Alfonso Cioffi, the Estate of Allen Frank Rozman v. Google, Inc.

N OTE: This disposition is nonprecedential.
United States Court of Appeals
for the Federal Circuit
______________________
ALFONSO CIOFFI, THE ESTATE OF ALLEN
FRANK ROZMAN,
Plaintiffs-Appellants
v.
GOOGLE, INC.,
Defendant-Appellee
______________________
2015-1194
______________________
Appeal from the United States District Court for the
Eastern District of Texas in No. 2:13-cv-00103-JRG-RSP,
Judge J. Rodney Gilstrap.
______________________
Decided: November 17, 2015
______________________
ERIC W. BENISEK, Vasquez, Benisek & Lindgren, LLP,
Lafayette, CA, argued for plaintiffs-appellants. Also
represented by ROBERT MCARTHUR.
STEPHANIE S KAFF , Farella Braun & Martel LLP, San
Francisco, CA, argued for defendant-appellee. Also repre-
sented by EUGENE Y. MAR , ANDREW P. N GUYEN.
______________________

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CIOFFI v. GOOGLE, INC. 2
Before O’MALLEY , P LAGER , and BRYSON, Circuit
Judges.
O’MALLEY , Circuit Judge.
Alfonso Cioffi and The Estate of Allen Rozman (collec-
tively “Appellants” or “Cioffi”) filed suit against Google,
Inc. (“Appellee” or “Google”) on February 5, 2013 in the
Eastern District of Texas alleging that the Google Chrome
web browser (the “Accused Products”) infringed four
reissue patents: U.S. Patent Nos. RE43,103 (the “’103
patent”); RE43,500 (the “’500 patent”); RE43,528 (the
“’528 patent”); and RE43,529 (the “’529 patent”). The
district court construed several disputed terms of the four
patents-at-issue. Based on these constructions, the
district court held claim 21 of the ’103 patent to be invalid
as indefinite, and the parties stipulated to non-
infringement of all of the other asserted claims.
On appeal, Cioffi challenges the construction of two
terms: (1) “web browser process” and (2) “critical file.”
Cioffi disputes the district court’s construction of the first
term as erroneously requiring a “direct” access capability
and the second term as erroneously including “critical
user files,” which renders the term indefinite. Because we
agree that the district court erred in construing both of
these terms, we reverse the district court’s claim con-
struction and remand for further proceedings.
I. BACKGROUND
A. The Reissue Patents
The four patents-at-issue are reissue patents originat-
ing from a patent issued as U.S. Patent No. 7,484,247 (the
“’247 patent”) on January 27, 2009. That patent, entitled
“System and Method For Protecting A Computer System
From Malicious Software,” was directed to a way of pro-
tecting a computer from malware by segregating the
suspected malware and directing it to execute and reveal
itself in a safe, isolated part of the computer. In March

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CIOFFI v. GOOGLE, INC. 3
2010, thirteen months after the ’247 patent issued, Cioffi
surrendered the patent pursuant to 35 U.S.C. § 251 and
sought reissue claims. The resulting four reissue patents-
at-issue have the same abstract and, along with the ’247
patent, share substantially identical specifications.
The patents-at-issue describe computer processes,
separated either logically or physically (using separate
processors), into first and second browser processes.
Potential malware downloaded from the Internet is
directed to execute within the second browser process, but
is not allowed to execute outside of the second browser
process. Thus, the potential malware is insulated from
and cannot damage any other aspect of the computer’s
systems, including memory space accessible by the first
browser process.
Figure 1 of the ’528 patent (shown below) illustrates
one preferred embodiment, involving two physically
separate processors: (1) a first web browser process exe-
cuted within first processor 120 with access to important
files stored in first memory space 110, and (2) a second
web browser process executed within second processor
140 with access to its own expendable memory space 130.
Untrusted content downloaded from the Internet is exe-
cuted in the second web browser process running in 140,
where it cannot damage important files stored in first
memory space 110.

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CIOFFI v. GOOGLE, INC. 4
’528 patent fig. 1.
During prosecution, the examiner initially rejected all
of the claims of the applications that ultimately issued as
the ’500, ’528, and ’529 patents (“the ’500, ’528, and ’529
patent applications”) under 35 U.S.C. § 102(b) in view of
U.S. Patent Application No. 2002/0002673 (“Narin”). J.A.
212-14. The examiner determined that Narin taught a
method of operating a computer system with a first logical
process capable of accessing data in a first memory space
and a second logical process capable of accessing data in a
second memory space. Id. The examiner found that the
second logical process of Narin hosts non-secure software
objects, and the data residing in the first memory space is
protected from corruption by malware downloaded from
the network and operating as part of the second logical
process. Id.
Cioffi responded with the argument that “Narin
teaches away from the closed process [corresponding to
the first browser process] being a browser process.” J.A.
256. In other words, Cioffi argued that Narin is distin-
guishable from the claimed invention because Narin does
not allow a browser program to be a part of the secure
application, which Cioffi describes as a “first browser
process.”
On November 14, 2011, the examiner issued a Final
Rejection Office Action maintaining its rejection of all the
claims of the ’500, ’528, and ’529 patent applications. The,
the examiner stated that:
Despite the Applicant’s arguments that the
claimed browser is a web browser, the specifica-
tion . . . describe[s] the first logical process as be-
ing a video game and ‘including but not [being]
limited to a word processor,’ respectively. Accord-
ing to the Applicant’s specification, the claimed
first logical process or first browser process could
include a web browser, such as Internet Explorer

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CIOFFI v. GOOGLE, INC. 5
or Netscape; a video game; or a word processor.
At the very least, the prior art’s disclosure reads
on the Applicant’s video game and word processor
interpretations of browser. . . . It is noted that fea-
tures upon which applicant relies, such as the
first browser process accessing Internet sites
and/or data, are not recited in the rejected claims.
Id. at 285-6 (¶¶6-8).
In response, Cioffi amended all of the pending claims
of the ’500, ’528, and ’529 patent applications to narrow
the first and second “browser process” to the first and
second “web browser process.” J.A. 798-810. Cioffi also
added a limitation, “capable of accessing data of a website
via the network,” to the first web browser process. J.A.
314. Cioffi then explained, “Narin fails to disclose . . . a
first web browser process capable of accessing data of a
website via a network of one or more computers (e.g., the
internet).” J.A. 332. The examiner allowed the claims.
B. Procedural History
On February 5, 2013, Cioffi filed suit against Google
asserting infringement of the ’500, ’528, ’529, and ’103
reissue patents by the Google Chrome web browser avail-
able for the Windows, Mac, Android, and Linux operating
systems. The claims originally asserted were:
’500 patent: claims 21, 23, 25, 29, 30, 31, 32, 37,
38, 39, 41, 42, 43, 52, 66, 67 and 70.
’528 patent: claims 1, 2, 5, 21, 23, 25, 30, 44, 46,
52, 53, 55, 57, 58, 64, 65, 66, 67 and 70.
’529 patent: claims 21, 23, 28, 30, 36, 38, 45, and
49.
’103 patent: claim 21.
Cioffi v. Google Inc., 2:13-cv-103, 2014 U.S. Dist. LEXIS
123760, *8 (E.D. Tex. Aug. 28, 2014). Following a Mark-

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CIOFFI v. GOOGLE, INC. 6
man hearing, the district court issued its Claim Construc-
tion Order on August 28, 2014. Id.
The district court adopted its preliminary construc-
tion of “web browser process” as a “process that can access
data on websites.” Id. at *21. The court found that Cioffi
had distinguished Narin during patent prosecution by
arguing that Narin discloses a “secure” or “closed” appli-
cation that controls a separate process that runs an “open
or untrusted application,” and that the “secure” applica-
tion cannot be a web browser. Id. at *14-15. The court
noted that, in response to the examiner’s rejection stating
that the features relied upon to overcome Narin were not
recited in the claims, Cioffi amended the claims to add
“web” before “browser” and “capable of accessing data of a
website via the network” before “first web browser pro-
cess.” Id. at *17. The court found that the patentees
relied on the added “web” limitation to overcome the
examiner’s rejection, and “that reliance should be given
effect by requiring that the ‘web browser process’ is capa-
ble of accessing data on websites.” Id. at *18-19.
The district court then addressed a statement that
Google made at the Markman hearing that it would agree
to the court’s preliminary construction with an under-
standing that the claim term requires “direct” access to
website data. While the court did not seek further brief-
ing or argument on this issue, it did address it. The court
stated that introducing the word “direct” would confuse
rather than clarify the scope of the claims, but continued:
To be clear, “can” in the Court’s construction does
not mean “must” and instead refers to a capabil-
ity. For this capability to be meaningful and con-
sistent with the prosecution history, however, a
“web browser process” must be capable of access-
ing a website without using another web browser
process. In other words, although the Court’s con-
struction does not preclude a web browser process

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CIOFFI v. GOOGLE, INC. 7
from accessing websites by using another web
browser process, a web browser process’s capabil-
ity of accessing websites must not require using
another web browser process.
Id. at *20-21 (emphasis in original).
The district court also adopted its preliminary finding
that the term “critical file” from the ’103 patent is indefi-
nite, and held, therefore, that claim 21 of the ’103 patent
is invalid. The court found that references to “critical
user files” found in the specification and prosecution
history suggest that the term “critical file” includes criti-
cal “user” files. Id. at *60. It held that what is critical to
a user is “entirely subjective,” and that “critical file,”
therefore, fails to inform a person of skill in the art about
the scope of the invention with reasonable certainty under
Nautilus, Inc. v. Biosig Instruments, Inc., 134 S. Ct. 2120,
2122 (2014). Id. at *61.
The parties filed objections to aspects of the Claim
Construction Order. Cioffi then served its Final Election
of Asserted Claims, in which it narrowed the asserted
claims to:
’500 patent: claims 21, 30, 32, 39, 43, 66, and 70
’528 patent: claims 5, 21, 23, 30, 44, 64, and 67
’529 patent: claims 23, 30, 36, 38, 45, and 49
See Final Judgment at 2-3, Cioffi, 2014 U.S. Dist. LEXIS
123760 (2:13-cv-103), ECF No. 104. The district court
overruled the parties’ objections. Order, Cioffi, 2014 U.S.
Dist. LEXIS 123760 (2:13-cv-103), ECF No. 97.
The parties then agreed that, based on the court’s
claim constructions, Cioffi could not prevail on the issue of
infringement. Cioffi’s First Amended Infringement Con-
tentions had identified the browser kernel of the Accused
Products as reading on the “first web browser process” of
the asserted claims and the rendering engine of the

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CIOFFI v. GOOGLE, INC. 8
Accused Products as reading on the “second web browser
process” of the asserted claims. The district court found
that the rendering engine of the Accused Products “is not
capable of and cannot access data of websites without
using the browser kernel in the Accused Products,” and,
therefore, the rendering engine cannot meet the “web
browser process” limitation under the Claim Construction
Order. Final Judgment at 2-3, Cioffi, 2014 U.S. Dist.
LEXIS 123760 (2:13-cv-103), ECF No. 104. The district
court entered a final judgment of non-infringement on
December 2, 2014. Id.
Cioffi timely appealed the district court’s judgment,
and we have jurisdiction under 28 U.S.C. § 1295(a)(1).
II. D ISCUSSION
Cioffi challenges the district court’s construction of
two claim terms: (1) “web browser process” and (2) “criti-
cal file.” Claim construction is a matter of law, which we
review de novo, but we review underlying factual findings
by the district court for clear error. Teva Pharms. USA,
Inc. v. Sandoz, Inc., 135 S. Ct. 831, 837-38 (2015). Gener-
ally, claim terms should be given their ordinary and
customary meaning from the perspective of a person
having ordinary skill in the art at the time of the effective
date of the patent application. Phillips v. AWH Corp., 415
F.3d 1303, 1312-13 (Fed. Cir. 2005) (en banc). To ascer-
tain the scope and meaning of the asserted claims, we
look to the words of the claims themselves, the specifica-
tion, the prosecution history, and any relevant extrinsic
evidence. Id. at 1315-17. This inquiry, at times, begins
and ends with the intrinsic evidence. In fact, the specifi-
cation is the single best guide to the meaning of the claim
terms; it is often dispositive. Id. at 1318 (“[T]he specifica-
tion ‘is always highly relevant to the claim construction
analysis. Usually, it is dispositive . . . .’”) (citation omit-
ted).

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CIOFFI v. GOOGLE, INC. 9
A. “Web Browser Process”
Cioffi argued in its opening brief on appeal that the
district court erred by construing “web browser process”
at all, rather than maintaining the term’s plain and
ordinary meaning. Appellant Br. 27. Cioffi has since
conceded, however, that the district court’s construction of
“web browser process” as a “process that can access data
on websites” is not reversible error.1
Given this concession, the sole remaining dispute with
respect to “web browser process” is whether the district
court erred by reading into that limitation a “direct”
access requirement. Under the district court’s construc-
tion, a “web browser process” does not have to access data
on websites without using another “web browser process,”
but “must be capable of accessing a website without using
another web browser process.” Cioffi, 2014 U.S. Dist.
LEXIS 123760 at *20-21 (emphasis added). Simply put,
the district court held that the “first web browser process”
must be capable of accessing the Internet directly without
the assistance of the “second web browser process,” and
the “second web browser process” must be capable of
accessing the Internet directly without the assistance of
the “first web browser process.”
1 See Appellant Reply Br. 2 (“Had the district court
stopped with its preliminary construction of ‘web browser
process’ to mean a ‘process that can access data on web-
sites’ its error in deciding to construe the term would have
been harmless . . . .”); Oral Argument at 1:20-2:03, avail-
able at http://oralarguments.cafc.uscourts.gov/default
.aspx?fl=2015-1194.mp3 (“what’s shown [at *21 of the
Claim Construction Order] is the court’s definition that a
‘web browser process’ is a ‘process that access data on
websites.’ That definition, as a practical matter, is ac-
ceptable to us.”).

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CIOFFI v. GOOGLE, INC. 10
Claim construction starts with the claim language.
Innova/Pure Water, Inc. v. Safari Water Filtration Sys.,
Inc., 381 F.3d 1111, 1116 (Fed. Cir. 2004). “Differences
among claims can [ ] be a useful guide in understanding
the meaning of particular claim terms.” Phillips, 415
F.3d at 1314. “[T]he presence of a dependent claim that
adds a particular limitation gives rise to a presumption
that the limitation in question is not present in the inde-
pendent claim.” Phillips, 415 F.3d at 1314-15 (citing
Liebel-Flarsheim Co. v. Medrad, Inc., 358 F.3d 898, 910
(Fed. Cir. 2004)).
Cioffi asserts that, under these claim differentiation
principles, the term “web browser process” alone cannot
be read to require a “direct” access capability. Cioffi first
points to independent claim 21 of the ’528 patent, claim-
ing it demonstrates that the “second web browser process”
does not need to be capable of directly accessing data on
websites without using another web browser. Claim 21
states that the “first web browser process” needs to be
“capable of passing data to the second web browser pro-
cess.” ’528 patent col. 21 ll. 12-14. Thus, this claim
implies that the “second web browser” can access data on
websites indirectly with assistance from the “first web
browser process.” Nothing in the language of claim 21
requires that either the first or the second web browser
process have direct access capability; instead, the claim
requires only that the second process: (1) execute website
data and (2) retrieve data that it executes. Id. In con-
trast, dependent claim 24 of the ’528 patent requires the
“second web browser process” to be “capable of directly
exchanging data with the network interface and with the
first web browser process.” ’528 patent col. 21 ll. 26-30.2
2 Claims 21 and 24 of the ‘528 patent are repre-
sentative. In its Reply Brief and at oral argument, Cioffi
clarifies that the same argument applies to claims 36 and

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CIOFFI v. GOOGLE, INC. 11
Cioffi asserts that the “directly exchanging data with the
network interface” limitation of claim 24 would be super-
fluous if claim 21 already required direct web access
capability.
According to Google, Cioffi’s claim differentiation ar-
gument fails because the court’s construction requiring
that the web browser process have the capability to access
data on a website directly does not render claims 21 and
24 of the ’528 patent identical in scope. Claim differentia-
tion principles do not apply here, according to Google,
because claim 24 has two additional limitations as com-
pared to claim 21. Dependent claim 24 not only adds a
“directly exchanges data with the network interface”
limitation, but also a “directly exchanges data with” “the
first web browser process” limitation. Id. Thus, according
to Google, only the first of these limitations would be
subsumed by the court’s construction.
We are not persuaded by Google’s arguments. If
claim 21 already required a capability for “direct” access
to the network, then the language of claim 24, which
recites that the “second web browser process is capable of
directly exchanging data with the network interface,”
would be entirely duplicative. Thus, the language of the
claims indicates that only in claim 24 does the second web
browser have to have a “direct” access capability. While
Google is correct that claim 24 adds another limitation
compared to claim 21, that argument does not change the
fact that the “directly exchanges data with a network”
limitation would be rendered superfluous. See Mfor-
mation Techs., Inc. v. Research in Motion Ltd., 764 F.3d
39 of the ’529 patent. See Appellant Reply Br. 5-7; Oral
Argument at 3:23-3:59, available at http://oralarguments
.cafc.uscourts.gov/default.aspx?fl=2015-1194.mp3. The
same argument also applies to claims 21 and 24 of the
’500 patent.

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CIOFFI v. GOOGLE, INC. 12
1392, 1399 (Fed. Cir. 2014) (favoring a construction that
does not render another limitation “superfluous”). Thus,
we find Cioffi’s claim differentiation argument compelling
and find that the addition of the direct access capability
limitation in claim 24 gives rise to a presumption that
claim 21 lacks such a limitation.
We do not find, moreover, that anything in the prose-
cution history overcomes the presumption created by
these claim differentiation principles. Google argues that,
during prosecution, Cioffi disclaimed a construction of
“web browser process” that is broad enough to cover
indirect access to website data in order to overcome
anticipation by Narin. And Google is correct that,
“[a]lthough claim differentiation is a useful analytic tool,
it cannot enlarge the meaning of a claim beyond that
which is supported by the patent documents, or relieve
any claim of limitations imposed by the prosecution
history. See, e.g., Retractable Techs., 653 F.3d at 1305
(‘[A]ny presumption created by the doctrine of claim
differentiation “will be overcome by a contrary construc-
tion dictated by the written description or prosecution
history.”’).” Fenner Invs., Ltd. v. Cellco P’ship, 778 F.3d
1320, 1327 (Fed. Cir. 2015). “The doctrine of prosecution
disclaimer attaches where an applicant, whether by
amendment or by argument, ‘unequivocally disavowed a
certain meaning to obtain his patent.’” Schindler Elevator
Corp. v. Otis Elevator Co., 593 F.3d 1275, 1285 (Fed. Cir.
2010) (quoting Omega Eng'g, Inc. v. Raytek Corp., 334
F.3d 1314, 1324 (Fed. Cir. 2003)).
According to Google, Cioffi would not have been able
to distinguish its claims from Narin if its “web browser
process” was permitted to indirectly access data on web-
sites through another browser process. Google contends
that the examiner rejected Cioffi’s initial, unamended
claim for a “browser process” because it would encompass
prior art video games in which a renderer (i.e., the first
process) relies on a second process to receive interactive

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CIOFFI v. GOOGLE, INC. 13
network data. ’247 patent col. 14 ll. 28-45. Google argues
that Cioffi thus surrendered indirect access to website
data when it amended “browser process” to “web browser
process” to exclude video game and word processing
applications from the prior art. Appellee Br. 32.
Cioffi responds that it never suggested in the course of
amending “browser process” to “web browser process” that
the “web browser process” must be capable of “directly”
accessing website data without the assistance of another
“web browser process.” Appellant Reply Br. 14. Instead,
Cioffi says the key to overcoming Narin was not that the
first “web browser process” could “directly” access website
data, but, rather, was that the first “web browser process”
could access website data at all.
In Fenner, on which Google relies, we held that the
patent’s specification and prosecution history narrowed
the meaning of the term “personal identification number”
beyond the construction proffered by the patentee not-
withstanding the patentee’s claim differentiation argu-
ment. 778 F.3d at 1327. The patentee argued that
“personal identification number” should be construed
broadly and could be associated with a particular user or
a particular device. But the court held that the patentee
could not walk away from what it had clearly stated
during prosecution—that unlike the prior art, “[t]he
present invention, on the other hand, is centered around
the mobile user, not the mobile telephone. The user is
identified by a personal code.” Id. at 1325. The patentee’s
main argument on appeal was that the examiner did not
rely on these statements, a point which we found to be
irrelevant. Id.
Unlike Fenner, the alleged disavowal of claim scope is
far from unequivocal in Cioffi’s case. The prosecution
history reveals that Cioffi distinguished Narin by arguing
that its first browser process was not functionally equiva-
lent to Narin’s “secure” or “trusted” application because

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CIOFFI v. GOOGLE, INC. 14
the first browser process of the reissue claims was capable
of accessing untrusted data from websites, which would
constitute “executable code from other sources that may
not be trusted.” J.A. 256-57. The examiner recognized
that Cioffi drew this distinction with Narin’s “secure”
application, but nevertheless rejected Cioffi’s claims
because “the features upon which applicant relies, such as
the first browser process accessing Internet sites and/or
data, are not recited in the rejected claims.” J.A. 286 (¶8).
Rather, the examiner felt that the first logical process
described in the specification was broad enough to encom-
pass non-web browsers such as a “video game” and a
“word processor.” Id. at ¶6. In response to this rejection,
Cioffi amended its claims to explicitly state that the “first
web browser” needed to be “capable of accessing data on
websites.” J.A. 314, 332.
Google refers to the following passage from the prose-
cution history, claiming that it shows that Cioffi dis-
claimed “indirect” access to website data by the first
browser process in order to overcome Narin:
As an example application 312 [the secure appli-
cation in Narin] may provide some type of web
browsing capability to its user, but rather than
performing the actual web browsing functions it-
self, application 312 may call upon a general-
purpose browsing program to perform the web
browsing.
J.A. 258, 590. See also Oral Argument at 18:01-19:18,
available at http://oralarguments.cafc.uscourts.gov/defau
lt.aspx?fl=2015-1194.mp3. This passage simply confirms
that the “secure” process of Narin cannot perform web
browsing functions itself, but can call upon the “open”
process to perform such functions. Nothing here suggests
that the “secure” process thereby gains access to website
data. Google further cites this passage:

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CIOFFI v. GOOGLE, INC. 15
Narin provides a technique for allowing an open
or untrusted application to provide untrusted or
open features for a secure application that are not
directly implemented within the secure applica-
tion (or closed application). In accordance there-
with, an open or untrusted application is run in a
separate auxiliary process from the closed or pro-
tected application. . . . The auxiliary process is
started by the closed process; the closed process
controls the lifetime of the auxiliary process and
terminates it when the open features that it pro-
vides are no longer necessary.
J.A. 588 (emphasis added). Google focuses on the phrase
“not directly implemented,” but nothing contained in this
passage clarifies that the “untrusted or open features”
that the untrusted application provides the secure appli-
cation include anything more than general web browsing
capability, as opposed to website data. And even if such
“features” included data from websites, nothing suggests
that “are not directly implemented” equates to “are indi-
rectly accessed.” In addition, the third sentence—stating
that the untrusted process is started, controlled, and
stopped by the “closed process”—also falls short of sug-
gesting that the “closed process” thereby gains access to
website data. Finally, the paragraph immediately follow-
ing that passage affirmatively suggests that whatever the
“untrusted features” provided to the “secure” application
might include they cannot include “executable code from
unknown sources”:
Narin teaches away from the closed process [the
first browser process] being a browser process. If
the application is trusted, running a browser in-
proc may subvert the security scheme of the
trusted application. If trust is to be maintained,
executable code from unknown sources cannot be
given access to the address space of the trusted

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CIOFFI v. GOOGLE, INC. 16
application and therefore cannot be run in pro-
cess.
J.A. 256-57 (emphasis added). Thus, nothing from the
prosecution history constitutes a clear and unmistakable
disavowal of “indirect” access. “There is no ‘clear and
unmistakable’ disclaimer if a prosecution argument is
subject to more than one reasonable interpretation, one of
which is consistent with a proffered meaning of the dis-
puted term.” Sandisk Corp. v. Memorex Prods., 415 F.3d
1278, 1287 (Fed. Cir. 2005). Here, Cioffi has offered a
reasonable alternative interpretation—that it differenti-
ated Narin by explaining that its first web browser pro-
cess, unlike Narin’s “secure” process, had access to
website data. We find nothing in the prosecution history
sufficient to overcome the presumption that “web browser
process” alone does not have a “direct” access capability
requirement.
B. “Critical File”
We now turn to the dispute over the district court’s
construction of “critical file” as including “critical user
files,” which both parties agree would render the term
indefinite under Nautilus, 134 S. Ct. at 2129. Under
Nautilus, 35 U.S.C. § 112 ¶ 2 requires that “a patent’s
claims, viewed in light of the specification and prosecution
history, inform those skilled in the art about the scope of
the invention with reasonable certainty.” Id. A claim
“must be sufficiently definite to inform the public of the
bounds of the protected invention, i.e., what subject
matter is covered by the exclusive rights of the patent.”
Ancora Techs., Inc. v. Apple, Inc., 744 F.3d 732, 737 (Fed.
Cir. 2014) (quoting Halliburton Energy Servs., Inc. v. M-I
LLC, 514 F.3d 1244, 1249 (Fed. Cir. 2008)).
Google points out three references to “user” files in
the specification of the ’247 patent:

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CIOFFI v. GOOGLE, INC. 17
With the network interface program constrained
in this way, malware programs are rendered una-
ble to automatically corrupt critical system and
user files located on the main memory storage ar-
ea.
. . .
It is an object of the present invention to provide a
computer system capable of preventing malware
programs from automatically corrupting critical
user and system files.
. . .
It is another object of the present invention to
provide a user with an easy and comprehensive
method of restoring critical system and user files
that may have been corrupted by a malware infec-
tion.
’247 patent col. 7 ll. 8-11, 40-44, 53-56 (emphasis added).
Google also points to the following references to “criti-
cal . . . user” files or data in the prosecution history:
Critical user data residing on the first electronic
memory space is thereby protected from corrup-
tion by a malicious (malware) process downloaded
from the network and executing on the second log-
ical process.
. . .
[M]alware programs are rendered unable to au-
tomatically corrupt critical system and user files
located on the main memory storage area.
J.A. 458-59 (emphasis added).
The question is whether these five references to “user”
files or data in the specification and prosecution history
are sufficient to require that we read a “user files” limita-
tion into the claim term “critical file.” On this point, our

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CIOFFI v. GOOGLE, INC. 18
recent decision in Ancora, 744 F.3d at 732, is instructive.
Ancora states that “[a] claim term should be given its
ordinary meaning in the pertinent context, unless the
patentee has made clear its adoption of a different defini-
tion or otherwise disclaimed that meaning.” Id. at 734.
There, we upheld the district court’s ruling that the terms
“volatile memory” and “non-volatile memory” were not
indefinite because the parties did not dispute that there
were “clear, settled, and objective” meanings for those
terms in the art, and three “passing references” in the
specification inconsistent with the established meanings
were insufficient to overcome the clear ordinary meaning.
Id. at 738.
In this case, the experts from both sides agreed that
“critical file” had a well-understood and objective defini-
tion to one of skill in the art. Cioffi’s expert, Mr. H.E.
(“Buster”) Dunsmore, stated that a person of skill would
understand that a “‘critical file’ refers to files required for
the proper operation of the computer’s systems.” Dun-
smore Decl. ¶ 35, Exhibit 24 of Google’s Responsive Claim
Construction Br., Cioffi, 2014 U.S. Dist. LEXIS 123760
(2:13-cv-103), ECF No. 66 (“Dunsmore Decl.”). Similarly,
Google’s expert, Dr. William A. Arbaugh, testified that,
“[a] person of ordinary skill in the art knows that ‘system
files’ are synonymous with ‘critical file’ and ‘critical sys-
tem file.’” Arbaugh Decl. at 32, Exhibit 23 of Google’s
Responsive Claim Construction Br., Cioffi, 2014 U.S. Dist.
LEXIS 123760 (2:13-cv-103), ECF No. 66 (emphasis
added) (“Arbaugh Decl.”).3
3 Based on this language, we disagree with Google’s
characterization of Dr. Arbaugh’s testimony as explaining
“that ‘system file’ can be a ‘critical file’ or a ‘critical system
file,’ not that ‘critical file’ means ‘system file’ or only
includes ‘system file.’” Appellee Br. 37.

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CIOFFI v. GOOGLE, INC. 19
The surrounding text of the experts’ declarations does
not alter this finding. The experts agreed that “critical
user file” is entirely subjective. See Dunsmore Decl. ¶ 35
(“users may disagree [sic] what is and is not critical to
them); Arbaugh Decl. at 32 (“it is my opinion that a
‘critical user file’ is entirely subjective because what is
critical to one person may not be critical to another”).
And the experts disagreed about whether “critical file”
must be construed to include “critical user files” based on
references to such files in the specification. See Dunsmore
Decl. ¶ 35 (“One of skill would understand that a critical
file would not be a user file”); Arbaugh Decl. at 33 (stating
that, in light of the specification and prosecution history,
a proposed construction of “critical file” that “does not
include the concept of ‘critical user files’ . . . is under-
inclusive”). But neither party’s expert suggested that
“critical file” alone is subjective or indefinite.
Our analysis thus shows that, without taking into
consideration the few references to “user files” or “user
data” in the intrinsic evidence, both sides’ experts agreed
on an objective and well-understood meaning for “critical
file.” Ancora teaches that, if there is a well-understood
meaning for a term in the art, we do not allow a few
inconsistent references in the specification to change this
meaning. This is because, if the terms at issue have “so
clear an ordinary meaning[,] a skilled artisan would not
be looking for clarification in the specification.” Ancora,
744 F.3d at 738. As in Ancora, “[t]here is no facial ambi-
guity or obscurity in the claim term,” and any ambiguity
only arises from the specification. Id.
Google argues that, unlike Ancora, where the “passing
references” inconsistent with the ordinary meaning were
“perplexing,” here, Cioffi deliberately intended to protect
critical user data and critical user files from malware as
part of its invention. See id. While the specification
references upon which Google relies do reference the
advantage of protecting files with which a particular user

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CIOFFI v. GOOGLE, INC. 20
might be concerned, we see nothing that indicates that
Cioffi intended its invention to do anything other than
protect “critical files” as that concept is widely understood
by those of skill in the art. We, thus, reject Google’s
argument, and find that the few “passing references” to
“user” files or data are insufficient to alter the well-
understood, objective meaning of “critical file” agreed
upon by the experts. We, therefore, reverse the district
court’s holding that “critical file” in claim 21 of the ’103
patent is indefinite.
III. CONCLUSION
For the foregoing reasons, we find that that the dis-
trict court incorrectly construed “web browser process” as
requiring a “direct” access capability and incorrectly
construed “critical file” as encompassing “critical user
files.” We, therefore, reverse the district court’s claim
constructions to the extent they are inconsistent with our
findings and reverse the district court’s finding that the
’103 patent is invalid as indefinite under 35 U.S.C. § 112
¶ 2. Because the parties stipulated to non-infringement
based on the district court’s erroneous constructions, we
also remand for further findings pursuant to this opinion.
REVERSED AND REMANDED

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