       NOTE: This disposition is nonprecedential.


  United States Court of Appeals
      for the Federal Circuit
                 ______________________

                 SPEEDTRACK, INC.,
                  Plaintiff-Appellant,

                            v.

        ENDECA TECHNOLOGIES, INC., AND
           WALMART.COM USA, LLC,
            Defendants-Cross-Appellants.
              ______________________

                       2012-1319
                 ______________________

   Appeal from the United States District Court for the
Northern District of California in No. 06-CV-7336, Judge
Phyllis J. Hamilton.
                 ______________________

                 Decided: April 16, 2013
                 ______________________

    RODERICK G. DORMAN, McKool Smith Hennigan, P.C.,
of Los Angeles, California, argued for plaintiff-appellant.
With him on the brief were ALAN P. BLOCK, MARC MORRIS,
and MIEKE MALMBERG; STEVEN J. POLLINGER and JOEL L.
THOLLANDER, of Austin, Texas.

   STEVEN M. BAUER, Proskauer Rose, LLP, of Boston,
Massachusetts, argued for defendants-cross appellants.
2                SPEEDTRACK, INC.   v. WALMART.COM USA, LLC

With him on the brief was JOEL CAVANAUGH. Of counsel
on the brief for defendant-cross appellant Walmat.com
USA, LLC was NOEL ANDREW LEIBNITZ, Farella, Braun +
Martel LLP, of San Francisco, California.
                ______________________

    Before DYK, MOORE, and WALLACH, Circuit Judges.
WALLACH, Circuit Judge.
     Speedtrack, Inc. (“Speedtrack”) is the assignee and
owner of U.S. Patent No. 5,544,360 (the “’360 patent”).
Speedtrack instituted a patent infringement action
against Walmart.com USA, LLC (“Walmart”) alleging
that Walmart infringed independent claims 1 and 20, as
well as dependent claims 2–4, 7, 11–14, and 21 of the ’360
patent (“asserted claims”). Endeca Technologies, Inc.
(“Endeca”) subsequently intervened against Speedtrack
seeking a declaratory judgment of noninfringement and
invalidity, claiming the allegedly infringing platform
utilized in Walmart’s online retail website was its propri-
etary product. After claim construction, the district court
granted Walmart and Endeca’s motion for summary
judgment of noninfringement from which Speedtrack now
appeals. Walmart and Endeca cross-appeal the district
court’s decision granting Speedtrack’s motion for sum-
mary judgment holding that the ’360 patent is not invalid.
The district court’s decisions are affirmed.
                      BACKGROUND
     The ’360 patent, entitled “Method for Accessing Com-
puter Files and Data, Using Linked Categories Assigned
to Each Data File Record on Entry of the Data File Rec-
ord,” is directed to a computer filing system for accessing
files and data according to user-designated criteria. ’360
patent at [57]. In particular, the invention allows a user
to define categories for files stored in a computer system
and edit those categories as they are used, label each file
with all applicable categories, and to link categories in
 SPEEDTRACK, INC.   v. WALMART.COM USA, LLC                3
user-definable ways. Id. col. 3 l. 66–col. 4 l. 2. In the
process of search and retrieval of files, the invention
ensures that the user defines a filter which will always
find at least one file, thus avoiding time in searching and
retrieving for data that cannot be matched. Id. col. 4 ll. 5–
9.
    Independent claim 1 recites, in part, the following:
    A method for accessing files in a data storage sys-
    tem of a computer system having means for read-
    ing and writing data from the data storage
    system, displaying information, and accepting us-
    er input, the method comprising the steps of:
        (a) initially creating in the computer system a
    category description table containing a plurality of
    category descriptions, each category description
    comprising a descriptive name, the category de-
    scriptions having no predefined hierarchical rela-
    tionship with such list or each other;
        (b) thereafter creating in the computer system
    a file information directory comprising at least
    one entry corresponding to a file on the data stor-
    age system, each entry comprising at least a
    unique file identifier for the corresponding file,
    and a set of category descriptions selected from
    the category description table; and
        (c) thereafter creating in the computer system
    a search filter comprising a set of category de-
    scriptions, wherein for each category description
    in the search filter there is guaranteed to be at
    least one entry in the file information directory
    having a set of category descriptions matching the
    set of category descriptions of the search filter.
Id. col. 16 l. 54–col. 17 l. 11. In addition, independent
claim 20 states, in relevant portion:
4                 SPEEDTRACK, INC.   v. WALMART.COM USA, LLC
    A method for accessing files in a data storage sys-
    tem of a computer system having means for read-
    ing and writing data from the data storage
    system, displaying information, and accepting us-
    er input, wherein each file located on the data
    storage system has a file name, the method com-
    prising the steps of:
        (a) initially defining in the computer system at
    least one list having a plurality of category de-
    scriptions, each category description comprising a
    descriptive name, the category descriptions hav-
    ing no predefined hierarchical relationship with
    such list or each other;
         (b) thereafter accepting user input associating
    with a file at least one category description from
    at least one defined list . . . .
Id. col. 20 ll. 1–14. Figure 5 is exemplary of the invention.




A Categories Window 50 is illustrated on the right side of
the display, with a File Window 52 on the left side. Id. col.
8 ll. 32–34. Category types 54 are shown at the top of the
 SPEEDTRACK, INC.   v. WALMART.COM USA, LLC              5
Categories Windows 50, with category descriptions 56
shown in the columns below. Id. col. 8 ll. 34–36. A display
of a tally 58 of the number of files matching selected
categories is also shown. Id. col. 8 ll. 36–38. The user may
edit the category type headings, category descriptions,
and selection of category descriptions to apply to particu-
lar files. Id. col. 8 ll. 39–42, 64–65.
    On November 29, 2006, Speedtrack instituted this ac-
tion against, among other defendants, Walmart, alleging
that Walmart’s online retail website infringes the ’360
patent. On April 12, 2007, the district court allowed
Endeca to file a complaint in intervention against Speed-
track because Walmart’s alleged infringing website uses
Endeca’s “Information Access Platform” in order to allow
users to search for products online. As such, Endeca
sought a declaratory judgment that Endeca’s “Information
Access Platform” does not infringe the ’360 patent and
that the patent is invalid. Endeca and Walmart (herein-
after, “Endeca”) proceeded jointly from this point forward.
    A claim construction hearing was held in March 2008,
and an order construing the claims issued on June 19,
2008. Speedtrack, Inc. v. Wal-Mart Stores, Inc., No. C06–
7336PJH, 2008 WL 2491701 (N.D. Cal. June 19, 2008). In
November 2008, the parties moved for summary judg-
ment on infringement and invalidity issues. While the
parties’ summary judgment motions were pending, the
Patent and Trademark Office (“PTO”) granted Endeca’s
request for an ex parte reexamination of the asserted
claims on January 12, 2009. The summary judgment
motions were terminated, and the district court litigation
was stayed pending reexamination.
    On March 3, 2011, the PTO issued its decision in the
reexamination proceedings, confirming the patentability
of the ’360 patent with an amendment—the addition of
one independent claim. Subsequently, at the district
court, the parties submitted cross-motions for summary
6                 SPEEDTRACK, INC.   v. WALMART.COM USA, LLC
judgment. Specifically, Speedtrack’s motion sought a
determination of infringement and a determination that
the ’360 patent was not invalid. Endeca’s motion was
limited to the issue of noninfringement.
    During the November 16, 2011 hearing on the parties’
cross-motions for summary judgment, the district court
recognized the need for further briefing with respect to
the proper construction of the claim term “category de-
scription.” After the parties submitted further briefing on
this matter, the district court issued an order on February
22, 2012, in relevant part: (1) granting Endeca’s motion
for summary judgment of noninfringement, which was
predicated on the construction of “category description”
and (2) granting Speedtrack’s motion for summary judg-
ment of validity. Speedtrack, Inc. v. Wal-Mart Stores, Inc.,
No. C06–7336PJH, 2012 WL 581338, at *11 (N.D. Cal.
Feb. 22, 2012) (“Summ. J. Decision”). Speedtrack timely
appeals and Endeca cross-appeals. We have jurisdiction
pursuant to 28 U.S.C. § 1295(a)(1).
                       DISCUSSION
     Speedtrack raises the following issues on appeal: (1)
whether the district court erred in the construction of the
the claim term “category description”; (2) whether the
district court erred in granting summary judgment of no
literal infringement based on an improper construction of
“category description”; (3) whether the district court
abused its discretion in holding that Endeca was not
judicially estopped from arguing that “category descrip-
tion” cannot consist solely of numeric identifiers; and (4)
whether the district court abused its discretion in refusing
to allow Speedtrack to amend its infringement conten-
tions. Endeca on cross-appeal raises whether the district
court erred in granting Speedtrack’s motion for summary
judgment of validity. We address the parties’ arguments
seriatim.
 SPEEDTRACK, INC.   v. WALMART.COM USA, LLC               7
                             A.
    1. The District Court Did Not Err in Construing
       “Category Description”
    We review a district court’s claim construction de no-
vo. Cybor Corp. v. FAS Techs., Inc., 138 F.3d 1448, 1454–
55 (Fed. Cir. 1998) (en banc). To ascertain the scope and
meaning of the asserted claims, we look to the words of
the claims themselves, the specification, the prosecution
history, and, if necessary, any relevant extrinsic evidence.
Chicago Bd. Options Exch., Inc. v. Int’l Sec. Exch., LLC,
677 F.3d 1361, 1366 (Fed. Cir. 2012) (citing Phillips v.
AWH Corp., 415 F.3d 1303, 1315–17 (Fed. Cir. 2005) (en
banc)).
    “This court reviews the district court’s grant or denial
of summary judgment under the law of the regional
circuit.” MicroStrategy, Inc. v. Bus. Objects, S.A., 429 F.3d
1344, 1349 (Fed. Cir. 2005). The Ninth Circuit reviews a
district court’s grant or denial of summary judgment de
novo. Surrell v. Cal. Water Serv. Co., 518 F.3d 1097, 1103
(9th Cir. 2008). Summary judgment may be granted only
where “there is no genuine dispute as to any material fact
and the movant is entitled to judgment as a matter of
law.” Fed. R. Civ. P. 56(a). In making this determination,
a court must “draw all reasonable inferences in favor of
the nonmoving party, and it may not make credibility
determinations or weigh the evidence.” Reeves v. Sander-
son Plumbing Prods., Inc., 530 U.S. 133, 150 (2000).
    The district court construed “category description” to
mean: “information that includes a name that is descrip-
tive of something about a stored file.” Summ. J. Decision
*9. The parties’ dispute here centers on whether “catego-
ry description” requires an alphabetic descriptive name or
whether the term may include a name composed solely of
nonalphbetic characters, e.g., consisting solely of num-
bers. Speedtrack argues for the latter, whereas Endeca
argues for the former definition. Upon review of the claim
8                 SPEEDTRACK, INC.   v. WALMART.COM USA, LLC
language, specification, and prosecution history, “category
description” is construed to require information that must
include, but which is not limited to, an alphabetic descrip-
tive name.
    Turning to the claim language, independent claims 1
and 20 require “category description” to comprise a “de-
scriptive name.” This reference is instructive in that
“category description” comprising a “descriptive name” is
expressly distinguished from a “category description
identifier.” For example, dependent claim 4 covers a
method for accessing files, wherein the step of creating a
category description table comprises, in part, the steps of:
“(3) creating a unique category description identifier
associated with the new category description; and (4)
storing the new category description and unique category
description identifier in the category description table.”
’360 patent col. 17 ll. 19–30 (emphases added). Thus, the
claims distinguish between a “category description” and a
“category description identifier,” in which case, we must
presume a difference in meaning and scope between the
two terms. Chicago Bd., 677 F.3d at 1369.
    The specification does not alter this presumption, but
rather, further defines “category description” differently
than “category description identifiers.” For instance, the
specification provides that each “category description” is a
“descriptive name,” which are in alphabetic form, e.g.,
“AGREEMENTS, E–MAIL, MEMOS, NEWSLETTER,
etc.” ’360 patent col. 5 ll. 7–11. Figure 5 also depicts
“category descriptions 56 arrayed in columns below the
category types 54” in alphabetic form. Id. fig. 5 (illustrat-
ing “category descriptions 56” as, e.g., ADVANCES, BETA
TESTING, BUGS, etc.).
    On the contrary, the specification provides an exam-
ple of “category description identifiers,” explaining that it
is “preferably a number, but other identifiers could be
used.” Id. col. 5 ll. 12–14 (emphasis added). The differ-
 SPEEDTRACK, INC.   v. WALMART.COM USA, LLC                  9
ences between a “category description” and “category
description identifiers” are further illuminated in that the
claimed invention can be implemented without using
“identifiers,” although the claimed invention must include
“category descriptions.” Id. col. 5 ll. 17–20; see also id. col.
5 ll. 15–16 (“If a user changes the name of a category
description, the associated identifier is not changed.”).
Hence, the claim language and the specification distin-
guish between “category description,” which comprises of
“descriptive names” and “category description identifiers,”
which preferably comprises numerical identifiers. Noth-
ing in the prosecution history alters this conclusion.
Accordingly, the intrinsic evidence supports a construc-
tion where a “category description” requires information
that must include, but which is not limited to, an alpha-
betic descriptive name.
    Speedtrack nevertheless argues that Figure 4, which
depicts a preferred embodiment of the file information
directory, shows that category descriptions are referred to
by numeric expressions and not by the associated alpha-
betic expression of names. Figure 4 is depicted below:
10                 SPEEDTRACK, INC.   v. WALMART.COM USA, LLC




The figure illustrates an example of a File Information
Directory where each entry has data fields that corre-
spond to the file name, file location, file creation time,
number of associated categories, and “an array of the
identifiers of the associated categories.” Id. col. 6. ll. 26–32
(emphasis added). It is the “identifiers” that are ex-
pressed in numeric form and not the “category descrip-
tion” as Speedtrack claims. Accordingly, Figure 4 does
not detract from the clear distinction in the ’360 patent
between “category description” and computer-generated
“category description identifiers,” which preferably may
be associated with the category description. ’360 patent
col 5 ll. 11-17.
The intrinsic evidence provides sufficient guidance in
construing “category description,” and as a result,
Speedtrack’s references to extrinsic evidence need not be
considered. Thus, “category description” means: “infor-
mation that includes a name that is descriptive of some-
thing about a stored file.” “Name,” as used in the claim
language, requires “information” that must include, but is
not limited to, a description in alphabetic form.
 SPEEDTRACK, INC.   v. WALMART.COM USA, LLC             11
Likewise, because the district court’s construction of this
disputed term is affirmed, we hold that the district court
did not err in granting Endeca’s motion for summary
judgment of noninfringement.          In particular, it was
Speedtrack’s burden to demonstrate that the “walmart-
sgmt0.records.binary” file in Endeca’s accused system
contains entries that are comprised of alphabetic descrip-
tive names, if it was to prove that Endeca’s accused
system infringes. Summ. J. Decision *10. Because it is
undisputed that these entries consist only of a series of
numerical identifiers, Endeca is entitled to summary
judgment of noninfringement as a matter of law. There-
fore, the district court’s decision granting Endeca’s motion
for summary judgment of noninfringement is affirmed.
   2. The District Court Did Not Abuse Its Discretion in
      Holding That Endeca Was Not Judicially Es-
      topped From Arguing That “Category Description”
      Cannot Consist Solely of Numeric Identifiers
    Judicial estoppel, which is not unique to patent law, is
reviewed under the law of the regional circuit in which
the trial court sits. Wang Labs., Inc. v. Applied Computer
Sci.,, Inc., 958 F.2d 355, 358 (Fed. Cir. 1992). The Ninth
Circuit reviews the district court’s application of judicial
estoppel for abuse of discretion. Hamilton v. State Farm
Fire & Cas. Co., 270 F.3d 778, 782 (9th Cir. 2001).
    Judicial estoppel is an equitable doctrine that pre-
cludes a party from gaining an advantage by asserting
one position, and then later seeking another advantage by
taking a clearly inconsistent position. Rissetto v. Plumbers
& Steamfitters Local 343, 94 F.3d 597, 600–01 (9th Cir.
1996). Courts invoke judicial estoppel for “general con-
sideration[s] of the orderly administration of justice and
regard for the dignity of judicial proceedings,” and to
“protect against a litigant playing fast and loose with the
courts.” Russell v. Rolfs, 893 F.2d 1033, 1037 (9th Cir.
1990).
12                 SPEEDTRACK, INC.   v. WALMART.COM USA, LLC
    Several factors typically inform the decision whether
to apply the doctrine in a particular case:
     First, a party’s later position must be “clearly in-
     consistent” with its earlier position.        Second,
     courts regularly inquire whether the party has
     succeeded in persuading a court to accept that
     party’s earlier position, so that judicial acceptance
     of an inconsistent position in a later proceeding
     would create “the perception that either the first
     or the second court was misled.” Absent success
     in a prior proceeding, a party’s later inconsistent
     position introduces no “risk of inconsistent court
     determinations,” and thus no threat to judicial in-
     tegrity. A third consideration is whether the par-
     ty seeking to assert an inconsistent position would
     derive an unfair advantage or impose an unfair
     detriment on the opposing party if not estopped.
     Additional considerations may inform the doc-
     trine’s application in specific factual contexts.
New Hampshire v. Maine, 532 U.S. 742, 750–51 (2001)
(citations omitted).
    The district court did not abuse its discretion in refus-
ing to apply judicial estoppel in this case. Speedtrack
argues that Endeca’s arguments related to the disputed
term “category description” were inconsistent with Ende-
ca’s earlier position. In particular, Speedtrack points to
Endeca’s request for reexamination of the ’360 patent and
the invalidity arguments it presented in the request to
the PTO—namely, contentions pertaining to U.S. Patent
No. 5,062,074 (“Kleinberger”). Speedtrack contends that
Endeca’s argument before the PTO depended in signifi-
cant part on the assertion that the Kleinberger reference’s
associated numeric identifiers satisfied the “category
description” limitation in claim 1. According to Speed-
track, that argument contradicts Endeca’s position before
the district court and here on appeal where it contends
 SPEEDTRACK, INC.   v. WALMART.COM USA, LLC             13
that “category description” must include, but is not lim-
ited to, an alphabetic descriptive name.
    The district court found Speedtrack’s arguments un-
persuasive. Specifically, the district court did not consid-
er Endeca’s invalidity arguments to be sufficiently
“clearly inconsistent” with its infringement arguments
before the district court as to present a basis for applica-
tion of judicial estoppel. As Endeca contends, its argu-
ments before the PTO challenged the ’360 patent’s
validity under the broader construction that Speedtrack
was advancing at the time in the district court.
    In addition, while Speedtrack faults Endeca’s position
after the reexamination proceedings, the district court
found nothing wrong with the parties’ arguments on
summary judgment which may have been modified in
view of the PTO’s March 3, 2011 decision confirming the
patentability of all the claims in the ’360 patent. Like-
wise, even if Endeca had taken such modified positions
post-reexamination, this court is not convinced that
Endeca was “successful” enough with its previous argu-
ments for judicial estoppel to attach, and thus, there was
no “the perception that either the first or the second court
was misled.” New Hampshire, 532 U.S. at 750 (internal
quotation marks and citation omitted). The district court
did not render decisions on infringement or invalidity
prior to the reexamination proceedings, and the PTO
itself never adopted Endeca’s contentions—the PTO
confirmed the patentability of the ’360 patent without any
narrowing amendments.
    Further, there was no unfair detriment to Speedtrack.
Id. at 751. Speedtrack argues that if it had known Ende-
ca’s position earlier, it would have made differing in-
fringement contentions, reexamination proceedings would
not have occurred, litigation would not have been stayed
for over two years, summary judgment would not have
been granted and this case would be before a jury and not
14                SPEEDTRACK, INC.   v. WALMART.COM USA, LLC
this court on appeal. These speculative assertions are
unpersuasive. Accordingly, because we are not left with a
firm conviction that the district court made a clear error
of judgment, we find no abuse of discretion in the district
court’s decision refusing to apply judicial estoppel in this
case.
     3. The District Court Did Not Abuse Its Discretion
        by Refusing to Allow Speedtrack to Amend Its In-
        fringement Contentions to Include a Doctrine of
        Equivalents Argument
     Decisions enforcing local rules in patent cases are re-
viewed for an abuse of discretion. O2 Micro Int’l Ltd. v.
Monolithic Power Sys., Inc., 467 F.3d 1355, 1366–67 (Fed.
Cir. 2006). According to Patent Local Rule 3–6 (N.D.
Cal.), 1 a party may amend its infringement contentions
upon a timely showing of “good cause.” As the parties
acknowledge, a good cause determination requires a
consideration of whether the moving party has been
diligent in amending its contentions. O2 Micro, 467 F.3d
at 1366–67. Here, the district court found that Endeca
first took the position that the accused method does not
read upon the “category description” limitation in a sup-
plemental response to Interrogatory No. 4 on June 23,
2011. J.A. 6. Rather than acting diligently, Speedtrack
waited six months to formally move to amend its in-


1    Not later than 14 days after the initial case manage-
ment conference a party claiming patent infringement
shall serve its infringement contentions on all parties.
Patent L.R. 3–1. Not later than 45 days after service
upon it of the infringement contentions, each party oppos-
ing a claim of patent infringement, shall serve on all
parties its invalidity contentions. Patent L.R. 3–3.
Amendment of the infringement contentions or the inva-
lidity contentions may be made only by order of the Court
upon a timely showing of good cause. Patent L.R. 3–6.
 SPEEDTRACK, INC.   v. WALMART.COM USA, LLC             15
fringement contentions to include, for the first time, a
doctrine of equivalents argument. The district court
found that this fact weighed against Speedtrack.
    In addition, the district court concluded that Endeca
would be prejudiced if Speedtrack was permitted to
amend its infringement contentions. For example, dis-
covery would have to be reopened and further dispositive
motions would have to be allowed that would ultimately
increase the scope of litigation and further delay resolu-
tion of the case. J.A. 7. Because these determinations
were reasonable, the district court did not abuse its
discretion.
                             B.
     On cross-appeal, Endeca contends that the district
court erred in granting Speedtrack’s motion for summary
judgment that the ’360 patent was not invalid. Under
Cardinal Chemical, once this court addresses infringe-
ment we generally must address counterclaims of invalid-
ity. See Cardinal Chem. Co. v. Morton Int’l, Inc., 508 U.S.
83, 113 (1993). Endeca’s cross-appeal however need not
be addressed here, because Endeca argued that we should
consider its cross-appeal only “if the Court decides to
vacate [the noninfringement] decision.” Appellees’ Br.
63–64. Accordingly, having affirmed the judgment of
noninfringement, we decline to reach Endeca’s argument
on cross-appeal.
                        CONCLUSION
    For the foregoing reasons, the district court’s claim
construction of “category description” and its nonin-
fringement decision are affirmed.
                        AFFIRMED
