Barrette Outdoor Living, Inc. v. Fortress Iron, Lp, Fortress Fence Products, LLC

United States Court of Appeals
for the Federal Circuit
______________________
BARRETTE OUTDOOR LIVING, INC.,
Plaintiff-Appellant
v.
FORTRESS IRON, LP, FORTRESS FENCE
PRODUCTS, LLC,
Defendants-Cross-Appellants
______________________
2024-1231, 2024-1359
______________________
Appeals from the United States District Court for the
Northern District of Texas in No. 3:21-cv-02008-E, Judge
Ada Elene Brown.
______________________
Decided: October 17, 2025
______________________
TYLER ROBERT M ARANDOLA, Duane Morris LLP, Phila-
delphia, PA, argued for plaintiff-appellant. Also repre-
sented by D AVID JON WOLFSOHN .
PAUL V. STORM, Foley & Lardner LLP, Dallas, TX, ar-
gued for defendants-cross-appellants. Also represented by
JOHN JACOB M AY.
______________________
Before M OORE, Chief Judge, LINN and CUNNINGHAM,
Circuit Judges.
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BARRETTE OUTDOOR LIVING , INC. v. FORTRESS IRON, LP 2
LINN , Circuit Judge.
Barrette Outdoor Living, Inc. (“Barrette”) appeals from
an entry of judgment of non-infringement by the U.S. Dis-
trict Court for the Northern District of Texas based on Bar-
rette’s stipulation that it could not prove—under the
district court’s construction of “boss,” “projection,” and
other related terms as fastener-less and integral—that
products sold by Fortress Iron, LP and Fortress Fence
Products, LLC (collectively, “Defendants”) infringe claims
1–7 of U.S. Patent No. 8,413,332 (“’332 patent”); claims 1,
2, 3, and 5–12 of U.S. Patent No. 8,413,965 (“’965 patent”);
claims 1, 2, 3, and 5–20 of U.S. Patent No. 9,551,164 (“’164
patent”); and claims 1, 2, and 4–13 of U.S. Patent
No. 9,963,905 (“’905 patent”). See Barrette Outdoor Living,
Inc. v. Fortress Iron, LP, No. 3:21-cv-02008-E, 2023 WL
8610184, at *1 (N.D. Tex. Nov. 14, 2023) (“Final Judg-
ment”) (citing J. App’x 145–51). Defendants cross-appeal
from a final judgment holding the asserted claims are not
indefinite. Id.
Because the district court correctly construed the
claims as limited to integral bosses and projections, we af-
firm the judgment of non-infringement. Because the dis-
trict court correctly determined that the asserted patents’
specification and prosecution histories would allow a
skilled artisan to ascertain the claims’ scope with reasona-
ble certainty, we affirm the judgment of no invalidity based
on indefiniteness.
BACKGROUND
I
Barrette owns the asserted patents, which share a com-
mon specification and parent application that issued as
U.S. Patent No. 9,151,075 (the “’075 patent”). Barrette Out-
door Living, Inc. v. Fortress Iron, LP, No. 3:21-cv-2008-E,
2023 WL 5503030, at *7 (N.D. Tex. Aug. 25, 2023) (“Mark-
man Order”).
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BARRETTE OUTDOOR LIVING , INC. v. FORTRESS IRON, LP 3
The patents’ common specification describes a fencing
assembly featuring pivoting, sliding connectors that con-
nect pickets to rails. This sliding pivotal connection pur-
portedly allows the pickets to rack (i.e., pivot with respect
to the rail) to a greater extent than prior art fencing assem-
blies. The connectors “can include small projections (e.g.,
bosses) that extend from one surface thereof and engage
holes (e.g., recesses) formed in the pickets” and “this pro-
vides a fastener-less but still pivotal connection.” See, e.g.,
’965 patent col. 1 ll. 42–46. Moreover, the Detailed De-
scription describes prior art assemblies that “incorporate
screws S and/or bolts to rotatably couple pickets P to rails
R” and notes that “[s]uch couplings are time consuming to
install,” whereas “the present invention utilizes a sliding
pivotal connection between the pickets 20 and the rails 30
that is very easy and fast to install.” Id. at col. 5 ll. 55–66.
Claim 1 of the ’965 patent recites:
1. A fencing/railing assembly adapted to be posi-
tioned between a pair of posts and mounted
thereto, the assembly comprising:
a plurality of vertical pickets, each picket compris-
ing an upper end and a lower end opposite the
upper end, each picket further comprising at
least one pivot hole formed therein between the
upper and lower ends;
a plurality of elongate rails extending transverse to
the pickets, each rail having a first end and a
second end opposite the first end, and having at
least an upper wall and a side wall, each rail fur-
ther comprising a plurality of picket openings
formed therein and spaced longitudinally along
the upper wall thereof, wherein the plurality of
pickets are each individually received in a re-
spective one of the plurality of picket openings;
and
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BARRETTE OUTDOOR LIVING , INC. v. FORTRESS IRON, LP 4
one or more connectors for connecting the plurality
of pickets to the plurality of rails, each connector
comprising an elongate strip with opposing first
and second sides, wherein at least one boss ex-
tends from the first side of the strip, and a slid-
ing surface is formed on the second side;
wherein each at least one boss of a respective con-
nector is inserted into the at least one pivot hole
in a respective one of the plurality of pickets
such that the connector is pivotably connected to
the picket, and
wherein the sliding surface of the respective con-
nector is slidably engaged with an inner surface
of the side wall of a respective one of the plural-
ity of rails;
whereby pivoting the upper end of the respective
picket towards the first end of the respective rail
causes the respective connector to slide along the
inner surface of the side wall of the respective
rail towards the second end of the respective rail,
and vice versa, in such a manner that a pivotal
range of the plurality of pickets relative to the
plurality of rails is at least about 20 degrees in
each direction.
Id. at claim 1.
While the claims of the ’965, ’332, and ’164 patents re-
cite bosses, the claims of the ’905 patent, instead, recite
connectors featuring “at least one projection.” See, e.g.,
’905 patent at claim 1.
II
During the prosecution of the ’075 patent, but after the
’332 and ’965 patents had already issued, the examiner re-
jected claim 1 because, among other reasons, U.S. Patent
Application Publication No. 2009/0065755 (“Sherstad”)
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BARRETTE OUTDOOR LIVING , INC. v. FORTRESS IRON, LP 5
discloses the claimed connector. In response, Barrette ar-
gued that Sherstad discloses “a conventional pivot hole and
pivot pin assembly,” and not “a slip-together connection
with the claimed integral boss.” J. App’x 499 (emphasis
added). Barrette further contended that “there is no dis-
closure . . . to substitute in the pivot-pin assembly of Sher-
stad,” and, even if there were, “the resulting structure
would not include the claimed integral boss and as such
would not provide the same slip-together functionality.”
Id. at 499–500 (emphasis added). The examiner neverthe-
less maintained the rejection, explaining that Sherstad’s
boss “can either be integral with the clip 130, or be a sepa-
rate pin member.” J. App’x 515.
Barrette subsequently cancelled the then-pending
claims and filed new claims that mirrored the claim lan-
guage of the already issued ’965 patent. After the appli-
cant’s amendments, the examiner allowed the claims and
the ’075 patent issued.
III
Barrette brought this lawsuit in district court alleging
that Defendants’ Athens Residential fences (“accused prod-
ucts”) infringed the asserted claims.
During Markman, Barrette argued that the terms
“boss,” “nub,” and “projection” should be construed accord-
ing to their plain and ordinary meaning; specifically, “Bar-
rette urge[d] that a ‘boss’ in the context of the Patents-in-
Suit is simply ‘a projection or protrusion.’”
J. App’x 1650–53. Defendants argued that the term “boss”
should be construed as limited to integral, fastener-less
structures. Markman Order, 2023 WL 5503030, at *6.
Defendants argued that the “sliding” terms (e.g., “slid-
ably engaged,” “slidably connected,” and “sliding surface”)
should be held indefinite, in part, because the specification
provides no guidance as to the minimum amount of force
needed to effectuate sliding or whether any mechanical
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BARRETTE OUTDOOR LIVING , INC. v. FORTRESS IRON, LP 6
obstructions are acceptable. J. App’x 1686–88. Defend-
ants also contended that the “causes” terms (e.g., “pivot-
ing . . . causes the respective connector to slide”) should be
held indefinite because Barrette disclaimed the ordinary
meaning of “causes” and the specification does not provide
sufficient guidance as to the scope of the term.
J. App’x 1688–89.
The district court noted that “the parties agree that the
terms ‘boss,’ ‘projection,’ and ‘nub’ are used interchangea-
bly.” Markman Order, 2023 WL 5503030, at *7 (citing ECF
No. 48 pg.29, also available at J. App’x 1651). Further, the
district court held that “the intrinsic evidence indicates
that the terms ‘boss,’ ‘projection,’ and ‘nub’ should be con-
strued the same.” Id. Concluding that the specification
identified fastener-less connections as advantageous and
disparaged prior art systems requiring fasteners, the dis-
trict court construed the “boss” terms as fastener-less. Id.
at *10–11. The district court also held that the prosecution
history of the ’075 patent further limited the “boss” terms
to integral structures by distinguishing the “claimed inte-
gral bosses” from the “conventional pivot hole and pivot pin
assembly” disclosed in Sherstad. Id. at *7–10.
The district court concluded that the “sliding” terms
are not indefinite. Id. at *21. The district court noted that
the specification contains examples of “slidably engaged”
and “slidably connected” structures in Figures 7C and 7D
and contrasts such connections with those present in prior
art systems that merely allowed for pivotal rotation. Id.
Further, the district court, concluding that Defendants’ in-
definiteness position relied “on the incorrect premise that
the ‘sliding’ terms must be described with calculations or
formulas to be definite,” rejected their contention that the
specification needed to provide guidance as to certain “fun-
damental parameters” to render the claims definite. Id.
at *23. The district court concluded the “sliding” terms,
when read in view of the specification, would inform a
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BARRETTE OUTDOOR LIVING , INC. v. FORTRESS IRON, LP 7
skilled artisan of the scope of the claims with reasonable
certainty. Id. at *21.
The district court also rejected Defendants’ position
that the “causes” terms are indefinite, concluding that the
prosecution history did not disclaim the ordinary meaning
of “causes” and a skilled artisan, reading the specification,
would ascertain the scope of the terms with reasonable cer-
tainty. Id. at *24.
After Markman, Barrette stipulated that it could not
prove infringement under the district court’s construction
of the “boss” terms because the accused products use non-
integral fasteners. Defendants stipulated that they could
not prove the claims invalid for indefiniteness under the
district court’s construction. The district court subse-
quently entered final judgment of non-infringement and no
indefiniteness. Final Judgment, 2023 WL 8610184, at *1.
Barrette appealed, and Defendants cross-appealed.
We have jurisdiction under 28 U.S.C. § 1295(a)(1).
D ISCUSSION
I
Claim construction, when based solely on the intrinsic
record, is a question of law that we review de novo. Wil-
liamson v. Citrix Online, LLC, 792 F.3d 1339, 1346
(Fed. Cir. 2015). Indefiniteness is also a question of law
reviewed without deference. Teva Pharms. USA, Inc.
v. Sandoz, Inc., 789 F.3d 1335, 1341 (Fed. Cir. 2015).
II
In its appeal, Barrette argues that the district court
committed two key errors in construing the “boss”
terms: first, the district court erred by concluding that the
specification disclaimed bosses with fasteners by disparag-
ing prior art assemblies that employed fasteners, and, sec-
ond, the district court erred by concluding that the
prosecution history disclaimed non-integral bosses and by
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BARRETTE OUTDOOR LIVING , INC. v. FORTRESS IRON, LP 8
applying that disclaimer to other terms with presumptively
different meanings. We address each argument in turn.
A
Barrette argues that the district court erred in constru-
ing the “boss” terms as fastener-less because the specifica-
tion does not criticize the use of fasteners but, instead,
distinguishes the prior art based on the use of a sliding piv-
otal connector that joins the picket to the rail without a di-
rect connection between the two. Barrette also argues that
the specification’s embodiments solve multiple problems in
the prior art (e.g., slow installation, poor racking ability,
etc.) and that its claims are not required to solve every
problem identified in the specification. Appellant’s Open-
ing Br. 60–61 (citing Honeywell, Inc. v. Victor Co. of Japan,
Ltd., 298 F.3d 1317, 1326 (Fed. Cir. 2002)).
Defendants argue that the district court correctly con-
strued the “boss” terms as fastener-less because the speci-
fication frequently criticizes the use of fasteners.
Specifically, Defendants contend that the specification’s
Summary of the Invention states that bosses provide “a fas-
tener-less but still pivotal connection.” Cross-Appellants’
Opening Br. 50–51 (citing ’965 patent col. 1 ll. 42–46). Fur-
ther, the detailed description describes prior art assemblies
that use fasteners to join the rails to the pickets as “time
consuming to install,” id. at 51–52 (citing ’965 patent col. 5
ll. 51–67), and contrasts such assemblies with the present
invention, which uses a connector boss strip “that is very
easy and fast to install.” Id. at 52–53 (citing ’965 patent
col. 5 ll. 55–67). Defendants also contend that quick instal-
lation is not merely an optional advantage that the claimed
bosses may provide in some but not all embodiments; ra-
ther, because the specification attributes the quick instal-
lation advantage to the use of bosses, a correct construction
of “boss” must ensure this advantage and, thus, the
claimed bosses must be fastener-less.
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BARRETTE OUTDOOR LIVING , INC. v. FORTRESS IRON, LP 9
We agree with Barrette that the specification does not
clearly and unmistakably disclaim bosses with fasteners.
Allowing for quick and easy installation is just one pur-
ported advantage disclosed by the asserted patents. It is
well-established that while a patent may present multiple
advantages over the prior art, not every embodiment of the
invention will embody every advancement. See Phillips
v. AWH Corp., 415 F.3d 1303, 1327 (Fed. Cir. 2005) (“We
have held that the fact that a patent asserts that an inven-
tion achieves several objectives does not require that each
of the claims be construed as limited to structures that are
capable of achieving all of the objectives.” (citation modi-
fied)). Claims, therefore, should not be construed to re-
quire every advancement disclosed in the specification. See
id.
Here, the asserted patents purport to provide at least
two advantages over prior art railing systems, namely
quick and easy installation and improved racking ability.
See ’965 patent col. 5 l. 64 – col. 6 l. 16. And the latter ad-
vantage does not call for a fastener-less connection. While
the specification criticizes “railing assemblies [that] incor-
porate screws . . . to rotatably couple pickets P to rails R”
because “[s]uch couplings are time consuming to install
and only allow for a limited range of rotation,” this does not
indicate that a fastener-less connection is required to
achieve an increased range of motion. Id. at col. 5 ll. 56–60.
Consistent with Barrette’s contention that the specifica-
tion’s criticism focuses on direct connections between the
picket and the rail, Figures 7A and 7B depict fencing as-
semblies with rails R connected to pickets P without the
use of an intermediate connector, whereas Figures 7C and
7D show fencing assemblies that employ a sliding
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BARRETTE OUTDOOR LIVING , INC. v. FORTRESS IRON, LP 10
connector 34 coupling the rails 30 to the pickets 20. Id. at
figs. 7A–7D.
Id.
Further, the specification credits the invention’s in-
creased racking ability to the connector strip’s ability to
slide within the rail. Id. at col. 6 ll. 1–9. Nothing in the
intrinsic record establishes that the use of fasteners is in-
compatible with the connector’s ability to slide. Because
the specification discloses multiple advantages—including
some that do not require a fastener-less connection—the
fastener-less limitation should not be read into the claims.
We further reject Defendants’ argument that because
the specification attributes the easy-to-install advantage to
the use of bosses, the term “bosses” should be construed as
always providing this advantage. In Phillips, we held that
the claimed baffles were not limited to those disposed at
acute and obtuse angles, in part, because projectile deflec-
tion was just one of several benefits provided by the
claimed invention even though the specification
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BARRETTE OUTDOOR LIVING , INC. v. FORTRESS IRON, LP 11
contemplated achieving projectile deflection via the use of
angled baffles. Phillips, 415 F.3d at 1327. In short, a pa-
tent may achieve a benefit via a particular structure, but
that does not mean that the structure must always provide
that benefit. Here, the asserted patents facilitate fast and
easy installation via the use of bosses, but a “boss” is not
limited to structures that always provide this advantage.
A skilled artisan, therefore, would not interpret the speci-
fication and claims of the asserted patents to mean that a
protruding structure without a fastener is a boss but that
a similar structure that employs a fastener is not. Accord-
ingly, we hold that the district court erred in limiting the
claims to fastener-less bosses.
B
1
The district court construed the term “boss” as limited
to integral structures in partial reliance on Barrette’s ar-
gument during prosecution that the Sherstad reference’s
disclosure of a discrete pivot pin assembly did not disclose
the “claimed integral boss.” Markman Order, 2023 WL
5503030, at *7–8.
Barrette argues that the district court erred in conclud-
ing that Barrette disclaimed non-integral bosses during
prosecution of the ’705 patent by distinguishing the Sher-
stad reference on the grounds that it failed to disclose “the
claimed integral boss.” Appellant’s Opening Br. 42–43 (cit-
ing J. App’x 499–500). Barrette contends that its pur-
ported statements of disavowal are not effective at least as
to any earlier issued patents, namely the ’965 and ’332 pa-
tents. Even if the office action response argument distin-
guishing Sherstad amounts to disclaimer, Barrette argues
that the prosecution history, when taken as a whole, does
not show clear and unmistakable disclaimer in view of the
examiner’s rejection—and Barrette’s subsequent abandon-
ment—of that argument. Appellant’s Opening Br. 43–45
(citing Ecolab, Inc. v. FMC Corp., 569 F.3d 1335, 1342–43
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BARRETTE OUTDOOR LIVING , INC. v. FORTRESS IRON, LP 12
(Fed. Cir. 2009); Malvern Panalytical Inc. v. TA Instru-
ments-Waters LLC, 85 F.4th 1365, 1376 (Fed. Cir. 2023)
(“[W]here an applicant abandons its unsuccessful argu-
ment, we conclude that the prosecution history lacks the
clarity necessary to establish prosecution disclaimer.”)).
Defendants contend that Barrette forfeited many of its
arguments by relying on portions of the prosecution history
never presented to the district court. On the merits, De-
fendants argue that Barrette’s contention that the exam-
iner did not agree with its argument is unavailing because
examiner agreement is not required for prosecution history
disclaimer. Cross-Appellants’ Opening Br. 43 (citing Fen-
ner Invs., Ltd. v. Cellco P’ship, 778 F.3d 1320, 1325 (Fed.
Cir. 2015)). Defendants also dispute Barrette’s reliance on
Malvern, because, unlike the prosecution history in Mal-
vern, the prosecution history here provides no indication
that Barrette’s statement regarding the “claimed integral
boss” was made in error or that Barrette acquiesced to the
examiner’s position. Id. at 43–44 (citing Malvern, 85 F.4th
at 1376).
As a preliminary matter, we reject Defendants’ position
that Barrette forfeited any argument based on portions of
the prosecution history not expressly presented to the dis-
trict court. We have long held that a party may cite por-
tions of the intrinsic record on appeal to support a
previously advanced construction even if the party did not
cite that evidence before the district court. See, e.g., Inter-
active Gift Express, Inc. v. Compuserve Inc., 256 F.3d 1323,
1346 (Fed. Cir. 2001) (noting that forfeiture “has not been
invoked . . . to prevent a party from clarifying or defending
the original scope of its claim construction, or from support-
ing its existing claim construction position with new cita-
tions to the specification”). The prosecution history, which
“consists of the complete record of the proceedings before
the [patent office] and includes the prior art cited during
the examination of the patent,” is intrinsic evidence that
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BARRETTE OUTDOOR LIVING , INC. v. FORTRESS IRON, LP 13
properly may be considered on appeal. Phillips, 415 F.3d
at 1317.
We disagree with Defendants’ contention that this
precedent is inapplicable in this case because Barrette did
not present to the district court the precise portions of the
prosecution history on which it now relies. “Courts must
take care . . . to interpret purported disavowals in the con-
text of the prosecution history as a whole.” Azurity
Pharms., Inc. v. Alkem Lab’ys Ltd., 133 F.4th 1359, 1366
(Fed. Cir. 2025); see also Ecolab, 569 F.3d at 1342 (“Even if
an isolated statement appears to disclaim subject matter,
the prosecution history as a whole may demonstrate that
the patentee committed no clear and unmistakable dis-
claimer.”). When a district court holds that a patentee dis-
claimed a term’s full scope based on a subset of the
prosecution history, the patentee may on appeal support its
original construction with citations to the overlooked por-
tions of the prosecution history.
On the merits, we agree with the district court that
Barrette disclaimed non-integral bosses during prosecu-
tion. As the district court observed, Barrette clearly distin-
guished Sherstad’s pivot pin assembly—featuring a
through-hole and “a loose pin member”—from the “claimed
integral boss.” J. App’x 499–500. In doing so, Barrette ex-
pressly clarified the scope of its claims. Barrette does not
meaningfully dispute this point,1 but instead argues its
1 Barrette argues in a footnote that it does not con-
cede that it meant to disclaim non-integral bosses in its of-
fice action response and that “Fortress failed to meet its
burden on that point too.” Appellant’s Opening Br. 44 n.9.
However, arguments raised only in a footnote are forfeited
as undeveloped. CommScope Techs. LLC v. Dali Wireless
Inc., 10 F.4th 1289, 1296 (Fed. Cir. 2021).
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BARRETTE OUTDOOR LIVING , INC. v. FORTRESS IRON, LP 14
subsequent communications with the patent office ren-
dered any purported disclaimer ambiguous.
Barrette relies upon views expressed in Ecolab and
Malvern to support its conclusion that prosecution dis-
claimer may not apply when a reasonable reader of the
prosecution history could conclude that the examiner re-
jected the applicant’s characterization of the scope of its in-
vention; the applicant never raised the disclaimer again;
and the applicant overcame the examiner’s rejections on
other grounds. In Ecolab, the patentee, FMC, attempted
to overcome prior art rejections by arguing that its claims
contemplated using peracetic acid (“PAA”) as the only an-
timicrobial agent. 569 F.3d at 1343. But the examiner re-
jected that argument, concluding that the pending claims
were not so limited. See id. (noting that the examiner con-
cluded that “the terminology ‘consisting essentially’ does
not mean that [FMC’s] sanitizing solution is consisted
‘solely’ of a peracetic acid solution”). FMC never raised that
argument again and overcame the rejections on other
grounds. Id. Consequently, we reasoned that the prosecu-
tion history did not contain a sufficiently clear disclaimer
because a reasonable reader of the prosecution history
could conclude that FMC’s statement regarding the scope
of its claims was made in error; the examiner corrected that
error; and FMC acquiesced to the examiner’s correction.
Id.
Likewise, in Malvern, we held that an applicant’s state-
ments regarding the scope of the invention did not rise to
the level of disclaimer where the examiner rejected the ap-
plicant’s prior characterization of the patent-at-issue. 85
F.4th at 1376. There, Malvern accused TA Instruments-
Waters (“Waters”) of infringing its patent on an isothermal
titration calorimeter (the “ITC patent”). Id. at 1367–68.
During the prosecution of an unrelated application, also as-
signed to Malvern, the examiner rejected several claims as
anticipated by the ITC patent. Id. at 1370 & n.3. In re-
sponse, the applicant argued that the ITC patent disclosed
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BARRETTE OUTDOOR LIVING , INC. v. FORTRESS IRON, LP 15
only manual systems whereas the application concerned
automatic systems. Id. Reading the ITC patent as encom-
passing both manual and automatic systems, the examiner
disagreed; consequently, the applicant had to overcome the
rejection on other grounds. Id. In the subsequent infringe-
ment action, the district court concluded that the ITC pa-
tent was limited to manual systems based on the
disclaiming statements made during the prosecution of the
unrelated application. Id. at 1371. We vacated the district
court’s construction, in part, because a reasonable reader
of the application’s prosecution history could conclude that
the applicant “recognized its error” when assessing the
scope of the ITC patent and “acquiesced to the examiner’s
views.” Id. at 1376 (emphasis added) (quoting Ecolab, 569
F.3d at 1343). Therefore, in both Ecolab and Malvern, the
patentee was not held to a narrower construction advanced
during prosecution because a reasonable reader of the file
wrapper could conclude that those arguments did not accu-
rately reflect the proper scope of the claims.
Moreover, the fact that an applicant secures allowance
on an independent ground does not render prior character-
izations of claim scope insufficiently clear for purposes of
prosecution disclaimer. See Uship Intell. Props., LLC
v. United States, 714 F.3d 1311, 1315 (Fed. Cir. 2013)
(holding that the prosecution disclaimer analysis “focuses
on what the applicant said, not on whether the representa-
tion was necessary or persuasive”). Here, although Bar-
rette maintains that the examiner rejected the view that
the claims required an integral boss, the examiner disa-
greed not with Barrette’s characterization of the “boss”
term in its own claims but with Barrette’s assessment of
the scope of Sherstad’s disclosure. See J. App’x 515 (indi-
cating that Sherstad disclosed a boss that “can either be
integral with the clip 130, or be a separate pin member”).
Unlike the prosecution histories in Ecolab and Malvern,
the prosecution history of the ’075 patent does not suggest
that the examiner disagreed with Barrette’s assessment of
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BARRETTE OUTDOOR LIVING , INC. v. FORTRESS IRON, LP 16
the scope of its claims, much less that Barrette acquiesced
to the examiner’s broader view of the claims. Thus, the
prosecution history would not suggest to a reasonable
reader that Barrette’s narrowing characterization of its
claims was incorrect.
Without an indication that Barrette’s characterization
of its claims was erroneous, the prosecution history would
lead a reasonable reader to conclude that Barrette clarified
the scope of the claimed invention and that the claimed in-
vention was not patentable over the examiner’s prior art
rejection. See J. App’x 515. The fact that Barrette’s dis-
claimer proved unavailing does not render it ineffective as
a disclaimer. See Uship, 714 F.3d at 1315 (“The fact that
the applicant may have given up more than was necessary
does not render the disclaimer ambiguous.”). Accordingly,
we conclude that Barrette clearly characterized the
claimed invention as limited to integral bosses, and the
subsequent communications with the patent office do not
render Barrette’s disclaimer ambiguous.
Moreover, the fact that Barrette cancelled the claims to
which the disclaimer applied and filed new claims similar
to those previously allowed in the ’332 and ’965 patents
does not defeat the determination of disclaimer. See Ha-
kim v. Cannon Avent Grp., PLC, 479 F.3d 1313, 1317–18
(Fed. Cir. 2007) (holding that, although an applicant had
the right to refile and attempt to broaden the claims, an
applicant cannot recapture claim scope that was surren-
dered). While applicants may rescind a disclaimer made
during prosecution when the applicant puts the examiner
on notice that previously examined prior art may need to
be revisited, see id. at 1318, Barrette conceded during oral
argument that it did not make such a rescission here. See
Oral Argument at 8:35–9:30, available at
cafc.uscourts.gov/oral-arguments/24-1231_07102025.mp3.
Additionally, we reject Barrette’s contention that the
purported disclaimer in the ’075 patent’s prosecution
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BARRETTE OUTDOOR LIVING , INC. v. FORTRESS IRON, LP 17
history cannot apply to the claims of the already issued
’965 and ’332 patents because “[a] statement made during
prosecution of related patents may be properly considered
in construing a term common to those patents, regardless
of whether the statement pre- or post-dates the issuance of
the particular patent at issue.” Teva Pharms., 789 F.3d at
1343 (emphasis added).
Accordingly, we conclude that the district court cor-
rectly determined that the patentee disclaimed non-inte-
gral bosses during prosecution.
2
Barrette also argues that the district court erred by ex-
tending the prosecution history disclaimer as to the term
“boss” to other claim terms, including “nub,” “projection,”
and “series of axles,” which are presumed to carry different
meanings and have different scopes. Barrette contends
that, contrary to the district court’s Markman order, it
never agreed that the specification uses the terms “boss,”
“projection,” and “nub” interchangeably. And, in Barrette’s
view, the intrinsic record confirms that the terms “nub”
and “series of axles” are not interchangeable with “bosses”
and “projections” because the claim language and specifi-
cation demonstrate that “nub” and “series of axles” are nar-
rower.
Defendants argue that Barrette did not argue to the
district court that the terms “nub,” “series of axles,” or “pro-
jections” should be construed differently than “bosses,” and
that Barrette’s arguments distinguishing those terms are
thus forfeited.
We agree with Defendants that Barrette forfeited its
argument that the term “projection” should be afforded a
different construction. Parties may not adopt a claim con-
struction position on appeal that is inconsistent with the
one taken before the district court. See Interactive Gift, 256
F.3d at 1346 (noting that the general rule that a federal
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BARRETTE OUTDOOR LIVING , INC. v. FORTRESS IRON, LP 18
appellate court does not consider an issue not presented to
the district court “has been applied to preclude a party from
adopting a new claim construction position on appeal”).
The claims of the ’905 patent recite “projections” rather
than “bosses.” While the specification provides some indi-
cation that projections may be broader than bosses, see,
e.g., ’965 patent col. 1 ll. 41–44 (noting that the connectors
“can include small projections (e.g., bosses)”), Barrette did
not argue before the district court that the term “projec-
tion” should be construed differently than bosses; in fact,
“Barrette urge[d] that a boss in the context of the Patents-
in-Suit is simply a projection or protrusion.” J. App’x 1651
(internal quotation marks omitted). Moreover, in its Mark-
man slides, Barrette referred to the limitation “wherein
each connector includes at least one projection” as a “boss”
term. J. App’x 2130. Because Barrette argued before the
district court that the terms “projection” and “boss” are
commensurate in scope, it may not argue differently here.
Further, Barrette’s argument that the terms “nub” and
“series of axles” are narrower than the terms “boss” and
“projection,” respectively, is unavailing. The claims of the
’164 patent require that “at least one boss includes a circu-
lar nub.” See, e.g., ’164 patent at claim 5. The specification
indicates, as Barrette contends, that the term “nub” is nar-
rower than the term “boss.” See ’965 patent col. 4 ll. 6–12
(noting that “the boss strip includes at least one inwardly
extending boss (e.g., a nub, pin, or other protruding struc-
ture)” (reference numbers omitted)); see also Appellant’s
Opening Br. 56 (“Claim differentiation thus confirms that
a ‘circular nub’ must have a narrower meaning than
‘boss’ . . . .”). But because the broader terms “boss” and
“projection” are integral, the narrower terms must be inte-
gral as well. Therefore, even if the district court erred in
concluding that the specification uses the terms “nub” and
“series of axles” interchangeably with “bosses,” the district
court did not err in construing the terms “nub” and “series
of axles” as integral structures.
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BARRETTE OUTDOOR LIVING , INC. v. FORTRESS IRON, LP 19
* * *
In its stipulation, Barrette conceded that the accused
products do not contain integral bosses, projections, nubs,
or series of axles. J. App’x 147. Thus, notwithstanding our
conclusion that the district court erred by construing the
claims to require fastener-less bosses, we affirm the judg-
ment of non-infringement because the district court cor-
rectly held that Barrette disclaimed non-integral bosses
and projections during prosecution.
III
We now turn to Defendants’ cross-appeal. Defendants
challenge the district court’s conclusions that the so-called
“sliding” terms (e.g., “sliding surface,” “slidably engaged,”
“slidably engaged,” etc.) and the “causes” term are not in-
definite.
A
Defendants contend that the “sliding” terms are func-
tional limitations in apparatus claims and, as such, “are
inherently ambiguous.” Cross-Appellants’ Opening
Br. 63–64 (citing Nevro Corp. v. Bos. Sci. Corp., 955 F.3d
35, 39 (Fed. Cir. 2020)). To resolve this ambiguity, Defend-
ants argue, the specification must provide guidance that
would allow a skilled artisan to compare a potentially in-
fringing product with the examples in the specification to
determine whether the infringing product falls within the
scope of the claims. Further, Defendants contend that they
provided unrebutted expert testimony as to the kind of in-
formation a skilled artisan would need to assess the scope
of the “sliding” terms and that the specification nowhere
provides this information, but that the district court erro-
neously disregarded this evidence.
We disagree with Defendants’ argument that the spec-
ification does not provide sufficient guidance. Claims are
invalid for indefiniteness if they, when read in the light of
the specification and the prosecution history, “fail to
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BARRETTE OUTDOOR LIVING , INC. v. FORTRESS IRON, LP 20
inform, with reasonable certainty, those skilled in the art
about the scope of the invention.” Nautilus, Inc. v. Biosig
Instruments, Inc., 572 U.S. 898, 901 (2014). A specifica-
tion’s guidance is sufficient where it “allow[s] a skilled ar-
tisan to compare a potentially infringing product with the
examples in the specification” to determine the scope of the
claim. Sonix Tech. Co. v. Publ’ns Int’l, Ltd., 844 F.3d 1370,
1377 (Fed. Cir. 2017) (internal quotation marks omitted).
But “[d]efiniteness does not require that a potential in-
fringer be able to determine ex ante if a particular act in-
fringes the claims.” Nevro, 955 F.3d at 40 (emphasis
added).
Here, the surrounding claim language provides guid-
ance as to the scope of the “sliding” terms. See ’965 patent
at claim 1 (“[P]ivoting the upper end of the respective
picket towards the first end of the respective rail causes the
respective connector to slide along the inner surface of the
side wall of the respective rail towards the second end of
the respective rail.”). Thus, while the asserted patents do
not define with mathematical precision the magnitude of
force needed for sliding to occur, the claims indicate what
sorts of actions suffice.
Moreover, the specification provides guidance as to the
scope of the “sliding” terms. For example, the Summary of
the Invention states that “the rails each have an inner pro-
file that is sized and shaped to slidably retain or capture
the connector between the rails and the picket, while per-
mitting the connector strip to slide relative to the rail” and
“the rail can have an inwardly extending shelf or ledge that
slidingly supports the connector strip so that the connector
strip slides atop the shelf.” ’965 patent col. 1 ll. 46–53 (em-
phasis added). The specification also states that “the con-
nector boss strip 34 slides within the rail 30 in the
transverse directions denoted by the arrows X when the
pickets 20 are pivoted in the angular directions denoted by
the arrows Y, thereby allowing the pivot point between the
connector hole 22 of the picket and the rail to slide one way
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BARRETTE OUTDOOR LIVING , INC. v. FORTRESS IRON, LP 21
or the other, as shown in FIGS. 7C-7D.” ’965 patent col. 6
ll. 1–6.
Id. at figs. 7C & 7D.
Thus, the specification provides numerous examples of
structures that are slidably engaged. Accordingly, we con-
clude that the specification provides sufficient guidance to
permit a skilled artisan to ascertain the claim scope with
reasonable certainty. See Nautilus, 572 U.S. at 901.
We also reject Defendants’ argument that the district
court erred by ignoring unrebutted expert testimony that a
skilled artisan would need to know certain characteristics
of the sliding mechanism to reasonably ascertain the scope
of the claim, including “the magnitude and direction of the
applied force, whether there is any hinderance to motion
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BARRETTE OUTDOOR LIVING , INC. v. FORTRESS IRON, LP 22
(e.g. adhesives, etc.), any aspect facilitating motion (e.g.
lubricant, friction reducing surface treatment,
etc.), . . . and the amount of surface area in contact.” See
Cross-Appellants’ Opening Br. 65 (quoting J. App’x 1758).
Our indefiniteness cases do not require this level of cer-
tainty; an inventor “need not define his invention with
mathematical precision in order to comply with the defi-
niteness requirement.” Sonix, 844 F.3d at 1377 (quoting
Invitrogen Corp. v. Biocrest Mfg., L.P., 424 F.3d 1374, 1384
(Fed. Cir. 2005)).
We also reject Defendants’ argument that the district
court’s construction of the “sliding” terms does not resolve
the ambiguity. The thrust of Defendants’ argument is that,
even after Markman, the claims are ambiguous because it
is not clear whether the claims read on the accused prod-
ucts. But definiteness “does not require that a potential
infringer be able to determine ex ante if a particular act
infringes.” Nevro, 955 F.3d at 40; see also SmithKline Bee-
cham Corp. v. Apotex Corp., 403 F.3d 1331, 1340–41 (Fed.
Cir. 2005) (“The test for indefiniteness does not depend on
a potential infringer’s ability to ascertain the nature of its
own accused product to determine infringement, but in-
stead on whether the claim delineates to a skilled artisan
the bounds of the invention.”). Thus, the fact that the dis-
trict court’s claim construction is not wholly dispositive of
the infringement inquiry does not, on its own, evince indef-
initeness.
B
Defendants argue that the limitation “pivot-
ing . . . causes the respective connector to slide along the
inner surface” is indefinite because, as the specification
and prosecution history indicate, some acts of pivoting re-
sult in sliding and others do not. Cross-Appellants’ Open-
ing Br. 71–72 & n.18. Essentially, in Defendants’ view,
“cause” implies a one-to-one relationship between two oc-
currences; causes are always followed by their
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BARRETTE OUTDOOR LIVING , INC. v. FORTRESS IRON, LP 23
corresponding effects. But, Defendants argue, Barrette
disclaimed that meaning during prosecution by explaining
that “the connectors of the presently claimed invention are
caused to move relative to the rails after the pickets en-
gaged the sides . . . of the openings of the rails.” Id.
at 73–74 (quoting J. App’x 410).
This argument lacks merit. Defendants, at most, have
shown that the asserted patents use the term “causes”
more narrowly than it is commonly used and that Barrette
clarified the meaning of the “causes” term during prosecu-
tion and in the specification. But this confirms that a
skilled artisan—reading the term in view of the surround-
ing claim language, specification, and prosecution his-
tory—could determine the scope of the term with
reasonable certainty. Accordingly, we conclude the district
court correctly determined that the “causes” terms are not
indefinite.
* * *
Because we identify no error in the district court’s in-
definiteness analysis, we affirm the judgment of no inva-
lidity for indefiniteness.
CONCLUSION
We have considered the parties’ other arguments but
do not find them persuasive. For these reasons, the district
court’s judgment of non-infringement and no indefinite-
ness is affirmed.
AFFIRMED
COSTS
Each party to bear its own costs.
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