  United States Court of Appeals
      for the Federal Circuit
              __________________________

               (Interference No. 105,606)
  SHANE C. HOLLMER AND LEE E. CLEVELAND,
                Appellants,

                           v.
  ELIYAHOU HARARI AND SANJAY MEHROTRA,
                Appellees.
              __________________________

                      2011-1276
              __________________________

    Appeal from the United States Patent and Trademark
Office, Board of Patent Appeals and Interferences.
               __________________________

                Decided: June 7, 2012
              __________________________

    DEANNE E. MAYNARD, Morrison & Foerster, LLP, of
Washington, DC, argued for appellants. With her on the
brief were ALEXANDER J. HADJIS and KRISTIN L.
YOHANNAN; and GREGORY W. REILLY, of San Diego, Cali-
fornia. Of counsel on the brief were MARTIN C. FLIESLER
and JOSEPH P. O’MALLEY, Fliesler Meyer LLP, of San
Francisco, California.
HOLLMER   v. HARARI                                        2


    WILLIAM A. BIRDWELL, Davis Wright Tremaine, LLP,
of Portland, Oregon, argued for appellees. With him on
the brief were TIMOTHY R. VOLPERT and SCOTT E.
WARNICK.
              __________________________

  Before PROST, MAYER, and O’MALLEY, Circuit Judges.
PROST, Circuit Judge.

     This case is a second appeal from the United States
Patent and Trademark Office, Board of Patent Appeals
and Interferences (“Board”) involving Patent Interference
No. 105,606(JL) between Eliyahou Harari and Sanjay
Mehrotra (collectively “Harari”), named inventors on
pending U.S. Patent Application No. 09/310,880 (“’880
application”), and Shane C. Hollmer and Lee E. Cleveland
(collectively “Hollmer”), named inventors on U.S. Patent
No. 5,828,601 (“’601 patent”). The Board entered judg-
ment against Hollmer after finding that Harari’s ’880
application was entitled to the benefit of the filing date of
Harari’s U.S. Patent Application No. 07/337,566 (“’566
application”) and thus preceded the date of conception for
Hollmer’s ’601 patent. Because the Board misinterpreted
our previous decision in Harari v. Hollmer, 602 F.3d 1348
(Fed. Cir. 2010) (“Harari I”), in finding that continuity
was maintained in the chain of priority between the ’566
application and the ’880 application involved in the inter-
ference, we reverse the Board’s decision and remand.

                      I. BACKGROUND

    Harari’s ’880 application was filed on May 14, 1999,
and is part of a chain of patent applications beginning
with the ’566 application, which was filed on April 13,
1989. The ’880 application is a continuation of U.S.
Patent Application No. 08/771,708 (“’708 application”),
3                                        HOLLMER   v. HARARI


which is a continuation of U.S. Patent Application No.
08/174,768 (“’768 application”), which is a continuation of
U.S. Patent Application No. 07/963,838 (“’838 applica-
tion”), which is a divisional of the original ’566 applica-
tion. 1

    The ’566 application was filed on the same day as Ha-
rari’s U.S. Patent Application No. 07/337,579 (“’579
application”). The following incorporation statement from
the ’566 application was copied into the subsequent
applications in the priority chain and is at the heart of
this appeal:

        Optimized erase implementations have been
    disclosed in two copending U.S. patent applica-
    tions. They are copending U.S. patent applica-
    tions, Serial No. 204,175, filed June 8, 1988, by
    Dr. Eliyahou Harari and one entitled “Multi-State
    EEprom Read and Write Circuits and Tech-
    niques,” filed on the same day as the present appli-
    cation, by Sanjay Mehrotra and Dr. Eliyahou
    Harari. The disclosures of the two applications
    are hereby incorporate[d] by reference.

J.A. 1204 (emphasis added). Harari’s ’579 application is
the above-referenced application titled “Multi-State
EEprom Read and Write Circuits and Techniques” that
was “filed on the same day” as the ’566 application.

    The ’880 application included a photocopy of the ’566
application, a transmittal sheet identifying the filing as a
continuation application, and a preliminary amendment.

        1  The ’838 and ’768 applications ultimately is-
sued as U.S. Patent Nos. 5,297,148 and 5,602,987, respec-
tively.
HOLLMER   v. HARARI                                        4


The preliminary amendment revised the above incorpora-
tion by reference language copied from the ’566 applica-
tion to refer to the ’579 application by both serial number
and filing date and added additional material from the
’579 application.

    During the interference proceedings before the Board,
Hollmer filed a motion arguing that Harari’s involved
claims were unpatentable under 35 U.S.C. § 112, first
paragraph, for lack of written description. Specifically,
Hollmer argued that the ’579 application was not properly
identified in the ’880 application’s original disclosure
because the ’579 application was not “filed on the same
day” as the ’880 application. As a result, Hollmer con-
tended, the material from the ’579 application in the
preliminary amendment was new matter under 35 U.S.C.
§ 132. The Board agreed, granting Hollmer’s motion and
entering judgment against Harari.

    On appeal in Harari I, we concluded that the Board
had applied an incorrect standard for determining
whether the ’579 application was incorporated into the
’880 application’s original disclosure, and we articulated a
narrow rule for reviewing such statements when an
applicant seeks to amend an ambiguous incorporation
statement at the “initial filing stage”: “The proper stan-
dard by which to evaluate the sufficiency of incorporation
by reference language, at this stage of the proceedings, is
whether the identity of the incorporated reference is clear
to a reasonable examiner in light of the documents pre-
sented.” Harari I, 602 F.3d at 1352-53 (emphasis added).
Applying this standard, we held that the reasonable
examiner, who had the benefit of the transmittal sheet
and the preliminary amendment, would understand that
the copied language from the original ’566 application in
the ’880 application referred to the ’579 application. Id. at
5                                         HOLLMER   v. HARARI


1353-54. As a result, the preliminary amendment was
not new matter. Id. We reversed and remanded to the
Board for further proceedings. Id. at 1354.

    On remand, the Board addressed Harari’s motion
seeking the benefit of the filing date of the ’566 applica-
tion for the ’880 application. To resolve this motion, the
Board had to determine whether the intervening ’838 and
’768 applications sufficiently incorporated the ’579 appli-
cation by reference such that 35 U.S.C. § 120’s continuity
requirements were satisfied. If they did, the ’880 applica-
tion was entitled to the benefit of the April 13, 1989 filing
date of the ’566 application; if they did not, the ’880
application was only entitled to the benefit of the Decem-
ber 20, 1996 filing date of the ’708 application, which
undisputedly discloses the ’579 application.

    The intervening ’838 and ’768 applications contain the
same incorporation language copied from the ’566 applica-
tion but, unlike the ’880 application, were never amended
to refer to the ’579 application by serial number and filing
date. In reviewing these intermediate applications, the
Board continued to apply the Harari I reasonable exam-
iner standard, finding that “[t]he determining attribute
[for determining the correct standard] is the status of
Harari’s involved [’880 application], which has not yet
issued as a patent.” J.A. 17. Using this standard, the
Board found that a reasonable examiner would have had
access to all of the filing papers, including the transmittal
sheets, for the ’838 and ’768 applications, and conse-
quently would have understood that the disputed incorpo-
ration by reference language in those applications
referred to the ’579 application. J.A. 16-17. Accordingly,
the Board determined that continuity between the ’566
and ’880 applications was maintained and that the ’880
application was entitled to the priority date of the ’566
HOLLMER   v. HARARI                                         6


application.   The Board entered judgment against
Hollmer, and Hollmer timely appealed. We have jurisdic-
tion under 28 U.S.C. § 1295(a)(4).

                       II. DISCUSSION

     This court reviews the Board’s factual findings for
substantial evidence and its legal determinations de novo.
In re Constr. Equip. Co., 665 F.3d 1254, 1255 (Fed. Cir.
2011). An application in an interference is entitled to the
filing date of an earlier-filed U.S. patent application if the
earlier application “meet[s] the requirements of 35 U.S.C.
§ 120 and 35 U.S.C. § 112[, paragraph 1,] for the subject
matter of the count.” Hyatt v. Boone, 146 F.3d 1348, 1352
(Fed. Cir. 1998) (footnotes omitted); see also Falkner v.
Inglis, 448 F.3d 1357, 1362 (Fed. Cir. 2006). 2 “[T]o gain

    2   Section 120 provides for claiming the benefit of a
priority date of an earlier application:

    An application for patent for an invention dis-
    closed in the manner provided by the first para-
    graph of section 112 of this title in an application
    previously filed in the United States . . . which is
    filed by an inventor or inventors named in the
    previously filed application shall have the same
    effect, as to such invention, as though filed on the
    date of the prior application . . . .

35 U.S.C. § 120 (2006). Section 112, paragraph 1, states:

    The specification shall contain a written descrip-
    tion of the invention, and of the manner and proc-
    ess of making and using it, in such full, clear,
    concise, and exact terms as to enable any person
    skilled in the art to which it pertains, or with
    which it is most nearly connected, to make and
    use the same, and shall set forth the best mode
    contemplated by the inventor of carrying out his
    invention.
7                                          HOLLMER   v. HARARI


the benefit of the filing date of an earlier application
under 35 U.S.C. § 120, each application in the chain
leading back to the earlier application must comply with
the written description requirement of 35 U.S.C. § 112.”
Zenon Envtl., Inc. v. U.S. Filter Corp., 506 F.3d 1370,
1378 (Fed. Cir. 2007) (quoting Lockwood v. Am. Airlines,
Inc., 107 F.3d 1565, 1571 (Fed. Cir. 1997)); see also In re
Hogan, 559 F.2d 595, 609 (CCPA 1977) (“[T]here has to be
a continuous chain of copending applications each of
which satisfies the requirements of § 112 with respect to
the subject matter presently claimed.” (quoting In re
Schneider, 481 F.2d 1350, 1356 (CCPA 1973))) (alteration
in original). Thus, if any application in the priority chain
fails to make the requisite disclosure of subject matter,
the later-filed application is not entitled to the benefit of
the filing date of applications preceding the break in the
priority chain. See Lockwood, 107 F.3d at 1571-72; Ho-
gan, 559 F.2d at 609 (finding that claim 15 was only
entitled to a 1967 filing date where “the disclosure to
support claim 15 appears in the 1953 and the 1967 appli-
cations, but not in the 1956 application”). Whether the
intervening patents in a chain of priority maintain the
requisite continuity of disclosure is a question of law we
review de novo. Zenon, 506 F.3d at 1379. Here, Harari
does not dispute that the intervening ’838 and ’768 appli-
cations must incorporate the ’579 application for the ’880
application to be entitled to the benefit of the filing date of
the original ’566 application. Whether and to what extent
a patent incorporates material by reference also is a legal
question we review de novo. Harari I, 602 F.3d at 1351.

    In Harari I, we concluded that when an examiner is
faced with an amendment clarifying ambiguous incorpo-
ration by reference language in an application that is “at

35 U.S.C. § 112 ¶ 1 (2006).
HOLLMER   v. HARARI                                       8


the initial filing stage,” the reasonable examiner standard
applies for determining whether a document was properly
incorporated. Id. at 1352-53. We contrasted this stan-
dard with the standard that generally applies to review-
ing such incorporation statements:           “[I]f we were
determining the validity of an issued patent containing
the disputed incorporation by reference statement . . . we
would be concerned with whether one of ordinary skill in
the art could identify the information incorporated.” Id.
at 1353 n.2. Because Harari I did “not involve an issued
patent or language that is intended to appear in an issued
patent,” we held that the proper inquiry focused on the
reasonable examiner, not the person of ordinary skill. Id.

    In this second appeal, we address whether this rea-
sonable examiner standard also applies for determining if
the intermediary ’838 and ’768 applications sufficiently
incorporate the ’579 application by reference such that
they satisfy § 120’s continuity requirements. Hollmer
argues that the Harari I reasonable examiner standard is
limited to situations in which an applicant seeks to clarify
an ambiguous incorporation statement through an
amendment that triggers a potential 35 U.S.C. § 132 new
matter problem. Where, as here, § 120 priority is at
issue, Hollmer contends that the incorporation by refer-
ence inquiry takes place within the § 120 context, apply-
ing the person of ordinary skill standard.

    Harari, on the other hand, argues that, under Harari
I, these intervening applications necessarily incorporate
the ’579 application by reference because the disputed
incorporation language in the ’838 and ’768 applications is
identical to the language in the ’880 application deemed
sufficient in Harari I. If the issue does remain open after
Harari I, moreover, Harari maintains that the incorpora-
tion statement is sufficient under the reasonable exam-
9                                         HOLLMER   v. HARARI


iner standard. According to Harari, Harari I set forth the
standard for identifying an incorporated document during
examination before the U.S. Patent and Trademark Office
(“PTO”)—the reasonable examiner standard—and that
standard is distinct from the one for identifying the
substantive material incorporated from that document—
the person of ordinary skill standard. Because here the
incorporation issue involves document identification,
Harari asserts that the Board correctly applied the rea-
sonable examiner standard in finding that the ’838 and
’768 applications adequately identify the ’579 applica-
tion. 3 Although we appreciate the Board’s difficulty in
determining how far to extend our holding in Harari I
given the opinion’s silence on this particular issue, we
agree with Hollmer that the Board should have applied
the person of ordinary skill standard in assessing the
disputed language in the ’838 and ’768 applications.

    First, we are not persuaded by Harari’s argument
that Harari I resolved this incorporation question. Ha-
rari I dealt specifically with the language of the ’880
application viewed in light of the preliminary amendment
and accompanying transmittal sheet; it did not consider
the intervening ’838 and ’768 applications—which never

        3    Alternatively, Harari argues that Hollmer
waived any arguments with respect to Harari I’s applica-
tion to this priority issue because Hollmer never pre-
sented these arguments to the Board on remand. We
disagree. The Board sua sponte applied Harari I in ruling
on Harari’s priority motion without asking for briefing or
comment on that point. Where the Board applies a legal
standard that governs its holding, the propriety of that
standard is properly before us on appeal. See Lebron v.
Nat’l R.R. Passenger Corp., 513 U.S. 374, 379 (1995) (“Our
practice ‘permit[s] review of an issue not pressed [by a
party] so long as it has been passed upon [by the court
below].’”) (citation omitted) (first alteration in original).
HOLLMER   v. HARARI                                     10


were amended—in the context of the § 120 priority analy-
sis.

    Second, with respect to the appropriate standard for
assessing the incorporation statements, we disagree with
Harari that the Harari I reasonable examiner standard
applies whenever the identity of an incorporated docu-
ment is at issue before the PTO. Questions surrounding
incorporation by reference statements do not arise in
isolation but instead generally manifest as an initial
hurdle that first must be crossed before reaching an
underlying issue. It is this underlying issue that provides
the framework for resolving the incorporation by refer-
ence question. For example, when the ultimate question
implicates the understanding of a person of ordinary skill,
such as determining whether the written description
requirement is satisfied, construing claims, or evaluating
the teachings of a prior art reference, we have reviewed
the incorporation statements from the person of ordinary
skill vantage point. See Harari v. Lee, 656 F.3d 1331,
1334 (Fed. Cir. 2011) (“[T]he standard is whether one
reasonably skilled in the art would understand the appli-
cation as describing with sufficient particularity the
material to be incorporated.”); Zenon, 506 F.3d at 1378-79
(same); Cook Biotech Inc. v. Acell, Inc., 460 F.3d 1365,
1376 (Fed. Cir. 2006) (same); Advanced Display Sys., Inc.
v. Kent State Univ., 212 F.3d 1272, 1283 (Fed. Cir. 2000)
(same). In assessing incorporation statements from this
point of view, our cases have required that “the host
document . . . identify with detailed particularity what
specific material it incorporates and clearly indicate
where that material is found in the various documents.”
Zenon, 506 F.3d at 1378 (quoting Cook Biotech, 460 F.3d
at 1376).
11                                        HOLLMER   v. HARARI


    In Harari I, we identified a narrow circumstance war-
ranting the application of the reasonable examiner stan-
dard, but we did not alter these traditional rules
governing the incorporation by reference inquiry. Specifi-
cally, Harari I’s modified standard applies when an
application is at the initial filing stage and the examiner
is evaluating an amendment that clarifies ambiguous
incorporation by reference language. Our predecessor
court applied an analogous standard under similar cir-
cumstances in In re Fouche, 439 F.2d 1237, 1239-40
(CCPA 1971).

    Here, unlike Harari I or Fouche, we are not consider-
ing an amendment seeking to clarify the incorporation
statements in the ’838 and ’768 applications. Instead, the
issue before us is whether these intervening applications
maintain continuity between the ’566 and ’880 applica-
tions by disclosing the ’579 application. The continuity
inquiry provides the backdrop for the incorporation by
reference analysis. In Zenon, where incorporation also
was at issue, we explained that the continuity inquiry is
undertaken using the “reasonable person of ordinary skill
in the art standard”:

     [T]he sole question before the district court was
     whether the intervening patents maintained the
     continuity of disclosure by incorporating by refer-
     ence the gas distribution system disclosed in the
     ’373 patent, entitling the ’319 patent to an earlier
     filing date. In this respect, the court was required
     to determine that question of law, which we re-
     view de novo, using the reasonable person of ordi-
     nary skill in the art standard.

Zenon, 506 F.3d at 1379. Although Zenon involved dis-
trict court litigation rather than a PTO interference
HOLLMER   v. HARARI                                      12


proceeding, we similarly have applied the person of ordi-
nary skill standard in interferences when assessing
priority under § 120, see Falkner v. Inglis, 448 F.3d 1357,
1365 (Fed. Cir. 2006), and see no reason to depart from
that standard here. Moreover, § 120 requires that the
disclosure actually appear within the specification, Lock-
wood, 107 F.3d at 1571-72 (“It is the disclosures of the
applications that count. Entitlement to a filing date does
not extend to subject matter which is not disclosed, but
would be obvious over what is expressly disclosed.”), and
amendments in later applications cannot cure an other-
wise defective application in the priority chain, see Encyc.
Britannica, Inc. v. Alpine Elecs. of Am., Inc., 609 F.3d
1345, 1351 (Fed. Cir. 2010) (holding that “[l]later applica-
tions cannot amend [an] application and restore its enti-
tlement to priority”). The incorporation by reference
analysis, therefore, is similarly constrained by the four
corners of the application.

     Applying the correct standard, we conclude that the
disputed language in the ’838 and ’768 applications does
not “identify with detailed particularity what specific
material it incorporates” to a person of ordinary skill.
Zenon, 506 F.3d at 1378. Unlike the ’566 application,
neither the ’838 application nor the ’768 application was
“filed on the same day” as, or “copending” with, the ’579
application. At least two other applications by named
inventors Mehrotra and Harari, however, were “copend-
ing” with the ’838 application and had the same title as
the ’579 application: U.S. Patent Application Nos.
07/508,273 and 07/734,221. J.A. 297. Thus, on its face,
the incorporation language does not directly lead one of
ordinary skill to the ’579 application but rather presents
several potential documents for incorporation. Such
ambiguity in incorporation does not suffice. As we have
previously cautioned, “[P]atent draftsmanship is an
13                                      HOLLMER   v. HARARI


exacting art, and no less care is required in drafting an
incorporation by reference statement than in any other
aspect of a patent application.” Zenon, 506 F.3d at 1382
n.3. Without the incorporation of the ’579 application in
the ’838 and ’768 applications, the ’880 application is not
entitled to the benefit of the priority date of the ’566
application.

                     III. CONCLUSION

     We have considered Harari’s additional arguments
and conclude that they similarly lack merit. For the
above reasons, we reverse the Board’s decision and re-
mand for the Board to enter judgment that the effective
filing date of the ’880 application is December 20, 1996—
the filing date of the ’708 application—and for further
proceedings consistent with this opinion.

              REVERSED AND REMANDED
