By Ambar Nayate and Al VredeveldShumaker & Sieffert, P.A.

The broadest reasonable interpretation (BRI) standard is a time-honored part of patent prosecution, but BRI has received renewed scrutiny recently due to its critical role in post-grant review proceedings.  In particular, broad interpretations of claim language may make it easier for a challenger in a post-grant proceeding to show that a reference discloses one or more features of a claim.  Accordingly, practitioners should have a solid understanding of what BRI is, how to draft patent applications in view of BRI, and how to conduct patent prosecution and post-grant proceedings in view of BRI.

The Manual of Patent Examination and Procedure (MPEP) § 2111 states, “During patent examination, the pending claims must be given their broadest reasonable interpretation consistent with the specification.”  Additionally, 37 CFR § 42.100 specifies that during an inter partes review, “A claim in an unexpired patent that will not expire before a final written decision is issued shall be given its broadest reasonable construction in light of the specification of the patent in which it appears.”  The authority of the U.S. Patent and Trademark Office (USPTO) to promulgate 37 CFR ​§ 42.100 was affirmed by the U.S. Supreme Court in Cuozzo Speed Technologies, LLC v. Lee, 136 S. Ct. 890 (2016).

MPEP § 2111 expresses the policy reasons for the BRI standard during prosecution: “Because applicant has the opportunity to amend the claims during prosecution, giving a claim its broadest reasonable interpretation will reduce the possibility that the claim, once issued, will be interpreted more broadly than is justified.  In re Yamamoto, 740 F.2d 1569, 1571 (Fed. Cir. 1984).”  The policy reasons supporting BRI can help practitioners to understand issues surrounding claim interpretation that may arise during patent application drafting and prosecuting, as compared to issues that arise under the Phillips standard applied during litigation.  For example, the Patent Office may force the Applicant to narrow claim terms to ensure that the terms are not interpreted more broadly than justified in litigation.  If the Phillips standard were used, then such narrowing of claims may not be needed.  Conversely, a court may construe a claim term during litigation too narrowly, allowing an infringer to undertake easy design-arounds or continue with activity that would otherwise constitute infringing activities but for the narrow interpretation.  The burden falls on the patent prosecutors to find the right balance in crafting claims that are sufficiently narrow to be granted by the patent office, but broad enough to encompass infringers.

The Phillips standard differs from BRI.  Under the Phillips standard, claim terms are interpreted based on intrinsic and extrinsic evidence and may therefore be read more narrowly.  As the name suggests, under BRI, the claim terms are not given their actual interpretation, but rather, their broadest interpretation.  Under Phillips, courts attempt to determine the actual interpretation based on intrinsic and extrinsic evidence, which can be narrower than the broadest interpretation.  For example, a Federal Circuit panel, in PPC Broadband, Inc. v. Corning Optical Comm’s, RF, LLC, 815 F.3d 734 (Fed. Cir. 2016) (hereinafter, “PPC Broadband 1”), provided analysis as to how BRI and Phillips constructions can lead to different results.  Indeed, the panel admitted that “in this case, the claim construction standard is outcome determinative.[1]” 

The issue in PPC Broadband 1 revolved around the term “continuity member.”  In PPC Broadband 1, a Federal Circuit panel stated that “Under Phillips, we would hold that the correct construction of the term ‘continuity member’ requires, as PPC Broadband argues, a continuous or consistent connection.[2]”  The Federal Circuit panel continued that “While the ordinary meaning of ‘continuity’ and ‘continuous’ often refers to something that is uninterrupted in time, these terms can also refer to something that is uninterrupted in space.”[3]  In the end, the Federal Circuit panel concluded that “the Board’s construction–‘that the continuity member need only make contact with the coupler/nut and the post to establish an electrical connection there,’ without requiring consistent or continuous contact–is the broadest reasonable construction.”[4]  Therefore, whether BRI or Phillips construction is applied can affect the interpretation of claim terms.  Practitioners should be aware of different results, especially given the opinion of the Federal Circuit that “[t]his case hinges on the claim construction standard applied–a scenario likely to arise with frequency.”[5]

Because the BRI standard is a critical aspect of post-grant proceedings, there have been a number of recent Federal Circuit decisions addressing BRI.  Several such decisions have circumscribed the BRI standard by describing limits to the interpretive framework.  Understanding these decisions can also help practitioners during drafting and prosecuting.

For example, in PPC Broadband, Inc. v. Corning Optical Comm’ns, 815 F.3d 747 (Fed. Cir. 2016) (hereinafter, “PPC Broadband 2”), a panel of the Federal Circuit reviewed a decision of the Patent Trials and Appeals Board (PTAB) regarding a patent claim for which validity hinged on the meaning of the word “around.”  In applying the BRI standard with respect to the word “around,” the PTAB “arrived at its construction by referencing the dictionaries cited by the parties and simply selecting the broadest definition therein.”  The PTAB had noted that one of the definitions of “around” in the AMERICAN HERITAGE COLLEGE DICTIONARY is “in the immediate vicinity of; near: She lives around Norfolk.”  Other definitions of the word “around” in the AMERICAN HERITAGE COLLEGE DICTIONARY include “1. On all sides of: trees around the field. 2. In such a position as to encircle or surround: a sash around the waist.”

In PPC Broadband 2, the court cautioned that “while such an approach may result in the broadest definition, it does not necessarily result in the broadest reasonable definition in light of the specification” (emphasis added).  The court further stated, “The Board’s approach in this case fails to account for how the claims themselves and the specification inform the ordinarily skilled artisan as to precisely which ordinary definition the patentee was using.”  In making this determination, the court noted that “’around’ occurs seven times in the specification. Every one of these occurrences relates to encircling or surrounding.”  Thus, the consistent use of a term according to only one definition tends to support the argument that a different definition of the same term is not a reasonable interpretation of the term.

In the case of In re Smith Int’l, 871 F.3d 1375 (Fed. Cir. 2017), a panel of the Federal Circuit provided further guidance on how to determine whether an interpretation of a claim term is reasonable under the BRI standard.  In this case, the PTAB stated that “nothing in the specification would disallow the examiner’s interpretation, rendering it ‘reasonable.’”[6]  Judge Lourie responded in In re Smith that “the correct inquiry is not whether the specification proscribes or precludes some broad reading of the claim term adopted by the examiner.  And it is not simply an interpretation that is not inconsistent with the specification.  It is an interpretation that corresponds with what and how the inventor describes his invention in the specification, i.e., an interpretation that is ‘consistent with the specification’”[7] (emphasis added).

Claim 28 and its dependent claims in the Smith patent[8] were directed to “[a]n expandable downhole tool for use in drilling assembly positioned within a wellbore having an original diameter borehole and an enlarged diameter borehole.”  The term at issue in claim 28 was “a body,” which the Board and the Examiner interpreted as “a broad term that may encompass other components such as ‘mandrel’ and ‘cam sleeve,’ reasoning that only the term ‘body’ is recited in the claims without further limiting features and that the specification neither defines the term ‘body’ nor prohibits the examiner’s broad reading of it.[9]”  The Board arrived at its conclusion based on an assertion that the “patentee here did not act as a lexicographer, and that the specification neither defines nor precludes the examiner’s reading of the term ‘body’.”[10]

The court responded that “following such logic, any description short of an express definition or disclaimer in the specification would result in an adoption of a broadest possible interpretation of a claim term, irrespective of repeated and consistent descriptions in the specification that indicate otherwise.[11]

In the end, the court found in In re Smith that the Board’s and Examiner’s interpretation was unreasonable and inconsistent with the specification, for the Smith patent “separately identifies and describes various components of its drilling tool, such as the ‘body,’ ‘moveable arms,’ ‘mandrel,’ ‘piston,’ and ‘drive ring,’ which do not support the Board’s broad reading of the claim term ‘body.’”[12]  The Federal Circuit panel also noted that the “[prior art reference] descriptions of its own drilling tool distinguish and separately describe its ‘body,’ ‘mandrel,’ and ‘cam sleeve.’”[13]

The patentee successfully argued for its preferred interpretation on several bases that practitioners should note.  Smith had consistently described “body” as an “outer housing,” and separate from “moveable arms,” “mandrel,” “piston,” and “drive ring.”  Therefore, reading terms like “moveable arms,” “mandrel,” “piston,” and “drive ring” as part of the “body” would be inconsistent with the specification.  Importantly, if the term “body” were interpreted to include “moveable arms,” “mandrel,” “piston,” and “drive ring,” then the term “downhole tool” used in the specification would be meaningless.  Furthermore, the cited prior art references also used body the same way in which Smith used the term body.

Practitioners should use terms consistently to avoid the possibility that a term can be given different meanings that are broader than what the inventor intended.  Indeed, by using terms consistently, two terms meant to be different will be interpreted as being different, instead of being conflated.  This was one reason why Smith was able to show that the term “body” was interpreted in an unreasonable way (e.g., “body” could not be interpreted in a way to include “tool” when the body was consistently described as being part of and not the entire tool).  Indeed, in PPC Broadband 2, 815 F.3d at 752, explained that “there is a canon of construction: the general assumption is that different terms have different meanings.”

Practitioners should also consider using terms in manners consistent with established terms in the art.  The Patent Office can, when needed, use a term in the prior art to help establish the reasonableness of an interpretation.  However, the Patent Office cannot mangle the term in the prior art to mean other than its definition or use in the prior art to show the reasonableness of an interpretation.  Here, the usage of body in the prior art was effective in showing that the Patent Office’s interpretation was unreasonable.

Owens Corning v. Fast Felt Corporation (Fed. Cir. 2017) is another case from which practitioners can glean valuable practice points.  Fast Felt sued Owens Corning for infringing U.S. Patent No. 8,137,757 (‘757 patent).  Owens Corning instituted IPR alleging that the claims were obvious.  Owens Corning was unable to convince the PTAB and appealed to the Federal Circuit.

Claim 1 of the ‘757 patent recites “depositing tab material onto the surface of said roofing or building cover material at a plurality of nail tabs from a lamination roll, said tab material bonding to the surface of said roofing or building cover material by pressure between said roll and said surface.”  In the IPR, the Board limited “roofing or building cover material” to material that either has been or would be coated or saturated with asphalt or asphalt mix.

The court in Owens Corning noted, “It is true that the preferred embodiments in the ‘757 patent focus on roofing materials that are or will be coated or saturated with asphalt or asphalt mix,”[14] but “[t]he claims are plainly not so limited,”[15] for “they are not even limited to ‘roofing materials,’ as they all expressly include ‘building cover material’ as well as roofing material.”[16]  The patentee, Fast Felt, sought an interpretation of “roofing or building cover material” to be that of the preferred embodiment, but the Federal Circuit found no reason to limit the claims in this way. 

Practitioners should unquestionably draft independent claims to broadly cover the invention.  However, practitioners should use dependent claims to meaningfully narrow the broad concepts.  Practitioners should use dependent claims to further define the broad terms to specify the more precise meaning of the terms.  Where preferred embodiments are known, dependent claims directed to those preferred embodiments can be useful.  Fast Felt, the patentee in Owens Corning, presumably concluded that even with the narrow interpretation of the claim, it would have prevailed in showing infringement.  Having claims specifically drawn to the preferred embodiment may have preserved a dependent claim with which to prove infringement even if the independent claim is found to be obvious.

When drafting, practitioners should ensure that terms are used consistently and well-developed.  During prosecution, practitioners should consider whether the Patent Office is interpreting the terms in a reasonable manner that is consistent with the specification.  Where unreasonable interpretations are advanced by the Patent Office, practitioners should consider different ways to rebut the interpretation.  However, in addressing claim interpretation during prosecution, practitioners should be careful to not create estoppel by arguing for a claim interpretation that excludes reasonably foreseeable infringement and negatively impacts the patent rights.


[1] PPC Broadband 1 at 815 F.3d at 741.

[2] Id.

[3] Id. at 741.

[4] Id. at 743.

[5] Id. at 741, emphasis added.

[6] In re Smith, 871 F.3d at 1383.

[7] Id. at 1382-1383.

[8] U.S. Patent No. 6,732,817 (‘817 patent).

[9] In re Smith at page 9.

[10] Id. at page 13.

[11] Id., emphasis in original.

[12] In re Smith at page 14.

[13] Id.

[14] Owens Corning at page 7.

[15] Id. at pages 7 and 8.

[16] Id. at page 8.