Dyfan, LLC v. Target Corporation

Case: 21-1725    Document: 44    Page: 1   Filed: 03/24/2022




   United States Court of Appeals
       for the Federal Circuit
                  ______________________

                      DYFAN, LLC,
                    Plaintiff-Appellant

                            v.

                TARGET CORPORATION,
                    Defendant-Appellee
                  ______________________

                        2021-1725
                  ______________________

    Appeal from the United States District Court for the
 Western District of Texas in No. 6:19-cv-00179-ADA, Judge
 Alan D. Albright.
                   ______________________

                 Decided: March 24, 2022
                 ______________________

    DEREK DAHLGREN, Devlin Law Firm LLC, Wilmington,
 DE, argued for plaintiff-appellant. Also represented by
 TIMOTHY DEVLIN, NADIIA LOIZIDES.

     CHRISTOPHER JOSEPH TYSON, Duane Morris LLP,
 Washington, DC, argued for defendant-appellee. Also rep-
 resented by MATTHEW YUNGWIRTH, Atlanta, GA.
                 ______________________
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 2                                  DYFAN, LLC   v. TARGET CORP.



         Before LOURIE, DYK, and STOLL, Circuit Judges.
 STOLL, Circuit Judge.
     Dyfan, LLC appeals from the United States District
 Court for the Western District of Texas’s final judgment of
 invalidity of the asserted patent claims. The district court
 held the claims invalid as indefinite under 

35 U.S.C. § 112

 ¶ 2 based on its view that certain claim limitations are in
 means-plus-function format under § 112 ¶ 6 and that the
 specification does not disclose sufficient structure corre-
 sponding to the recited functions. Because we conclude
 that the disputed claim limitations are not drafted in
 means-plus-function format, we reverse the district court’s
 judgment of invalidity and remand for further proceedings.
                         BACKGROUND
                                I
      U.S. Patent Nos. 9,973,899 and 10,194,292 (the “pa-
 tents-in-suit”) 1 are titled “System for Location Based Trig-
 gers for Mobile Devices.” The patents-in-suit describe
 improved systems for delivering messages to users based
 on their locations. For example, the shared specification
 discloses a communications system that provides users
 with information tailored to their particular interests or
 needs based on their presence within a specified location,
 such as a shopping center that has different retail stores
 within it. ’292 patent col. 5 l. 40–col. 6 l. 11. Exemplary
 systems include “a building” having “broadcast short-range
 communications unit[s]” at fixed locations that broadcast
 messages to mobile devices within communications range
 of the respective units. Id. at col. 39 l. 61–col. 42 l. 18. The
 mobile devices execute “applications” or “code” to receive



     1   The ’292 patent is a continuation of the ’899 patent
 and the two share a common specification, so we generally
 cite only the ’292 patent.
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 DYFAN, LLC   v. TARGET CORP.                                 3



 and process the broadcast messages. Id.; see also ’899 pa-
 tent col. 29 l. 9–col. 30 l. 63. A server communicates with
 the mobile devices via the internet to provide location-rel-
 evant information. ’292 patent col. 39 l. 61–col. 42 l. 18.
     Claim 15 of the ’292 patent is representative of the
 claims on appeal:
     15. A system, comprising:
     a building . . . including:
        a first broadcast short-range communications
     unit. . .
         a second broadcast short-range communica-
     tions unit. . .
     code configured to be executed by at least one of the
     plurality of mobile devices, the code, when exe-
     cuted, configured to:
         cause display, via a display of the at least one
     mobile device, of an option for causing first visual
     information and second visual information to be
     output via the at least one mobile device . . .
         receive an indication of a receipt, from the first
     broadcast short-range communications unit and
     via the first wireless communications protocol, of
     the one or more first broadcast messages including
     the at least one first value,
         in response to the indication of the receipt,
     from the first broadcast short-range communica-
     tions unit and via the first wireless communication
     protocol, of the one or more first broadcast mes-
     sages including the at least one first value: cause
     to be sent, from the at least one mobile device and
     via a second wireless communications protocol and
     an Internet Protocol over the Internet at least in
     part, at least one first message . . .
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 4                                 DYFAN, LLC   v. TARGET CORP.



     at least one server that is configured to communi-
     cate with the at least one mobile device via the In-
     ternet . . .
     said code, when executed, further configured to:
         receive, from the at least one server and via the
     second wireless communications protocol, the first
     response message including the first location-rele-
     vant information,
         in response to the receipt, from the at least one
     server and via the second wireless communications
     protocol and the Internet Protocol over the Inter-
     net at least in part, of the first response message
     including the first location-relevant information:
     cause to be output, via the at least one mobile de-
     vice, the first visual information based on the first
     location-relevant information,
         receive, from the at least one server and via the
     second wireless communications protocol, the sec-
     ond response message including the second loca-
     tion-relevant information,
         after the first visual information is caused to be
     output based on the first location-relevant infor-
     mation; after the at least one mobile device is moved
     in the building; and in response to the receipt, from
     the at least one server and via the second wireless
     communications protocol, of the second response
     message including the second location-relevant in-
     formation: cause to be output, via the at least one
     mobile device, the second visual information based
     on the second location-relevant information;
     wherein the system is configured such that the first
     visual information is automatically caused to be
     output without requiring communication of the at
     least one first message with the first broadcast
     short-range communications unit after the receipt
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 DYFAN, LLC   v. TARGET CORP.                                5



     of the indication of the receipt of the one or more
     first broadcast messages, and the second visual in-
     formation is automatically caused to be output
     without requiring communication of the at least
     one second message with the second broadcast
     short-range communications unit after the receipt
     of the indication of the receipt of the one or more
     second broadcast messages.
 Id. at col. 39 l. 61–col. 42 l. 18 (emphases added to repre-
 sentative disputed limitations).
                                II
     On February 28, 2019, Dyfan sued Target Corp. for in-
 fringement of various claims of the patents-in-suit. During
 claim construction proceedings, Target argued that each of
 the asserted claims included limitations that should be
 construed as means-plus-function limitations. Moreover,
 according to Target, the specification failed to disclose
 structure corresponding to these means-plus-function lim-
 itations and thus the claims were invalid as indefinite.
     On December 19, 2019, the district court held a claim
 construction hearing. On November 24, 2020, the district
 court issued a claim construction order in which it con-
 cluded that the disputed (1) “code”/“application” limita-
 tions and (2) “system” limitations were invalid as
 indefinite. 2 Dyfan, LLC v. Target Corp., No. W-19-CV-


     2   The district court addressed the 11 disputed limi-
 tations containing “code” or “application,” (“the ‘code’/‘ap-
 plication’ limitations”) and 14 disputed limitations
 containing “system,” (“the ‘system’ limitations”) by analyz-
 ing a representative “code” limitation and a representative
 “system” limitation because the parties made “the same ar-
 guments” for each of the limitations in the respective
 groups. Claim Construction Order, 

2020 WL 8617821

,
 at *7–9. As the parties have not challenged this approach
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 6                                 DYFAN, LLC   v. TARGET CORP.



 00179-ADA, 

2020 WL 8617821

 (W.D. Tex. Nov. 24, 2020)
 (Claim Construction Order).
     The district court held that § 112 ¶ 6 applied to the
 “code”/“application” limitations and assigned a “special-
 purpose computer function” as the corresponding struc-
 ture. Id. at *6. Finding no “algorithm for the claimed spe-
 cial-purpose computer-implemented function” in the
 specification, the district court concluded that the relevant
 claims were “indefinite for failing to disclose corresponding
 structure.” Id. at *7. The district court likewise held that
 the “system” limitations were subject to § 112 ¶ 6 because
 they recited “purely functional language without sufficient
 structure,” and proclaimed it was “unclear which of the re-
 cited components perform the specified function.” Id. at *7.
 The district court concluded that those relevant claims
 were “indefinite for lack of corresponding structure” as
 well. Id. at *8.
      Based on the district court’s claim construction order,
 the parties stipulated to final judgment that the asserted
 claims are invalid as indefinite under § 112 ¶ 2. The dis-
 trict court entered judgment accordingly.
     Dyfan appeals. We have jurisdiction under 

28 U.S.C. § 1295

(a)(1).
                         DISCUSSION
                               I
     “Regarding questions of claim construction, including
 whether claim language invokes 

35 U.S.C. § 112

 [¶] 6, the
 district court’s determinations based on evidence intrinsic
 to the patent as well as its ultimate interpretations of the
 patent claims are legal questions that we review de novo.”


 on appeal, we will do the same here. We note that our anal-
 ysis with respect to the “code” limitations applies recipro-
 cally to the “application” limitations.
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 DYFAN, LLC   v. TARGET CORP.                                 7



 Williamson v. Citrix Online, LLC, 

792 F.3d 1339, 1346

 (Fed. Cir. 2015). If the district court, “in construing the
 claims, makes underlying findings of fact based on extrin-
 sic evidence, we review such findings of fact for clear error.”
 

Id.

                                II
     Section 112 governs the specification of a patent. Sec-
 tion 112 ¶ 6 provides:
     An element in a claim for a combination may be
     expressed as a means or step for performing a spec-
     ified function without the recital of structure, ma-
     terial, or acts in support thereof, and such claim
     shall be construed to cover the corresponding
     structure, material, or acts described in the speci-
     fication and equivalents thereof.
 Section 112 ¶ 6 offers patent applicants two options: (1) re-
 cite, in the claim, a function without reciting structure for
 performing the function and limit the claims to the struc-
 ture, materials, or acts disclosed in the specification (or
 their equivalents), in which case § 112 ¶ 6 applies, or (2) re-
 cite both a function and the structure for performing that
 function in the claim, in which case § 112 ¶ 6 is inapplica-
 ble. Williamson, 792 F.3d at 1347–48 (en banc in relevant
 part). Limitations that invoke § 112 ¶ 6 are generally
 known as “means-plus-function” or “step-plus-function”
 limitations.
     The overall means-plus-function analysis is a two-step
 process. See id. at 1349–51. The first step is to determine
 whether a claim limitation is drafted in means-plus-func-
 tion format, which requires us to construe the limitation to
 determine whether it connotes sufficiently definite struc-
 ture to a person of ordinary skill in the art. Id. at 1349. If
 the limitation connotes sufficiently definite structure, it is
 not drafted in means-plus-function format, and § 112 ¶ 6
 does not apply. If, however, we conclude that the limitation
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 8                                  DYFAN, LLC   v. TARGET CORP.



 is in means-plus-function format, we perform the second
 step of determining “what structure, if any, disclosed in the
 specification corresponds to the claimed function.” Id. at
 1351.
      Because invoking § 112 ¶ 6 is typically a choice left to
 the claim drafter, we presume at the first step of the anal-
 ysis that a claim limitation is subject to § 112 ¶ 6 when the
 claim language includes the term “means.” Id. at 1348
 (noting that this court has “long recognized the importance
 of the presence or absence of the word ‘means’”). The in-
 verse is also true—we presume that a claim limitation is
 not drafted in means-plus-function format in the absence
 of the term “means” Id. We have made clear, however,
 that this presumption is rebuttable. The presumption can
 be overcome if a challenger demonstrates that the claim
 term “fails to ‘recite sufficiently definite structure.’” Id. at
 1349. We have also held that “nonce words that reflect
 nothing more than verbal constructs may be used in a
 claim in a manner that is tantamount to using the word
 ‘means,’” and can invoke § 112 ¶ 6. Id. at 1350. We have
 emphasized that “the essential inquiry is not merely the
 presence or absence of the word ‘means,’ but whether the
 words of the claim are understood by persons of ordinary
 skill in the art to have a sufficiently definite meaning as
 the name for structure.” Id. at 1348; accord Zeroclick, LLC
 v. Apple Inc., 

891 F.3d 1003, 1007

 (Fed. Cir. 2018). “What
 is important is . . . that the term, as the name for structure,
 has a reasonably well understood meaning in the art.”
 Greenberg v. Ethicon Endo-Surgery, Inc., 

91 F.3d 1580, 1583

 (Fed. Cir. 1996).
     Intrinsic evidence, such as the claims themselves and
 the prosecution history, can be informative in determining
 whether the disputed claim language recites sufficiently
 definite structure or was intended to invoke § 112 ¶ 6. Ap-
 ple Inc. v. Motorola, Inc., 

757 F.3d 1286, 1299

 (Fed. Cir.
 2014); see also Phillips v. AWH Corp., 

415 F.3d 1303, 1317

 (Fed. Cir. 2005) (en banc) (The prosecution history “often
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 DYFAN, LLC   v. TARGET CORP.                                9



 inform[s] the meaning of the claim language by demon-
 strating how the inventor understood the invention.”). In
 addition, because this inquiry turns on the understanding
 of a person of ordinary skill in the art, we often look to ex-
 trinsic evidence when determining whether a disputed lim-
 itation would have connoted structure to a person of
 ordinary skill. Linear Tech. Corp. v. Impala Linear Corp.,
 

379 F.3d 1311

, 1320 (Fed. Cir. 2004) (noting expert witness
 testimony and technical dictionaries “help determine
 whether a claim term” would have had an “understood
 meaning in the art”) (quoting CCS Fitness, Inc. v. Bruns-
 wick Corp., 

288 F.3d 1359, 1369

 (Fed. Cir. 2002)).
      Claim terms “need not connote a single, specific struc-
 ture,” and may instead “describe a class of structures” and
 still recite “sufficiently definite structure” to not invoke
 § 112 ¶ 6. Apple, 

757 F.3d at 1300

. In Apple, we explained
 that structure can be recited in various ways, including
 through the use of “a claim term with a structural defini-
 tion that is either provided in the specification or generally
 known in the art,” or a description of the claim limitation’s
 operation and “how the function is achieved in the context
 of the invention.” 

Id. at 1299

.
      In cases where it is clear that a claim term itself con-
 notes some structure to a person of ordinary skill in the art,
 “the presumption that § 112, ¶ 6 does not apply is determi-
 native” in the absence of “more compelling evidence of the
 understanding of one of ordinary skill in the art.” Apex Inc.
 v. Raritan Comput., Inc., 

325 F.3d 1364, 1373

 (Fed. Cir.
 2003). For example, in Apex, the disputed claim limitations
 included a set of “circuit” limitations. 

Id. at 1369

. Raritan
 relied on district court decisions addressing the definition
 of “circuit means”; expert testimony that the term “circuit”
 would have been “understood by one of ordinary skill in the
 art as a very broad term”; and the description of preferred
 embodiments in the specification to establish that “circuit”
 did not connote sufficiently definite structure to a person of
 ordinary skill. 

Id.

 at 1373–74. We disagreed, however, and
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 10                                 DYFAN, LLC   v. TARGET CORP.



 found that “this evidence [was] not sufficient to rebut the
 § 112, ¶ 6 presumption” because it “fail[ed] to show by a
 preponderance of the evidence that one of ordinary skill in
 the art believes the term does not recite sufficiently defi-
 nite structure.” Id. at 1373. Relying on a dictionary defi-
 nition that defined “circuit” as a “combination of a number
 of electrical devices and conductors that, when intercon-
 nected to form a conducting path, fulfill some desired func-
 tion,” we determined that “‘circuit,’ by itself connotes some
 structure.” Id. (quotation omitted).
     We have also explained, however, that even in the ab-
 sence of terms such as “means,” claims are nevertheless
 subject to § 112 ¶ 6 when the limitation in question has “no
 commonly understood meaning and is not generally viewed
 by one skilled in the art to connote a particular structure.”
 Media Rights Techs., Inc. v. Capital One Fin. Corp., 

800 F.3d 1366, 1372

 (Fed. Cir. 2015). For example, in Rain
 Computing, Inc. v. Samsung Electronics America, Inc., we
 determined that the claim limitation “user identification
 module” did not “provide any indication of structure” and
 that the surrounding claim language failed to provide “any
 structure for performing the claimed function,” thus invok-
 ing § 112 ¶ 6 without reciting “means.” 

989 F.3d 1002, 1006

 (Fed. Cir. 2021).
                              III
     With these legal principles in mind, we turn to the
 claim limitations at issue. The district court concluded
 that the disputed limitations are subject to § 112 ¶ 6 and
 indefinite under § 112 ¶ 2 for lack of corresponding struc-
 ture in the specification. We disagree with this conclusion.
     The means-plus-function analysis asks two questions.
 First: Is the disputed claim limitation drafted in means-
 plus-function format? Williamson, 

792 F.3d at 1349

. Sec-
 ond, if and only if the answer to the first question is “yes”:
 What, if any, is the structure corresponding to the claimed
 function? 

Id. at 1351

. As we explain below, only the first
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 DYFAN, LLC   v. TARGET CORP.                                11



 question of the means-plus-function analysis is relevant in
 this case. 3
                                A
     We begin with the “code”/“application” limitations. The
 representative limitation analyzed by the parties and the
 district court is:
     said code, when executed, further configured to . . .
     after the first visual information is caused to be
     output based on the first location-relevant infor-
     mation; after the at least one mobile device is
     moved in the building; and in response to the re-
     ceipt, from the at least one server and via the sec-
     ond wireless communications protocol, of the
     second response message including the second lo-
     cation-relevant information: cause to be output,
     via the at least one mobile device, the second visual
     information based on the second location-relevant
     information . . . .
 ’292 patent col. 41 l. 47–col. 42 l. 6.
     The district court correctly “start[ed] with the pre-
 sumption that § 112, ¶ 6 does not apply” because “means”
 does not appear in the limitation. Claim Construction Or-
 der, 

2020 WL 8617821

, at *6. To overcome this presump-
 tion, Target had to show, by a preponderance of the
 evidence, that persons of ordinary skill in the art would not
 have understood the “code”/“application” limitations to



     3    We note that under the second step of the means-
 plus-function analysis, the district court looked to the spec-
 ifications of the ’292 and ’899 patents and did not find suf-
 ficient structure corresponding to the recited functions of
 the disputed limitations to avoid the application of § 112
 ¶ 6. Because we end the analysis at the first step, we need
 not reach or address errors with respect to the second step.
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 12                                DYFAN, LLC   v. TARGET CORP.



 connote structure in light of the claim as a whole. Apex,
 325 F.3d at 1372–73 (“From a procedural standpoint, this
 presumption imposes on [the party challenging the pre-
 sumption] the burden of going forward with evidence to re-
 but . . . the presumption” by showing that a person of
 ordinary skill in the art “believes the term does not recite
 sufficiently definite structure.”) (quotation omitted); Lin-
 ear Tech., 379 F.3d at 1319–20. The district court con-
 cluded that it did. But the district court erred by ignoring
 key evidence—unrebutted deposition testimony from Tar-
 get’s own expert, Dr. Goldberg—regarding how a person of
 ordinary skill would have understood the “code”/“applica-
 tion” limitations. Claim Construction Order, 

2020 WL 8617821

, at *8.
      Dr. Goldberg testified that here, “application” is “a
 term of art” that a person of ordinary skill in the art would
 have understood as a particular structure. See, e.g.,
 J.A. 886 (Goldberg Dep. 58:4–6). More specifically, Dr.
 Goldberg testified that the term “application” would have
 been commonly understood to mean a “computer program
 intended to provide some service to a user,” and that devel-
 opers could have, at the relevant time, selected existing
 “off-the-shelf software” to perform specific services and
 functions. J.A. 884–86 (Goldberg Dep. 53:21–58:21); J.A.
 924 (Goldberg Dep. 211:1–212:1).
     Additionally, Dr. Goldberg testified that persons of or-
 dinary skill would have understood that the word “code,”
 when coupled with language describing its operation, here
 connotes structure. See, e.g., J.A. 882–83 (Goldberg Dep.
 44:16–48:16); J.A. 884–85 (Goldberg Dep. 52:25–54:18);
 J.A. 886 (Goldberg Dep. 59:25–62:14). Dr. Goldberg ex-
 plained that a person of ordinary skill would understand
 that “code” is “a bunch of software instructions.” J.A. 909
 (Goldberg Dep. 152:10–25). Dr. Goldberg also testified that
 a person of ordinary skill would have known that the
 claimed function of displaying information could be
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 DYFAN, LLC   v. TARGET CORP.                               13



 implemented using “off-the-shelf” code or applications.
 J.A. 884–85 (Goldberg Dep. 53:21–54:18).
     None of this testimony is rebutted. Dr. Goldberg’s tes-
 timony thus demonstrates that, contrary to the district
 court’s unsupported assertion, the claim limitations do not
 recite “purely functional language.” Claim Construction
 Order, 

2020 WL 8617821

, at *6. Instead, Dr. Goldberg’s
 unrebutted testimony demonstrates that the “code”/“appli-
 cation” limitations here connote a class of structures to a
 person of ordinary skill. 

Id.

     The district court also erred by not following our court’s
 recent decision in Zeroclick. There, the district court deter-
 mined that the claim limitations “program” and “user in-
 terface code” invoked § 112 ¶ 6. Zeroclick, 891 F.3d at
 1006–07. We reversed, explaining that the district court
 erred by “not giving effect to the unrebutted presumption
 against the application of § 112, ¶ 6.” Id. at 1008. We fur-
 ther explained that a person of ordinary skill in the art
 would have been able to “reasonably discern from the claim
 language” that the disputed limitations “program” and
 “user interface code” were references to conventional pro-
 grams or code “existing in [the] prior art at the time of the
 invention[]” and were not used as “generic terms or black
 box recitations of structure or abstractions.” Id. Because
 the disputed limitations were references to conventional
 structures known to persons of ordinary skill in the perti-
 nent art, and because the district court failed to properly
 apply the presumption and “made no pertinent finding that
 compel[led] the conclusion” that the limitations “user inter-
 face program” or “code” were used “in common parlance as
 substitute for ‘means,’” we rejected the district court’s de-
 termination that the claims were subject to § 112 ¶ 6 and
 vacated judgment of invalidity. Id. at 1009. That same
 rationale applies here, particularly in view of Dr. Gold-
 berg’s unrebutted testimony that “code” and “application”
 would have connoted structure to a person of ordinary skill
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 14                                 DYFAN, LLC   v. TARGET CORP.



 and given the availability of off-the-shelf code to perform
 the recited claim functions.
     Unlike in the mechanical arts, the specific structure of
 software code and applications is partly defined by its func-
 tion. Apple, 757 F.3d at 1298–99. In determining whether
 software limitations like those at issue here recite suffi-
 cient structure, we can look beyond the initial “code” or “ap-
 plication” term to the functional language to see if a person
 of ordinary skill would have understood the claim limita-
 tion as a whole to connote sufficiently definite structure.
 Zeroclick, 

891 F.3d at 1008

 (concluding that the disputed
 terms are used “not as generic terms or black box recita-
 tions of structure or abstractions, but rather as specific ref-
 erences to conventional . . . code, existing in prior art at the
 time of the inventions.”); Linear Tech., 379 F.3d at 1320
 (“[W]hen the structure-connoting term . . . is coupled with
 a description of the [term’s] operations, sufficient struc-
 tural meaning generally will be conveyed to persons of or-
 dinary skill in the art, and § 112 ¶ 6 presumptively will not
 apply.”); Apple, 757 F.3d at 1298–99. Dr. Goldberg ex-
 plained that here, “code” and “application” (which them-
 selves connote structure) in combination with the
 recitation of the code or application’s operation would have
 connoted structure to persons of ordinary skill.
     Reviewing the alleged means-plus-function limitation
 in full, the claim requires code configured to be imple-
 mented on a mobile device to display information via a dis-
 play of the mobile device, receive information (including
 location-relevant information) via a wireless communica-
 tions protocol, and display visual information based on the
 received location-relevant information after certain condi-
 tions are met. See J.A. 906 (Goldberg Dep. 140:23–141:13).
 Dr. Goldberg testified that persons of ordinary skill in the
 art would have known of off-the-shelf code and applications
 for displaying any desired information. He explained: “[I]f
 the developer knows what he wants to display, then there
 are software modules he can use to generate the display of
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 DYFAN, LLC   v. TARGET CORP.                                15



 the content that he wants to display. . . . [I]f the developer
 knows exactly how they want to take information that’s
 been received and generate a message from that, then the
 developer would know how to do that using a software li-
 brary.” J.A. 924 (Goldberg Dep. 213:4–213:25). As Dr.
 Goldberg further explained, wireless communication “pro-
 tocol[s]” were terms of art well-understood by persons of
 ordinary skill, J.A. 876 (Goldberg Dep. 18:17–21:10), and
 conventional off-the-shelf “code” on a mobile device “would
 implement the [communication] protocols,” J.A. 882 (Gold-
 berg Dep. 43:10–45:9). Accordingly, because the recited
 functions can be performed by conventional off-the-shelf
 software, a person of ordinary skill in the art would have
 understood the alleged means-plus-function “code” limita-
 tions in the asserted claims to connote structure. See Zero-
 click, 

891 F.3d at 1008

.
     For all these reasons, we conclude that the “code”/“ap-
 plication” limitations are not written in means-plus-func-
 tion format because they would have connoted sufficiently
 definite structure to persons of ordinary skill in the art.
                                B
     We turn next to the disputed “system” limitations. Alt-
 hough “system” in representative claim 15 of the ’292 pa-
 tent also appears in the preamble, the disputed “system”
 limitation appears in the “wherein” clause:
     15. A system, comprising:
     a building . . .
     a first broadcast short-range communications
     unit . . .
     a second broadcast short-range communications
     unit . . .
     code . . .
     said code, when executed, further configured to . . .
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 16                                 DYFAN, LLC   v. TARGET CORP.



          . . . cause to be output, via the at least one mo-
      bile device, the first visual information based on
      the first location-relevant information. . .
          . . . cause to be output, via the at least one mo-
      bile device, the second visual information based on
      the second location-relevant information. . .
      at least one server . . .
      wherein the system is configured such that the first
      visual information is automatically caused to be
      output without requiring communication of the at
      least one first message with the first broadcast
      short-range communications unit after the receipt
      of the indication of the receipt of the one or more
      first broadcast messages, and the second visual in-
      formation is automatically caused to be output
      without requiring communication of the at least
      one second message with the second broadcast
      short-range communications unit after the receipt
      of the indication of the receipt of the one or more
      second broadcast messages.
 ’292 patent col. 39 l. 61–col. 42 l. 18 (emphasis added to
 disputed limitation).
     At the outset, we presume that § 112 ¶ 6 does not apply
 here because the disputed limitation does not recite
 “means.” Williamson, 

792 F.3d at 1348

. The district court
 did not properly apply this presumption for the “system”
 limitations. In the absence of the word “means,” Target
 bore the burden of demonstrating by a preponderance of
 the evidence that the “system” limitation in the wherein
 clause fails to recite sufficiently definite structure. See
 Apex, 

325 F.3d at 1373

; Linear Tech., 379 F.3d at 1319–20.
    We conclude that Target did not satisfy this burden.
 Both Target and the district court suggest that “‘system’
 may be a nonce word” used as a substitute for the word
 “means.” The district court noted that it had, in other
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 DYFAN, LLC   v. TARGET CORP.                                17



 cases, found that “system” functioned as a “verbal con-
 struct that is not recognized as the name of structure.”
 Claim Construction Order, 

2020 WL 8617821

, at *8 (citing
 Joao Control & Monitoring Sys., LLC v. Protect Am., Inc.,
 No. 1-14-cv-134-LY, 

2015 WL 4937464

, at *5 (W.D. Tex.
 Aug. 18, 2015)). We agree that, in a vacuum, the term “sys-
 tem” may well be a nonce term. But in this case, the claim
 language itself defines the “system” to include specified
 structure. The “system” limitation in the wherein clause
 derives antecedent basis from the “system” recited in the
 preamble, which the claim states comprises “a building”
 having “a first broadcast short-range communications
 unit,” “a second broadcast short-range communications
 unit,” “code” executed by at least one “mobile device,” and
 “at least one server.” ’292 patent col. 39 l. 61–col. 42 l. 18.
 Each of these limitations recited in the claims are struc-
 tural components of the “system.” 4
      Target and the district court further assert that, even
 if “system” connotes some structure in the context of this
 claim, “the claims do not specify which of the components
 in the system perform [the recited] function” in the wherein
 clause. Claim Construction Order, 

2020 WL 8617821

,
 at *7. According to the district court, it is possible that “an
 unspecified black box component in lieu of the recited com-
 ponents performs the specified function.” 

Id.

 We disagree.
      As noted above, the claim states that the “system” in-
 cludes “a building” having “a first broadcast short-range
 communications unit,” “a second broadcast short-range
 communications unit,” “code” executed by at least one “mo-
 bile device,” and “at least one server.” ’292 patent col. 39
 l. 61–col. 42 l. 6. The wherein clause at issue further


     4  Dr. Goldberg admitted that “system,” as recited in
 the wherein clause, “is referring to, in total, all the compo-
 nents of the system already laid out” previously in the
 claim. J.A. 917 (Goldberg Dep. 184:14–185:21).
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 18                                DYFAN, LLC   v. TARGET CORP.



 specifies that “the system is configured such that the first
 visual information is automatically caused to be output . . .
 and the second visual information is automatically caused
 to be output . . . .” 

Id.

 at col. 42 ll. 7–18.
      The claim limitations preceding the wherein clause
 make clear that the “code” causes the output (or display) of
 visual information based on “location-relevant infor-
 mation.” 

Id.

 at col. 39 l. 61–col. 42 l. 6. In particular, the
 claim limitations specify that “said code, when executed . . .
 cause[s] to be output, via the at least one mobile device, the
 first visual information based on the first location-relevant
 information” and “cause[s] to be output, via the at least one
 mobile device, the second visual information based on the
 second location-relevant information.” 

Id.

 The message is
 transmitted via a wireless communications protocol differ-
 ent from the protocol over which the broadcast message
 was received. 

Id.

 In response to receiving the message, the
 server retrieves and transmits “location-relevant infor-
 mation” to the mobile device. 

Id.

 Building on the earlier
 limitations, the wherein clause of representative claim 15
 establishes that the previously recited function—output-
 ting visual information—performed by the “code” compo-
 nent of the “system” is performed automatically without
 the reinvolvement of the short-range communication units.
 

Id.

 at col. 42 ll. 7–18. Although the wherein clause does not
 expressly refer to the previously recited “code,” it refer-
 ences specific functions that are defined or introduced in
 the code limitations and thus demonstrates that it is the
 code that performs the function recited in the wherein
 clause. Furthermore, as we explained above in Sec-
 tion III.A, here, “code,” both alone and in the context of the
 recited claim limitation, connotes sufficiently definite
 structure to a person of ordinary skill in the art.
     For the reasons above, we conclude that the “system”
 limitations are not written in means-plus-function format
 because they connote sufficiently definite structure to per-
 sons of ordinary skill in the art.
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 DYFAN, LLC   v. TARGET CORP.                                19



                                ***
      We recognize that the asserted claims are not models
 of clarity, but poor claim drafting does not allow courts to
 bypass the presumption that a claim does not invoke § 112
 ¶ 6 in the absence of the word “means.” Nor does it relieve
 courts of their duty to evaluate whether that presumption
 has been overcome.
                          CONCLUSION
     We have considered the parties’ remaining arguments
 and find them unpersuasive. For the foregoing reasons, we
 disagree with the district court’s claim constructions and
 therefore reverse the district court’s judgment of invalidity
 and remand for further proceedings.
                REVERSED AND REMANDED
                                COSTS
 No costs.