of the recent Federal Circuit Decision in Pods, Inc. v. Porta Stor et al. (Fed. Cir. 2006-1504 decided April 27, 2007). In that case, the patentee, in attempting to traverse a rejection of a claim through argument, characterized the invention as allowing "the carrier frame to be elevated and positioned at a rectangular-shaped frame with respect to the container, the vehicle and the ground." This assertion, the Court reasoned, supported the construction of a separate claim that recited only "a carrier frame" to mean a four-sided frame.

As the Pods case illustrates, with a blanket statement about "the invention," a prosecutor can risk "grafting" limitations onto each and every claim in the application, even claims that were previously allowed or are later presented, since each claim defines "the invention." Further, even if this estoppel is successfully avoided in later litigation, it will surely cause a complication that could have been avoided. Still further, these explanations tend to gain very little ground during examination, and very often provoke a form paragraph from the examiner explaining that the asserted features are not in the claims.

For these reasons, using the example of the Pods case, IF one entertains presenting a discussion about an invention, a better practice might be the following approach:

Independent claim 1 recites a carrier frame including right and left longitudinal elements [and] having front and rear transverse elements . . .

By at least these claim features, a carrier frame can be elevated and positioned at a rectangular-shaped frame with respect to a container, a vehicle and the ground. As a result, increased utility and durability can be realized.

I submit that the latter approach, focused on claim features instead of "the invention," more safely presents an advantage by more likely limiting any argument estoppel that may result to only this claim 1.

A final note, ALWAYS be mindful of Southwall Techs., Inc. v. Cardinal IG Co., 54 F.3d 1570 (Fed. Cir. 1995) in which the Federal Circuit held that clear assertions made during prosecution, whether or not those assertions were even necessary to secure allowance, may create estoppel.


The word "reference" is a term of art that tends to imply status as prior art, since litigators and, more importantly, federal courts very commonly describe art cited against claims as "prior art" or a "prior art reference." When given the option, therefore, I prefer not to use the term "reference" when referring to cited art. I submit that a patent prosecutor, as an advocate for an applicant, can be equally as accurate and persuasive during prosecution by using the alternative terms "citation" or "cited art," while at the same time producing a prosecution history avoids any negative implications that may be associated with the term "reference." Remember, there is no rule that any item cited against the claims must be called a reference, so why not select the least disadvantageous term?


It is my belief that a prosecution history that avoids use of the term "limitation" when referring to a claim feature is of greater value in litigation than one in which a prosecutor has used this term. Based on my experience, for some reason, judges and juries seem to attach increased significance to the word "limitation" in legal arguments; perhaps it is because the very word "limitation" has a narrowing connotation that makes it easier for them to adopt a narrower claim construction. For this reason, when I have the option, I prefer not to use the term "limitation," regardless of how the Examiner characterizes claim elements. Instead, I submit that a better choice is to use the term "feature," a term that is rather benign and equally as accurate as "limitation." So, for example, I might write:

The Office Action contends that the widget of the Smith patent meets the aforementioned feature of independent claim 1.

* * * * *

For at least these reasons, the Smith patent cannot teach at least the feature of independent claim 1.

Applicant's Admitted Prior Art (AAPA)

Many applications, not incorrectly or improperly, discuss known art when explaining the need for the solution provided by a claimed invention. Typically, these discussions, located in the background section of the application, are fair game to apply against the claims of the application. And, when cited by an Examiner, these discussions are commonly characterized as "Applicant's Admitted Prior Art (AAPA)."

Even if this characterization by the Examiner is not incorrect, a practitioner, as an advocate for an applicant, can produce a far more valuable prosecution history by using a more benign characterization of any such discussion. Like the term "limitation," based on my experience, for some reason, judges and juries seem to attach increased significance to the word "admitted." So, when possible, I usually characterize art discussed in an application as "conventional." Thus, for example, I may write:

Claim 1 stands rejected under 35 U.S.C. 102 as anticipated by the widget discussed in the background section of Applicant's disclosure (hereinafter "the conventional widget").

* * * * *

The Office Action contends that the conventional widget includes the aforementioned feature of independent claim 1.

The Examiner

There are two schools of thought about referring to "the Examiner" in communications to the patent office. One says it is a better practice to not make an Applicant's arguments personal by personally challenging an Examiner's positions. The other school says it is acceptable. I subscribe to the former school because I do not believe that a patentability argument will be any more effective when it is made personal. In fact, if there is any effect of making a response personal, I submit that it would most likely be detrimental. So, when I have the option, I choose to use alternative sentence/argument constructions that do not require reference to "the Examiner," such as "the Office Action" or "the Office." So, for example, I may write:

The Office Action rejects claim 1 as anticipated by ...


The Office Action states ...


The Office contends ...

Of course, every rule has an exception. When thanking the Examiner or when an Examiner has taken the time to suggest a solution to a rejection or objection, I submit that it can only be advantageous to acknowledge this effort. In doing so, I may write:

The Office Action objected to claim 5 on formal grounds. In response, Applicant has amended this claim in the manner kindly suggested by the Examiner.


The Office Action objected to paragraph [0032] of the Specification for an informality. In response, Applicant has amended this paragraph to improve its idiomatic English form in view of the Examiner's comments.

Prior Art

It is my belief that use of the phrase "prior art" in prosecution yields a less valuable prosecution history than one which avoids use of this phrase. The primary reason is that the phrase "prior art" is a phrase of art that arguably constitutes an admission of the status of asserted art as prior art, undermining any later argument to the contrary. Thus, when the option is available, I use the alternative phrases "cited art" or "asserted art." This phrase is equally as accurate and persuasive, but without the potential liabilities associated with the use of the phrase "prior art." As is the case with the term "reference," there is no rule that asserted art must be called "prior art," so why not select the least disadvantageous alternative term?

About the Author

Michael E. Kondoudis is a DC patent attorney and the principal of The Law Office of Michael E. Kondoudis, PC, a Washington DC patent law firm. Mike is also the author of Patentably Defined, a leading U.S. patent prosecution blog.

Michael Kondoudis