MPEP § 2173 — MPEP § 2173
Current through: 2022-07-01

2173-Claims Must Particularly Point Out and Distinctly Claim the Invention 
 
 

 
 
 
 
 
 
 
 

 

 
 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
 
 

 
 
 
 
 
 
 
 
 
 
 

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 Manual of Patent Examining Procedure 

 Chapter 2100 

 Section 2173 
 

 
 
 
 
 
 2173 Claims Must Particularly Point Out and Distinctly Claim the
 Invention [R-10.2019]
 

 Optimizing patent quality by providing clear notice to the
 public of the boundaries of the inventive subject matter protected by a patent grant
 fosters innovation and competitiveness. Accordingly, providing high quality patents is one
 of the agency’s guiding principles. The Office recognizes that issuing patents with clear
 and definite claim language is a key component to enhancing the quality of patents and
 raising confidence in the patent process. 
 

 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second paragraph
 requires that a patent application specification shall conclude with one or more claims
 particularly pointing out and distinctly claiming the subject matter which the inventor or
 a joint inventor regards as the invention. (Note that although pre-AIA 35 U.S.C.
 112 , second paragraph, uses the phrase “which applicant regards as his
 invention,” pre‑AIA 37
 CFR 1.41(a) provides that a patent is applied for in the name or
 names of the actual inventor or inventors.) In patent examining parlance, the claim
 language must be “definite” to comply with 35 U.S.C. 112(b) or pre-AIA 35 U.S.C.
 112 , second paragraph. Conversely, a claim that does not comply with
 this requirement of 35 U.S.C. 112(b) or pre-AIA 35 U.S.C.
 112 , second paragraph is “indefinite.” 
 

 The primary purpose of this requirement of definiteness of claim language
 is to ensure that the scope of the claims is clear so the public is informed of the
 boundaries of what constitutes infringement of the patent. A secondary purpose is to
 provide a clear measure of what the inventor or a joint inventor regards as the invention
 so that it can be determined whether the claimed invention meets all the criteria for
 patentability and whether the specification meets the criteria of 35 U.S.C.
 112(a) or pre-AIA 35 U.S.C. 112 , first paragraph
 with respect to the claimed invention.
 

 It is of utmost importance that patents issue with definite
 claims that clearly and precisely inform persons skilled in the art of the boundaries of
 protected subject matter. Therefore, claims that do not meet this standard must be rejected
 under 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second paragraph
 as indefinite. Such a rejection requires that the applicant respond by explaining why the
 language is definite or by amending the claim, thus making the record clear regarding the
 claim boundaries prior to issuance. As an indefiniteness rejection requires the applicant
 to respond by explaining why the language is definite or by amending the claim, such
 rejections must clearly identify the language that causes the claim to be indefinite and
 thoroughly explain the reasoning for the rejection.
 

 
 2173.01 Interpreting the Claims [R-10.2019]

 [Editor Note: This MPEP section is applicable to applications
 subject to the first inventor to file (FITF) provisions of the AIA except that the
 relevant date is the "effective filing date" of the claimed invention instead of the
 "time of the invention," which is only applicable to applications subject to
 pre-AIA 35
 U.S.C. 102 . See 35 U.S.C. 100 (note) and
 MPEP
 § 2150 et seq.] 

 A fundamental principle contained in 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph is that applicants are their own lexicographers. They can define in the claims
 what the inventor or a joint inventor regards as the invention essentially in whatever
 terms they choose so long as any special meaning assigned to a term is clearly set forth
 in the specification. See MPEP § 2111.01 . Applicant may use functional language,
 alternative expressions, negative limitations, or any style of expression or format of
 claim which makes clear the boundaries of the subject matter for which protection is
 sought. As noted by the court in In re Swinehart, 439 F.2d 210, 160
 USPQ 226 (CCPA 1971), a claim may not be rejected solely because of the type of language
 used to define the subject matter for which patent protection is sought.
 

 I. BROADEST REASONABLE INTERPRETATION The first step to examining a claim to determine if
 the language is definite is to fully understand the subject matter of the invention
 disclosed in the application and to ascertain the boundaries of that subject matter
 encompassed by the claim. During examination, a claim must be given its broadest
 reasonable interpretation consistent with the specification as it would be
 interpreted by one of ordinary skill in the art. Because the applicant has the
 opportunity to amend claims during prosecution, giving a claim its broadest
 reasonable interpretation will reduce the possibility that the claim, once issued,
 will be interpreted more broadly than is justified. In re
 Yamamoto, 740 F.2d 1569, 1571, 222 USPQ 934, 936 (Fed. Cir.
 1984); In re Zletz, 893 F.2d 319, 321, 13 USPQ2d 1320, 1322 (Fed.
 Cir. 1989) (“During patent examination the pending claims must be interpreted as
 broadly as their terms reasonably allow.”). The focus of the inquiry regarding the
 meaning of a claim should be what would be reasonable from the perspective of one of
 ordinary skill in the art. In re Suitco Surface, Inc., 603 F.3d
 1255, 1260, 94 USPQ2D 1640, 1644 (Fed. Cir. 2010); In re Buszard, 
 504 F.3d 1364, 84 USPQ2d 1749 (Fed. Cir. 2007). In Buszard, the
 claim was directed to a flame retardant composition comprising a flexible
 polyurethane foam reaction mixture. Buszard, 504 F.3d at 1365, 84
 USPQ2d at 1749. The Federal Circuit found that the Board’s interpretation that
 equated a “flexible” foam with a crushed “rigid” foam was not reasonable.
 Id. at 1367, 84 USPQ2d at 1751. Persuasive argument was
 presented that persons experienced in the field of polyurethane foams know that a
 flexible mixture is different than a rigid foam mixture. Id. at
 1366, 84 USPQ2d at 1751. See MPEP § 2111 for a full discussion of
 broadest reasonable interpretation. 
 

 Under a broadest reasonable interpretation, words of
 the claim must be given their plain meaning, unless such meaning is inconsistent with
 the specification. The plain meaning of a term means the ordinary and customary
 meaning given to the term by those of ordinary skill in the art at the time of the
 invention. The ordinary and customary meaning of a term may be evidenced by a variety
 of sources, including the words of the claims themselves, the specification,
 drawings, and prior art. However, the best source for determining the meaning of a
 claim term is the specification - the greatest clarity is obtained when the
 specification serves as a glossary for the claim terms. The presumption that a term
 is given its ordinary and customary meaning may be rebutted by the applicant by
 clearly setting forth a different definition of the term in the specification.
 In re Morris, 127 F.3d 1048, 1054, 44 USPQ2d 1023, 1028 (Fed.
 Cir. 1997) (the USPTO looks to the ordinary use of the claim terms taking into
 account definitions or other “enlightenment” contained in the written description);
 But c.f. In re Am. Acad. of Sci. Tech. Ctr., 367 F.3d 1359, 1369,
 70 USPQ2d 1827, 1834 (Fed. Cir. 2004) (“We have cautioned against reading limitations
 into a claim from the preferred embodiment described in the specification, even if it
 is the only embodiment described, absent clear disclaimer in the specification.”);
 In re Bigio, 381 F.3d 1320, 1325, 72 USPQ2d 1209, 1211 (Fed.
 Cir. 2004) (The claims at issue were drawn to a “hair brush.” The court upheld the
 Board’s refusal to import from the specification a limitation that would apply the
 term only to hairbrushes for the scalp. “[T]his court counsels the PTO to avoid the
 temptation to limit broad claim terms solely on the basis of specification
 passages.”). When the specification sets a clear path to the claim language, the
 scope of the claims is more easily determined and the public notice function of the
 claims is best served. See MPEP § 2111.01 for a full discussion
 of the plain meaning of claim language.
 

 If an Office action has issued where the plain
 meaning of the claim terms was used, applicant may point out that the term has been
 given a special definition. Since there is a presumption that claim terms are given
 their plain meaning, and the use of special definitions is an exception, the
 applicant must point to where the specification as filed provides a clear and
 intentional use of a special definition for the claim term to be treated as having a
 special definition.
 

 An applicant may not add a special definition or
 disavowal after the filing date of the application. However, an applicant may point
 out or explain in remarks where the specification as filed contains a special
 definition or disavowal. 
 

 II. DETERMINE WHETHER OR NOT EACH CLAIM LIMITATION INVOKES 35 U.S.C. 112(f) or
 PRE-AIA 35 U.S.C. 112, SIXTH PARAGRAPH As part of the claim interpretation analysis,
 examiners should determine whether each limitation invokes 35 U.S.C.
 112(f) or pre-AIA 35 U.S.C. 112 , sixth
 paragraph or not. If the claim limitation invokes 35 U.S.C.
 112(f) or pre-AIA 35 U.S.C. 112 , sixth
 paragraph, the claim limitation must “be construed to cover the corresponding
 structure, material, or acts described in the specification and equivalents thereof.”
 35
 U.S.C. 112(f) and pre-AIA 35 U.S.C. 112 , sixth
 paragraph; see also In re Donaldson Co., 16 F.3d 1189, 1193, 29
 USPQ2d 1845, 1849 (Fed. Cir. 1994) (en banc) (“[W]e hold that
 paragraph six applies regardless of the context in which the interpretation of
 means-plus-function language arises, i.e., whether as part of a patentability
 determination in the PTO or as part of a validity or infringement determination in a
 court.”). See MPEP §
 2181 , subsection I. for more information regarding the
 determination of whether a limitation invokes 35 U.S.C.
 112(f) or pre-AIA 35 U.S.C. 112 , sixth
 paragraph, and means- (or step-) plus- function claim limitations. 
 

 

 
 2173.02 Determining Whether Claim Language is Definite [R-01.2024]

 [Editor Note: This MPEP section is applicable regardless of whether an
 application is examined under the AIA or under pre-AIA law. For applications subject
 to the first inventor to file (FITF) provisions of the AIA, the relevant time is
 "before the effective filing date of the claimed invention". For applications subject
 to pre-AIA 35
 U.S.C. 102 , the relevant time is "at the time of the
 invention". See MPEP § 2150 et seq. Many of the
 court decisions discussed in this section involved applications or patents subject to
 pre-AIA 35
 U.S.C. 102 . These court decisions may be applicable to
 applications and patents subject to AIA 35 U.S.C. 102 but the
 relevant time is before the effective filing date of the claimed invention and not at
 the time of the invention.] 

 During prosecution, applicant has an opportunity and a
 duty to amend ambiguous claims to clearly and precisely define the metes and bounds of
 the claimed invention. The claim places the public on notice of the scope of the
 patentee’s right to exclude. See, e.g., Johnson & Johnston Assoc. Inc. v.
 R.E. Serv. Co., 285 F.3d 1046, 1052, 62 USPQ2d 1225, 1228 (Fed. Cir. 2002)
 (en banc) . As the Federal Circuit stated in Halliburton
 Energy Servs., Inc. v. M-I LLC, 514 F.3d 1244, 1255, 85 USPQ2d 1654, 1663
 (Fed. Cir. 2008): 
 

 
 We note that the patent drafter is in the best
 position to resolve the ambiguity in the patent claims, and it is highly desirable
 that patent examiners demand that applicants do so in appropriate circumstances so
 that the patent can be amended during prosecution rather than attempting to resolve
 the ambiguity in litigation. 
 

 
 A decision on whether a claim is indefinite under
 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph requires a determination of whether those skilled in the art would understand
 what is claimed when the claim is read in light of the specification.
 Power-One, Inc. v. Artesyn Techs., Inc., 599 F.3d 1343, 1350, 94
 USPQ2d 1241, 1245 (Fed. Cir. 2010); Orthokinetics, Inc. v. Safety Travel
 Chairs, Inc., 806 F.2d 1565, 1 USPQ2d 1081 (Fed. Cir. 1986). In
 Orthokinetics, a claim directed to a wheel chair included the
 phrase “so dimensioned as to be insertable through the space between the doorframe of an
 automobile and one of the seats thereof.” 806 F.2d at 1568, 1 USPQ2d at 1082. The court
 found the phrase to be as accurate as the subject matter permits, since automobiles are
 of various sizes. Id. at 1576, 1 USPQ2d at 1088. “As long as those of
 ordinary skill in the art realized the dimensions could be easily obtained,
 §
 112 , 2d para. requires nothing more.” Id. Claim
 terms are typically given their ordinary and customary meaning as understood by one of
 ordinary skill in the pertinent art, and the generally understood meaning of particular
 terms may vary from art to art. See MPEP § 2111.01 . Therefore, it is
 important to analyze claim terms in view of the application’s specification from the
 perspective of those skilled in the relevant art since a particular term used in one
 patent or application may not have the same meaning when used in a different
 application. Medrad, Inc. v. MRI Devices Corp., 401 F.3d 1313, 1318,
 74 USPQ2d 1184, 1188 (Fed. Cir. 2005).
 

 I. CLAIMS UNDER EXAMINATION ARE CONSTRUED DIFFERENTLY THAN PATENTED CLAIMS Patented claims are not given the broadest reasonable
 interpretation during court proceedings involving infringement and validity, and can
 be interpreted based on a fully developed prosecution record. While "absolute
 precision is unattainable" in patented claims, the definiteness requirement "mandates
 clarity." Nautilus, Inc. v. Biosig Instruments, Inc., 572 U.S.
 898, 910, 110 USPQ2d 1688, 1693 (2014). A court will not find a patented claim
 indefinite unless the claim interpreted in light of the specification and the
 prosecution history fails to "inform those skilled in the art about the scope of the
 invention with reasonable certainty." Id. at 899, 110 USPQ2d at
 1689.
 

 The Office does not interpret claims when examining
 patent applications in the same manner as the courts. In re
 Packard, 751 F.3d 1307, 1312, 110 USPQ2d 1785, 1788 (Fed. Cir. 2014);
 In re Morris, 127 F.3d 1048, 1054, 44 USPQ2d 1023, 1028 (Fed.
 Cir. 1997); In re Zletz, 893 F.2d 319, 321-22, 13 USPQ2d 1320,
 1321-22 (Fed. Cir. 1989). During prosecution the Office construes claims by giving
 them their broadest reasonable interpretation consistent with the specification in an
 effort to establish a clear record of what the applicant intends to claim. Such claim
 construction during prosecution may effectively result in a lower threshold for
 ambiguity than a court's determination. Packard , 751 F.3d at
 1323-24, 110 USPQ2d at 1796-97 (Plager, J., concurring). However, applicant has the
 ability to amend the claims during prosecution to ensure that the meaning of the
 language is clear and definite prior to issuance or provide a persuasive explanation
 (with evidence as necessary) that a person of ordinary skill in the art would not
 consider the claim language unclear. In re Buszard, 504 F.3d 1364,
 1366, 84 USPQ2d 1749, 1750 (Fed. Cir. 2007)(claims are given their broadest
 reasonable interpretation during prosecution “to facilitate sharpening and clarifying
 the claims at the application stage”); see also In re Yamamoto, 
 740 F.2d 1569, 1571, 222 USPQ 934, 936 (Fed. Cir. 1984); In re
 Zletz, 893 F.2d 319, 322, 13 USPQ2d 1320, 1322 (Fed. Cir. 1989);
 Ex parte McAward, Appeal 2015-006416 (PTAB Aug. 25, 2017)
 (precedential). 
 

 See MPEP § 2111 et seq. for a detailed discussion of claim interpretation during
 the examination process. The lower threshold is also applied because the patent
 record is in development and not fixed during examination, and the agency does not
 rely on it for interpreting claims. Packard, 751 F.3d at 1325, 110
 USPQ2d at 1798 (Plager, J., concurring). Burlington Indus. Inc. v.
 Quigg, 822 F.2d 1581, 1583, 3 USPQ2d 1436, 1438 (Fed. Cir. 1987)
 (“Issues of judicial claim construction such as arise after patent issuance, for
 example during infringement litigation, have no place in prosecution of pending
 claims before the PTO, when any ambiguity or excessive breadth may be corrected by
 merely changing the claim.”).
 

 During examination, after applying the broadest
 reasonable interpretation consistent with the specification to the claim, if the
 metes and bounds of the claimed invention are not clear, the claim is indefinite and
 should be rejected. Packard, 751 F.3d at 1311, 110 USPQ2d at 1787
 (“[W]hen the USPTO has initially issued a well-grounded rejection that identifies
 ways in which language in a claim is ambiguous, vague, incoherent, opaque, or
 otherwise unclear in describing and defining the claimed invention, and thereafter
 the applicant fails to provide a satisfactory response, the USPTO can properly reject
 the claim as failing to meet the statutory requirements of §
 112(b) .”); Zletz, 893 F.2d at 322, 13 USPQ2d
 at 1322. For example, if the language of a claim, given its broadest reasonable
 interpretation, is such that a person of ordinary skill in the relevant art would
 read it with more than one reasonable interpretation, then a rejection under
 35
 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph is appropriate. Examiners, however, are cautioned against confusing claim
 breadth with claim indefiniteness. A broad claim is not indefinite merely because it
 encompasses a wide scope of subject matter provided the scope is clearly defined.
 Instead, a claim is indefinite when the boundaries of the protected subject matter
 are not clearly delineated and the scope is unclear. For example, a genus claim that
 covers multiple species is broad, but is not indefinite because of its breadth, which
 is otherwise clear. But a genus claim that could be interpreted in such a way that it
 is not clear which species are covered would be indefinite (e.g., because there is
 more than one reasonable interpretation of what species are included in the claim).
 See MPEP §
 2173.05(h) , subsection I., for more information regarding
 the determination of whether a Markush claim satisfies the requirements of
 35
 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph.
 

 II. THRESHOLD REQUIREMENTS OF CLARITY AND PRECISION The examiner’s focus during examination of claims for compliance
 with the requirement for definiteness of 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph, is whether the claim meets the threshold requirements of clarity and
 precision set forth in the statute, not whether more suitable language or modes of
 expression are available. When the examiner is satisfied that patentable subject
 matter is disclosed, and it is apparent to the examiner that the claims are directed
 to such patentable subject matter, the examiner should allow claims which define the
 patentable subject matter with the required degree of particularity and distinctness.
 Some latitude in the manner of expression and the aptness of terms should be
 permitted so long as 35 U.S.C. 112(b) or
 pre-AIA
 35 U.S.C. 112 , second paragraph, is satisfied. Examiners are
 encouraged to suggest claim language to applicants to improve the clarity or
 precision of the language used, but should not insist on their own preferences if
 other modes of expression selected by applicants satisfy the statutory
 requirement.
 

 The essential inquiry pertaining to this requirement is whether the
 claims set out and circumscribe a particular subject matter with a reasonable degree
 of clarity and particularity. “As the statutory language of ‘particular[ity]' and
 'distinct[ness]' indicates, claims are required to be cast in clear—as opposed to
 ambiguous, vague, indefinite—terms. It is the claims that notify the public of what
 is within the protections of the patent, and what is not.”
 Packard, 751 F.3d at 1313, 110 USPQ2d at 1788. Definiteness of
 claim language must be analyzed, not in a vacuum, but in light of:
 

 
 (A) The content of the particular application disclosure; 

 (B) The teachings of the prior art; and

 (C) The claim interpretation that would be given by one possessing
 the ordinary level of skill in the pertinent art at the time the invention was
 made. 
 

 
 In reviewing a claim for compliance with 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph, the examiner must consider the claim as a whole to determine whether the
 claim apprises one of ordinary skill in the art of its scope and, therefore, serves
 the notice function required by 35 U.S.C. 112(b) or
 pre-AIA 35
 U.S.C. 112 , second paragraph, by providing clear warning to
 others as to what constitutes infringement of the patent. See, e.g., Solomon
 v. Kimberly-Clark Corp., 216 F.3d 1372, 1379, 55 USPQ2d 1279, 1283 (Fed.
 Cir. 2000). See also In re Larsen, 10 Fed. App'x 890 (Fed. Cir.
 2001) (The preamble of the Larsen claim recited only a hanger and
 a loop but the body of the claim positively recited a linear member. The court
 observed that the totality of all the limitations of the claim and their interaction
 with each other must be considered to ascertain the inventor’s contribution to the
 art. Upon review of the claim in its entirety, the court concluded that the claim at
 issue apprises one of ordinary skill in the art of its scope and, therefore, serves
 the notice function required by 35 U.S.C. 112 .).
 

 If the language of the claim is such that a person of ordinary skill
 in the art could not interpret the metes and bounds of the claim so as to understand
 how to avoid infringement, a rejection of the claim under 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph, is appropriate. See IBSA Institut Biochimique, S.A. v. Teva
 Pharm. USA, Inc., 966 F.3d 1374, 1378-81, 2020 USPQ2d 10865 (Fed. Cir.
 2020) (The court affirmed a district court’s finding of indefiniteness based upon a
 detailed analysis of the claim language itself as well as intrinsic and extrinsic
 evidence); Morton Int’l, Inc. v. Cardinal Chem. Co., 5 F.3d 1464,
 1470, 28 USPQ2d 1190, 1195 (Fed. Cir. 1993). However, if the language used by
 applicant satisfies the statutory requirements of 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph, the claim must not be rejected under
 35
 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph. 
 

 Examiners should note that Office policy is not to employ
 per se rules to make technical rejections. Examples of claim
 language which have been held to be indefinite set forth in MPEP § 2173.05(d) 
 are fact specific and should not be applied as per
 se rules. 
 

 III. RESOLVING INDEFINITE CLAIM LANGUAGE 
 

 A. Examiner Must Establish a Clear Record Examiners are urged to carefully carry out their
 responsibilities to see that the application file contains a complete and accurate
 picture of the Office’s consideration of the patentability of an application. See
 MPEP §
 1302.14 , subsection I. In order to provide a complete
 application file history and to enhance the clarity of the prosecution history
 record, an examiner should provide clear explanations of all actions taken during
 prosecution of the application. See MPEP § 707.07(f) . Thus, when a
 rejection under 35 U.S.C. 112(b) or
 pre-AIA 35
 U.S.C. 112 , second paragraph, is appropriate based on the
 examiner’s determination that a claim term or phrase is prima
 facie indefinite, the examiner should clearly communicate in an
 Office action any findings and reasons which support the rejection and avoid a
 mere conclusion that the claim term or phrase is indefinite. See
 MPEP §
 706.03 and MPEP § 707.07(g) .
 

 MPEP §
 2173.05 provides numerous examples of rationales that
 may support a rejection under 35 U.S.C. 112(b) or
 pre-AIA 35
 U.S.C. 112 , second paragraph, such as functional claim
 limitations, relative terminology/terms of degree, lack of antecedent basis, etc.
 Only by providing a complete explanation in the Office action as to the basis for
 determining why a particular term or phrase used in the claim is indefinite will
 the examiner enhance the clarity of the prosecution history record. 
 

 B. An Office Action Should Provide a Sufficient Explanation The Office action must set forth the specific term
 or phrase that is indefinite and why the metes and bounds are unclear. Since a
 rejection requires the applicant to respond by explaining why claim language would
 be recognized by a person of ordinary skill in the art as definite or by amending
 the claim, the Office action should provide enough information for the applicant
 to prepare a meaningful response. “Because claims delineate the patentee’s right
 to exclude, the patent statute requires that the scope of the claims 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.” Halliburton Energy Servs., Inc. v. M-I LLC, 514 F.3d
 1244, 1249, 85 USPQ2d 1654, 1658 (Fed. Cir. 2008). Thus, during prosecution,
 claims are given their broadest reasonable interpretation consistent with the
 specification “to facilitate sharpening and clarifying the claims at the
 application stage” when claims are readily changed. In re
 Buszard, 504 F.3d 1364, 1366 (Fed. Cir. 2007); see also In
 re Yamamoto, 740 F.2d 1569, 1571 (Fed. Cir. 1984); In re
 Zletz, 893 F.2d 319, 322, 13 USPQ2d 1320, 1322 (Fed. Cir. 1989). 
 

 To comply with 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph, applicants are required to make the terms that are used to define the
 invention clear and precise, so that the metes and bounds of the subject matter
 that will be protected by the patent grant can be ascertained. See
 MPEP §
 2173.05(a) , subsection I. It is important that a person
 of ordinary skill in the art be able to interpret the metes and bounds of the
 claims so as to understand how to avoid infringement of the patent that ultimately
 issues from the application being examined. See MPEP § 2173.02 ,
 subsection II (citing Morton Int ’l, Inc. v. Cardinal Chem.
 Co., 5 F.3d 1464, 1470, 28 USPQ2d 1190, 1195 (Fed. Cir. 1993)); see
 also Halliburton Energy Servs., 514 F.3d at 1249, 85 USPQ2d at
 1658 (“Otherwise, competitors cannot avoid infringement, defeating the public
 notice function of patent claims.”). Examiners should bear in mind that “[a]n
 essential purpose of patent examination is to fashion claims that are precise,
 clear, correct, and unambiguous. Only in this way can uncertainties of claim scope
 be removed, as much as possible, during the administrative process.”
 Zletz, 893 F.2d at 322, 13 USPQ2d at 1322. 
 

 Accordingly, when rejecting a claim as
 prima facie indefinite under 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph, the examiner should provide enough information in the Office action to
 permit applicant to make a meaningful response, as the indefiniteness rejection
 requires the applicant to explain or provide evidence as to why the claim language
 is not indefinite or amend the claim. For example, in making a prima
 facie case of indefiniteness, the examiner should point out the
 specific term or phrase that is indefinite, explain in detail why such term or
 phrase renders the metes and bounds of the claim scope unclear and, whenever
 practicable, indicate how the indefiniteness issues may be resolved to overcome
 the rejection. See MPEP § 707.07(d) . If the applicant does not adequately
 respond to the prima facie case, the examiner may make the
 indefiniteness rejection final. Packard, 751 F.3d at 1312, 110
 USPQ2d at 1788.
 

 The focus during the examination of claims for
 compliance with the requirement for definiteness under 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph, is whether the claim meets the threshold requirements of clarity and
 precision, not whether more suitable language or modes of expression are
 available. See MPEP
 § 2173.02 , subsection II. Examiners are encouraged to
 suggest claim language to applicants to improve the clarity or precision of the
 language used, but should not insist on their own preferences if other modes of
 expression selected by applicants satisfy the statutory requirement. Furthermore,
 when the examiner determines that more information is necessary to ascertain the
 meaning of a claim term, a requirement for information under 37 CFR 1.105 
 may be appropriate. See MPEP § 704.10 regarding
 requirements for information. 
 

 It is highly desirable to have applicants resolve
 ambiguity by amending the claims during prosecution of the application rather than
 attempting to resolve the ambiguity in subsequent litigation of the issued patent.
 Halliburton Energy Servs., 514 F.3d at 1255, 85 USPQ2d at
 1663. Thus, in response to an examiner’s rejection for indefiniteness, an
 applicant may resolve the ambiguity by amending the claim, or by providing a
 persuasive explanation on the record that a person of ordinary skill in the
 relevant art would not consider the claim language unclear. In re
 Packard, 751 F.3d 1307, 1311, 110 USPQ2d 1785, 1787 (Fed. Cir. 2014).
 For the latter option, in some cases, it may be necessary for the applicant to
 provide a separate definition (such as from an art-recognized dictionary) to show
 how the ordinarily-skilled artisan would have understood the claim language at
 issue. Id. 

 If the examiner considers applicant’s arguments
 and/or amendments to be persuasive, the examiner should indicate in the next
 Office communication that the previous rejection under 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph, has been withdrawn and provide an explanation as to what prompted the
 change in the examiner’s position (e.g., by making specific reference to portions
 of applicant’s remarks). 
 

 By providing an explanation as to the action taken, the examiner
 will enhance the clarity of the prosecution history record. As noted by the
 Supreme Court in Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki
 Co., 535 U.S. 722, 122 S.Ct. 1831, 1838, 62 USPQ2d 1705, 1710 (2002),
 a clear and complete prosecution file record is important in that “[p]rosecution
 history estoppel requires that the claims of a patent be interpreted in light of
 the proceedings in the PTO during the application process.” In
 Festo, the Court held that “a narrowing amendment made to
 satisfy any requirement of the Patent Act may give rise to an estoppel.” With
 respect to amendments made to comply with the requirements of 35 U.S.C.
 112 , the Court stated that “[i]f a § 112 
 amendment is truly cosmetic, then it would not narrow the patent’s scope or raise
 an estoppel. On the other hand, if a § 112 amendment is necessary
 and narrows the patent’s scope—even if only for the purpose of better
 description—estoppel may apply.” Id. at 1840, 62 USPQ2d at
 1712. The Court further stated that “when the court is unable to determine the
 purpose underlying a narrowing amendment—and hence a rationale for limiting the
 estoppel to the surrender of particular equivalents—the court should presume that
 the patentee surrendered all subject matter between the broader and the narrower
 language…the patentee should bear the burden of showing that the amendment does
 not surrender the particular equivalent in question.” Id. at
 1842, 62 USPQ2d at 1713. Thus, whenever possible, the examiner should make the
 record clear by providing explicit reasoning for making or withdrawing any
 rejection related to 35 U.S.C. 112(b) or
 pre-AIA 35
 U.S.C. 112 , second paragraph.
 

 C. Provide Claim Interpretation in Reasons for Allowance When Record is
 Unclear Pursuant to 37 CFR 1.104(e) , if the
 examiner believes that the record of the prosecution as a whole does not make
 clear the reasons for allowing a claim or claims, the examiner may set forth such
 reasoning in reasons for allowance. Further, prior to allowance, the examiner may
 also specify allowable subject matter and provide reasons for indicating such
 allowable subject matter in an Office communication. See MPEP § 1302.14 ,
 subsection I. One of the primary purposes of 37 CFR 1.104(e) is to improve
 the quality and reliability of issued patents by providing a complete file history
 which should clearly reflect the reasons why the application was allowed. Such
 information facilitates evaluation of the scope and strength of a patent by the
 patentee and the public and may help avoid or simplify subsequent litigation of an
 issued patent. See MPEP § 1302.14 , subsection I. In meeting the need for
 the application file history to speak for itself, it is incumbent upon the
 examiner in exercising their responsibility to the public to see that the file
 history is complete. See MPEP § 1302.14 , subsection I. 
 

 For example, when allowing a claim based on a claim
 interpretation which might not be readily apparent from the record of the
 prosecution as a whole, the examiner should set forth in reasons for allowance the
 claim interpretation applied in determining that the claim is allowable over the
 prior art. See MPEP
 § 1302.14 , subsection II.G. This is especially the case
 where the application is allowed after an interview. The examiner should ensure,
 however, that statements of reasons for allowance do not place unwarranted
 interpretations, whether broad or narrow, upon the claims. See
 MPEP §
 1302.14 , subsection I. 
 

 D. Open Lines of Communication with the Applicant – When Indefiniteness
 Is the Only Issue, Attempt Resolution through an Interview before Resorting
 to a Rejection Examiners are reminded that interviews can be an
 effective examination tool and are encouraged to initiate an interview with the
 applicant or applicant’s representative at any point during the pendency of an
 application, if the interview can help further prosecution, shorten pendency, or
 provide a benefit to the examiner or applicant. Issues of claim interpretation and
 clarity of scope may lend themselves to resolution through an examiner interview.
 For example, the examiner may initiate an interview to discuss, among other
 issues, the broadest reasonable interpretation of a claim in light of the
 specification, the meaning of a particular claim limitation, and the scope and
 clarity of preamble language, functional language, intended use language, and
 means-plus-function limitations, etc. 
 

 An interview can serve to develop and clarify such
 issues and lead to a mutual understanding between the examiner and the applicant,
 potentially eliminating the need for the examiner to resort to making a rejection
 under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph. The examiner is reminded that the substance of any interview, whether
 in person, by video conference, or by telephone must be made of record in the
 application, whether or not an agreement was reached at the interview. See
 MPEP §
 713.04 ; see also 37 CFR 1.2 (“The action of the
 Patent and Trademark Office will be based exclusively on the written record in the
 Office. No attention will be paid to any alleged oral promise, stipulation, or
 understanding in relation to which there is disagreement or doubt.”). Examples of
 35 U.S.C.
 112 issues that should be made of record after the interview
 include: why the discussed claim term is or is not sufficiently clear; why the
 discussed claim term is or is not inconsistent with the specification; why the
 discussed claim term does or does not invoke 35 U.S.C.
 112(f) or pre-AIA 35 U.S.C. 112 , sixth
 paragraph (and if it does, the identification of corresponding structure,
 material, or acts in the specification for a 35 U.S.C.
 112(f) or pre-AIA 35 U.S.C. 112 , sixth
 paragraph limitation); and any claim amendments discussed that would resolve
 identified ambiguities. 
 

 

 
 2173.03 Correspondence Between Specification and Claims [R-07.2022]

 The specification should ideally serve as a glossary to the claim terms
 so that the examiner and the public can clearly ascertain the meaning of the claim
 terms. Correspondence between the specification and claims is required by
 37 CFR
 1.75(d)(1) , which provides that claim terms must find clear
 support or antecedent basis in the specification so that the meaning of the terms may be
 ascertainable by reference to the specification. Glossaries of terms used in the claims
 are a helpful device for ensuring adequate definition of terms used in claims. If the
 specification does not provide the needed support or antecedent basis for the claim
 terms, the specification should be objected to under 37 CFR 1.75(d)(1) . See
 MPEP §
 608.01(o) and MPEP § 2181 , subsection IV. Applicant
 will be required to make appropriate amendment to the description to provide clear
 support or antecedent basis for the claim terms provided no new matter is introduced, or
 amend the claim. 
 

 A claim, although clear on its face, may also be
 indefinite when a conflict or inconsistency between the claimed subject matter and the
 specification disclosure renders the scope of the claim uncertain as inconsistency with
 the specification disclosure or prior art teachings may make an otherwise definite claim
 take on an unreasonable degree of uncertainty. In re Moore, 439 F.2d
 1232, 1235-36, 169 USPQ 236, 239 (CCPA 1971); In re Cohn, 438 F.2d
 989, 169 USPQ 95 (CCPA 1971); In re Hammack, 427 F.2d 1378, 166 USPQ 204 (CCPA 1970). For example, a
 claim with a limitation of “the clamp means including a clamp body and first and second
 clamping members, the clamping members being supported by the clamp body” was determined
 to be indefinite because the terms “first and second clamping members” and “clamp body”
 were found to be vague in light of the specification which showed no “clamp member”
 structure being “supported by the clamp body.” In re Anderson, 1997
 U.S. App. Lexis 167 (Fed. Cir. January 6, 1997) (unpublished). In
 Cohn, a claim was directed to a process of treating an aluminum
 surface with an alkali silicate solution and included a further limitation that the
 surface has an “opaque” appearance. Id. The specification, meanwhile,
 associated the use of an alkali silicate with a glazed or porcelain-like finish, which
 the specification distinguished from an opaque finish. Cohn, 438 F.2d
 at 993, 169 USPQ at 98. Noting that no claim may be read apart from and independent of
 the supporting disclosure on which it is based, the court found that the claim was
 internally inconsistent based on the description, definitions and examples set forth in
 the specification relating to the appearance of the surface after treatment, and
 therefore indefinite. Id. In addition, inconsistencies in the meaning
 of terms or phrases between claims may render the scope of the claims to be uncertain.
 Tvngo Ltd. (BVI) v. LG Elecs. Inc., 861 Fed. Appx. 453, 459-60,
 2021 USPQ2d 697 (Fed. Cir. 2021) ("The issue is not breadth of the dependent claims but
 their use of the disputed phrase in a way that contradicts the independent claims. The
 dependent claims state that 'said overlay activation criterion includes . . . a user
 command information,' which conflicts with the independent claim's use of this same
 phrase."). "When faced with this unknown and undefined phrase, a skilled artisan would
 look for clarification not only in the specification but also in '[o]ther claims of the
 patent in question,' which 'can also be valuable sources of enlightenment as to the
 meaning of a claim term.'" Id. at 460 (quoting Philips v.
 AWH Corp., 415 F.3d 1303, 1314, 75 USPQ2d 1321, 1327 (Fed. Cir. 2005)).
 

 

 
 2173.04 Breadth Is Not Indefiniteness [R-10.2019]

 Breadth of a claim is not to be equated with indefiniteness.
 In re Miller, 441 F.2d 689, 169 USPQ 597 (CCPA 1971); In re
 Gardner, 427 F.2d 786, 788, 166 USPQ 138, 140 (CCPA 1970) ("Breadth is not
 indefiniteness."). A broad claim is not indefinite merely because it encompasses a wide
 scope of subject matter provided the scope is clearly defined. But a claim is indefinite
 when the boundaries of the protected subject matter are not clearly delineated and the
 scope is unclear. For example, a genus claim that covers multiple species is broad, but
 is not indefinite because of its breadth, which is otherwise clear. But a genus claim
 that could be interpreted in such a way that it is not clear which species are covered
 would be indefinite (e.g., because there is more than one reasonable interpretation of
 what species are included in the claim).
 

 Undue breadth of the claim may be addressed under different statutory
 provisions, depending on the reasons for concluding that the claim is too broad. If the
 claim is too broad because it does not set forth that which the inventor or a joint
 inventor regards as the invention as evidenced by statements outside of the application
 as filed, a rejection under 35 U.S.C. 112(b) or
 pre-AIA 35 U.S.C.
 112 , second paragraph, would be appropriate. If the claim is too
 broad because it is not supported by the original description or by an enabling
 disclosure, a rejection under 35 U.S.C. 112(a) or
 pre-AIA 35 U.S.C.
 112 , first paragraph, would be appropriate. If the claim is too
 broad because it reads on the prior art, a rejection under either 35 U.S.C. 102 or
 103 would be appropriate. 
 

 

 
 2173.05 Specific Topics Related to Issues Under 35 U.S.C. 112(b) or
 Pre-AIA 35 U.S.C. 112, Second Paragraph [R-11.2013]
 

 The following sections are devoted to a discussion of specific topics
 where issues under 35 U.S.C. 112(b) or
 pre-AIA 35 U.S.C.
 112 , second paragraph, have been addressed. These sections are not
 intended to be an exhaustive list of the issues that can arise under 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph, but are intended to provide guidance in areas that have been addressed with
 some frequency in recent examination practice. The court and Board decisions cited are
 representative. As with all appellate decisions, the results are largely dictated by the
 facts in each case. The use of the same language in a different context may justify a
 different result.
 

 See MPEP
 § 2181 for guidance in determining whether an applicant has
 complied with the requirements of 35 U.S.C. 112(b) or
 pre-AIA 35 U.S.C.
 112 , second paragraph, when 35 U.S.C.
 112(f) or pre-AIA 35 U.S.C. 112 , sixth
 paragraph, is invoked.
 

 
 2173.05(a) New Terminology [R-07.2022]
 I. THE MEANING OF EVERY TERM SHOULD BE APPARENT The meaning of every term used in a claim should be apparent from
 the prior art or from the specification and drawings at the time the application
 is filed. Claim language may not be “ambiguous, vague, incoherent, opaque, or
 otherwise unclear in describing and defining the claimed invention.” In
 re Packard, 751 F.3d 1307, 1311, 110 USPQ2d 1785, 1787 (Fed. Cir.
 2014). Applicants need not confine themselves to the terminology used in the prior
 art, but are required to make clear and precise the terms that are used to define
 the invention whereby the metes and bounds of the claimed invention can be
 ascertained. During patent examination, the pending claims must be given the
 broadest reasonable interpretation consistent with the specification. In
 re Morris, 127 F.3d 1048, 1054, 44 USPQ2d 1023, 1027 (Fed. Cir.
 1997); In re Prater, 415 F.2d 1393, 162 USPQ 541 (CCPA 1969).
 See also MPEP §
 2111 - § 2111.01 . When the specification
 states the meaning that a term in the claim is intended to have, the claim is
 examined using that meaning, in order to achieve a complete exploration of the
 applicant’s invention and its relation to the prior art. In re
 Zletz, 893 F.2d 319, 13 USPQ2d 1320 (Fed. Cir. 1989).
 

 II. THE REQUIREMENT FOR CLARITY AND PRECISION MUST BE BALANCED WITH THE
 LIMITATIONS OF THE LANGUAGE Courts have recognized that it is not only permissible, but often
 desirable, to use new terms that are frequently more precise in describing and
 defining the new invention. In re Fisher, 427 F.2d 833, 166 USPQ 18 (CCPA 1970). Although it is
 difficult to compare the claimed invention with the prior art when new terms are
 used that do not appear in the prior art, this does not make the new terms
 indefinite. 
 

 New terms are often used when a new technology is in its infancy
 or is rapidly evolving. The requirements for clarity and precision must be
 balanced with the limitations of the language and the science. If the claims, read
 in light of the specification, reasonably apprise those skilled in the art both of
 the utilization and scope of the invention, and if the language is as precise as
 the subject matter permits, the statute ( 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph) demands no more. Packard, 751 F.3d at 1313, 110
 USPQ2d at 1789 ("[H]ow much clarity is required necessarily invokes some standard
 of reasonable precision in the use of language in the context of the
 circumstances."). This does not mean that the examiner must accept the best effort
 of applicant. If the language is not considered as precise as the subject matter
 permits, the examiner should provide reasons to support the conclusion of
 indefiniteness and is encouraged to suggest alternatives that would not be subject
 to rejection.
 

 III. TERMS USED CONTRARY TO THEIR ORDINARY MEANING MUST BE CLEARLY REDEFINED IN
 THE WRITTEN DESCRIPTION Consistent with the well-established axiom in patent law that a
 patentee or applicant is free to be his or her own lexicographer, a patentee or
 applicant may use terms in a manner contrary to or inconsistent with one or more
 of their ordinary meanings if the written description clearly redefines the terms.
 See, e.g., Process Control Corp. v. HydReclaim Corp., 190 F.3d
 1350, 1357, 52 USPQ2d 1029, 1033 (Fed. Cir. 1999) (“While we have held many times
 that a patentee can act as his own lexicographer to specifically define terms of a
 claim contrary to their ordinary meaning,” in such a situation the written
 description must clearly redefine a claim term “so as to put a reasonable
 competitor or one reasonably skilled in the art on notice that the patentee
 intended to so redefine that claim term.”); Hormone Research Foundation
 Inc. v. Genentech Inc., 904 F.2d 1558, 15 USPQ2d 1039 (Fed. Cir. 1990).
 Accordingly, when there is more than one meaning for a term, it is incumbent upon
 applicant to make clear which meaning is being relied upon to claim the invention.
 Until the meaning of a term or phrase used in a claim is clear, a rejection under
 35
 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph is appropriate. It is appropriate to compare the meaning of terms given
 in technical dictionaries in order to ascertain the accepted meaning of a term in
 the art. In re Barr, 444 F.2d 588, 170 USPQ 330 (CCPA 1971).
 See also MPEP
 § 2111.01 .
 

 

 
 2173.05(b) Relative Terminology [R-01.2024]

 The use of relative terminology in claim language, including terms
 of degree, does not automatically render the claim indefinite under 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph. Seattle Box Co., Inc. v. Industrial Crating & Packing,
 Inc., 731 F.2d 818, 221 USPQ 568 (Fed. Cir. 1984). Acceptability of the
 claim language depends on whether one of ordinary skill in the art would understand
 what is claimed, in light of the specification. Clearone, Inc. v. Shure
 Acquisition Holdings, Inc., 35 F.4th 1345, 1349, 2022 USPQ2d 509 (Fed.
 Cir. 2022) (“Based on the intrinsic record alone, we conclude that the written
 description provides, with reasonable certainty, the scope of the term
 self-similar.”).
 

 I. TERMS OF DEGREE Terms of degree are not necessarily indefinite.
 “Claim language employing terms of degree has long been found definite where it
 provided enough certainty to one of skill in the art when read in the context of
 the invention.” Interval Licensing LLC v. AOL, Inc., 766 F.3d
 1364, 1370, 112 USPQ2d 1188, 1192-93 (Fed. Cir. 2014) (citing Eibel
 Process Co. v. Minnesota & Ontario Paper Co., 261 U.S. 45, 65-66
 (1923) (finding ‘substantial pitch’ sufficiently definite because one skilled in
 the art ‘had no difficulty … in determining what was the substantial pitch needed’
 to practice the invention)). Thus, when a term of degree is used in the claim, the
 examiner should determine whether the specification provides some standard for
 measuring that degree. Hearing Components, Inc. v. Shure Inc., 
 600 F.3d 1357, 1367, 94 USPQ2d 1385, 1391 (Fed. Cir. 2010); Enzo Biochem,
 Inc., v. Applera Corp., 599 F.3d 1325, 1332, 94 USPQ2d 1321, 1326
 (Fed. Cir. 2010); Seattle Box Co., Inc. v. Indus. Crating & Packing,
 Inc., 731 F.2d 818, 826, 221 USPQ 568, 574 (Fed. Cir. 1984). If the
 specification does not provide some standard for measuring that degree, a
 determination must be made as to whether one of ordinary skill in the art could
 nevertheless ascertain the scope of the claim (e.g., a standard that is recognized
 in the art for measuring the meaning of the term of degree). For example, in
 Ex parte Oetiker, 23 USPQ2d 1641 (Bd. Pat. App. & Inter.
 1992), the phrases “relatively shallow,” “of the order of,” “the order of about
 5mm,” and “substantial portion” were held to be indefinite because the
 specification lacked some standard for measuring the degrees intended.
 

 The claim is not indefinite if the specification
 provides examples or teachings that can be used to measure a degree even without a
 precise numerical measurement (e.g., a figure that provides a standard for
 measuring the meaning of the term of degree). See, e.g., Interval
 Licensing LLC v. AOL, Inc., 766 F.3d 1364, 1371-72, 112 USPQ2d 1188,
 1193 (Fed. Cir. 2014) (observing that although there is no absolute or
 mathematical precision required, “[t]he claims, when read in light of the
 specification and the prosecution history, must provide objective boundaries for
 those of skill in the art”). 
 

 Proper claim interpretation regarding a term of
 degree requires determining whether its usage within the context of the claim(s)
 and specification is clear. The identification of a claim term as one of degree
 alone is not enough to conclude a claim is indefinite. Clearone, Inc. v.
 Shure Acquisition Holdings, Inc., 35 F.4th 1345, 1349, 1351, 2022
 USPQ2d 509 (Fed. Cir. 2022) (noting that “claim 57 does not use the term similar
 in isolation as a term of degree but in the context of a self-referential or
 self-repeating geometric pattern for configuring microphones in an array, . .
 .”).
 

 During prosecution, an applicant may also overcome
 an indefiniteness rejection by providing evidence that the meaning of the term of
 degree can be ascertained by one of ordinary skill in the art when reading the
 disclosure. For example, in Enzo Biochem, the applicant
 submitted a declaration under 37 CFR 1.132 showing examples
 that met the claim limitation and examples that did not. Enzo
 Biochem, 599 F.3d at 1335, 94 USPQ2d at 1328 (noting that applicant
 overcame an indefiniteness rejection over “not interfering substantially” claim
 language by submitting a declaration under 37 CFR 1.132 listing eight
 specific linkage groups that applicant declared did not substantially interfere
 with hybridization or detection). 
 

 Even if the specification uses the same term of
 degree as in the claim, a rejection is proper if the scope of the term is not
 understood when read in light of the specification. While, as a general
 proposition, broadening modifiers are standard tools in claim drafting in order to
 avoid reliance on the doctrine of equivalents in infringement actions, when the
 scope of the claim is unclear a rejection under 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph, is proper. See In re Wiggins, 488 F. 2d 538, 541,
 179 USPQ 421, 423 (CCPA 1973).
 

 When relative terms are used in claims wherein the improvement
 over the prior art rests entirely upon size or weight of an element in a
 combination of elements, the adequacy of the disclosure of a standard is of
 greater criticality.
 

 II. REFERENCE TO AN OBJECT THAT IS VARIABLE MAY RENDER A CLAIM
 INDEFINITE A claim may be rendered indefinite when a limitation of the claim
 is defined by reference to an object and the relationship between the limitation
 and the object is not sufficiently defined. That is, where the elements of a claim
 have two or more plausible constructions such that the examiner cannot readily
 ascertain positional relationship of the elements, the claim may be rendered
 indefinite. See, e.g., Ex parte Miyazaki, 89 USPQ2d 1207 (Bd.
 Pat. App. & Inter. 2008) (precedential) and Ex parte
 Brummer, 12 USPQ2d 1653 (Bd. Pat. App. & Inter. 1989). In
 Miyazaki, the Board held that claims to a large printer were
 not sufficiently definite because:
 

 
 The language of claim 1 attempts to claim the
 height of the paper feeding unit in relation to a user of a specific height who
 is performing operations on the printer.... Claim 1 fails to specify, however,
 a positional relationship of the user and the printer to each other. 
 

 
 Miyazaki, 89 USPQ2d at 1212. In Brummer, the
 Board held that a limitation in a claim to a bicycle that recited “said front and
 rear wheels so spaced as to give a wheelbase that is between 58 percent and 75
 percent of the height of the rider that the bicycle was designed for” was
 indefinite because the relationship of parts was not based on any known standard
 for sizing a bicycle to a rider, but on a rider of unspecified build.
 Brummer, 12 USPQ2d at 1655.
 

 On the other hand, a claim limitation specifying
 that a certain part of a pediatric wheelchair be “so dimensioned as to be
 insertable through the space between the doorframe of an automobile and one of the
 seats” was held to be definite. Orthokinetics, Inc. v. Safety Travel Chairs, Inc., 806 F.2d 1565, 1 USPQ2d 1081 (Fed.
 Cir. 1986). The court stated that the phrase “so dimensioned” is as accurate as
 the subject matter permits, noting that the patent law does not require that all
 possible lengths corresponding to the spaces in hundreds of different automobiles
 be listed in the patent, let alone that they be listed in the claims.
 

 III. APPROXIMATIONS 
 

 A. “About” In determining the range encompassed by the term “about,” one
 must consider the context of the term as it is used in the specification and
 claims of the application. Ortho-McNeil Pharm., Inc. v. Caraco Pharm.
 Labs., Ltd., 476 F.3d 1321, 1326, 81 USPQ2d 1427, 1432 (Fed. Cir.
 2007). In W.L. Gore & Associates, Inc. v. Garlock, Inc., 721 F.2d 1540, 220 USPQ 303 (Fed. Cir. 1983),
 the court held that a limitation defining the stretch rate of a plastic as
 “exceeding about 10% per second” is definite because infringement could clearly
 be assessed through the use of a stopwatch. However, in another case, the court
 held that claims reciting “at least about” were invalid for indefiniteness
 where there was close prior art and there was nothing in the specification,
 prosecution history, or the prior art to provide any indication as to what
 range of specific activity is covered by the term “about.” Amgen, Inc. v. Chugai Pharmaceutical Co., 927 F.2d 1200, 18 USPQ2d 1016
 (Fed. Cir. 1991).
 

 B. “Essentially” The phrase “a silicon dioxide source that is essentially free
 of alkali metal” was held to be definite because the specification contained
 guidelines and examples that were considered sufficient to enable a person of
 ordinary skill in the art to draw a line between unavoidable impurities in
 starting materials and essential ingredients. In re Marosi, 710 F.2d 799, 218 USPQ 289 (CCPA 1983). The court
 further observed that it would be impractical to require applicants to specify
 a particular number as a cutoff between their invention and the prior art.
 

 C. “Similar” The term “similar” in the preamble of a claim that was
 directed to a nozzle “for high-pressure cleaning units or similar apparatus”
 was held to be indefinite since it was not clear what applicant intended to
 cover by the recitation “similar” apparatus. Ex parte Kristensen, 10 USPQ2d 1701 (Bd. Pat. App. & Inter.
 1989).
 

 A claim in a design patent application which read: “The
 ornamental design for a feed bunk or similar structure as shown and described.”
 was held to be indefinite because it was unclear from the specification what
 applicant intended to cover by the recitation of “similar structure.”
 Ex parte Pappas, 23 USPQ2d 1636 (Bd. Pat. App. & Inter.
 1992).
 

 D. “Substantially” The term “substantially” is often used in conjunction with
 another term to describe a particular characteristic of the claimed invention.
 It is a broad term. In re Nehrenberg, 280 F.2d 161, 126 USPQ 383 (CCPA 1960). The
 court held that the limitation “to substantially increase the efficiency of the
 compound as a copper extractant” was definite in view of the general guidelines
 contained in the specification. In re Mattison, 509 F.2d 563, 184 USPQ 484 (CCPA 1975). The court
 held that the limitation “which produces substantially equal E and H plane
 illumination patterns” was definite because one of ordinary skill in the art
 would know what was meant by “substantially equal.” Andrew
 Corp. v. Gabriel Electronics, 847 F.2d 819, 6 USPQ2d 2010 (Fed. Cir.
 1988).
 

 E. “Type” The addition of the word “type” to an otherwise definite
 expression (e.g., Friedel-Crafts catalyst) extends the scope of the expression
 so as to render it indefinite. Ex parte Copenhaver, 109 USPQ 118 (Bd. Pat. App. & Inter. 1955).
 Likewise, the phrase “ZSM-5-type aluminosilicate zeolites” was held to be
 indefinite because it was unclear what “type” was intended to convey. The
 interpretation was made more difficult by the fact that the zeolites defined in
 the dependent claims were not within the genus of the type of zeolites defined
 in the independent claim. Ex parte Attig, 7 USPQ2d 1092 (Bd. Pat. App. & Inter. 1986).
 

 IV. SUBJECTIVE TERMS When a subjective term is used in the claim, the
 examiner should determine whether the specification supplies some objective
 standard for measuring the scope of the term. Some objective standard must be
 provided in order to allow the public to determine the scope of the claim. A claim
 term that requires the exercise of subjective judgment without restriction may
 render the claim indefinite. In re Musgrave, 431 F.2d 882, 893,
 167 USPQ 280, 289 (CCPA 1970). Claim scope cannot depend solely on the
 unrestrained, subjective opinion of a particular individual purported to be
 practicing the invention. Datamize LLC v. Plumtree Software,
 Inc., 417 F.3d 1342, 1350, 75 USPQ2d 1801, 1807 (Fed. Cir. 2005));
 see also Interval Licensing LLC v. AOL, Inc., 766 F.3d 1364,
 1373, 112 USPQ2d 1188 (Fed. Cir. 2014) (holding the claim phrase “unobtrusive
 manner” indefinite because the specification did not “provide a reasonably clear
 and exclusive definition, leaving the facially subjective claim language without
 an objective boundary”). 
 

 For example, in Datamize, the
 invention was directed to a computer interface screen with an “aesthetically
 pleasing look and feel.” Datamize, 417 F.3d at 1344-45, 75
 USPQ2d at 1802-03. The meaning of the term “aesthetically pleasing” depended
 solely on the subjective opinion of the person selecting features to be included
 on the interface screen. Nothing in the intrinsic evidence (e.g., the
 specification) provided any guidance as to what design choices would result in an
 “aesthetically pleasing” look and feel. 417 F.3d at 1352, 75 USPQ2d at 1808. The
 claims were held indefinite because the interface screen may be “aesthetically
 pleasing” to one user but not to another. 417 F.3d at 1350, 75 USPQ2d at 1806. See
 also Ex parte Anderson, 21 USPQ2d 1241 (Bd. Pat. App. &
 Inter. 1991) (the terms “comparable” and “superior” were held to be indefinite in
 the context of a limitation relating the characteristics of the claimed material
 to other materials). 
 

 During prosecution, the applicant may overcome a
 rejection by amending the claim to remove the subjective term, or by providing
 evidence that the meaning of the term can be ascertained by one of ordinary skill
 in the art when reading the disclosure. However, “[f]or some facially subjective
 terms, the definiteness requirement is not satisfied by merely offering examples
 that satisfy the term within the specification.” DDR Holdings, LLC v.
 Hotels.com, L.P., 773 F.3d 1245, 1261, 113 USPQ2d 1097, 1108 (Fed.
 Cir. 2014).
 

 

 
 2173.05(c) Numerical Ranges and Amounts Limitations [R-11.2013]

 Generally, the recitation of specific numerical ranges in a claim
 does not raise an issue of whether a claim is definite.
 

 I. NARROW AND BROADER RANGES IN THE SAME CLAIM Use of a narrow numerical range that falls within a broader range
 in the same claim may render the claim indefinite when the boundaries of the claim
 are not discernible. Description of examples and preferences is properly set forth
 in the specification rather than in a single claim. A narrower range or preferred
 embodiment may also be set forth in another independent claim or in a dependent
 claim. If stated in a single claim, examples and preferences lead to confusion
 over the intended scope of the claim. In those instances where it is not clear
 whether the claimed narrower range is a limitation, a rejection under
 35
 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph should be made. The Examiner should analyze whether the metes and bounds
 of the claim are clearly set forth. Examples of claim language which have been
 held to be indefinite are (A) “a temperature of between 45 and 78 degrees Celsius,
 preferably between 50 and 60 degrees Celsius”; and (B) “a predetermined quantity,
 for example, the maximum capacity.”
 

 While a single claim that includes both a broad and a narrower
 range may be indefinite, it is not improper under 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C.112 , second
 paragraph, to present a dependent claim that sets forth a narrower range for an
 element than the range set forth in the claim from which it depends. For example,
 if claim 1 reads “A circuit … wherein the resistance is 70-150 ohms.” and claim 2
 reads “The circuit of claim 1 wherein the resistance is 70-100 ohms.”, then claim
 2 should not be rejected as indefinite. 
 

 II. OPEN-ENDED NUMERICAL RANGES Open-ended numerical ranges should be carefully analyzed for
 definiteness. For example, when an independent claim recites a composition
 comprising “at least 20% sodium” and a dependent claim sets forth specific amounts
 of nonsodium ingredients which add up to 100%, apparently to the exclusion of
 sodium, an ambiguity is created with regard to the “at least” limitation (unless
 the percentages of the nonsodium ingredients are based on the weight of the
 nonsodium ingredients). On the other hand, the court held that a composition
 claimed to have a theoretical content greater than 100% (i.e., 20-80% of A, 20-80%
 of B and 1-25% of C) was not indefinite simply because the claims may be read in
 theory to include compositions that are impossible in fact to formulate. It was
 observed that subject matter which cannot exist in fact can neither anticipate nor
 infringe a claim. In re Kroekel, 504 F.2d 1143, 183 USPQ 610 (CCPA 1974).
 

 In a claim directed to a chemical reaction process, a limitation
 required that the amount of one ingredient in the reaction mixture should “be
 maintained at less than 7 mole percent” based on the amount of another ingredient.
 The examiner argued that the claim was indefinite because the limitation sets only
 a maximum amount and is inclusive of substantially no ingredient resulting in
 termination of any reaction. The court did not agree, holding that the claim was
 clearly directed to a reaction process, and explaining that “[t]he imposition of a
 maximum limit on the quantity of one of the reactants without specifying a minimum
 does not warrant distorting the overall meaning of the claim to preclude
 performing the claimed process.” In re Kirsch, 498 F.2d 1389, 1394, 182 USPQ 286, 290 (CCPA 1974).
 

 Some terms have been determined to have the following meanings in
 the factual situations of the reported cases: the term “up to” includes zero as a
 lower limit, In re Mochel, 470 F.2d 638, 176 USPQ 194 (CCPA 1974); and “a moisture
 content of not more than 70% by weight” reads on dry material, Ex
 parte Khusid, 174 USPQ 59 (Bd. App. 1971).
 

 III. “EFFECTIVE AMOUNT” The common phrase “an effective amount” may or may not be
 indefinite. The proper test is whether or not one skilled in the art could
 determine specific values for the amount based on the disclosure. See In
 re Mattison, 509 F.2d 563, 184 USPQ 484 (CCPA 1975). The phrase
 “an effective amount . . . for growth stimulation” was held to be definite where
 the amount was not critical and those skilled in the art would be able to
 determine from the written disclosure, including the examples, what an effective
 amount is. In re Halleck, 422 F.2d 911, 164 USPQ 647 (CCPA 1970). The phrase “an
 effective amount” has been held to be indefinite when the claim fails to state the
 function which is to be achieved and more than one effect can be implied from the
 specification or the relevant art. In re Fredericksen, 213 F.2d 547, 102 USPQ 35 (CCPA 1954). The more
 recent cases have tended to accept a limitation such as “an effective amount” as
 being definite when read in light of the supporting disclosure and in the absence
 of any prior art which would give rise to uncertainty about the scope of the
 claim. In Ex parte Skuballa, 12 USPQ2d 1570 (Bd. Pat. App. & Inter. 1989), the
 Board held that a pharmaceutical composition claim which recited an “effective
 amount of a compound of claim 1” without stating the function to be achieved was
 definite, particularly when read in light of the supporting disclosure which
 provided guidelines as to the intended utilities and how the uses could be
 effected.
 

 

 
 2173.05(d) Exemplary Claim Language (“for example,” “such
 as”) [R-07.2015]
 

 Description of examples or preferences is properly set forth in the
 specification rather than the claims. If stated in the claims, examples and
 preferences may lead to confusion over the intended scope of a claim. In those
 instances where it is not clear whether the claimed narrower range is a limitation, a
 rejection under 35 U.S.C. 112(b) or
 pre-AIA 35
 U.S.C. 112 , second paragraph should be made. The examiner
 should analyze whether the metes and bounds of the claim are clearly set forth. Note
 that the mere use of the phrase “such as” or “for example" in a claim does not by
 itself render the claim indefinite.
 

 Examples of claim language which have been held to be
 indefinite because the intended scope of the claim was unclear are: 
 

 
 (A) “R is halogen, for example, chlorine”; 

 (B) “material such as rock wool or asbestos” Ex
 parte Hall, 83 USPQ 38 (Bd. App. 1949); 
 

 (C) “lighter hydrocarbons, such, for example, as the vapors or gas
 produced” Ex parte Hasche, 86 USPQ 481 (Bd. App. 1949); 
 

 (D) “normal operating conditions such as while in the container of
 a proportioner” Ex parte Steigerwald, 131 USPQ 74 (Bd. App. 1961); and
 

 (E) “coke, brick, or like material”. Ex
 parte Caldwell, 1906 C.D. 58 (Comm’r Pat. 1906).
 

 
 The above examples of claim language which have been held to be
 indefinite are fact specific and should not be applied as
 per se rules. See MPEP § 2173.02 for guidance
 regarding when it is appropriate to make a rejection under 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph.
 

 

 
 2173.05(e) Lack of Antecedent Basis [R-01.2024]

 A claim is indefinite when it contains words or phrases whose
 meaning is unclear. In re Packard, 751 F.3d 1307, 1314, 110 USPQ2d
 1785, 1789 (Fed. Cir. 2014). The lack of clarity could arise where a claim refers to
 “said lever” or “the lever,” where the claim contains no earlier recitation or
 limitation of a lever and where it would be unclear as to what element the limitation
 was making reference. Similarly, if two different levers are recited earlier in the
 claim, the recitation of “said lever” in the same or subsequent claim would be
 unclear where it is uncertain which of the two levers was intended. A claim which
 refers to “said aluminum lever,” but recites only “a lever” earlier in the claim, is
 indefinite because it is uncertain as to the lever to which reference is made.
 Obviously, however, the failure to provide explicit antecedent basis for terms does
 not always render a claim indefinite. If the scope of a claim would be reasonably
 ascertainable by those skilled in the art, then the claim is not indefinite.
 Ex parte Porter, 25 USPQ2d 1144, 1145 (Bd. Pat. App. &
 Inter. 1992) (“controlled stream of fluid” provided reasonable antecedent basis for
 “the controlled fluid”). Inherent components of elements recited have antecedent
 basis in the recitation of the elements themselves. For example, the limitation “the
 outer surface of said sphere” would not require an antecedent recitation that the
 sphere has an outer surface. See Bose Corp. v. JBL, Inc., 274 F.3d
 1354, 1359, 61 USPQ2d 1216, 1218-19 (Fed. Cir 2001) (holding that recitation of “an
 ellipse” provided antecedent basis for “an ellipse having a major diameter” because
 “[t]here can be no dispute that mathematically an inherent characteristic of an
 ellipse is a major diameter”).
 

 I. EXAMINER SHOULD SUGGEST CORRECTIONS TO ANTECEDENT PROBLEMS Antecedent problems in the claims are typically drafting
 oversights that are easily corrected once they are brought to the attention of
 applicant. The examiner’s task of making sure the claim language complies with the
 requirements of the statute should be carried out in a positive and constructive
 way, so that minor problems can be identified and easily corrected, and so that
 the major effort is expended on more substantive issues. However, even though
 indefiniteness in claim language is of semantic origin, it is not rendered
 unobjectionable simply because it could have been corrected. In re
 Hammack, 427 F.2d 1384, 1388 n.5, 166 USPQ 209, 213 n.5 (CCPA
 1970).
 

 II. A CLAIM TERM WHICH HAS NO ANTECEDENT BASIS IN THE DISCLOSURE IS NOT
 NECESSARILY INDEFINITE The mere fact that a term or phrase used in the claim has no
 antecedent basis in the specification disclosure does not mean, necessarily, that
 the term or phrase is indefinite. There is no requirement that the words in the
 claim must match those used in the specification disclosure. Applicants are given
 a great deal of latitude in how they choose to define their invention so long as
 the terms and phrases used define the invention with a reasonable degree of
 clarity and precision. 
 

 III. A CLAIM IS NOT PER SE INDEFINITE IF THE BODY OF THE
 CLAIM RECITES ADDITIONAL ELEMENTS WHICH DO NOT APPEAR IN THE PREAMBLE The mere fact that the body of a claim recites additional
 elements which do not appear in the claim’s preamble does not render the claim
 indefinite under 35 U.S.C. 112(b) or
 pre-AIA 35
 U.S.C. 112 , second paragraph. See In re
 Larsen, 10 Fed. App’x 890 (Fed. Cir. 2001) (The preamble of the
 Larsen claim recited only a hanger and a loop but the body
 of the claim positively recited a linear member. The examiner rejected the claim
 under 35 U.S.C.
 112 , second paragraph, because the omission from the claim’s
 preamble of a critical element (i.e., a linear member) renders that claim
 indefinite. The court reversed the examiner’s rejection and stated that the
 totality of all the limitations of the claim and their interaction with each other
 must be considered to ascertain the inventor’s contribution to the art. Upon
 review of the claim in its entirety, the court concluded that the claim at issue
 apprises one of ordinary skill in the art of its scope and, therefore, serves the
 notice function required by 35 U.S.C. 112 , paragraph 2.).
 
 

 

 
 2173.05(f) Reference to Limitations in Another Claim [R-11.2013]

 A claim which makes reference to a preceding claim to define a
 limitation is an acceptable claim construction which should not necessarily be
 rejected as improper or confusing under 35 U.S.C. 112(b) or
 pre-AIA 35
 U.S.C. 112 , second paragraph. For example, claims which read:
 “The product produced by the method of claim 1.” or “A method of producing ethanol
 comprising contacting amylose with the culture of claim 1 under the following
 conditions .....” are not indefinite under 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph, merely because of the reference to another claim. See also Ex
 parte Porter, 25 USPQ2d 1144 (Bd. Pat. App. & Inter. 1992) (where
 reference to “the nozzle of claim 7” in a method claim was held to comply with
 35 U.S.C.
 112 , second paragraph). However, where the format of making
 reference to limitations recited in another claim results in confusion, then a
 rejection would be proper under 35 U.S.C. 112(b) or
 pre-AIA
 35 U.S.C. 112 , second paragraph. 
 

 When examining a dependent claim, the examiner should
 also determine whether the claim complies with 35 U.S.C.
 112(d) or pre-AIA 35 U.S.C. 112 , fourth
 paragraph. See MPEP §
 608.01(n) , subsection III.
 

 

 
 2173.05(g) Functional Limitations [R-07.2022]

 A claim term is functional when it recites a feature “by what it
 does rather than by what it is” (e.g., as evidenced by its specific structure or
 specific ingredients). In re Swinehart, 439 F.2d 210, 212, 169 USPQ 226, 229 (CCPA 1971). There
 is nothing inherently wrong with defining some part of an invention in functional
 terms. Functional language does not, in and of itself, render a claim improper.
 Id. In fact, 35 U.S.C. 112(f) and
 pre-AIA 35
 U.S.C. 112 , sixth paragraph, expressly authorize a form of
 functional claiming (means- (or step-) plus- function claim limitations discussed in
 MPEP §
 2181 et seq. ). Functional language may also be employed to limit the
 claims without using the means-plus-function format. See, e.g., K-2 Corp. v.
 Salomon S.A., 191 F.3d 1356, 1363, 52 USPQ2d 1001, 1005 (Fed. Cir.
 1999). Unlike means-plus-function claim language that applies only to purely
 functional limitations, Phillips v. AWH Corp., 415 F.3d 1303,
 1311, 75 USPQ2d 1321, 1324 (Fed. Cir. 2005) (en banc) 
 (“Means-plus-function claiming applies only to purely functional limitations that do
 not provide the structure that performs the recited function.”), functional claiming
 often involves the recitation of some structure followed by its function. For
 example, in In re Schreiber, the claims were directed to a conical
 spout (the structure) that “allow[ed] several kernels of popped popcorn to pass
 through at the same time” (the function). In re Schreiber, 128
 F.3d 1473, 1478, 44 USPQ2d 1429, 1431 (Fed. Cir. 1997). As noted by the court in
 Schreiber, “[a] patent applicant is free to recite features of
 an apparatus either structurally or functionally.” Id. 

 A functional limitation must be evaluated and considered, just like
 any other limitation of the claim, for what it fairly conveys to a person of ordinary
 skill in the pertinent art in the context in which it is used. A functional
 limitation is often used in association with an element, ingredient, or step of a
 process to define a particular capability or purpose that is served by the recited
 element, ingredient or step. In Innova/Pure Water Inc. v. Safari Water
 Filtration Sys. Inc., 381 F.3d 1111, 1117-20, 72 USPQ2d 1001, 1006-08
 (Fed. Cir. 2004), the court noted that the claim term “operatively connected” is “a
 general descriptive claim term frequently used in patent drafting to reflect a
 functional relationship between claimed components,” that is, the term “means the
 claimed components must be connected in a way to perform a designated function.” “In
 the absence of modifiers, general descriptive terms are typically construed as having
 their full meaning.” Id. at 1118, 72 USPQ2d at 1006. In the patent
 claim at issue, “subject to any clear and unmistakable disavowal of claim scope, the
 term ‘operatively connected’ takes the full breath of its ordinary meaning, i.e.,
 ‘said tube [is] operatively connected to said cap’ when the tube and cap are arranged
 in a manner capable of performing the function of filtering.” Id. 
 at 1120, 72 USPQ2d at 1008.
 

 Other examples of permissible function language include the
 following. 
 

 
 It was held that the limitation used to define a
 radical on a chemical compound as “incapable of forming a dye with said oxidizing
 developing agent” although functional, was perfectly acceptable because it set
 definite boundaries on the patent protection sought. In re
 Barr, 444 F.2d 588, 170 USPQ 330 (CCPA 1971). 
 

 

 
 In a claim that was directed to a kit of component
 parts capable of being assembled, the court held that limitations such as “members
 adapted to be positioned” and “portions . . . being resiliently dilatable whereby
 said housing may be slidably positioned” serve to precisely define present
 structural attributes of interrelated component parts of the claimed assembly.
 In re Venezia, 530 F.2d 956, 189 USPQ 149 (CCPA 1976).
 

 

 Notwithstanding the permissible instances, the use of
 functional language in a claim may fail “to provide a clear-cut indication of the
 scope of the subject matter embraced by the claim” and thus be indefinite.
 In re Swinehart, 439 F.2d 210, 213 (CCPA 1971). For example,
 when claims merely recite a description of a problem to be solved or a function or
 result achieved by the invention, the boundaries of the claim scope may be unclear.
 Halliburton Energy Servs., Inc. v. M-I LLC, 514 F.3d 1244,
 1255, 85 USPQ2d 1654, 1663 (Fed. Cir. 2008) (noting that the Supreme Court explained
 that a vice of functional claiming occurs “when the inventor is painstaking when he
 recites what has already been seen, and then uses conveniently functional language at
 the exact point of novelty”) (quoting General Elec. Co. v. Wabash Appliance
 Corp., 304 U.S. 364, 371 (1938)); see also United Carbon Co. v.
 Binney & Smith Co., 317 U.S. 228, 234, 55 USPQ 381 (1942) (holding
 indefinite claims that recited substantially pure carbon black “in the form of
 commercially uniform, comparatively small, rounded smooth aggregates having a spongy
 or porous exterior”). Further, without reciting the particular structure, materials
 or steps that accomplish the function or achieve the result, all means or methods of
 resolving the problem may be encompassed by the claim. Ariad
 Pharmaceuticals., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1353, 94
 USPQ2d 1161, 1173 (Fed. Cir. 2010) (en banc) . See also
 Datamize LLC v. Plumtree Software Inc., 417 F.3d 1342, 75
 USPQ2d 1801 (Fed. Cir. 2005) where a claim directed to a software based system for
 creating a customized computer interface screen recited that the screen be
 “aesthetically pleasing,” which is an intended result and does not provide a clear
 cut indication of scope because it imposed no structural limits on the screen.
 Unlimited functional claim limitations that extend to all means or methods of
 resolving a problem may not be adequately supported by the written description or may
 not be commensurate in scope with the enabling disclosure, both of which are required
 by 35
 U.S.C. 112(a) and pre-AIA 35 U.S.C. 112 , first
 paragraph. In re Hyatt, 708 F.2d 712, 714, 218 USPQ 195, 197 (Fed.
 Cir. 1983); Ariad, 598 F.3d at 1340, 94 USPQ2d at 1167. For
 instance, a single means claim covering every conceivable means for achieving the
 stated result was held to be invalid under 35 U.S.C. 112 , first paragraph
 because the court recognized that the specification, which disclosed only those means
 known to the inventor, was not commensurate in scope with the claim.
 Hyatt, 708 F.2d at 714-715, 218 USPQ at 197. For more
 information regarding the written description requirement and enablement requirement
 under 35
 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112 , first
 paragraph, see MPEP §§
 2161 - 2164.08(c) . Examiners should keep in
 mind that whether or not the functional limitation complies with 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph, is a different issue from whether the limitation is properly supported
 under 35
 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112 , first
 paragraph, or is distinguished over the prior art. 
 

 When a claim limitation employs functional language,
 the examiner’s determination of whether the limitation is sufficiently definite will
 be highly dependent on context (e.g., the disclosure in the specification and the
 knowledge of a person of ordinary skill in the art). Halliburton Energy
 Servs., 514 F.3d at 1255, 85 USPQ2d at 1663. For example, a claim that
 included the term “fragile gel” was found to be indefinite because the definition of
 the term in the specification was functional, i.e., the fluid is defined by what it
 does rather than what it is (“ability of the fluid to transition quickly from gel to
 liquid, and the ability of the fluid to suspend drill cuttings at rest”), and it was
 ambiguous as to the requisite degree of the fragileness of the gel, the ability of
 the gel to suspend drill cuttings (i.e., gel strength), and/or some combination of
 the two. Halliburton Energy Servs., 514 F.3d at 1255-56, 85 USPQ2d
 at 1663. In another example, the claims directed to a tungsten filament for electric
 incandescent lamps were held invalid for including a limitation that recited
 “comparatively large grains of such size and contour as to prevent substantial
 sagging or offsetting during a normal or commercially useful life for such a lamp or
 other device.” General Elec. Co., 304 U.S. at 370-71, 375. The
 Court observed that the prior art filaments also “consisted of comparatively large
 crystals” but they were “subject to offsetting” or shifting, and the Court further
 found that the phrase “of such size and contour as to prevent substantial sagging and
 offsetting during a normal or commercially useful life for a lamp or other device”
 did not adequately define the structural characteristics of the grains (e.g., the
 size and contour) to distinguish the claimed invention from the prior art.
 Id. at 370. Similarly, a claim was held invalid because it
 recited “sustantially (sic) pure carbon black in the form of commercially uniform,
 comparatively small, rounded smooth aggregates having a spongy or porous exterior.”
 United Carbon Co., 317 U.S. at 234. In the latter example, the
 Court observed various problems with the limitation: “commercially uniform” meant
 only the degree of uniformity buyers desired; “comparatively small” did not add
 anything because no standard for comparison was given; and “spongy” and “porous” are
 synonyms that the Court found unhelpful in distinguishing the claimed invention from
 the prior art. Id. at 233. 
 

 In comparison, a claim limitation reciting
 “transparent to infrared rays” was held to be definite because the specification
 showed that a substantial amount of infrared radiation was always transmitted even
 though the degree of transparency varied depending on certain factors.
 Swinehart, 439 F.2d at 214, 169 USPQ at 230. Likewise, the
 claims in another case were held definite because applicant provided “a general
 guideline and examples sufficient to enable a person of ordinary skill in the art to
 determine whether a process uses a silicon dioxide source ‘essentially free of alkali
 metal’ to make a reaction mixture ‘essentially free of alkali metal’ to produce a
 zeolitic compound ‘essentially free of alkali metal.’” In re
 Marosi, 710 F.2d 799, 803, 218 USPQ 289, 293 (Fed. Cir. 1983). 
 

 Examiners should consider the following factors when
 examining claims that contain functional language to determine whether the language
 is ambiguous: (1) whether there is a clear cut indication of the scope of the subject
 matter covered by the claim; (2) whether the language sets forth well-defined
 boundaries of the invention or only states a problem solved or a result obtained; and
 (3) whether one of ordinary skill in the art would know from the claim terms what
 structure or steps are encompassed by the claim. These factors are examples of points
 to be considered when determining whether language is ambiguous and are not intended
 to be all inclusive or limiting. Other factors may be more relevant for particular
 arts. The primary inquiry is whether the language leaves room for ambiguity or
 whether the boundaries are clear and precise. 
 

 During prosecution, applicant may resolve the
 ambiguities of a functional limitation in a number of ways. For example: (1) “the
 ambiguity might be resolved by using a quantitative metric (e.g., numeric limitation
 as to a physical property) rather than a qualitative functional feature” (see
 Halliburton Energy Servs., 514 F.3d at 1255-56, 85 USPQ2d at
 1663); (2) applicant could demonstrate that the “specification provide[s] a formula
 for calculating a property along with examples that meet the claim limitation and
 examples that do not” (see id. at 1256, 85 USPQ2d at 1663 (citing
 Oakley, Inc. v. Sunglass Hut Int’l, 316 F.3d 1331, 1341, 65
 USPQ2d 1321, 1326 (Fed. Cir. 2003))); (3) applicant could demonstrate that the
 specification provides a general guideline and examples sufficient to teach a person
 skilled in the art when the claim limitation was satisfied (see
 Marosi, 710 F.2d at 803, 218 USPQ at 292); or (4) applicant
 could amend the claims to recite the particular structure that accomplishes the
 function. 
 

 

 
 2173.05(h) Alternative Limitations [R-01.2024]
 I. MARKUSH GROUPS A claim which recites a list of alternatives to
 define a limitation is an acceptable claim construction which should not
 necessarily be rejected as confusing under 35 U.S.C.
 112(b) or as improper. See MPEP §
 2117 for guidelines regarding the determination of
 whether a Markush grouping is improper.
 

 Treatment of claims reciting alternatives is not governed by the
 particular format used (e.g., alternatives may be set forth as “a material
 selected from the group consisting of A, B, and C” or “wherein the material is A,
 B, or C”). See, e.g., the Supplementary Examination Guidelines for
 Determining Compliance with 35 U.S.C. 112 and for Treatment of Related Issues
 in Patent Applications (“Supplementary Guidelines”), 76 Fed. Reg.
 7162, 7166 (February 9, 2011). Claims that set forth a list of alternatives from
 which a selection is to be made are typically referred to as Markush claims, after
 the appellant in Ex parte Markush, 1925 Dec. Comm’r Pat. 126,
 127 (1924). The listing of specified alternatives within a Markush claim is
 referred to as a Markush group or Markush grouping. Abbott Labs v. Baxter
 Pharmaceutical Products, Inc., 334 F.3d 1274, 1280-81, 67 USPQ2d
 1191, 1196-97 (Fed. Cir. 2003) (citing to several sources that describe Markush
 groups).
 

 See MPEP §
 2117 for a general discussion of Markush claims and
 guidelines regarding the determination of whether a Markush grouping is improper,
 and MPEP §
 803.02 for a discussion of election requirements in
 Markush claims.
 

 A Markush grouping is a closed group of
 alternatives, i.e., the selection is made from a group “consisting of” (rather
 than “comprising” or “including”) the alternative members. Abbott
 Labs., 334 F.3d at 1280, 67 USPQ2d at 1196. If a Markush grouping
 requires a material selected from an open list of alternatives (e.g., selected
 from the group “comprising” or “consisting essentially of” the recited
 alternatives), the claim should generally be rejected under 35 U.S.C.
 112(b) as indefinite because it is unclear what other
 alternatives are intended to be encompassed by the claim. See In re
 Kiely, 2022 USPQ2d 532 at 2* (Fed. Cir. 2022) (each independent claim
 recites "a selection from the group comprising a person, an
 animal, an animated character, a creature, an alien, a toy, a structure, a
 vegetable, and a fruit.” … (emphasis added). “Given the breadth of variation among
 the specified alternatives and the use of the open-ended word ’comprising’ to
 define the scope of the list, we affirm the Board's conclusion that the pending
 claims recite improper Markush language and are indefinite under §
 112(b) .”). If a claim is intended to encompass combinations
 or mixtures of the alternatives set forth in the Markush grouping, the claim may
 include qualifying language preceding the recited alternatives (such as “at least
 one member” selected from the group), or within the list of alternatives (such as
 “or mixtures thereof”). Id. at 1281. See also
 MPEP §
 2111.03 . 
 

 A Markush grouping may include a large number of
 alternatives, and as a result a Markush claim may encompass a large number of
 alternative members or embodiments, but a claim is not necessarily indefinite
 under 35 U.S.C. 112(b) for such breadth. In re
 Gardner, 427 F.2d 786, 788, 166 USPQ 138, 140 (CCPA 1970) (“Breadth
 is not indefiniteness.”). In certain circumstances, however, a Markush group may
 be so expansive that persons skilled in the art cannot determine the metes and
 bounds of the claimed invention. For example, if a claim defines a chemical
 compound using one or more Markush groups, and that claim encompasses a massive
 number of distinct alternative members, the claim may be indefinite under
 35
 U.S.C. 112(b) if one skilled in the art cannot determine its
 metes and bounds due to an inability to envision all of the compounds defined by
 the Markush group(s). In such a circumstance, a rejection of the claim for
 indefiniteness under 35 U.S.C. 112(b) is
 appropriate.
 

 The use of Markush claims of diminishing scope should not, in
 itself, be considered a sufficient basis for objection to or rejection of claims.
 However, if such a practice renders the claims indefinite or if it results in
 undue multiplicity, an appropriate rejection should be made. 
 

 Similarly, the double inclusion of an element by members of a
 Markush group is not, in itself, sufficient basis for objection to or rejection of
 claims. Rather, the facts in each case must be evaluated to determine whether or
 not the multiple inclusion of one or more elements in a claim renders that claim
 indefinite. The mere fact that a compound may be embraced by more than one member
 of a Markush group recited in the claim does not necessarily render the scope of
 the claim unclear. For example, the Markush group, “selected from the group
 consisting of amino, halogen, nitro, chloro and alkyl” should be acceptable even
 though “halogen” is generic to “chloro.” See, e.g., Eli Lilly & Co.
 v. Teva Parenteral Meds., 845 F.3d 1357, 1371,121 USPQ2d 1277, 1287
 (Fed. Cir. 2017) (redundancy of including both “vitamin B12” and “cyanocobalamin”
 (which were recognized on the record as referencing the same compound) within a
 Markush group of methylmalonic acid lowering agents did not render the claims
 indefinite).
 

 II. “OPTIONALLY” Another alternative format which requires some analysis before
 concluding whether or not the language is indefinite involves the use of the term
 “optionally.” In Ex parte Cordova, 10 USPQ2d 1949 (Bd. Pat. App. & Inter. 1989) the
 language “containing A, B, and optionally C” was considered acceptable alternative
 language because there was no ambiguity as to which alternatives are covered by
 the claim. A similar holding was reached with regard to the term “optionally” in
 Ex parte Wu, 10 USPQ2d 2031 (Bd. Pat. App. & Inter. 1989). In the
 instance where the list of potential alternatives can vary and ambiguity arises,
 then it is proper to make a rejection under 35 U.S.C.
 112(b) and explain why there is confusion.
 

 

 
 2173.05(i) Negative Limitations [R-07.2022]

 The current view of the courts is that there is nothing inherently
 ambiguous or uncertain about a negative limitation. So long as the boundaries of the
 patent protection sought are set forth definitely, albeit negatively, the claim
 complies with the requirements of 35 U.S.C. 112(b) or
 pre-AIA
 35 U.S.C. 112 , second paragraph. Some older cases were critical
 of negative limitations because they tended to define the invention in terms of what
 it was not, rather than pointing out the invention. Thus, the court observed that the
 limitation “R is an alkenyl radical other than 2-butenyl and 2,4-pentadienyl” was a
 negative limitation that rendered the claim indefinite because it was an attempt to
 claim the invention by excluding what the inventors did not invent rather than
 distinctly and particularly pointing out what they did invent. In re
 Schechter, 205 F.2d 185, 98 USPQ 144 (CCPA 1953).
 

 A claim which recited the limitation “said homopolymer being free
 from the proteins, soaps, resins, and sugars present in natural Hevea rubber” in
 order to exclude the characteristics of the prior art product, was considered
 definite because each recited limitation was definite. In re
 Wakefield, 422 F.2d 897, 899, 904, 164 USPQ 636, 638, 641 (CCPA 1970).
 In addition, the court found that the negative limitation “incapable of forming a dye
 with said oxidized developing agent” was definite because the boundaries of the
 patent protection sought were clear. In re Barr, 444 F.2d 588, 170
 USPQ 330 (CCPA 1971).
 

 Any negative limitation or exclusionary proviso must have basis in
 the original disclosure. If alternative elements are positively recited in the
 specification, they may be explicitly excluded in the claims. See In re
 Johnson, 558 F.2d 1008, 1019, 194 USPQ 187, 196 (CCPA 1977) (“[the]
 specification, having described the whole, necessarily described the part
 remaining.”). See also Ex parte Grasselli, 231 USPQ 393 (Bd. App.
 1983), aff’d mem., 738 F.2d 453 (Fed. Cir. 1984). In describing
 alternative features, the applicant need not articulate advantages or disadvantages
 of each feature in order to later exclude the alternative features. See
 Inphi Corporation v. Netlist, Inc., 805 F.3d 1350, 1356-57, 116
 USPQ2d 2006, 2010-11 (Fed. Cir. 2015). The mere absence of a positive recitation is
 not basis for an exclusion. However, a lack of literal basis in the specification for
 a negative limitation may not be sufficient to establish a prima
 facie case for lack of descriptive support. Ex parte
 Parks, 30 USPQ2d 1234, 1236 (Bd. Pat. App. & Inter. 1993). “Rather,
 as with positive limitations, the disclosure must only 'reasonably convey[] to those
 skilled in the art that the inventor had possession of the claimed subject matter as
 of the filing date.' ... While silence will not generally suffice to support a
 negative claim limitation, there may be circumstances in which it can be established
 that a skilled artisan would understand a negative limitation to necessarily be
 present in a disclosure.” Novartis Pharms. Corp. v. Accord Healthcare,
 Inc., 38 F.4th 1013, 2022 USPQ2d 569 (Fed. Cir. 2022) (quoting
 Ariad Pharm. Inc. v. Eli Lilly & Co., 589 F.3d 1336, 1351,
 94 USPQ2d 1161, 1172). Any claim containing a negative limitation which does not have
 basis in the original disclosure should be rejected under 35 U.S.C.
 112(a) or pre-AIA 35 U.S.C. 112 , first
 paragraph, as failing to comply with the written description requirement. See
 MPEP §
 2163 - § 2163.07(b) for a discussion of the
 written description requirement of 35 U.S.C. 112(a) and
 pre-AIA 35
 U.S.C. 112 , first paragraph.
 

 

 
 2173.05(j) Old Combination [R-11.2013]
 A CLAIM SHOULD NOT BE REJECTED ON THE GROUND OF OLD COMBINATION With the passage of the 1952 Patent Act, the courts and the Board
 have taken the view that a rejection based on the principle of old combination is
 NO LONGER VALID. Claims should be considered proper so long as they comply with
 the provisions of 35 U.S.C. 112(b) or
 pre-AIA 35
 U.S.C. 112 , second paragraph. 
 

 A rejection on the basis of old combination was based on the
 principle applied in Lincoln Engineering Co. v. Stewart-Warner
 Corp., 303 U.S. 545, 37 USPQ 1 (1938). The principle was that an
 inventor who made an improvement or contribution to but one element of a generally
 old combination, should not be able to obtain a patent on the entire combination
 including the new and improved element. A rejection required the citation of a
 single reference which broadly disclosed a combination of the claimed elements
 functionally cooperating in substantially the same manner to produce substantially
 the same results as that of the claimed combination. The case of In re
 Hall, 208 F.2d 370, 100 USPQ 46 (CCPA 1953) illustrates an
 application of this principle.
 

 The court pointed out in In re Bernhart, 417
 F.2d 1395, 163 USPQ 611 (CCPA 1969) that the statutory language (particularly
 point out and distinctly claim) is the only proper basis for an old combination
 rejection, and in applying the rejection, that language determines what an
 applicant has a right and obligation to do. A majority opinion of the Board of
 Appeals held that Congress removed the underlying rationale of Lincoln
 Engineering in the 1952 Patent Act, and thereby effectively
 legislated that decision out of existence. Ex parte Barber, 187
 USPQ 244 (Bd. App. 1974). Finally, the Court of Appeals for the Federal Circuit,
 in Radio Steel and Mfg. Co. v. MTD Products, Inc., 731 F.2d
 840, 221 USPQ 657 (Fed. Cir. 1984), followed the Bernhart case, and ruled that a claim was not invalid under Lincoln
 Engineering because the claim complied with the requirements of
 35 U.S.C.
 112 , second paragraph. Accordingly, a claim should not be
 rejected on the ground of old combination.
 

 

 
 2173.05(k) Aggregation [R-08.2012]

 A claim should not be rejected on the ground of “aggregation.”
 In re Gustafson, 331 F.2d 905, 141 USPQ 585 (CCPA 1964) (an
 applicant is entitled to know whether the claims are being rejected under
 35 U.S.C.
 101 , 102 , 103 , or
 112 ); In re Collier, 397 F.2d 1003, 1006,
 158 USPQ 266, 268 (CCPA 1968) (“[A] rejection for ‘aggregation’ is
 non-statutory.”).
 

 If a claim omits essential matter or fails to interrelate essential
 elements of the invention as defined by applicant(s) in the specification, see
 MPEP
 § 2172.01 .
 

 

 

 
 2173.05(l) [Reserved]

 

 

 
 2173.05(m) Prolix [R-08.2012]

 Examiners should reject claims as prolix only when they contain such
 long recitations or unimportant details that the scope of the claimed invention is
 rendered indefinite thereby. Claims are rejected as prolix when they contain long
 recitations that the metes and bounds of the claimed subject matter cannot be
 determined.
 

 

 
 2173.05(n) Multiplicity [R-11.2013]

 
 37 CFR 1.75 Claim(s). 

 
 (a) The specification must conclude with a claim particularly
 pointing out and distinctly claiming the subject matter which the applicant
 regards as his invention or discovery.
 

 (b) More than one claim may be presented provided they differ
 substantially from each other and are not unduly multiplied.
 

 
 *****

 

 Where, in view of the nature and scope of applicant’s invention,
 applicant presents an unreasonable number of claims which are repetitious and
 multiplied, the net result of which is to confuse rather than to clarify, a rejection
 on undue multiplicity based on 35 U.S.C. 112(b) or
 pre-AIA 35
 U.S.C. 112 , second paragraph, may be appropriate. As noted by
 the court in In re Chandler, 319 F.2d 211, 225, 138 USPQ 138, 148
 (CCPA 1963), “applicants should be allowed reasonable latitude in stating their
 claims in regard to number and phraseology employed. The right of applicants to
 freedom of choice in selecting phraseology which truly points out and defines their
 inventions should not be abridged. Such latitude, however, should not be extended to
 sanction that degree of repetition and multiplicity which beclouds definition in a
 maze of confusion. The rule of reason should be practiced and applied on the basis of
 the relevant facts and circumstances in each individual case.” See also In
 re Flint, 411 F.2d 1353, 1357, 162 USPQ 228, 231 (CCPA 1969). Undue
 multiplicity rejections based on 35 U.S.C. 112(b) or
 pre-AIA 35
 U.S.C. 112 , second paragraph, should be applied judiciously and
 should be rare. 
 

 If an undue multiplicity rejection under 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph, is appropriate, the examiner should contact applicant by telephone
 explaining that the claims are unduly multiplied and will be rejected under
 35
 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph. Note MPEP §
 408 . The examiner should also request that applicant select
 a specified number of claims for purpose of examination. If applicant is willing to
 select, by telephone, the claims for examination, an undue multiplicity rejection on
 all the claims based on 35 U.S.C. 112(b) or
 pre-AIA 35
 U.S.C. 112 , second paragraph, should be made in the next Office
 action along with an action on the merits on the selected claims. If applicant
 refuses to comply with the telephone request, an undue multiplicity rejection of all
 the claims based on 35 U.S.C. 112(b) or
 pre-AIA 35
 U.S.C. 112 , second paragraph, should be made in the next Office
 action. Applicant’s reply must include a selection of claims for purpose of
 examination, the number of which may not be greater than the number specified by the
 examiner. In response to applicant’s reply, if the examiner adheres to the undue
 multiplicity rejection, it should be repeated and the selected claims will be
 examined on the merits. This procedure preserves applicant’s right to have the
 rejection on undue multiplicity reviewed by the Patent Trial and Appeal Board. 
 

 Also, it is possible to reject one claim over an allowed claim if
 they differ only by subject matter old in the art. This ground of rejection is set
 forth in Ex parte Whitelaw, 1915 C.D. 18, 219 O.G. 1237 (Comm’r Pat. 1914). The
 Ex parte Whitelaw doctrine is restricted to cases where the claims are
 unduly multiplied or are substantial duplicates. Ex parte Kochan, 
 131 USPQ 204, 206 (Bd. App. 1961).
 

 

 
 2173.05(o) Double Inclusion [R-08.2012]

 There is no per se rule that “double inclusion”
 is improper in a claim. In re Kelly, 305 F.2d 909, 916, 134 USPQ
 397, 402 (CCPA 1962) (“Automatic reliance upon a ‘rule against double inclusion’ will
 lead to as many unreasonable interpretations as will automatic reliance upon a ‘rule
 allowing double inclusion’. The governing consideration is not double
 inclusion, but rather is what is a reasonable construction of the
 language of the claims.”). Older cases, such as Ex parte White, 
 127 USPQ 261 (Bd. App. 1958) and Ex parte Clark, 174 USPQ 40 (Bd.
 App. 1971) should be applied with care, according to the facts of each case.
 

 The facts in each case must be evaluated to determine whether or not
 the multiple inclusion of one or more elements in a claim gives rise to
 indefiniteness in that claim. The mere fact that a compound may be embraced by more
 than one member of a Markush group recited in the claim does not lead to any
 uncertainty as to the scope of that claim for either examination or infringement
 purposes. On the other hand, where a claim directed to a device can be read to
 include the same element twice, the claim may be indefinite. Ex parte
 Kristensen, 10 USPQ2d 1701 (Bd. Pat. App. & Inter. 1989).
 

 

 
 2173.05(p) Claim Directed to Product-By- Process or Product and
 Process [R-07.2022]
 

 There are many situations where claims are permissively drafted to
 include a reference to more than one statutory class of invention. 
 

 I. PRODUCT-BY-PROCESS A product-by-process claim, which is a product claim that defines
 the claimed product in terms of the process by which it is made, is
 proper. Purdue Pharma v. Epic Pharma, 811 F.3d 1345, 1354,
 117 USPQ2d 1733, 1739 (Fed. Cir. 2016); In re Luck, 476 F.2d
 650, 177 USPQ 523 (CCPA 1973); In re Pilkington, 411 F.2d 1345,
 162 USPQ 145 (CCPA 1969); and In re Steppan, 394 F.2d 1013, 156
 USPQ 143 (CCPA 1967). A claim to a device, apparatus, manufacture, or composition
 of matter may contain a reference to the process in which it is intended to be
 used without being objectionable under 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph, so long as it is clear that the claim is directed to the product and
 not the process.
 

 An applicant may present claims of varying scope even if it is
 necessary to describe the claimed product in product-by-process terms. Ex
 parte Pantzer, 176 USPQ 141 (Bd. App. 1972).
 

 II. PRODUCT AND PROCESS IN THE SAME CLAIM A single claim which claims both an apparatus and the method
 steps of using the apparatus is indefinite under 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph. See In re Katz Interactive Call Processing Patent
 Litigation, 639 F.3d 1303, 1318, 97 USPQ2d 1737, 1748-49 (Fed. Cir.
 2011). In Katz, a claim directed to “[a] system with an
 interface means for providing automated voice messages…to certain of said
 individual callers, wherein said certain of said individual callers
 digitally enter data ” was determined to be indefinite because the
 italicized claim limitation is not directed to the system, but rather to actions
 of the individual callers, which creates confusion as to when direct infringement
 occurs. Katz, 639 F.3d at 1318, 97 USPQ2d at 1749 (citing
 IPXL Holdings v. Amazon.com, Inc., 430 F.3d 1377, 1384, 77
 USPQ2d 1140, 1145 (Fed. Cir. 2005), in which a system claim that recited “an input
 means” and required a user to use the input means was found to be indefinite
 because it was unclear “whether infringement … occurs when one creates a system
 that allows the user [to use the input means], or whether infringement occurs when
 the user actually uses the input means.”); Ex parte Lyell, 17 USPQ2d 1548 (Bd. Pat. App. & Inter. 1990) (claim
 directed to an automatic transmission workstand and the method of using it held
 ambiguous and properly rejected under 35 U.S.C. 112 , second
 paragraph).
 

 In contrast, when a claim recites a product and
 additional limitations which focus on the capabilities of the system, not the
 specific actions or functions performed by the user, the claim may be definite
 under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph. See Mastermine Software, Inc. v. Microsoft Corp., 
 874 F.3d 1307, 124 USPQ2d 1618 (Fed. Cir. 2017). 
 

 

 
 2173.05(q) “Use” Claims [R-10.2019]

 Attempts to claim a process without setting forth any steps involved
 in the process generally raises an issue of indefiniteness under 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph. For example, a claim which read: “[a] process for using monoclonal
 antibodies of claim 4 to isolate and purify human fibroblast interferon” was held to
 be indefinite because it merely recites a use without any active, positive steps
 delimiting how this use is actually practiced. Ex parte Erlich, 3 USPQ2d 1011 (Bd. Pat. App. & Inter. 1986). 
 

 “Use” claims that do not purport to claim a process, machine,
 manufacture, or composition of matter fail to comply with 35 U.S.C. 101 .
 In re Moreton, 288 F.2d 708, 709, 129 USPQ 227, 228 (CCPA
 1961)(“one cannot claim a new use per se , because it is not among
 the categories of patentable inventions specified in 35 U.S.C. §
 101 ”). In Ex parte Dunki, 153 USPQ 678 (Bd. App. 1967), the Board held the following
 claim to be an improper definition of a process: “The use of a high carbon austenitic
 iron alloy having a proportion of free carbon as a vehicle brake part subject to
 stress by sliding friction.” In Clinical Products Ltd. v. Brenner, 
 255 F. Supp. 131, 149 USPQ 475 (D.D.C. 1966), the district court held the following
 claim was definite, but that it was not a proper process claim under
 35 U.S.C.
 101 : “The use of a sustained release therapeutic agent in the
 body of ephedrine absorbed upon polystyrene sulfonic acid.” 
 

 Although a claim should be interpreted in light of the specification
 disclosure, it is generally considered improper to read limitations contained in the
 specification into the claims. See In re Prater, 415 F.2d 1393, 162 USPQ 541 (CCPA 1969) and In re
 Winkhaus, 527 F.2d 637, 188 USPQ 129 (CCPA 1975), which discuss the
 premise that one cannot rely on the specification to impart limitations to the claim
 that are not recited in the claim. 
 

 I. A “USE” CLAIM MAY BE REJECTED UNDER 35 U.S.C 101 AND/OR 112 It is appropriate to reject a claim that recites a use but fails
 to recite steps under 35 U.S.C. 101 and
 35
 U.S.C. 112(b) if the facts support both rejections. For
 failure to recite a claim within one of the statutory classes under
 35 U.S.C.
 101 , the appropriate form paragraph is
 7.05.01 . For indefiniteness under
 35
 U.S.C. 112(b) , the appropriate form paragraph is
 7.34.01 .
 

 II. BOARD HELD STEP OF “UTILIZING” WAS NOT INDEFINITE It is often difficult to draw a fine line between what is
 permissible, and what is objectionable from the perspective of whether a claim is
 definite. In the case of Ex parte Porter, 25 USPQ2d 1144 (Bd. Pat. App. & Inter. 1992), the
 Board held that a claim which clearly recited the step of “utilizing” was not
 indefinite under 35 U.S.C. 112 , second paragraph. (Claim was to “A method
 for unloading nonpacked, nonbridging and packed, bridging flowable particle
 catalyst and bead material from the opened end of a reactor tube which comprises
 utilizing the nozzle of claim 7.”).
 

 

 
 2173.05(r) Omnibus Claim [R-10.2019]

 Some applications are filed with an omnibus claim which reads as
 follows: A device substantially as shown and described. This claim should be rejected
 under 35
 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph, because it is indefinite in that it fails to point out what is included or
 excluded by the claim language. See Ex parte Fressola, 27 USPQ2d 1608 (Bd. Pat. App. & Inter. 1993), for a
 discussion of the history of omnibus claims and an explanation of why omnibus claims
 do not comply with the requirements of 35 U.S.C. 112(b) or
 pre-AIA 35
 U.S.C. 112 , second paragraph.
 

 Such a claim can be rejected using form paragraph
 7.35 . See
 MPEP §
 2175 . 
 

 

 
 2173.05(s) Reference to Figures or Tables [R-10.2019]

 Where possible, claims are to be complete in themselves.
 Incorporation by reference to a specific figure or table “is permitted only in
 exceptional circumstances where there is no practical way to define the invention in
 words and where it is more concise to incorporate by reference than duplicating a
 drawing or table into the claim. Incorporation by reference is a necessity doctrine,
 not for applicant’s convenience.” Ex parte Fressola, 27 USPQ2d 1608, 1609 (Bd. Pat. App. & Inter. 1993)
 (citations omitted). 
 

 Reference characters corresponding to elements recited in the
 detailed description and the drawings may be used in conjunction with the recitation
 of the same element or group of elements in the claims. Generally, the presence or
 absence of such reference characters does not affect the scope of a claim. See
 MPEP §
 608.01(m) for information pertaining to the treatment of
 reference characters in a claim.
 

 

 
 2173.05(t) Chemical Formula [R-11.2013]

 Claims to chemical compounds and compositions containing chemical
 compounds often use formulas that depict the chemical structure of the compound.
 These structures should not be considered indefinite nor speculative in the absence
 of evidence that the assigned formula is in error. The absence of corroborating
 spectroscopic or other data cannot be the basis for finding the structure indefinite.
 See Ex parte Morton, 134 USPQ 407 (Bd. App. 1961), and Ex
 parte Sobin, 139 USPQ 528 (Bd. App. 1962). 
 

 A claim to a chemical compound is not indefinite merely because a
 structure is not presented or because a partial structure is presented. For example,
 the claim language at issue in In re Fisher, 427 F.2d 833, 166 USPQ 18 (CCPA 1970) referred to a
 chemical compound as a “polypeptide of at least 24 amino acids having the following
 sequence.” A rejection under pre-AIA 35 U.S.C. 112 , second
 paragraph, for failure to identify the entire structure was reversed and the court
 held: “While the absence of such a limitation obviously broadens the claim and raises
 questions of sufficiency of disclosure, it does not render the claim indefinite.”
 Chemical compounds may be claimed by a name that adequately describes the material to
 one skilled in the art. See Martin v. Johnson, 454 F.2d 746, 172 USPQ 391 (CCPA 1972). A compound of
 unknown structure may be claimed by a combination of physical and chemical
 characteristics. See Ex parte Brian, 118 USPQ 242 (Bd. App. 1958). A compound may also be
 claimed in terms of the process by which it is made without raising an issue of
 indefiniteness. 
 

 

 
 2173.05(u) Trademarks or Trade Names in a Claim [R-07.2022]

 The presence of a trademark or trade name in a claim is not,
 per se, improper under 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph, but the claim should be carefully analyzed to determine how the mark or
 name is used in the claim. It is important to recognize that a trademark or trade
 name is used to identify a source of goods, and is not the name of the goods
 themselves. Thus a trademark or trade name does not define or describe the goods
 associated with the trademark or trade name. See definitions of trademark and trade
 name in MPEP §
 608.01(v) . 
 

 If the trademark or trade name is used in a claim as a limitation to
 identify or describe a particular material or product, the claim does not comply with
 the requirements of the 35 U.S.C. 112(b) or
 pre-AIA 35
 U.S.C. 112 , second paragraph. Ex parte Simpson, 218 USPQ 1020 (Bd. App. 1982). See also Eli
 Lilly & Co. v. Apotex, Inc., 837 Fed. Appx. 780, 784-85, 2020 USPQ2d
 11531 (Fed. Cir. 2020) ("Following Patent Office procedure, the Examiner in this case
 rejected the claims of the '821 application as indefinite because they improperly
 used the trade name 'ALIMTA.' In response to the rejection, Lilly canceled its claims
 reciting the trade name and pursued claims using the generic name for the same
 substance, which mooted the rejection. Additionally, as the district court observed,
 the Examiner 'explicitly noted that pemetrexed disodium was 'also known by the trade
 name ALIMTA' ' in the contemporaneous obviousness rejection."). The claim scope is
 uncertain since the trademark or trade name cannot be used properly to describe any
 particular material or product. In fact, the value of a trademark would be lost to
 the extent that it became the generic name of a product, rather than used as an
 identification of a source or origin of a product. Thus, the use of a trademark or
 trade name in a claim to describe a material or product would not only render a claim
 indefinite, but would also constitute an improper use of the trademark or trade name.
 If the applicant responds to such a rejection by replacing the trademark or trade
 name with a generic term, the examiner should determine whether there is sufficient
 support in the application for use of a generic term. See MPEP § 2163 ,
 subsection II.A.3(b). 
 

 If a trademark or trade name appears in a claim and is not intended
 as a limitation in the claim, the question of why it is in the claim should be
 addressed. If its presence in the claim causes confusion as to the scope of the
 claim, then the claim should be rejected under 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph.
 

 

 
 2173.05(v) Mere Function of Machine [R-11.2013]

 Process or method claims are not subject to rejection by U.S. Patent
 and Trademark Office examiners under 35 U.S.C. 112(b) or
 pre-AIA 35
 U.S.C. 112 , second paragraph, solely on the ground that they
 define the inherent function of a disclosed machine or apparatus. In
 re Tarczy-Hornoch, 397 F.2d 856, 158 USPQ 141 (CCPA 1968). The court
 in Tarczy-Hornoch held that a process claim, otherwise patentable,
 should not be rejected merely because the application of which it is a part discloses
 an apparatus which will inherently carry out the recited steps.
 

 

 

 
 2173.06 Practice Compact Prosecution [R-07.2022]
 I. INTERPRET THE CLAIM AND APPLY ART WITH AN EXPLANATION OF HOW AN INDEFINITE
 TERM IS INTERPRETED The goal of examination is to clearly articulate any
 rejection early in the prosecution process so that the applicant has the chance to
 provide evidence of patentability and otherwise reply completely at the earliest
 opportunity. See MPEP §
 706 . Under the principles of compact prosecution, the
 examiner should review each claim for compliance with every statutory requirement for
 patentability in the initial review of the application and identify all of the
 applicable grounds of rejection in the first Office action to avoid unnecessary
 delays in the prosecution of the application. See 37 CFR 1.104(a)(1) (“On taking up
 an application for examination or a patent in a reexamination proceeding, the
 examiner shall make a thorough study thereof and shall make a thorough investigation
 of the available prior art relating to the subject matter of the claimed invention.
 The examination shall be complete with respect both to compliance of the application
 . . . with the applicable statutes and rules and to the patentability of the
 invention as claimed, as well as with respect to matters of form, unless otherwise
 indicated.”). 
 

 Thus, when the examiner determines that a claim term or
 phrase renders the claim indefinite, the examiner should make a rejection based on
 indefiniteness under 35 U.S.C. 112(b) or
 pre-AIA 35
 U.S.C. 112 , second paragraph, as well as a rejection(s) in view
 of the prior art under 35 U.S.C. 102 or
 103 that renders the prior art applicable based on the
 examiner’s interpretation of the claim. See In re Packard, 751
 F.3d 1307, 1312, 110 USPQ2d 1785, 1788 (Fed. Cir. 2014) (stating that the
 prima facie case is appropriately used for making an
 indefiniteness rejection). When making a rejection over prior art in these
 circumstances, it is important that the examiner state on the record how the
 claim term or phrase is being interpreted with respect to the prior art
 applied in the rejection. By rejecting each claim on all reasonable grounds
 available, the examiner can avoid piecemeal examination. See MPEP § 707.07(g) 
 (“Piecemeal examination should be avoided as much as possible. The examiner
 ordinarily should reject each claim on all valid grounds available . . . .”). 
 

 II. PRIOR ART REJECTION OF CLAIM REJECTED AS INDEFINITE All words in a claim must be considered in judging the patentability
 of a claim against the prior art. In re Wilson, 424 F.2d 1382, 165
 USPQ 494 (CCPA 1970). The fact that terms may be indefinite does not make the claim
 obvious over the prior art. When the terms of a claim are considered to be
 indefinite, at least two approaches to the examination of an indefinite claim
 relative to the prior art are possible.
 

 First, where the degree of uncertainty is not great, and where the
 claim is subject to more than one interpretation and at least one interpretation
 would render the claim unpatentable over the prior art, an appropriate course of
 action would be for the examiner to enter two rejections: (A) a rejection based on
 indefiniteness under 35 U.S.C. 112(b) or
 pre-AIA 35
 U.S.C. 112 , second paragraph; and (B) a rejection over the
 prior art based on the interpretation of the claims which renders the prior art
 applicable. See, e.g., Ex parte Ionescu, 222 USPQ 537 (Bd. App.
 1984). When making a rejection over prior art in these circumstances, it is important
 for the examiner to point out how the claim is being interpreted. Second, where there
 is a great deal of confusion and uncertainty as to the proper interpretation of the
 limitations of a claim, it would not be proper to reject such a claim on the basis of
 prior art. As stated in In re Steele, 305 F.2d 859, 134 USPQ 292 (CCPA 1962), a rejection under
 35 U.S.C.
 103 should not be based on considerable speculation about the
 meaning of terms employed in a claim or assumptions that must be made as to the scope
 of the claims. 
 

 The first approach is recommended from an examination standpoint
 because it avoids piecemeal examination in the event that the examiner’s
 35 U.S.C.
 112 , second paragraph rejection is not affirmed, and may give
 applicant a better appreciation for relevant prior art if the claims are redrafted to
 avoid the 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph rejection.
 

 

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 2101-2102-[Reserved] 

 2103-Patent Examination Process 

 2104-Requirements of 35 U.S.C. 101 
 2104.01-Barred by Atomic Energy Act 

 
 

 2105-Patent Eligible Subject Matter — Living Subject Matter 

 2106-Patent Subject Matter Eligibility 
 2106.01-[Reserved] 

 2106.02-[Reserved] 

 2106.03-Eligibility Step 1: The Four Categories of Statutory Subject Matter 

 2106.04-Eligibility Step 2A: Whether a Claim is Directed to a Judicial Exception 
 2106.04(a)-Abstract Ideas 
 2106.04(a)(1)-Examples of Claims That Do Not Recite Abstract Ideas 

 2106.04(a)(2)-Abstract Idea Groupings 

 2106.04(a)(3)-Tentative Abstract Ideas 

 
 

 2106.04(b)-Laws of Nature, Natural Phenomena & Products of Nature 

 2106.04(c)-The Markedly Different Characteristics Analysis 

 2106.04(d)-Integration of a Judicial Exception Into A Practical Application 
 2106.04(d)(1)-Evaluating Improvements in the Functioning of a Computer, or an Improvement to Any Other Technology or Technical Field in
 Step 2A Prong Two 

 2106.04(d)(2)-Particular Treatment and Prophylaxis in Step 2A Prong Two 

 
 

 
 

 2106.05-Eligibility Step 2B: Whether a Claim Amounts to Significantly More 
 2106.05(a)-Improvements to the Functioning of a Computer or To Any Other Technology or Technical Field 

 2106.05(b)-Particular Machine 

 2106.05(c)-Particular Transformation 

 2106.05(d)-Well-Understood, Routine, Conventional Activity 

 2106.05(e)-Other Meaningful Limitations 

 2106.05(f)-Mere Instructions To Apply An Exception 

 2106.05(g)-Insignificant Extra-Solution Activity 

 2106.05(h)-Field of Use and Technological Environment 

 
 

 2106.06-Streamlined Analysis 
 2106.06(a)-Eligibility is Self Evident 

 2106.06(b)-Clear Improvement to a Technology or to Computer Functionality 

 
 

 2106.07-Formulating and Supporting Rejections For Lack Of Subject Matter Eligibility 
 2106.07(a)-Formulating a Rejection For Lack of Subject Matter Eligibility 
 2106.07(a)(1)-Form Paragraphs for use in Lack of Subject Matter Eligibility Rejections 

 
 

 2106.07(b)-Evaluating Applicant’s Response 

 2106.07(c)-Clarifying the Record 

 
 

 
 

 2107-Guidelines for Examination of Applications for Compliance with the Utility Requirement 
 2107.01-General Principles Governing Utility Rejections 

 2107.02-Procedural Considerations Related to Rejections for Lack of Utility 

 2107.03-Special Considerations for Asserted Therapeutic or Pharmacological Utilities 

 
 

 2108-[Reserved] 

 2109-Inventorship 

 2109.01-Joint Inventorship 

 2110-[Reserved] 

 2111-Claim Interpretation; Broadest Reasonable Interpretation 
 2111.01-Plain Meaning 

 2111.02-Effect of Preamble 

 2111.03-Transitional Phrases 

 2111.04-“Adapted to,” “Adapted for,” “Wherein,” “Whereby,” and Contingent Clauses 

 2111.05-Functional and Nonfunctional Descriptive Material 

 
 

 2112-Requirements of Rejection Based on Inherency; Burden of Proof 
 2112.01-Composition, Product, and Apparatus Claims 

 2112.02-Process Claims 

 
 

 2113-Product-by-Process Claims 

 2114-Apparatus and Article Claims — Functional Language 

 2115-Material or Article Worked Upon by Apparatus 

 2116-Novel, Nonobvious Starting Material or End Product 
 2116.01-Novel, Nonobvious Starting Material or End Product 

 
 

 2117-Markush Claims 

 2118-2119-[Reserved] 

 2120-Rejection on Prior Art 
 2120.01-Rejections Under 35 U.S.C. 102(a)(1) and (a)(2) and Pre-AIA 35 U.S.C. 102(a), (b), or (e): Printed Publication or Patent 

 2120.02-Rejections Under 35 U.S.C. 102(a)(1) or Pre-AIA 35 U.S.C. 102(a) or (b): Knowledge by Others, or Public Use, or On Sale 

 
 

 2121-Prior Art; General Level of Operability Required to Make a Prima Facie Case 
 2121.01-Use of Prior Art in Rejections Where Operability is in Question 

 2121.02-Compounds and Compositions — What Constitutes Enabling Prior Art 

 2121.03-Plant Genetics — What Constitutes Enabling Prior Art 

 2121.04-Apparatus and Articles — What Constitutes Enabling Prior Art 

 
 

 2122-Discussion of Utility in the Prior Art 

 2123-Rejection Over Prior Art’s Broad Disclosure Instead of Preferred Embodiments 

 2124-Exception to the Rule That the Reference Must be Prior Art 
 2124.01-Tax Strategies Deemed Within the Prior Art 

 
 

 2125-Drawings as Prior Art 

 2126-Availability of a Document as a “Patent” for Purposes of Rejection Under 35 U.S.C. 102(a) or Pre-AIA 35 U.S.C. 102(a), (b),
 and (d) 
 2126.01-Date of Availability of a Patent as a Reference 

 2126.02-Scope of Reference’s Disclosure Which Can Be Used to Reject Claims When the Reference Is a “Patent” but Not a “Publication” 

 
 

 2127-Domestic and Foreign Patent Applications as Prior Art 

 2128-“Printed Publications” as Prior Art 
 2128.01-Level of Public Accessibility Required 

 2128.02-Date Publication Is Available as a Reference 

 
 

 2129-Admissions as Prior Art 

 2130-[Reserved] 

 2131-Anticipation — Application of 35 U.S.C. 102 
 2131.01-Multiple Reference 35 U.S.C. 102 Rejections 

 2131.02-Genus-Species Situations 

 2131.03-Anticipation of Ranges 

 2131.04-Secondary Considerations 

 2131.05-Nonanalogous or Disparaging Prior Art 

 
 

 2132-Pre-AIA 35 U.S.C. 102(a) 
 2132.01-Overcoming a Pre-AIA 35 U.S.C. 102(a) Rejection based on a Printed Publication or Patent 

 
 

 2133-Pre-AIA 35 U.S.C. 102(b) 
 2133.01-Rejections of Continuation-In-Part (CIP) Applications 

 2133.02-Rejections Based on Publications and Patents 
 2133.02(a)-Overcoming a Pre-AIA 35 U.S.C. 102(b) Rejection Based on a Printed Publication or Patent 

 
 

 2133.03-Rejections Based on “Public Use” or “On Sale” 
 2133.03(a)-“Public Use” 

 2133.03(b)-“On Sale” 

 2133.03(c)-The “Invention” 

 2133.03(d)-“In This Country” 

 2133.03(e)-Permitted Activity; Experimental Use 
 2133.03(e)(1)-Commercial Exploitation 

 2133.03(e)(2)-Intent 

 2133.03(e)(3)-“Completeness” of the Invention 

 2133.03(e)(4)-Factors Indicative of an Experimental Purpose 

 2133.03(e)(5)-Experimentation and Degree of Supervision and Control 

 2133.03(e)(6)-Permitted Experimental Activity and Testing 

 2133.03(e)(7)-Activity of an Independent Third Party Inventor 

 
 

 
 

 
 

 2134-Pre-AIA 35 U.S.C. 102(c) 

 2135-Pre-AIA 35 U.S.C. 102(d) 
 2135.01-The Four Requirements of Pre-AIA 35 U.S.C. 102(d) 

 
 

 2136-Pre-AIA 35 U.S.C. 102(e) 
 2136.01-Status of Unpublished or Published as Redacted U.S. Application as a Reference Under Pre-AIA 35 U.S.C. 102(e) 

 2136.02-Content of the Prior Art Available Against the Claims 

 2136.03-Critical Reference Date 

 2136.04-Different Inventive Entity; Meaning of “By Another” 

 2136.05-Overcoming a Rejection Under Pre-AIA 35 U.S.C. 102(e) 
 2136.05(a)-Antedating a Pre-AIA 35 U.S.C. 102(e) Reference 

 2136.05(b)-Showing The Reference Is Describing An Inventor's Or At Least One Joint Inventor's Own Work 

 
 

 
 

 2137-Pre-AIA 35 U.S.C. 102(f) 
 2137.01-[Reserved] 

 2137.02-[Reserved] 

 
 

 2138-Pre-AIA 35 U.S.C. 102(g) 
 2138.01-Interference Practice 

 2138.02-“The Invention Was Made in This Country” 

 2138.03-“By Another Who Has Not Abandoned, Suppressed, or Concealed It” 

 2138.04-“Conception” 

 2138.05-“Reduction to Practice” 

 2138.06-“Reasonable Diligence” 

 
 

 2139-Rejections Under Pre-AIA 35 U.S.C. 102 
 2139.01-Effective Filing Date of a Claimed Invention Under Pre-AIA 35 U.S.C. 102 

 2139.02-Determining Whether To Apply Pre-AIA 35 U.S.C. 102(a), (b), or (e) 

 2139.03-Form Paragraphs for Use in Rejections Under Pre-AIA 35 U.S.C. 102 

 
 

 2140-[Reserved] 

 2141-Examination Guidelines for Determining Obviousness Under 35 U.S.C. 103 
 2141.01-Scope and Content of the Prior Art 
 2141.01(a)-Analogous and Nonanalogous Art 

 
 

 2141.02-Differences Between Prior Art and Claimed Invention 

 2141.03-Level of Ordinary Skill in the Art 

 
 

 2142-Legal Concept of Prima Facie Obviousness 

 2143-Examples of Basic Requirements of a Prima Facie Case of Obviousness 
 2143.01-Suggestion or Motivation To Modify the References 

 2143.02-Reasonable Expectation of Success Is Required 

 2143.03-All Claim Limitations Must Be Considered 

 
 

 2144-Supporting a Rejection Under 35 U.S.C. 103 
 2144.01-Implicit Disclosure 

 2144.02-Reliance on Scientific Theory 

 2144.03-Reliance on Common Knowledge in the Art or “Well Known” Prior Art 

 2144.04-Legal Precedent as Source of Supporting Rationale 

 2144.05-Obviousness of Similar and Overlapping Ranges, Amounts, and Proportions 

 2144.06-Art Recognized Equivalence for the Same Purpose 

 2144.07-Art Recognized Suitability for an Intended Purpose 

 2144.08-Obviousness of Species When Prior Art Teaches Genus 

 2144.09-Close Structural Similarity Between Chemical Compounds (Homologs, Analogues, Isomers) 

 
 

 2145-Consideration of Applicant’s Rebuttal Arguments and Evidence 

 2146-Pre-AIA 35 U.S.C. 103(c) 
 2146.01-Prior Art Disqualification Under Pre-AIA 35 U.S.C. 103(c) 

 2146.02-Establishing Common Ownership or Joint Research Agreement Under Pre-AIA 35 U.S.C. 103(c) 

 2146.03-Examination Procedure With Respect to Pre-AIA 35 U.S.C. 103(c) 
 2146.03(a)-Provisional Rejection (Obviousness) Under 35 U.S.C. 103(a) Using Provisional Prior Art Under Pre-AIA 35 U.S.C. 102(e) 

 
 

 
 

 2147-Biotechnology Process Applications; Pre-AIA 35 U.S.C. 103(b) 

 2148-Form Paragraphs for Use in Rejections Under Pre-AIA 35 U.S.C. 103 

 2149-[Reserved] 

 2150-Examination Guidelines for 35 U.S.C. 102 and 103 as Amended by the First Inventor To File Provisions of the Leahy-Smith America
 Invents Act 

 2151-Overview of the Changes to 35 U.S.C. 102 and 103 in the AIA 

 2152-Detailed Discussion of AIA 35 U.S.C. 102(a) and (b) 
 2152.01-Effective Filing Date of the Claimed Invention 

 2152.02-Prior Art Under AIA 35 U.S.C. 102(a)(1) (Patented, Described in a Printed Publication, or in Public Use, on Sale, or Otherwise
 Available to the Public) 
 2152.02(a)-Patented 

 2152.02(b)-Described in a Printed Publication 

 2152.02(c)-In Public Use 

 2152.02(d)-On Sale 

 2152.02(e)-Otherwise Available to the Public 

 2152.02(f)-No Requirement of “By Others” 

 
 

 2152.03-Admissions 

 2152.04-The Meaning of “Disclosure” 

 2152.05-Determining Whether To Apply 35 U.S.C. 102(a)(1) or 102(a)(2) 

 2152.06-Overcoming a 35 U.S.C. 102(a)(1) or 102(a)(2) Rejection 

 2152.07-Form Paragraphs for Use in Rejections Under AIA 35 U.S.C. 102 

 
 

 2153-Prior Art Exceptions Under 35 U.S.C. 102(b)(1) to AIA 35 U.S.C. 102(a)(1) 
 2153.01-Prior Art Exception Under AIA 35 U.S.C. 102(b)(1)(A) To AIA 35 U.S.C. 102(a)(1) (Grace Period Inventor-Originated Disclosure
 Exception) 
 2153.01(a)-Grace Period Inventor-Originated Disclosure Exception 

 2153.01(b)-[Reserved] 

 
 

 2153.02-Prior Art Exception Under AIA 35 U.S.C. 102(b)(1)(B) to AIA 35 U.S.C. 102(a)(1) (Inventor-Originated Prior Public Disclosure
 Exception) 

 
 

 2154-Provisions Pertaining to Subject Matter in a U.S. Patent or Application Effectively Filed Before the Effective Filing Date
 of the Claimed Invention 
 2154.01-Prior Art Under AIA 35 U.S.C. 102(a)(2) “U.S. Patent Documents” 
 2154.01(a)-WIPO Published Applications 

 2154.01(b)-Determining When Subject Matter Was Effectively Filed Under AIA 35 U.S.C. 102(d) 

 2154.01(c)-Requirement Of “Names Another Inventor” 

 2154.01(d)-Provisional Rejections Under 35 U.S.C. 102(a)(2); Reference Is a Copending U.S. Patent Application 

 
 

 2154.02-Prior Art Exceptions Under 35 U.S.C. 102(b)(2) to AIA 35 U.S.C. 102(a)(2) 
 2154.02(a)-Prior Art Exception Under AIA 35 U.S.C. 102(b)(2)(A) to AIA 35 U.S.C. 102(a)(2) (Inventor-Originated Disclosure Exception) 

 2154.02(b)-Prior Art Exception Under AIA 35 U.S.C. 102(b)(2)(B) to AIA 35 U.S.C. 102(a)(2) (Inventor-Originated Prior Public Disclosure
 Exception) 

 2154.02(c)-Prior Art Exception Under AIA 35 U.S.C. 102(b)(2)(C) to AIA 35 U.S.C. 102(a)(2) (Common Ownership or Obligation of Assignment) 

 
 

 
 

 2155-Use of Affidavits or Declarations Under 37 CFR 1.130 To Overcome Prior Art Rejections 
 2155.01-Showing That the Disclosure Was Made by the Inventor or a Joint Inventor 

 2155.02-Showing That the Subject Matter Disclosed Had Been Previously Publicly Disclosed by the Inventor or a Joint Inventor 

 2155.03-Showing That the Disclosure was Made, or That Subject Matter had Been Previously Publicly Disclosed, by Another Who Obtained
 the Subject Matter Disclosed Directly or Indirectly From the Inventor or a Joint Inventor 

 2155.04-Enablement 

 2155.05-Who May File an Affidavit or Declaration Under 37 CFR 1.130 

 2155.06-Situations in Which an Affidavit or Declaration Is Not Available 

 
 

 2156-Joint Research Agreements 

 2157-Improper Naming of Inventors 

 2158-AIA 35 U.S.C. 103 
 2158.01-Form Paragraphs for Use in Rejections Under AIA 35 U.S.C. 103 

 
 

 2159-Applicability Date Provisions and Determining Whether an Application Is Subject to the First Inventor To File Provisions of
 the AIA 
 2159.01-Applications Filed Before March 16, 2013 

 2159.02-Applications Filed on or After March 16, 2013 

 2159.03-Applications Subject to the AIA but Also Containing a Claimed Invention Having an Effective Filing Date Before March 16, 2013 

 2159.04-Applicant Statement in Transition Applications Containing a Claimed Invention Having an Effective Filing Date on or After
 March 16, 2013 

 
 

 2160-[Reserved] 

 2161-Three Separate Requirements for Specification Under 35 U.S.C. 112(a) or Pre-AIA 35 U.S.C. 112, First Paragraph 
 2161.01-Computer Programming, Computer Implemented Inventions, and 35 U.S.C. 112(a) or Pre-AIA 35 U.S.C. 112, First Paragraph 

 
 

 2162-Policy Underlying 35 U.S.C. 112(a) or Pre-AIA 35 U.S.C. 112, First Paragraph 

 2163-Guidelines for the Examination of Patent Applications Under the 35 U.S.C. 112(a) or Pre-AIA 35 U.S.C. 112, first paragraph,
 “Written Description” Requirement 
 2163.01-Support for the Claimed Subject Matter in Disclosure 

 2163.02-Standard for Determining Compliance With the Written Description Requirement 

 2163.03-Typical Circumstances Where Adequate Written Description Issue Arises 

 2163.04-Burden on the Examiner with Regard to the Written Description Requirement 

 2163.05-Changes to the Scope of Claims 

 2163.06-Relationship of Written Description Requirement to New Matter 

 2163.07-Amendments to Application Which Are Supported in the Original Description 
 2163.07(a)-Inherent Function, Theory, or Advantage 

 2163.07(b)-Incorporation by Reference 

 
 

 
 

 2164-The Enablement Requirement 
 2164.01-Test of Enablement 
 2164.01(a)-Undue Experimentation Factors 

 2164.01(b)-How to Make the Claimed Invention 

 2164.01(c)-How to Use the Claimed Invention 

 
 

 2164.02-Working and Prophetic Examples 

 2164.03-Relationship of Predictability of the Art and the Enablement Requirement 

 2164.04-Burden on the Examiner Under the Enablement Requirement 

 2164.05-Determination of Enablement Based on Evidence as a Whole 
 2164.05(a)-Specification Must Be Enabling as of the Filing Date 

 2164.05(b)-Specification Must Be Enabling to Persons Skilled in the Art 

 
 

 2164.06-Quantity of Experimentation 
 2164.06(a)-Examples of Enablement Issues-Missing Information 

 2164.06(b)-Examples of Enablement Issues — Biological and Chemical Cases 

 2164.06(c)-Examples of Enablement Issues – Computer Programming Cases 

 
 

 2164.07-Relationship of Enablement Requirement to Utility Requirement of 35 U.S.C. 101 

 2164.08-Enablement Commensurate in Scope With the Claims 
 2164.08(a)-Single Means Claim 

 2164.08(b)-Inoperative Subject Matter 

 2164.08(c)-Critical Feature Not Claimed 

 
 

 
 

 2165-The Best Mode Requirement 
 2165.01-Considerations Relevant to Best Mode 

 2165.02-Best Mode Requirement Compared to Enablement Requirement 

 2165.03-Requirements for Rejection for Lack of Best Mode 

 2165.04-Examples of Evidence of Concealment 

 
 

 2166-Rejections Under 35 U.S.C. 112(a) or Pre-AIA 35 U.S.C. 112, First Paragraph 

 2167-2170-[Reserved] 

 2171-Two Separate Requirements for Claims Under 35 U.S.C. 112(b) or Pre-AIA 35 U.S.C. 112, Second Paragraph 

 2172-Subject Matter Which the Inventor or a Joint Inventor Regards as The Invention 
 2172.01-Unclaimed Essential Subject Matter 

 
 

 2173-Claims Must Particularly Point Out and Distinctly Claim the Invention 
 2173.01-Interpreting the Claims 

 2173.02-Determining Whether Claim Language is Definite 

 2173.03-Correspondence Between Specification and Claims 

 2173.04-Breadth Is Not Indefiniteness 

 2173.05-Specific Topics Related to Issues Under 35 U.S.C. 112(b) or Pre-AIA 35 U.S.C. 112, Second Paragraph 
 2173.05(a)-New Terminology 

 2173.05(b)-Relative Terminology 

 2173.05(c)-Numerical Ranges and Amounts Limitations 

 2173.05(d)-Exemplary Claim Language (“for example,” “such as”) 

 2173.05(e)-Lack of Antecedent Basis 

 2173.05(f)-Reference to Limitations in Another Claim 

 2173.05(g)-Functional Limitations 

 2173.05(h)-Alternative Limitations 

 2173.05(i)-Negative Limitations 

 2173.05(j)-Old Combination 

 2173.05(k)-Aggregation 

 2173.05(l)-[Reserved] 

 2173.05(m)-Prolix 

 2173.05(n)-Multiplicity 

 2173.05(o)-Double Inclusion 

 2173.05(p)-Claim Directed to Product-By- Process or Product and Process 

 2173.05(q)-“Use” Claims 

 2173.05(r)-Omnibus Claim 

 2173.05(s)-Reference to Figures or Tables 

 2173.05(t)-Chemical Formula 

 2173.05(u)-Trademarks or Trade Names in a Claim 

 2173.05(v)-Mere Function of Machine 

 
 

 2173.06-Practice Compact Prosecution 

 
 

 2174-Relationship Between the Requirements of 35 U.S.C. 112(a) and (b) or Pre-AIA 35 U.S.C. 112, First and Second Paragraphs 

 2175-Form Paragraphs for Use in Rejections Under 35 U.S.C. 112(b) or Pre-AIA 35 U.S.C. 112, Second Paragraph 

 2176-2180-[Reserved] 

 2181-Identifying and Interpreting a 35 U.S.C. 112(f) or Pre-AIA 35 U.S.C. 112, Sixth Paragraph Limitation 

 2182-Search and Identification of the Prior Art 

 2183-Making a Prima Facie Case of Equivalence 

 2184-Determining Whether an Applicant Has Met the Burden of Proving Nonequivalence After a Prima Facie Case Is Made 

 2185-Related Issues Under 35 U.S.C. 112(a) or (b) and Pre-AIA 35 U.S.C. 112, First or Second Paragraphs 

 2186-Relationship to the Doctrine of Equivalents 

 2187-Form Paragraphs for Use Relating to 35 U.S.C. 112(f) or Pre-AIA 35 U.S.C. 112, Sixth Paragraph 

 2188-2189-[Reserved] 

 2190-Prosecution Laches and Res Judicata 

 

 

 
 

 
 
 

 
 

 

 
 
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