MPEP § 2181 — MPEP § 2181
Current through: 2022-07-01

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

 
 
 
 
 
 
 
 

 

 
 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
 
 

 
 
 
 
 
 
 
 
 
 
 

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 Manual of Patent Examining Procedure 

 Chapter 2100 

 Section 2181 
 

 
 
 
 
 
 2181 Identifying and Interpreting a 35 U.S.C. 112(f) or Pre-AIA 35
 U.S.C. 112, Sixth Paragraph Limitation [R-07.2022]
 

 This section sets forth guidelines for the examination of
 35 U.S.C.
 112(f) or pre-AIA 35 U.S.C. 112 , sixth paragraph,
 “means or step plus function” limitations in a claim. Throughout this section, reference is
 made to 35
 U.S.C. 112(f) , however the guidance is equally applicable to
 pre-AIA 35 U.S.C.
 112 , sixth paragraph.
 

 The Court of Appeals for the Federal Circuit, in its en
 banc decision In re Donaldson Co., 16 F.3d 1189, 1194, 29
 USPQ2d 1845, 1850 (Fed. Cir. 1994), stated:
 

 
 Per our holding, the "broadest reasonable interpretation" that an
 examiner may give means-plus-function language is that statutorily mandated in paragraph
 six. Accordingly, the PTO may not disregard the structure disclosed in the specification
 corresponding to such language when rendering a patentability determination. 
 

 
 In Williamson v. Citrix Online, LLC, 792
 F.3d 1339, 1349, 115 USPQ2d 1105, 1111 (Fed. Cir. 2015) the court stated:
 

 
 [t]he standard is whether the words of the claim are
 understood by persons of ordinary skill in the art to have a sufficiently definite
 meaning as the name for structure. 
 

 
 Therefore, the broadest reasonable interpretation of a claim
 limitation that invokes 35 U.S.C. 112(f) is the structure,
 material or act described in the specification as performing the entire claimed function
 and equivalents to the disclosed structure, material or act. As a result, section
 112(f) limitations will, in some cases, be afforded a more narrow
 interpretation than a limitation that is not crafted in “means plus function” format.
 Structural elements may appear in both product claims and process claims; thus, all claim
 types should be reviewed for the presence of “means-plus-function” limitations.
 Rain Computing, Inc. v. Samsung Elecs. Am. Inc., 989 F.3d 1002, 1006,
 2021 USPQ2d 284, (Fed. Cir. 2021) (“Applicants are free to invoke § 112 ¶ 6 for
 a claim term nested in a method claim. We have never held otherwise.”). See also
 Media Rights Technologies, Inc. v. Capital One Financial Corp., 800
 F.3d 1366, 1374, 116 USPQ2d 1144 (Fed. Cir. 2015) (holding that the term “compliance
 mechanism” in a method claim was a means-plus-function term).
 

 I. DETERMINING WHETHER A CLAIM LIMITATION INVOKES 35 U.S.C. 112(f) or PRE-AIA 35
 U.S.C. 112, SIXTH PARAGRAPH The USPTO must apply 35 U.S.C. 112(f) in appropriate
 cases, and give claims their broadest reasonable interpretation (BRI), in light of and
 consistent with the written description of the invention in the application. In
 determining the BRI, examiners should establish the meaning of each claim term
 consistent with the specification as it would be interpreted by one of ordinary skill in
 the art, including identifying and construing functional claim limitations. If a claim
 limitation recites a term and associated functional language, the examiner should
 determine whether the claim limitation invokes 35 U.S.C.
 112(f) . Application of 35 U.S.C.
 112(f) is driven by the claim language, not by applicant’s intent
 or mere statements to the contrary included in the specification or made during
 prosecution. See In re Donaldson Co., 16 F.3d at 1194, 29 USPQ2d at
 1850 (stating that 35 U.S.C. 112 , sixth paragraph “merely sets a limit on how
 broadly the PTO may construe means-plus-function language under the rubric of reasonable
 interpretation’”). The Federal Circuit has held that applicants (and reexamination
 patentees) before the USPTO have the opportunity and the obligation to define their
 inventions precisely during proceedings before the USPTO. See In re
 Morris, 127 F.3d 1048, 1056–57, 44 USPQ2d 1023, 1029–30 (Fed. Cir. 1997)
 ( 35 U.S.C.
 112 , second paragraph places the burden of precise claim drafting
 on the applicant); In re Zletz, 893 F.2d 319, 322, 13 USPQ2d 1320,
 1322 (Fed. Cir. 1989) (manner of claim interpretation that is used by courts in
 litigation is not the manner of claim interpretation that is applicable during
 prosecution of a pending application before the USPTO); Sage Prods., Inc. v.
 Devon Indus., Inc., 126 F.3d 1420, 1425, 44 USPQ2d 1103, 1107 (Fed. Cir.
 1997) (patentee who had a clear opportunity to negotiate broader claims during
 prosecution but did not do so, may not seek to expand the claims through the doctrine of
 equivalents, for it is the patentee, not the public, who must bear the cost of failure
 to seek protection for this foreseeable alteration of its claimed structure). 
 

 A claim limitation is presumed to invoke
 35 U.S.C.
 112(f) when it explicitly uses the term “means” or “step” and
 includes functional language. The presumption that 35 U.S.C.
 112(f) applies is overcome when the limitation further includes
 the structure, material or acts necessary to perform the recited function. See
 TriMed, Inc. v. Stryker Corp., 514 F.3d 1256, 1259-60, 85 USPQ2d
 1787, 1789 (Fed. Cir. 2008) (“Sufficient structure exists when the claim language
 specifies the exact structure that performs the function in question without need to
 resort to other portions of the specification or extrinsic evidence for an adequate
 understanding of the structure.”); see also Altiris, Inc. v. Symantec
 Corp., 318 F.3d 1363, 1376, 65 USPQ2d 1865, 1874 (Fed. Cir. 2003).
 

 By contrast, a claim limitation that does not use the
 term “means” or “step” will trigger the rebuttable presumption that 35 U.S.C.
 112(f) does not apply. See, e.g., Phillips v. AWH
 Corp., 415 F.3d 1303, 1310, 75 USPQ2d 1321, 1324 (Fed. Cir. 2005)
 (en banc) ; CCS Fitness, Inc. v. Brunswick
 Corp., 288 F.3d 1359, 1369, 62 USPQ2d 1658, 1664 (Fed. Cir. 2002);
 Personalized Media Communications, LLC v. International Trade
 Commission, 161 F.3d 696, 703-04, 48 USPQ2d 1880, 1886–87 (Fed. Cir. 1998).
 Even in the face of this presumption, the examiner should nonetheless consider whether
 the presumption is overcome. The presumption that 35 U.S.C.
 112(f) does not apply to a claim limitation that does not use the
 term "means" is overcome when "the claim term fails to 'recite sufficiently definite
 structure' or else recites 'function without reciting sufficient structure for
 performing that function.'" Williamson, 792 F.3d at 1349, 115 USPQ2d
 at 1111 (Fed. Cir. 2015) ( en banc ) (quoting Watts v. XL
 Systems, Inc., 232 F.3d 877, 880, 56 USPQ2d 1836, 1838 (Fed. Cir. 2000);
 see also Personalized Media Communications, LLC v. International Trade
 Commission, 161 F. 3d 696, 704, 48 USPQ2d 1880, 1887 (Fed. Cir. 1998).
 

 Instead of using “means” in such cases, a substitute
 term acts as a generic placeholder for the term “means” and would not be recognized by
 one of ordinary skill in the art as being sufficiently definite structure for performing
 the claimed function. "The standard is whether the words of the claim are understood by
 persons of ordinary skill in the art to have a sufficiently definite meaning as the name
 for structure." Williamson, 792 F.3d at 1349, 115 USPQ2d at 1111; see
 also Greenberg v. Ethicon Endo-Surgery, Inc., 91 F.3d 1580, 1583, 39
 USPQ2d 1783, 1786 (Fed. Cir. 1996). 
 

 Accordingly, examiners will apply 35 U.S.C.
 112(f) to a claim limitation if it meets the following 3-prong
 analysis:
 

 
 (A) the claim limitation uses the term “means” or “step” or a term
 used as a substitute for “means” that is a generic placeholder (also called a
 nonce term or a non-structural term having no specific structural meaning) for
 performing the claimed function;
 

 (B) the term “means” or “step” or the generic placeholder is modified
 by functional language, typically, but not always linked by the transition word
 “for” (e.g., “means for”) or another linking word or phrase, such as "configured
 to" or "so that"; and
 

 (C) the term “means” or “step” or the generic placeholder is not
 modified by sufficient structure, material, or acts for performing the claimed
 function.
 

 
 A determination that a claim is being interpreted
 according to 35 U.S.C. 112(f) should be expressly stated in the examiner’s
 Office action. If a claim limitation uses the term “means” or “step,” but the examiner
 determines that either the second prong or the third prong of the 3-prong analysis is
 not met, then in these situations, the examiner must include a statement in the Office
 action explaining the reasons why a claim limitation which uses the term “means” or
 “step” is not being treated under 35 U.S.C. 112(f) .
 

 In response to the Office action that finds that
 35 U.S.C.
 112(f) is invoked, if applicant does not want to have the claim
 limitation interpreted under 35 U.S.C. 112(f) , applicant may: (1)
 present a sufficient showing to establish that the claim limitation recites sufficient
 structure to perform the claimed function so as to avoid interpretation under
 35 U.S.C.
 112(f) ; or (2) amend the claim limitation in a way that avoids
 interpretation under 35 U.S.C. 112(f) (e.g., by reciting
 sufficient structure to perform the claimed function).
 

 In the event that it is unclear whether the claim
 limitation falls within the scope of 35 U.S.C. 112(f) , a rejection under
 35 U.S.C.
 112(b) may be appropriate.
 

 A. The Claim Limitation Uses the Term “Means” or “Step” or a Generic
 Placeholder (A Term That Is Simply A Substitute for “Means”) With respect to the first prong of this analysis, a claim element
 that does not include the term “means” or “step” triggers a rebuttable presumption
 that 35
 U.S.C. 112(f) does not apply. When the claim limitation does
 not use the term “means,” examiners should determine whether the presumption that
 35
 U.S.C. 112(f) does not apply is overcome. The presumption may
 be overcome if the claim limitation uses a generic placeholder (a term that is simply
 a substitute for the term “means”). The following is a list of non-structural generic
 placeholders that may invoke 35 U.S.C. 112(f) :
 “mechanism for,” “module for,” “device for,” “unit for,” “component for,”
 “element for,” “member for,” “apparatus for,” “machine for,” or “system
 for.” Welker Bearing Co., v. PHD, Inc., 550 F.3d 1090, 1096, 89 USPQ2d
 1289, 1293-94 (Fed. Cir. 2008); Mass. Inst. of Tech. v. Abacus
 Software, 462 F.3d 1344, 1354, 80 USPQ2d 1225, 1228 (Fed. Cir. 2006);
 Personalized Media, 161 F.3d at 704, 48 USPQ2d at 1886–87;
 Mas-Hamilton Group v. LaGard, Inc., 156 F.3d 1206, 1214-1215,
 48 USPQ2d 1010, 1017 (Fed. Cir. 1998). Note that there is no fixed list of generic
 placeholders that always result in 35 U.S.C. 112(f) interpretation,
 and likewise there is no fixed list of words that always avoid 35 U.S.C.
 112(f) interpretation. Every case will turn on its own unique
 set of facts.
 

 "The standard is whether the words of the claim are
 understood by persons of ordinary skill in the art to have a sufficiently definite
 meaning as the name for structure." Williamson v. Citrix Online, 
 LLC, 792 F.3d 1339, 1349, 115 USPQ2d 1105, 1111 (Fed. Cir. 2015). The issue in
 Williamson was whether a “distributed learning control module”
 limitation in claims directed to a distributed learning system should be interpreted
 as a means-plus-function limitation. See Williamson, 792 F.3d at
 1347, 115 USPQ2d at 1110. The Federal Circuit concluded that "the 'distributed
 learning control module' limitation fails to recite sufficiently definite structure
 and that the presumption against means-plus function claiming is rebutted."
 Id. at 1351, 115 USPQ2d at 1113. In support, the Federal
 Circuit determined that "the word 'module' does not provide any indication of
 structure because it sets forth the same black box recitation of structure for
 providing the same specified function as if the term ‘means’ had been used."
 Id. at 1350–51, 115 USPQ2d at 1112.
 

 If persons of ordinary skill in the art reading the
 specification understand the term to have a sufficiently definite meaning as the name
 for the structure that performs the function, even when the term covers a broad class
 of structures or identifies the structures by their function (e.g., “filters,”
 “brakes,” “clamp,” “screwdriver,” and “locks”) 35 U.S.C.
 112(f) will not apply. Apex Inc. v. Raritan Computer,
 Inc., 325 F.3d 1364, 1372-73, 66 USPQ2d 1444, 1451-52 (Fed. Cir. 2003);
 CCS Fitness, 288 F.3d at 1369, 62 USPQ2d at 1664;
 Watts v. XL Sys. Inc., 232 F.3d 877, 880-81, 56 USPQ2d 1836,
 1839 (Fed. Cir. 2000); Personalized Media, 161 F.3d at 704, 48
 USPQ2d at 1888; Greenberg v. Ethicon Endo-Surgery, Inc., 91 F.3d
 1580, 1583, 39 USPQ2d 1783, 1786 (Fed. Cir. 1996) (“Many devices take their names
 from the functions they perform.”). Similarly, the terms “code” and “application”
 have been found not to be generic placeholders where persons of ordinary skill in the
 art would understand the terms in combination with the function performed by the code
 or application as connoting structure. Dyfan, LLC v. Target Corp., 
 28 F.4th 1360, 1368-69, 2022 USPQ2d 288 (Fed. Cir. 2022); see also
 Zeroclick, LLC v. Apple Inc., 891 F.3d 1003, 1008-1009, 126
 USPQ2d 1765 (Fed. Cir. 2018) (finding that “a person of ordinary skill in the art
 could reasonably discern from the claim language that the words ‘program’ … and ‘user
 interface code’ … are used not as generic terms or black box recitations of structure
 or abstractions….”). The term is not required to denote a specific structure or a
 precise physical structure to avoid the application of 35 U.S.C.
 112(f) . See Watts, 232 F.3d at 880, 56
 USPQ2d at 1838; Inventio AG v. Thyssenkrupp Elevator Americas
 Corp., 649 F.3d 1350, 99 USPQ2d 1112 (Fed. Cir. 2011) (holding that the
 claim terms "modernizing device" and "computing unit" when read in light of the
 specification connoted sufficient, definite structure to one of skill in the art to
 preclude application of 35 U.S.C. 112 , sixth paragraph).
 The following are examples of structural terms that have been found not 
 to invoke 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112 , paragraph
 6: “circuit,” “detent mechanism,” “digital detector,” “reciprocating member,”
 “connector assembly,” “perforation,” “sealingly connected joints,” and “eyeglass
 hanger member.” See Mass. Inst. of Tech., 462 F.3d at 1355-1356,
 80 USPQ2d at 1332 (the court found the recitation of "aesthetic correction circuitry"
 sufficient to avoid pre-AIA 35 U.S.C. 112 , paragraph 6, treatment because the term
 circuit, combined with a description of the function of the circuit, connoted
 sufficient structure to one of ordinary skill in the art.); Linear Tech.
 Corp. v. Impala Linear Corp., 379 F.3d 1311, 1321, 72 USPQ2d 1065, 1071
 (Fed. Cir. 2004); Apex, 325 F.3d at 1373, 66 USPQ2d at 1452;
 Greenberg, 91 F.3d at 1583-84, 39 USPQ2d at 1786;
 Personalized Media, 161 F.3d at 704-05, 39 USPQ2d at 1786;
 CCS Fitness, 288 F.3d at 1369-70, 62 USPQ2d at 1664-65;
 Cole v. Kimberly-Clark Corp., 102 F.3d 524, 531, 41 USPQ2d
 1001, 1006 (Fed. Cir. 1996); Watts, 232 F.3d at 881, 56 USPQ2d at
 1839; Al-Site Corp. v. VSI Int’l, Inc., 174 F.3d 1308, 1318-19, 50
 USPQ2d 1161, 1166-67 (Fed. Cir. 1999). 
 

 For a term to be considered a substitute for “means,”
 and lack sufficient structure for performing the function, it must serve as a generic
 placeholder and thus not limit the scope of the claim to any specific manner or
 structure for performing the claimed function. It is important to remember that there
 are no absolutes in the determination of terms used as a substitute for “means” that
 serve as generic placeholders. The examiner must carefully consider the term in light
 of the specification and the commonly accepted meaning in the technological art.
 Every application will turn on its own facts. 
 

 If the examiner has not interpreted a claim limitation
 as invoking 35 U.S.C. 112(f) and an applicant
 wishes to have the claim limitation treated under 35 U.S.C.
 112(f) applicant must either: (A) amend the claim to include
 the phrase “means” or “step”; or (B) rebut the presumption that 35 U.S.C.
 112(f) does not apply by showing that the claim limitation is
 written as a function to be performed and does not recite sufficient structure,
 material, or acts to perform that function. See Watts, 232 F.3d at
 881, 56 USPQ2d at 1839 (Fed. Cir. 2000) (Claim limitations were held not to invoke
 35 U.S.C.
 112 , sixth paragraph, because the absence of the term “means”
 raised the presumption that the limitations were not in means-plus-function form and
 the applicant did not rebut that presumption.); see also Masco Corp. v.
 United States, 303 F.3d 1316, 1327, 64 USPQ2d 1182, 1189 (Fed. Cir.
 2002) (“[W]here a method claim does not contain the term ‘step[s] for,’ a limitation
 of that claim cannot be construed as a step-plus-function limitation without a
 showing that the limitation contains no act.”).
 

 Some of the following examples illustrate situations where the term
 “means” or “step” was not used but either the Board or courts nevertheless determined
 that the claim limitation fell within the scope of 35 U.S.C.
 112(f) . Note that the examples are fact specific and should not
 be applied as per se rules. See Signtech USA, Ltd. v.
 Vutek, Inc., 174 F.3d 1352, 1356, 50 USPQ2d 1372, 1374–75 (Fed.
 Cir.1999) (“ink delivery means positioned on …” invokes 35 U.S.C. 112 ,
 sixth paragraph since the phrase “ink delivery means” is equivalent to “means for ink
 delivery”); Seal-Flex, Inc. v. Athletic Track and Court
 Construction, 172 F.3d 836, 850, 50 USPQ2d 1225, 1234 (Fed. Cir. 1999)
 (Rader, J., concurring) (“Claim elements without express step-plus-function language
 may nevertheless fall within Section 112 , Para. 6 if they
 merely claim the underlying function without recitation of acts for performing that
 function…. In general terms, the ‘underlying function’ of a method claim element
 corresponds to what that element ultimately accomplishes in
 relationship to what the other elements of the claim and the claim as a whole
 accomplish. ‘Acts,’ on the other hand, correspond to how the
 function is accomplished…. If the claim element uses the phrase ‘step for,’ then
 Section
 112 , Para. 6 is presumed to apply…. On the other hand, the term
 ‘step’ alone and the phrase ‘steps of’ tend to show that Section 112 ,
 Para. 6 does not govern that limitation.”); Personalized Media, 
 161 F.3d at 703–04, 48 USPQ2d at 1886–87 (Fed. Cir. 1998);
 Mas-Hamilton, 156 F.3d at 1213, 48 USPQ2d at 1016 (Fed. Cir.
 1998) (“lever moving element for moving the lever” and “movable link member for
 holding the lever…and for releasing the lever” were construed as means-plus-function
 limitations invoking 35 U.S.C. 112 , sixth paragraph
 since the claimed limitations were described in terms of their function rather than
 their mechanical structure); Ethicon, Inc. v. United States Surgical
 Corp., 135 F.3d 1456, 1463, 45 USPQ2d 1545, 1550 (Fed. Cir. 1998) (“use
 of the word ‘means’ gives rise to a presumption that the inventor used the term
 advisedly to invoke the statutory mandates for means-plus-function clauses”)
 (quotation omitted). However, compare Al-Site Corp. v. VSI Int’l,
 Inc., 174 F.3d 1308, 1317-19, 50 USPQ2d 1161, 1166-67 (Fed. Cir. 1999)
 (holding that although the claim elements “eyeglass hanger member” and “eyeglass
 contacting member” include a function, these claim elements do not invoke
 35 U.S.C.
 112 , sixth paragraph because the claims themselves contain
 sufficient structural limitations for performing these functions); O.I.
 Corp. v. Tekmar, 115 F.3d 1576, 1583, 42 USPQ2d 1777, 1782 (Fed. Cir.
 1997) (method claim that paralleled means-plus-function apparatus claim but lacked
 “step for” language did not invoke 35 U.S.C. 112 , sixth paragraph). 
 

 When applicant uses the term “means” or “step” in the
 preamble, a rejection under 35 U.S.C. 112(b) may be
 appropriate when it is unclear whether the preamble is reciting a means- (or step-)
 plus- function limitation or whether the preamble is merely stating the intended use
 of the claimed invention. When applicant merely states an intended use of the claimed
 invention in the preamble (e.g., "A device for printing, comprising ..."), the
 examiner should not construe such language as reciting a means-plus-function
 limitation.
 

 The examiner is reminded that, absent a determination
 that a claim limitation invokes 35 U.S.C. 112(f) , the broadest
 reasonable interpretation will not be limited to “corresponding structure… and
 equivalents thereof.” Morris, 127 F.3d at 1055, 44 USPQ2d at 1028
 (“no comparable mandate in the patent statute that relates the claim scope of non-§
 112 paragraph 6 claims to particular matter found in the specification”).
 

 B. The Term “Means” or “Step” or the Generic Placeholder Must Be Modified By
 Functional Language With respect to the second prong of this analysis, it must be clear
 that the element in the claims is set forth, at least in part, by the function it
 performs as opposed to the specific structure, material, or acts that perform the
 function. See York Prod., Inc. v. Central Tractor Farm & Family
 Center, 99 F.3d 1568, 1574, 40 USPQ2d 1619, 1624 (Fed. Cir. 1996)
 (holding that a claim limitation containing the term “means” does not invoke
 pre-AIA 35
 U.S.C. 112 , sixth paragraph, if the claim limitation does not
 link the term “means” to a specific function); Caterpillar Inc. v. Detroit
 Diesel Corp., 961 F.Supp. 1249, 1255, 41 USPQ2d 1876, 1882 (N.D. Ind.
 1996) (stating that pre-AIA 35 U.S.C. 112 , sixth paragraph, “applies to functional
 method claims where the element at issue sets forth a step for reaching a particular
 result, but not the specific technique or procedure used to achieve the
 result.”); O.I. Corp., 115 F.3d at 1582-83, 42 USPQ2d at 1782
 (With respect to process claims, “[ pre-AIA 35 U.S.C. 112 , sixth
 paragraph] is implicated only when steps plus function without
 acts are present…. If we were to construe every process claim containing steps
 described by an ‘ing’ verb, such as passing, heating, reacting, transferring, etc.,
 into a step-plus-function, we would be limiting process claims in a manner never
 intended by Congress.” (emphasis in original)); see also Baran v. Medical
 Device Techs., Inc., 616 F.3d 1309, 1317, 96 USPQ2d 1057, 1063 (Fed.
 Cir. 2010) (the claimed function may include the functional language that precedes
 the phrase “means for.”). However, “the fact that a particular mechanism…is defined
 in functional terms is not sufficient to convert a claim element containing that term
 into a ‘means for performing a specified function’ within the meaning of
 section
 112(6) .” Greenberg v. Ethicon Endo-Surgery,
 Inc., 91 F.3d 1580, 1583, 39 USPQ2d 1783, 1786 (Fed. Cir. 1996) (“detent
 mechanism” defined in functional terms was not intended to invoke 35 U.S.C. 112 ,
 sixth paragraph); see also Al-Site Corp. v. VSI International
 Inc., 174 F.3d 1308, 1318, 50 USPQ2d 1161, 1166–67 (Fed. Cir. 1999)
 (although the claim elements “eyeglass hanger member” and “eyeglass contacting
 member” include a function, these claim elements do not invoke pre-AIA 35 U.S.C.
 112 , sixth paragraph, because the claims themselves contain
 sufficient structural limitations for performing those functions). Also, a statement
 of function appearing only in the claim preamble is generally insufficient to invoke
 35
 U.S.C. 112(f) . O.I. Corp., 115 F.3d at 1583,
 42 USPQ2d at 1782 (“[A] statement in a preamble of a result that necessarily follows
 from performing a series of steps does not convert each of those steps into step-
 plus-function clauses. The steps of ‘passing’ are not individually associated in the
 claims with functions performed by the steps of passing.”). 
 

 The mere use of the term “means” with no associated
 function rebuts the presumption that 35 U.S.C. 112(f) is invoked. A
 function must be recited within the claim limitation, but it is not necessary that a
 particular format be used. Typically, the claim limitation will use the linking word
 “for” to associate “means” or a generic placeholder with the function. However, other
 linking words may be used, such as “so that” or “configured to”, provided it is clear
 that the claim element is reciting a function. In certain circumstances, it is also
 not necessary to use a linking word if other words used with “means”, or the generic
 placeholder, convey the function. Such words, however, cannot convey specific
 structure for performing the function or the phrase will not be treated as invoking
 35
 U.S.C. 112(f) . For example, “ink delivery means”, “module
 configured to deliver ink” and “means for ink delivery” could all be interpreted as
 claim elements that invoke 35 U.S.C. 112(f) . See
 Signtech USA, 174 F.3d at 1356, 50 USPQ2d at 1374-75.
 

 C. The Term “Means” or “Step” or the Generic Placeholder Must Not Be
 Modified By Sufficient Structure, Material, or Acts for Achieving the Specified
 Function With respect to the third prong of this analysis, the term “means”
 or “step” or the generic placeholder recited in the claim must not be modified by
 sufficiently definite structure, material, or acts for achieving the specified
 function. See Seal-Flex, 172 F.3d at 849, 50 USPQ2d at 1234
 (Rader, J., concurring) (“Even when a claim element uses language that generally
 falls under the step-plus-function format, however, [35 U.S.C.] 112 
 ¶ 6 still does not apply when the claim limitation itself recites sufficient acts for
 performing the specified function.”); Envirco Corp. v. Clestra Cleanroom,
 Inc., 209 F.3d 1360, 54 USPQ2d 1449 (Fed. Cir. 2000) (holding “second
 baffle means” does not invoke 35 U.S.C. 112 , sixth paragraph,
 because the word “baffle” itself imparts structure and the claim further recites the
 structure of the baffle); Rodime PLC v. Seagate Technology, Inc., 
 174 F.3d 1294, 1303–04, 50 USPQ2d 1429, 1435–36 (Fed. Cir. 1999) (holding
 “positioning means for moving” does not invoke 35 U.S.C. 112 , sixth paragraph,
 because the claim further provides a list of the structure underlying the means and
 the detailed recitation of the structure for performing the moving function removes
 this element from the purview of 35 U.S.C. 112 , sixth paragraph);
 Cole v. Kimberly-Clark Corp., 102 F.3d 524, 531, 41 USPQ2d
 1001, 1006 (Fed. Cir. 1996) (holding “perforation means…for tearing” does not invoke
 35 U.S.C.
 112 , sixth paragraph, because the claim describes the structure
 supporting the tearing function (i.e., perforation)). In other situations, the
 Federal Circuit has come to a different conclusion. See Unidynamics Corp. v.
 Automatic Prod. Int’l, 157 F.3d 1311, 1319, 48 USPQ2d 1099, 1104 (Fed.
 Cir. 1998) (holding that “spring means” invokes 35 U.S.C. 112 , sixth
 paragraph).
 

 Examiners will apply 35 U.S.C.
 112(f) to a claim limitation that uses the term “means” or
 generic placeholder associated with functional language, unless that term is (1)
 preceded by a structural modifier, defined in the specification as a particular
 structure or known by one skilled in the art, that denotes the type of structural
 device (e.g., “filters”), or (2) otherwise modified by sufficient structure or
 material for achieving the claimed function. Similarly, examiners will apply
 35
 U.S.C. 112(f) to a claim limitation that uses the term “step
 for” unless that term is modified by sufficient acts for performing the claimed
 function. 
 

 A limitation will not invoke 35 U.S.C.
 112(f) if there is a structural modifier that further describes
 the term “means” or the generic placeholder. For example, although a generic
 placeholder like “mechanism” standing alone may invoke 35 U.S.C.
 112(f) when coupled with a function, it will not invoke
 35
 U.S.C. 112(f) when it is preceded by a structural modifier
 (e.g., “detent mechanism”). Greenberg, 91 F.3d at 1583, 39 USPQ2d
 at 1786 (holding that the term “detent mechanism” did not invoke 35 U.S.C. 112 ,
 sixth paragraph because the structural modifier “detent” denotes a type of structural
 device with a generally understood meaning in the mechanical arts). By contrast, a
 generic placeholder (e.g., “mechanism,” “element,” “member”) coupled with a function
 may invoke 35 U.S.C. 112(f) when it is preceded by a non-structural
 modifier that does not have any generally understood structural meaning in the art
 (e.g., “colorant selection mechanism,” “lever moving element,” or “movable link
 member”). See Massachusetts Inst. of Tech., 462 F.3d at 1354, 80
 USPQ2d at 1231 (The claim recited use of a colorant selection mechanism, to which the
 court performed a means-plus-function analysis under pre-AIA 35 U.S.C.
 112 , sixth paragraph. The court held that the term "colorant
 selection", which modifies the generic term "mechanism", was not defined in the
 specification, had no dictionary definition, nor any generally understood meaning in
 the art, the term does not connote sufficient structure to a person of ordinary skill
 in the art to avoid pre-AIA 35 U.S.C. 112 , sixth paragraph treatment.);
 Mas-Hamilton, 156 F.3d at 1214-1215, 48 USPQ2d at 1017; see
 also Williamson v. Citrix Online, LLC, 792 F.3d 1339, 1351, 115
 USPQ2d 1105, 1113 (Fed. Cir. 2015) (determining that “[t]he prefix ‘distributed
 learning control’ does not impart any structural significance to the term
 [‘module’]”). 
 

 To determine whether a word, term, or phrase coupled
 with a function denotes structure, examiners may check whether: (1) the specification
 provides a description sufficient to inform one of ordinary skill in the art that the
 term denotes structure; (2) general and subject matter specific dictionaries provide
 evidence that the term has achieved recognition as a noun denoting structure; and/or
 (3) the prior art provides evidence that the term is an art-recognized structure to
 perform the claimed function. Ex parte Rodriguez, 92 USPQ2d 1395,
 1404 (Bd. Pat. App. & Int. 2009) (precedential). 
 

 During examination, however, applicants have the
 opportunity and the obligation to define their inventions precisely, including
 whether a claim limitation invokes 35 U.S.C. 112(f) . Thus, if the
 term “means” or “step” or a generic placeholder is modified by sufficient structure,
 material or acts for achieving the specified function, the USPTO will consider that
 presumption has been rebutted and will not apply 35 U.S.C.
 112(f) until such modifying language is deleted from the claim
 limitation. 
 

 It is necessary to decide on an element by element basis whether
 35
 U.S.C. 112(f) applies. Not all terms in a means-plus-function
 or step-plus-function clause are limited to what is disclosed in the written
 description and equivalents thereof, since 35 U.S.C.
 112(f) applies only to the interpretation of the means or step
 that performs the recited function. See, e.g., IMS Technology Inc. v. Haas
 Automation Inc., 206 F.3d 1422, 54 USPQ2d 1129 (Fed. Cir. 2000) (the
 term “data block” in the phrase “means to sequentially display data block inquiries”
 was not the means that caused the sequential display, and its meaning was not limited
 to the disclosed embodiment and equivalents thereof). Each claim must be
 independently reviewed to determine the applicability of 35 U.S.C.
 112(f) even where the application contains substantially
 similar process and apparatus claims. O.I. Corp., 115 F.3d at
 1583-1584, 42 USPQ2d at 1782 (“We understand that the steps in the method claims are
 essentially in the same language as the limitations in the apparatus claim, albeit
 without the ‘means for’ qualification…. Each claim must be independently reviewed in
 order to determine if it is subject to the requirements of section 112 , ¶
 6. Interpretation of claims would be confusing indeed if claims that are not means-
 or step- plus function were to be interpreted as if they were, only because they use
 language similar to that used in other claims that are subject to this
 provision.”).
 

 II. DESCRIPTION NECESSARY TO SUPPORT A CLAIM LIMITATION WHICH INVOKES 35 U.S.C.
 112(f) or PRE-AIA 35 U.S.C. 112, SIXTH PARAGRAPH 35 U.S.C.
 112(f) states that a claim limitation expressed in means- (or
 step-) plus-function language “shall be construed to cover the corresponding
 structure…described in the specification and equivalents thereof.” “If one employs means
 plus function language in a claim, one must set forth in the specification an adequate
 disclosure showing what is meant by that language. If an applicant fails to set forth an
 adequate disclosure, the applicant has in effect failed to particularly point out and
 distinctly claim the invention as required by the 35 U.S.C.
 112(b) [or the second paragraph of pre-AIA section
 112 ].” In re Donaldson Co., 16 F.3d 1189, 1195,
 29 USPQ2d 1845, 1850 (Fed. Cir. 1994) (en banc) .
 

 A. The Corresponding Structure Must Be Disclosed In the Specification Itself
 in a Way That One Skilled In the Art Will Understand What Structure Will
 Perform the Recited Function The proper test for meeting the definiteness requirement is that the
 corresponding structure (or material or acts) of a means- (or step-) plus-function
 limitation must be disclosed in the specification itself in a way that one skilled in
 the art will understand what structure (or material or acts) will perform the recited
 function. See Atmel Corp. v. Information Storage Devices, Inc., 
 198 F.3d 1374, 1381, 53 USPQ2d 1225, 1230 (Fed. Cir. 1999). In
 Atmel, the patentee claimed an apparatus that included a “high
 voltage generating means” limitation, thereby invoking 35 U.S.C. 112 ,
 sixth paragraph. The specification incorporated by reference a non-patent document
 from a technical journal, which described a particular high voltage generating
 circuit. The Federal Circuit concluded that the title of the article in the
 specification may, by itself, be sufficient to indicate to one skilled in the art the
 precise structure of the means for performing the recited function, and it remanded
 the case to the district court “to consider the knowledge of one skilled in the art
 that indicated, based on unrefuted testimony, that the specification disclosed
 sufficient structure corresponding to the high-voltage means limitation.”
 Id. at 1382, 53 USPQ2d at 1231.
 

 If there is no disclosure of structure, material or acts for
 performing the recited function, the claim fails to satisfy the requirements of
 35
 U.S.C. 112(b) . The disclosure of the structure (or material or
 acts) may be implicit or inherent in the specification if it would have been clear to
 those skilled in the art what structure (or material or acts) corresponds to the
 means- (or step-) plus-function claim limitation. See id. at 1380,
 53 USPQ2d at 1229; In re Dossel, 115 F.3d 942, 946-47, 42 USPQ2d
 1881, 1885 (Fed. Cir. 1997). However, “[a] bare statement that known techniques or
 methods can be used does not disclose structure” in the context of a means plus
 function limitation. Biomedino, LLC v. Waters Technology Corp., 
 490 F.3d 946, 952, 83 USPQ2d 1118, 1123 (Fed. Cir. 2007) (Disclosure that an
 invention “may be controlled by known differential pressure, valving and control
 equipment” was not a disclosure of any structure corresponding to the claimed
 “control means for operating [a] valving ” and the claim was held indefinite). See
 also Budde v. Harley-Davidson, Inc., 250 F.3d 1369, 1376, 58
 USPQ2d 1801, 1806 (Fed. Cir. 2001); Cardiac Pacemakers, Inc. v. St. Jude
 Med., Inc ., 296 F.3d 1106, 1115-18, 63 USPQ2d 1725, 1731-34 (Fed. Cir.
 2002) (Court interpreted the language of the “third monitoring means for monitoring
 the ECG signal…for activating …” to require the same means to perform both functions
 and the only entity referenced in the specification that could possibly perform both
 functions is the physician. The court held that excluding the physician, no structure
 accomplishes the claimed dual functions. Because no structure disclosed in the
 embodiments of the invention actually performs the claimed dual functions, the
 specification lacks corresponding structure as required by 35 U.S.C. 112 ,
 sixth paragraph, and fails to comply with 35 U.S.C. 112 , second
 paragraph.).
 

 Whether a claim reciting an element in means- (or step-)
 plus-function language fails to comply with 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph, because the specification does not disclose adequate structure (or
 material or acts) for performing the recited function is closely related to the
 question of whether the specification meets the description requirement in
 35
 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112 , first
 paragraph. See In re Noll, 545 F.2d 141, 149, 191 USPQ 721, 727
 (CCPA 1976) (unless the means-plus-function language is itself unclear, a claim
 limitation written in means-plus- function language meets the definiteness
 requirement in 35
 U.S.C. 112 , second paragraph, so long as the specification
 meets the written description requirement in 35 U.S.C. 112 , first paragraph).
 In Aristocrat Techs. Australia PTY Ltd. v. Int’l Game Tech., 
 521 F.3d 1328, 1336-37, 86 USPQ2d 1235, 1242 (Fed. Cir. 2008), the court stated:
 

 
 Enablement of a device requires only the disclosure
 of sufficient information so that a person of ordinary skill in the art could make
 and use the device. A section 112[(f) or pre-AIA] paragraph 6 disclosure, however,
 serves the very different purpose of limiting the scope of the claim to the
 particular structure disclosed, together with equivalents. … For example, in
 Atmel Corp. v. Information Storage Devices, Inc., 198 F.3d
 1374, 1380[, 53 USPQ2d 1225, 1230] (Fed. Cir. 1999), the court embraced the
 proposition that ‘consideration of the understanding of one skilled in the art in
 no way relieves the patentee of adequately disclosing sufficient structure in the
 specification.’ It is not enough for the patentee simply to state or later argue
 that persons of ordinary skill in the art would know what structures to use to
 accomplish the claimed function. The court in Biomedino, LLC v. Waters
 Technologies Corp., 490 F.3d 946, 953[, 83 USPQ2d 1118, 1123] (Fed.
 Cir. 2007), put the point this way: "The inquiry is whether one of skill in the
 art would understand the specification itself to disclose a structure, not simply
 whether that person would be capable of implementing that structure." 
 

 
 The invocation of 35 U.S.C.
 112(f) does not exempt an applicant from compliance with
 35
 U.S.C. 112(a) and 35 U.S.C. 112(b) or
 pre-AIA 35
 U.S.C. 112 , first and second paragraphs. See
 Donaldson, 16 F.3d at 1195, 29 USPQ2d at 1850; In re
 Knowlton, 481 F.2d 1357, 1366, 178 USPQ 486, 493 (CCPA 1973) (“[The
 sixth paragraph of section 112] cannot be read as creating an exception either to the
 description requirement of the first paragraph … or to the definiteness requirement
 found in the second paragraph of section 112 . Means-plus-function
 language can be used in the claims, but the claims must still accurately define the
 invention.”).
 

 Under certain limited circumstances, the written description does
 not have to explicitly describe the structure (or material or acts) corresponding to
 a means- (or step-) plus-function limitation to particularly point out and distinctly
 claim the invention as required by 35 U.S.C. 112(b) or
 pre-AIA 35
 U.S.C. 112 , second paragraph. See Dossel, 
 115 F.3d at 946, 42 USPQ2d at 1885. Under proper circumstances, drawings may provide
 a written description of an invention as required by 35 U.S.C. 112 .
 Vas-Cath, Inc. v. Mahurkar, 935 F.2d 1555, 1565, 19 USPQ2d
 1111, 1118 (Fed. Cir. 1991). Further, disclosure of structure corresponding to
 a means-plus-function limitation may be implicit in the written description if it
 would have been clear to those skilled in the art what structure must perform the
 function recited in the means-plus-function limitation. See Atmel Corp. v.
 Information Storage Devices Inc., 198 F.3d 1374, 1379, 53 USPQ2d 1225,
 1228 (Fed. Cir. 1999) (stating that the “one skilled in the art” analysis should
 apply in determining whether sufficient structure has been disclosed to support a
 means-plus-function limitation); Dossel, 115 F.3d at 946–47, 42
 USPQ2d at 1885 (“Clearly, a unit which receives digital data, performs complex
 mathematical computations and outputs the results to a display must be implemented by
 or on a general or special purpose computer (although it is not clear why the written
 description does not simply state ‘computer’ or some equivalent phrase).”). 
 

 A claim may also be indefinite when the 3-prong
 analysis for determining whether the claim limitation should be interpreted under
 35
 U.S.C. 112(f) is inconclusive because of ambiguous words in the
 claim. After taking into consideration the language in the claims, the specification,
 and how those of ordinary skill in the art would understand the language in the
 claims in light of the disclosure, the examiner should make a determination regarding
 whether the words in the claim recite sufficiently definite structure that performs
 the claimed function. If the applicant disagrees with the examiner’s interpretation
 of the claim limitation, the applicant has the opportunity during the application
 process to present arguments, and amend the claim if needed, to clarify whether
 35
 U.S.C. 112(f) applies.
 

 B. Computer-Implemented Means-Plus-Function Limitations For a computer-implemented 35 U.S.C.
 112(f) claim limitation, the specification must disclose an
 algorithm for performing the claimed specific computer function, or else the claim is
 indefinite under 35 U.S.C. 112(b) . See
 Net MoneyIN, Inc. v. Verisign. Inc., 545 F.3d 1359, 1367, 88
 USPQ2d 1751, 1757 (Fed. Cir. 2008). See also In re Aoyama, 656
 F.3d 1293, 1297, 99 USPQ2d 1936, 1939 (Fed. Cir. 2011) (“[W]hen the disclosed
 structure is a computer programmed to carry out an algorithm, ‘the disclosed
 structure is not the general purpose computer, but rather that special purpose
 computer programmed to perform the disclosed algorithm.’”) (quoting WMS
 Gaming, Inc. v. Int’l Game Tech., 184 F.3d 1339, 1349, 51 USPQ2d 1385,
 1391 (Fed. Cir. 1999)).
 

 In cases involving a special purpose
 computer-implemented means-plus-function limitation, the Federal Circuit has
 consistently required that the structure be more than simply a general purpose
 computer or microprocessor and that the specification must disclose an algorithm for
 performing the claimed function. See, e.g., Noah Systems Inc. v. Intuit
 Inc., 675 F.3d 1302, 1312, 102 USPQ2d 1410, 1417 (Fed. Cir. 2012);
 Aristocrat, 521 F.3d at 1333, 86 USPQ2d at 1239. 
 

 For a computer-implemented means-plus-function claim
 limitation invoking 35 U.S.C. 112(f) the Federal
 Circuit has stated that “a microprocessor can serve as structure for a
 computer-implemented function only where the claimed function is ‘coextensive’ with a
 microprocessor itself.” EON Corp. IP Holdings LLC v. AT&T Mobility
 LLC, 785 F.3d 616, 622, 114 USPQ2d 1711, 1714 (Fed. Cir. 2015), citing
 In re Katz Interactive Call Processing Patent Litigation, 639
 F.3d 1303, 1316, 97 USPQ2d 1737, 1747 (Fed. Cir. 2011). “‘It is only in the rare
 circumstances where any general-purpose computer without any special programming can
 perform the function that an algorithm need not be disclosed.’” EON
 Corp., 785 F.3d at 621, 114 USPQ2 at 1714, quoting Ergo
 Licensing, LLC v. CareFusion 303, Inc., 673 F.3d 1361, 1365, 102 USPQ2d
 1122, 1125 (Fed. Cir. 2012). “‘[S]pecial programming’ includes any functionality that
 is not ‘coextensive’ with a microprocessor or general purpose computer.” EON
 Corp., 785 F.3d at 623, 114 USPQ2d at 1715 (citations omitted).
 “Examples of such coextensive functions are ‘receiving’ data, ‘storing’ data, and
 ‘processing’ data—the only three functions on which the Katz court vacated the
 district court’s decision and remanded for the district court to determine whether
 disclosure of a microprocessor was sufficient.” 785 F.3d at 622, 114 USPQ2d at 1714.
 Thus, “[a] microprocessor or general purpose computer lends sufficient structure only
 to basic functions of a microprocessor. All other computer-implemented functions
 require disclosure of an algorithm.” Id., 114 USPQ2d at 1714 
 

 To claim a means for performing a specific
 computer-implemented function and then to disclose only a general purpose computer as
 the structure designed to perform that function amounts to pure functional claiming.
 Aristocrat, 521 F.3d 1328 at 1333, 86 USPQ2d at 1239. In this
 instance, the structure corresponding to a 35 U.S.C.
 112(f) claim limitation for a computer-implemented function
 must include the algorithm needed to transform the general purpose computer or
 microprocessor disclosed in the specification. Aristocrat, 521
 F.3d at 1333, 86 USPQ2d at 1239; Finisar Corp. v. DirecTV Group,
 Inc., 523 F.3d 1323, 1340, 86 USPQ2d 1609, 1623 (Fed. Cir. 2008);
 WMS Gaming, Inc. v. Int’l Game Tech., 184 F.3d 1339, 1349, 51
 USPQ2d 1385, 1391 (Fed. Cir. 1999); Rain Computing, Inc. v. Samsung
 Electronics America Co., 989 F.3d 1002, 1007-8, 2021 USPQ2d 284 (Fed.
 Cir. 2021).
 

 The corresponding structure is not simply a general
 purpose computer by itself but the special purpose computer as programmed to perform
 the disclosed algorithm. Aristocrat, 521 F.3d at 1333, 86 USPQ2d
 at 1239. Thus, the specification must sufficiently disclose an algorithm to transform
 a general purpose microprocessor to the special purpose computer. See
 Aristocrat, 521 F.3d at 1338, 86 USPQ2d at 1241. (“Aristocrat
 was not required to produce a listing of source code or a highly detailed description
 of the algorithm to be used to achieve the claimed functions in order to satisfy
 35 U.S.C. §
 112 ¶ 6. It was required, however, to at least disclose the
 algorithm that transforms the general purpose microprocessor to a ‘special purpose
 computer programmed to perform the disclosed algorithm.’” (quoting WMS
 Gaming, 184 F.3d at 1349, 51 USPQ2d at 1391.)) An algorithm is defined,
 for example, as “a finite sequence of steps for solving a logical or mathematical
 problem or performing a task.” Microsoft Computer Dictionary, Microsoft Press, 5th
 edition, 2002. Applicant may express the algorithm in any understandable terms
 including as a mathematical formula, in prose, in a flow chart, or “in any other
 manner that provides sufficient structure.” Finisar, 523 F.3d at
 1340, 86 USPQ2d at 1623; see also Intel Corp. v. VIA Techs., Inc .,
 319 F.3d 1357, 1366, 65 USPQ2d 1934, 1941 (Fed. Cir. 2003); In re
 Dossel, 115 F.3d 942, 946-47, 42 USPQ2d 1881, 1885 (Fed. Cir. 1997);
 Typhoon Touch Inc. v. Dell Inc., 659 F.3d 1376, 1385, 100
 USPQ2d 1690, 1697 (Fed. Cir. 2011); In re Aoyama, 656 F.3d at
 1306, 99 USPQ2d at 1945.
 

 The Federal Circuit case law regarding special purpose
 computer-implemented means-plus-function claims is divided into two distinct groups.
 The first group includes cases in which the specification discloses no algorithm, and
 the second group includes cases in which the specification does disclose an
 algorithm, but an issue exists as to whether the disclosure is adequate to perform
 the entire claimed function(s). The sufficiency of the algorithm is determined in
 view of what one of ordinary skill in the art would understand as sufficient to
 define the structure and make the boundaries of the claim understandable. See
 Noah, 675 F.3d at 1313, 102 USPQ2d at 1417.
 

 Accordingly, a rejection under 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph is appropriate if the specification discloses no corresponding algorithm
 associated with a computer or microprocessor. Aristocrat, 521 F.3d
 at 1337-38, 86 USPQ2d at 1242. For example, in Advanced Ground Information
 Systems, Inc. v. Life360, Inc., 830 F.3d 1341, 119 USPQ2d 1526 (Fed.
 Cir. 2016), the Federal Circuit determined that the term "symbol generator" is a
 computer-implemented means-plus- function limitation and that "[t]he specifications
 of the patents-in-suit do not disclose an operative algorithm for the claim elements
 reciting 'symbol generator.'" 830 F.3d at 1348-49, 119 USPQ2d at 1529-30. The Federal
 Circuit upheld the district court’s determination that the term "symbol generator" is
 indefinite, observing that "although the district court recognized that the
 specification describes, in general terms, that symbols are generated based on the
 latitude and longitude of the participants, it nonetheless determined that the
 specification fails to disclose an algorithm or description as to how those symbols
 are actually generated." 830 F.3d at 1349, 119 USPQ2d at 1530 (internal quotation
 marks and alterations omitted). See also, Blackboard, Inc. v. Desire2Learn,
 Inc., 574 F.3d 1371, 1382-83, 91 USPQ2d 1481, 1490-91 (Fed. Cir. 2009)
 (concluding that the description of a server computer’s “access control manager”
 software feature was insufficient disclosure of corresponding structure to support
 the computer-implemented “means for assigning” limitation because “what the patent
 calls the ‘access control manager’ is simply an abstraction that describes the
 function of controlling access to course materials … [b]ut how it does so is left
 undisclosed.”); Aristocrat, 521 F.3d at 1334-35, 86 USPQ2d at 1240
 (explaining that “the [patent’s] description of the embodiments is simply a
 description of the outcome of the claimed functions, not a description of the
 structure, i.e., the computer programmed to execute a particular algorithm”).
 

 Mere reference to a general purpose computer with
 appropriate programming without providing an explanation of the appropriate
 programming, or simply reciting “software” without providing detail about the means
 to accomplish a specific software function, would not be an adequate disclosure of
 the corresponding structure to satisfy the requirements of 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph. Aristocrat, 521 F.3d at 1334, 86 USPQ2d at 1239;
 Finisar, 523 F.3d at 1340-41, 86 USPQ2d at 1623. In addition,
 merely referencing a specialized computer (e.g., a “bank computer”), some undefined
 component of a computer system (e.g., “access control manager”), “logic,” “code,” or
 elements that are essentially a black box designed to perform the recited function,
 will not be sufficient because there must be some explanation of how the computer or
 the computer component performs the claimed function. Blackboard, Inc. v.
 Desire2Learn, Inc., 574 F.3d 1371, 1383-85, 91 USPQ2d 1481, 1491-93
 (Fed. Cir. 2009); Net MoneyIN, Inc. v. VeriSign, Inc., 545 F.3d
 1359, 1366-67, 88 USPQ2d 1751, 1756-57 (Fed. Cir. 2008); Ex parte
 Rodriguez, 92 USPQ2d 1395, 1405-06 (Bd. Pat. App. & Inter. 2009). 
 

 If the specification explicitly discloses an
 algorithm, the sufficiency of the disclosure of the algorithm must be determined in
 light of the level of ordinary skill in the art. Aristocrat, 521
 F.3d at 1337, 86 USPQ2d at 1241; AllVoice Computing PLC v. Nuance Commc’ns,
 Inc., 504 F.3d 1236, 1245, 84 USPQ2d 1886, 1893 (Fed. Cir. 2007);
 Intel Corp., 319 F.3d at 1366-67, 65 USPQ2d 1934, 1941
 (knowledge of a person of ordinary skill in the art can be used to make clear how to
 implement a disclosed algorithm). The examiner should determine whether one skilled
 in the art would know how to program the computer to perform the necessary steps
 described in the specification (i.e., the invention is enabled), and that the
 inventor was in possession of the invention (i.e., the invention meets the written
 description requirement). Thus, the specification must sufficiently disclose an
 algorithm to transform a general purpose microprocessor to a special purpose computer
 so that a person of ordinary skill in the art can implement the disclosed algorithm
 to achieve the claimed function. Aristocrat, 521 F.3d at 1338, 86
 USPQ2d at 1242.
 

 

 The sufficiency of the algorithm is determined in
 view of what one of ordinary skill in the art would understand as sufficient to
 define the structure and make the boundaries of the claim understandable. For
 example, in Williamson, the Federal Circuit found that the term
 “distributed learning control module” is a means-plus- function limitation that
 performs three specialized functions ( i.e., “receiving,”,
 “relaying,” and “coordinating”), which “must be implemented in a special purpose
 computer.” Williamson, 792 F.3d at 1351-52, 115 USPQ2d at 1113.
 The Federal Circuit explained that “[w]here there are multiple claimed functions, as
 we have here, the [specification] must disclose adequate corresponding structure to
 perform all of the claimed functions.” Id., 115 USPQ2d at 1115.
 Yet the Federal Circuit determined that the specification “fails to disclose any
 structure corresponding to the ‘coordinating’ function.” Id. at
 1354, 115 USPQ2d at 1115. Specifically, the Federal Circuit found no “disclosure of
 an algorithm corresponding to the claimed ‘coordinating’ function,” concluding that
 the figures in the specification relied upon by patentee as disclosing the required
 algorithm, instead describe “a presenter display interface” and not an algorithm
 corresponding to the claimed “coordinating” function. Id. at
 1353-54, 115 USPQ2d at 1114-15. Accordingly, the Federal Circuit affirmed the
 district court’s judgment that claims containing the “distributed learning control
 module” limitation are invalid for indefiniteness under 35 U.S.C.
 112(b) . Id. at 1354, 115 USPQ2d at 1115. See
 also Noah, 675 F.3d at 1319, 102 USPQ2d at 1421 (holding that
 “[c]omputer- implemented means-plus- function claims are indefinite unless the
 specification discloses an algorithm to perform the function associated with the
 limitation[,]” and that “[w]hen the specification discloses an algorithm that only
 accomplishes one of multiple identifiable functions performed by a means-plus-
 function limitation, the specification is treated as if it disclosed no
 algorithm.”).
 

 Similarly in Media Rights Technologies, Inc.
 v. Capital One Financial Corp., 800 F.3d 1366, 1374, 116 USPQ2d 1144,
 1149 (Fed. Cir. 2015), the Federal Circuit determined that the term ‘‘compliance
 mechanism’’ is a means-plus-function limitation that performs four computer
 implemented functions ( i.e., "controlling data output by diverting
 a data pathway; monitoring the controlled data pathway; managing an output path by
 diverting a data pathway; and stopping the play of media content"). The Federal
 Circuit determined “that the specification fails to adequately disclose the structure
 to perform all four of [the ‘compliance mechanism’s’] functions” and affirmed the
 district court’s decision that the “compliance mechanism” limitation is indefinite.
 Id. at 1375, 116 USPQ2d at 1150. Specifically, the Federal
 Circuit found that “the specification fails to disclose an operative algorithm for
 both the ‘controlling data output’ and ‘managing output path’ functions[,]” which
 ‘‘both require diverting a data pathway[,]” because the recited C++ source code in
 the specification “only returns various error messages” and “does not, accordingly,
 explain how to perform the diverting function[.]” Id. at 1374–75,
 116 USPQ2d at 1149-50. “Additionally, the specification does not disclose sufficient
 structure for the ‘monitoring’ function[,]” because the disclosed “set of rules . . .
 which the ‘copyright compliance mechanism’ applies to monitor the data pathway to
 ensure there is no unauthorized recording of electronic media . . . provides no
 detail about the rules themselves or how the ‘copyright compliance mechanism’
 determines whether the rules are being enforced.” Id. at 1375, 116
 USPQ2d at 1150. 
 

 In several Federal Circuit cases, the patentees argued
 that the requirement for the disclosure of an algorithm can be avoided if one of
 ordinary skill in the art is capable of writing the software to convert a general
 purpose computer to a special purpose computer to perform the claimed function. See,
 e.g., Blackboard, 574 F.3d at 1385, 91 USPQ2d at 1493;
 Biomedino, 490 F.3d at 952, 83 USPQ2d at 1123; Atmel
 Corp., 198 F.3d at 1380, 53 USPQ2d at 1229. Such argument was found to
 be unpersuasive because the understanding of one skilled in the art does not relieve
 the patentee of the duty to disclose sufficient structure to support
 means-plus-function claim terms. Blackboard, 574 F.3d at 1385, 91
 USPQ2d at 1493 (“A patentee cannot avoid providing specificity as to structure simply
 because someone of ordinary skill in the art would be able to devise a means to
 perform the claimed function.”); Atmel Corp., 198 F.3d at 1380, 53
 USPQ2d at 1229 (“[C]onsideration of the understanding of one skilled in the art in no
 way relieves the patentee of adequately disclosing sufficient structure in the
 specification.”). The specification must explicitly disclose the algorithm for
 performing the claimed function, and simply reciting the claimed function in the
 specification will not be a sufficient disclosure for an algorithm which, by
 definition, must contain a sequence of steps. Blackboard, 574 F.3d
 at 1384, 91 USPQ2d at 1492 (stating that language that simply describes the function
 to be performed describes an outcome, not a means for achieving that outcome);
 Microsoft Computer Dictionary, Microsoft Press, 5th edition, 2002; see also
 Encyclopaedia Britannica, Inc. v. Alpine Elecs., Inc., 355 Fed.
 App'x 389, 394-95 (Fed. Cir. 2009) (holding that implicit or inherent disclosure of a
 class of algorithms for performing the claimed functions is not sufficient, and the
 purported “one-step” algorithm is not an algorithm at all) (unpublished).
 EON Corp. IP Holdings LLC v. AT&T Mobility LLC, 785 F.3d
 616, 623, 114 USPQ2d 1711, 1716 (Fed. Cir. 2015) (disagreeing “that a microprocessor
 can serve as sufficient structure for a software function if a person of ordinary
 skill in the art could implement the software function");
 Blackboard, 574 F.3d at 1385, 91 USPQ2d at 1492 (explaining
 that “[t]he fact that an ordinarily skilled artisan might be able to design a program
 to create an access control list based on the system users’ predetermined roles goes
 to enablement[,]” whereas “[t]he question before us is whether the specification
 contains a sufficiently precise description of the ‘corresponding structure’ to
 satisfy [pre-AIA] section 112 , paragraph 6, not whether a person of skill in the
 art could devise some means to carry out the recited function”).
 

 Often the supporting disclosure for a
 computer-implemented invention discusses the implementation of the functionality of
 the invention through hardware, software, or a combination of both. In this
 situation, a question can arise as to which mode of implementation supports the
 means-plus-function limitation. The language of 35 U.S.C.
 112(f) requires that the recited “means” for performing the
 specified function shall be construed to cover the corresponding “structure or
 material” described in the specification and equivalents thereof. Therefore, by
 choosing to use a means-plus-function limitation and invoke 35 U.S.C.
 112(f) applicant limits that claim limitation to the disclosed
 structure, i.e., implementation by hardware or the combination of hardware and
 software, and equivalents thereof. Therefore, the examiner should not construe the
 limitation as covering pure software implementation. 
 

 However, if there is no corresponding structure
 disclosed in the specification (i.e., the limitation is only supported by software
 and does not correspond to an algorithm and the computer or microprocessor programmed
 with the algorithm), the limitation should be deemed indefinite as discussed above,
 and the claim should be rejected under 35 U.S.C. 112(b) or
 pre-AIA 35
 U.S.C. 112 , second paragraph. It is important to remember that
 claims must be interpreted as a whole; so, a claim that includes a
 means-plus-function limitation that corresponds to software per se 
 (and is thus indefinite for lacking structural support in the specification) is not
 necessarily directed as a whole to software per se unless the claim lacks other
 structural limitations. 
 

 As noted below in subsection III., if it is unclear
 whether there is sufficient supporting structure or whether the algorithm is adequate
 to perform the entire claimed function, it is appropriate to reject the claim under
 35
 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph.
 

 When a claim containing a computer-implemented
 35
 U.S.C. 112(f) claim limitation is found to be indefinite under
 35
 U.S.C. 112(b) for failure to disclose sufficient corresponding
 structure (e.g., the computer and the algorithm) in the specification that performs
 the entire claimed function, it will also lack written description under
 35
 U.S.C. 112(a) . See MPEP § 2163.03 , subsection VI.
 Examiners should further consider whether the disclosure contains sufficient
 information regarding the subject matter of the claims as to enable one skilled in
 the pertinent art to make and use the full scope of the claimed invention in
 compliance with the enablement requirement of 35 U.S.C.
 112(a) . See MPEP § 2161.01 , subsection III, and
 MPEP §
 2164.08 .
 

 C. The Supporting Disclosure Clearly Links or Associates the Disclosed
 Structure, Material, or Acts to the Claimed Function The structure disclosed in the written description of
 the specification is the corresponding structure only if the written description of
 the specification or the prosecution history clearly links or associates 
 that structure to the function recited in a means- (or step-) plus-function claim
 limitation under 35 U.S.C. 112(f) or
 pre-AIA 35
 U.S.C. 112 , sixth paragraph. See B. Braun Medical
 Inc., v. Abbott Laboratories, 124 F.3d 1419, 1424, 43 USPQ2d 1896, 1900
 (Fed. Cir. 1997). The requirement that a particular structure be clearly linked with
 the claimed function in order to qualify as corresponding structure is the
 quid pro quo for the convenience of employing 35 U.S.C.
 112(f) or pre-AIA 35 U.S.C. 112 , sixth
 paragraph, and is also supported by the requirement of 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph, that an invention must be particularly pointed out and distinctly claimed.
 See Medical Instrumentation & Diagnostics Corp. v. Elekta AB, 
 344 F.3d 1205, 1211, 68 USPQ2d 1263, 1268 (Fed. Cir. 2003). For a means- (or step-)
 plus- function claim limitation that invokes 35 U.S.C.
 112(f) or pre-AIA 35 U.S.C. 112 , sixth
 paragraph, a rejection under 35 U.S.C. 112(b) or
 pre-AIA 35
 U.S.C. 112 , second paragraph, is appropriate if one of ordinary
 skill in the art cannot identify what structure, material, or acts disclosed in the
 written description of the specification perform the claimed function.
 

 III. DETERMINING 35 U.S.C. 112(b) or PRE-AIA 35 U.S.C. 112 SECOND PARAGRAPH COMPLIANCE
 WHEN 35 U.S.C. 112(f) or Pre-AIA 35 U.S.C. 112 SIXTH PARAGRAPH IS INVOKED Once the examiner determines that a claim limitation is a
 means-plus-function limitation invoking 35 U.S.C. 112(f) or
 pre-AIA 35 U.S.C.
 112 , sixth paragraph, the examiner should determine the claimed
 function and then review the written description of the specification to determine
 whether the corresponding structure, material, or acts that perform the claimed function
 are disclosed. Note that drawings may provide a written description of an invention as
 required by 35 U.S.C.
 112 . See Vas-Cath Inc. v. Mahurkar, 935 F.2d
 1555, 1565, 19 USPQ2d 1111, 1117 (Fed. Cir. 1991). The corresponding structure,
 material, or acts may be disclosed in the original drawings, figures, tables, or
 sequence listing. However, the corresponding structure, material, or acts cannot include
 any structure, material, or acts disclosed only in the material incorporated by
 reference or a prior art reference. See Pressure Prods. Med. Supplies, Inc. v.
 Greatbatch Ltd., 599 F.3d 1308, 1317, 94 USPQ2d 1261, 1267 (Fed. Cir. 2010)
 (stating, “[s]imply mentioning prior art references in a patent does not suffice as a
 specification description to give the patentee outright claim to all of the structures
 disclosed in those references.”); Atmel Corp. v. Info. Storage Devices,
 Inc., 198 F.3d 1374, 1381, 53 USPQ2d 1225, 1230 (Fed. Cir. 1999). The
 disclosure must be reviewed from the point of view of one skilled in the relevant art to
 determine whether that person would understand the written description to disclose the
 corresponding structure, material, or acts. Tech. Licensing Corp. v. Videotek,
 Inc., 545 F.3d 1316, 1338, 88 USPQ2d 1865, 1879 (Fed. Cir. 2008);
 Med. Instrumentation & Diagnostics Corp. v. Elekta AB, 344
 F.3d 1205, 1211-12, 68 USPQ2d 1263, 1269 (Fed. Cir. 2003). To satisfy the definiteness
 requirement under 35 U.S.C. 112(b) or
 35 U.S.C.
 112 , second paragraph, the written description must clearly link
 or associate the corresponding structure, material, or acts to the claimed function.
 Telcordia Techs., Inc. v. Cisco Systems, Inc., 612 F.3d 1365,
 1376, 95 USPQ2d 1673, 1682 (Fed. Cir. 2010). A rejection under 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph is appropriate if the written description fails to link or associate the
 disclosed structure, material, or acts to the claimed function, or if there is no
 disclosure (or insufficient disclosure) of structure, material, or acts for performing
 the claimed function. Donaldson, 16 F.3d at 1195, 29 USPQ2d at 1850.
 A bare statement that known techniques or methods can be used would not be a sufficient
 disclosure to support a means-plus-function limitation. Biomedino, LLC v.
 Waters Techs. Corp., 490 F.3d 946, 953, 83 USPQ2d 1118, 1123 (Fed. Cir.
 2007). 
 

 A rejection under 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph may be appropriate in the following situations when examining
 means-plus-function claim limitations under 35 U.S.C. 112(f) or
 pre-AIA 35 U.S.C.
 112 , sixth paragraph:
 

 
 (1) when it is unclear whether a claim limitation
 invokes 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112 , sixth
 paragraph;
 

 (2) when 35 U.S.C.
 112(f) or pre-AIA 35 U.S.C. 112 , sixth
 paragraph is invoked and there is no disclosure or there is insufficient
 disclosure of structure, material, or acts for performing the claimed function;
 and/or
 

 (3) when 35 U.S.C.
 112(f) or pre-AIA 35 U.S.C. 112 , sixth
 paragraph is invoked and the supporting disclosure fails to clearly link or
 associate the disclosed structure, material, or acts to the claimed function.
 

 
 A claim may be indefinite when the 3-prong analysis for
 determining whether the claim limitation should be interpreted under 35 U.S.C.
 112(f) is inconclusive because of ambiguous words in the claim.
 After taking into consideration the language in the claims, the specification, and how
 those of ordinary skill in the art would understand the language in the claims in light
 of the disclosure, the examiner should make a determination regarding whether the words
 in the claim recite sufficiently definite structure that performs the claimed function.
 If the applicant disagrees with the examiner’s interpretation of the claim limitation,
 the applicant has the opportunity during the examination process to present arguments,
 and amend the claim if needed, to clarify whether 35 U.S.C.
 112(f) applies.
 

 When the examiner cannot identify the corresponding
 structure, material, or acts, a rejection under 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph should be made. In some cases, a requirement for information under
 37 CFR
 1.105 may be made to require the identification of the
 corresponding structure, material, or acts. See MPEP § 704.11(a) , Example R. If a
 requirement for information under 37 CFR 1.105 is made and the
 applicant states that the applicant lacks such information or the reply does not
 identify the corresponding structure, material, or acts, a rejection under
 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 paragraph should be made. For more information, see MPEP § 704.12 
 (“Replies to requirements for information must be complete and filed within the time
 period set including any extensions. Failure to reply within the time period set will
 result in the abandonment of the application.”). 
 

 If the written description sets forth the corresponding
 structure, material, or acts in compliance with 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 , second
 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) or pre-AIA 35 U.S.C. 112 , sixth
 paragraph. However, functional limitations that are not recited in the claim, or
 structural limitations from the written description that are unnecessary to perform the
 claimed function, cannot be imported into the claim. Welker Bearing, 
 550 F.3d 1090, 1097, 89 USPQ2d 1289, 1294 (Fed. Cir.2008); Wenger Mfg., Inc. v.
 Coating Mach. Sys., Inc., 239 F.3d 1225, 1233, 57 USPQ2d 1679, 1685 (Fed.
 Cir. 2001). 
 

 The following guidance is provided to determine whether 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: 
 

 
 (A) If the corresponding structure, material or acts are described in
 the specification in specific terms (e.g., an emitter-coupled voltage comparator),
 are linked to or associated with the claimed function and one skilled in the art
 could identify the structure, material or acts from that description as being
 adequate to perform the claimed function, then the requirements of
 35
 U.S.C. 112(b) and (f) 
 or pre-AIA 35
 U.S.C. 112 , second and sixth paragraphs and are satisfied.
 See Atmel, 198 F.3d at 1382, 53 USPQ2d 1231. 
 

 (B) If the corresponding structure, material or acts are described in
 the specification in broad generic terms and the specific details of which are
 incorporated by reference to another document (e.g., attachment means disclosed in
 U.S. Patent No. X, which is hereby incorporated by reference, or a comparator as
 disclosed in the Y article, which is hereby incorporated by reference), Office
 personnel must review the description in the specification, without relying on any
 material from the incorporated document, and apply the 
 "one skilled in the art"
 
 
 analysis to
 determine whether one skilled in the art could identify the corresponding
 structure (or material or acts) for performing the recited function to satisfy the
 definiteness requirement of 35 U.S.C. 112(b) or
 pre-AIA 35
 U.S.C. 112 , second paragraph. See Default Proof
 Credit Card System, Inc. v. Home Depot U.S.A., Inc., 412 F.3d 1291,
 75 USPQ2d 1116 (Fed. Cir. 2005) (“The inquiry under [35 U.S.C.] § 112, ¶ 2, does
 not turn on whether a patentee has ‘incorporated by reference’ material into the
 specification relating to structure, but instead asks first ‘whether structure is
 described in the specification, and, if so, whether one skilled in the art would
 identify the structure from that description.’”).
 
 (1) If one skilled in the art would be able to identify the
 structure, material or acts from the description in the specification for
 performing the recited function, then the requirements of 35 U.S.C.
 112(b) or pre-AIA 35 U.S.C. 112 ,
 second paragraph, are satisfied. See Atmel Corp. 198 F.3d
 at 1379, 53 USPQ2d at 1228 (stating that the “one skilled in the art”
 analysis should apply in determining whether sufficient structure has been
 disclosed to support a means-plus-function limitation). See also
 Dossel, 115 F.3d at 946-47, 42 USPQ2d at 1885 (The
 function recited in the means-plus-function limitation involved
 
 "reconstructing"
 
 
 
 data. The issue was whether the structure underlying this
 
 "reconstructing"
 
 
 
 function was adequately described in the written description to satisfy
 35 U.S.C. 112(b) or
 pre-AIA
 35 U.S.C. 112 , second paragraph. The court stated that
 
 "[n]either the written description
 nor the claims uses the magic word ‘computer,’ nor do they quote computer
 code that may be used in the invention. Nevertheless, when the written
 description is combined with claims 8 and 9, the disclosure satisfies the
 requirements of Section 112 , Para.
 2."
 
 
 The court concluded that based on the specific
 facts of the case, one skilled in the art would recognize the structure for
 performing the 
 "reconstructing"
 
 
 function since 
 "a unit which receives digital data, performs complex
 mathematical computations and outputs the results to a display must be
 implemented by or on a general or special purpose
 computer."
 
 
 ). 
 

 (2) If one skilled in the art would not 
 be able to identify the structure, material or acts from description in the
 specification for performing the recited function, then applicant will be
 required to amend the specification to contain the material incorporated by
 reference, including the clear link or associated structure, material or
 acts to the function recited in the claim. See 37 CFR
 1.57(d)(3) . Applicant should not be required to insert
 all of the subject matter described in the entire referenced document into
 the specification. To maintain a concise specification, applicant should
 only include the relevant portions of the referenced document that
 correspond to the means- (or step-) plus-function limitation.
 

 
 

 IV. DETERMINING WHETHER 35 U.S.C. 112(a) or PRE-AIA 35 U.S.C. 112, FIRST PARAGRAPH
 SUPPORT EXISTS A means- (or step-) plus-function limitation that is
 found to be indefinite under 35 U.S.C. 112(b) based on failure of
 the specification to disclose corresponding structure, material or act that performs the
 entire claimed function also lacks adequate written description and may not be
 sufficiently enabled to support the full scope of the claim. The principal function of
 claims is to provide notice of the boundaries of the right to exclude by defining the
 limits of the invention, and means-plus-function claims rely on the disclosure to define
 those limits. Accordingly, an inadequate disclosure may give rise to both an
 indefiniteness rejection for a means-plus-function limitation and a failure to satisfy
 the written description and enablement requirements of section
 112(a) or pre-AIA section 112 , first
 paragraph. 
 

 When a claim containing a computer-implemented
 35 U.S.C.
 112(f) claim limitation is found to be indefinite under
 35 U.S.C.
 112(b) for failure to disclose sufficient corresponding structure
 (e.g., the computer and the algorithm) in the specification that performs the entire
 claimed function, it will also lack written description under section
 112(a) . See MPEP § 2163.03 , subsection VI.
 Examiners should further consider whether the disclosure contains sufficient information
 regarding the subject matter of the claims as to enable one skilled in the pertinent art
 to make and use the full scope of the claimed invention in compliance with the
 enablement requirement of section 112(a) . See
 MPEP §
 2161.01 , subsection III, and MPEP § 2164.08 .
 

 The Federal Circuit has recognized the problem of
 providing a sufficient disclosure for functional claiming, particularly with generic
 claim language, explaining that “The problem is especially acute with genus claims that
 use functional language to define the boundaries of a claimed genus. In such a case, the
 functional claim may simply claim a desired result, and may do so without describing
 species that achieve that result. But the specification must demonstrate that the
 applicant [inventor] has made a generic invention that achieves the claimed result and
 do so by showing that the applicant [inventor] has invented species sufficient to
 support a claim to the functionally-defined genus.” Ariad Pharmaceuticals Inc.
 v. Eli & Lilly Co., 598 F.3d 1336, 1349, 94 USPQ2d 1161, 1171 (Fed.
 Cir. 2010) (en banc) .
 

 Thus, the means- (or step-) plus- function claim must
 still be analyzed to determine whether there exists corresponding adequate support for
 such claim limitation under 35 U.S.C. 112(a) or
 pre-AIA 35 U.S.C.
 112 , first paragraph. In considering whether there is
 35 U.S.C.
 112(a) or pre-AIA 35 U.S.C. 112 , first
 paragraph support for the claim limitation, the examiner must consider whether the
 specification describes the claimed invention in sufficient detail to establish that the
 inventor or joint inventor(s) had possession of the claimed invention as of the
 application's filing date. Additionally, any analysis of whether a particular claim is
 supported by the disclosure in an application requires a determination of whether that
 disclosure, when filed, contained sufficient information regarding the subject matter of
 the claim as to enable one skilled in the pertinent art to make and use the claimed
 invention. This enablement requirement of 35 U.S.C. 112(a) is separate and
 distinct from the written description requirement. Ariad, 598 F.3d at
 1342, 94 USPQ2d at 1165. The enablement requirement serves a different purpose than the
 written description requirement in that it ensures that the invention is communicated to
 the interested public in a meaningful way. See MPEP § 2164 . In considering whether
 there is 35 U.S.C. 112
 , para. 1 support for the claim limitation, the examiner must
 consider not only the original disclosure contained in the summary and detailed
 description of the invention portions of the specification, but also the original
 claims, abstract, and drawings. See In re Mott, 539 F.2d 1291, 1299,
 190 USPQ 536, 542–43 (CCPA 1976) (claims); In re Anderson, 471 F.2d
 1237, 1240, 176 USPQ 331, 333 (CCPA 1973) (claims); Hill-Rom Co. v. Kinetic
 Concepts, Inc., 209 F.3d 1337, 54 USPQ2d 1437 (Fed. Cir. 2000)
 (unpublished) (abstract); In re Armbruster, 512 F.2d 676, 678–79, 185
 USPQ 152, 153–54 (CCPA 1975) (abstract); Anderson, 471 F.2d at 1240,
 176 USPQ at 333 (abstract); Vas-Cath Inc. v. Mahurkar, 935 F.2d 1555,
 1564, 19 USPQ2d 1111, 1117 (drawings); In re Wolfensperger, 302 F.2d
 950, 955–57, 133 USPQ 537, 541– 43 (CCPA 1962) (drawings).
 

 Merely restating a function associated with a
 means-plus-function limitation is insufficient to provide the corresponding structure
 for definiteness. See, e.g., Noah, 675 F.3d at 1317, 102 USPQ2d at
 1419; Blackboard, 574 F.3d at 1384, 91 USPQ2d at 1491;
 Aristocrat, 521 F.3d at 1334, 86 USPQ2d at 1239. It follows
 therefore that such a mere restatement of function in the specification without more
 description of the means that accomplish the function would also likely fail to provide
 adequate written description under section 112(a) or pre-AIA section
 112 , first paragraph.
 

 37 CFR
 1.75(d)(1) provides, in part, that “the terms and phrases used in
 the claims must find clear support or antecedent basis in the description so that the
 meaning of the terms in the claims may be ascertainable by reference to the
 description.” In the situation in which the written description only implicitly or
 inherently sets forth the structure, materials, or acts corresponding to a means- (or
 step-) plus-function, and the examiner concludes that one skilled in the art would
 recognize what structure, materials, or acts perform the function recited in a means-
 (or step-) plus-function, the examiner should either: (A) have the applicant clarify the
 record by amending the written description such that it expressly recites what
 structure, materials, or acts perform the function recited in the claim element; or (B)
 state on the record what structure, materials, or acts perform the function recited in
 the means- (or step-) plus-function limitation. Even if the disclosure implicitly sets
 forth the structure, materials, or acts corresponding to a means- (or step-)
 plus-function claim element in compliance with 35 U.S.C.
 112(a) and (b) or pre-AIA 35 U.S.C.
 112 , first and second paragraphs, the USPTO may still require the
 applicant to amend the specification pursuant to 37 CFR 1.75(d) and
 MPEP
 § 608.01(o) to explicitly state, with reference to the terms
 and phrases of the claim element, what structure, materials, or acts perform the
 function recited in the claim element in a manner that does not add prohibited new
 matter to the specification. See 35 U.S.C. 112(f) or
 pre-AIA 35 U.S.C.
 112 , sixth paragraph (“An element in a claim for a combination may
 be expressed as a means or step for performing a specified function without the recital
 of structure, material, or acts in support thereof, and such claim shall be construed to
 cover the corresponding structure, material, or acts described in the
 specification and equivalents thereof.” (emphasis added)); see also
 B. Braun Medical, 124 F.3d at 1424, 43 USPQ2d at 1900 (holding
 that “pursuant to this provision [ 35 U.S.C. 112, sixth paragraph],
 structure disclosed in the specification is ‘corresponding’ structure only if the
 specification or prosecution history clearly links or associates that structure to the
 function recited in the claim. This duty to link or associate structure to function is
 the quid pro quo for the convenience of employing 112 , paragraph
 6.”); Medical Instrumentation and Diagnostic Corp. v. Elekta AB, 344
 F.3d 1205, 1218, 68 USPQ2d 1263, 1268 (Fed. Cir. 2003) (Although one of skill in the art
 would have been able to write a software program for digital to digital conversion, such
 software did not fall within the scope of “means for converting” images as claimed
 because nothing in the specification or prosecution history clearly linked or associated
 such software with the function of converting images into a selected format.);
 Wolfensperger, 302 F.2d at 955, 133 USPQ at 542 (just because the
 disclosure provides support for a claim element does not mean that the USPTO cannot
 enforce its requirement that the terms and phrases used in the claims find clear support
 or antecedent basis in the written description).
 

 V. SINGLE MEANS CLAIMS A single means claim is a claim that recites a means-plus-function
 limitation as the only limitation of a claim. 35 U.S.C.
 112(f) or pre-AIA 35 U.S.C. 112 , sixth
 paragraph, by its terms is limited to “an element in a claim for a combination.”
 Therefore, single means claims that do not recite a combination cannot invoke
 section
 112(f) or pre-AIA section 112 , sixth
 paragraph. As such, they are not limited to the structure, material or act disclosed in
 the specification that performs the claimed function. Thus, a single means limitation
 that is properly construed will cover all means of performing the claimed function. The
 long-recognized problem with a single means claim is that it covers every conceivable
 means for achieving the stated result, while the specification discloses at most only
 those means known to the inventor. In re Hyatt, 708 F.2d 712, 218
 USPQ 195 (Fed. Cir. 1983). A claim of such breadth reads on subject matter that is not
 enabled by the specification, and therefore, should be rejected under section
 112(a) or pre-AIA section 112 , first
 paragraph. See also MPEP
 § 2164.08(a) .
 

 It is important to distinguish between claims that recite
 multiple functional limitations (a common practice particularly in the computer-related
 arts) and claims that recite a single element in means-plus-function terms (rare in most
 arts). In computer-implemented inventions, a microprocessor may be programmed with
 different algorithms, with each algorithm performing a separate function. Each of these
 separately programmed functions should be interpreted as a separate element.
 

 Applicants frequently draft claims to computer-related
 inventions using a shorthand drafting technique that recites a generic placeholder, such
 as a “system”, that performs a series of functions. This shorthand drafting technique
 does not avoid invoking 35 U.S.C. 112(f) or
 pre-AIA section
 112 , sixth paragraph. See MPEP § 2181 , subsection II.B. Each
 function recited in this manner should be interpreted as a separate section
 112(f) or pre-AIA section 112 , sixth paragraph
 limitation.
 

 For example, consider the following claim:

 
 9. An image processing assembly that filters pixel
 values, comprising:
 

 
 a system configured to:

 extract a first pixel value; and

 compare the first pixel value to a pixel
 threshold to filter pixel values that exceed the threshold value. 
 

 
 Assume the specification that supports this claim
 discloses that the system is a microprocessor programmed with two separate
 algorithms, one for performing the extraction and another for comparing the pixel
 values. A proper interpretation would treat these elements as separate limitations
 each of which invoke treatment under section 112(f) or
 pre-AIA section
 112 , sixth paragraph since the word “system” has no structural
 meaning and in this case is serving as a generic placeholder for “means”. 
 

 The claim elements under 35 U.S.C.
 112(f) or pre-AIA section 112 , sixth
 paragraph would be interpreted as:
 

 
 system configured to extract a first pixel
 value; and 
 

 system configured to compare the first pixel
 value to a pixel threshold to filter pixel values that exceed the threshold
 value.
 

 
 

 This claim would not be considered a "single means"
 claim.
 

 Compare this type of claim to the claim in
 Hyatt that was found to recite only a single element, which is
 drafted in “means-plus-function” format but fails to be in a combination. 
 

 
 35. A Fourier transform processor for generating Fourier
 transformed incremental output signals in response to incremental input signals, said
 Fourier transform processor comprising incremental means for incrementally generating
 the Fourier transformed incremental output signals in response to the incremental input
 signals.
 

 

 In re Hyatt, 708 F.2d 712, 714-715, 218
 USPQ 195, 197 (Fed. Cir. 1983) (A single means claim which covered every conceivable means
 for achieving the stated purpose was held nonenabling for the scope of the claim because
 the specification disclosed at most only those means known to the inventor.)
 

 VI. ENSURE THAT THE RECORD IS CLEAR When an examiner interprets a claim limitation under the
 provisions of 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112 , sixth
 paragraph, the Office action should specify that the examiner has done so. A claim
 limitation is presumed to invoke 35 U.S.C. 112(f) when it explicitly
 uses the term “means” and includes functional language without corresponding structure
 recited in the claim. When the examiner has determined that 35 U.S.C.
 112(f) applies, the examiner should also specify what the
 specification identifies as the corresponding structure. If the corresponding structure
 for the claimed function is not clearly identifiable in the specification, the Office
 action should, nevertheless, attempt to identify what structure is most closely
 associated with the means- (or step-) plus-function limitation to facilitate a prior art
 search. This is especially true when there may be confusion as to which disclosed
 implementation of the invention supports the limitation, as explained in subsection
 II.B., above. By contrast, a claim limitation that does not use the term “means” will
 trigger the presumption that 35 U.S.C. 112(f) does not apply.
 

 When 35 U.S.C. 112(f) issues are raised,
 the two rebuttable presumptions regarding the application of 35 U.S.C.
 112(f) should be established in the prosecution record. Examiners
 should apply the applicable presumption and the 3-prong analysis to interpret a
 functional claim limitation in accordance with 35 U.S.C.
 112(f) including determining if the claim sets forth sufficient
 structure for performing the recited function. A determination that a claim is being
 interpreted according to 35 U.S.C. 112(f) should be expressly
 stated in the Office action. By this, the applicant and the public are notified as to
 the claim construction used by the examiner during prosecution. Also, if the applicant
 intends a different claim construction, the issue can be clarified early in prosecution.
 In response to the Office action that determined 35 U.S.C.
 112(f) was invoked, if applicant does not want to have the claim
 limitation interpreted under 35 U.S.C. 112(f) applicant may: (1)
 present a sufficient showing to establish that the claim limitation recites sufficient
 structure to perform the claimed function so as to avoid interpretation under
 35 U.S.C.
 112(f) ; or (2) amend the claim limitation in a way that avoids
 interpretation under 35 U.S.C. 112(f) (e.g., by reciting
 sufficient structure to perform the claimed function). 
 

 See MPEP § 2187 for applicable form
 paragraphs.
 

 When allowing a claim that was treated under
 35 U.S.C.
 112(f) the examiner should indicate that the claim was interpreted
 under the provisions of 35 U.S.C. 112(f) in reasons for
 allowance if such an explanation has not previously been made of record. As noted above,
 the indication should also clarify the associated structure if not readily apparent in
 the specification. 
 

 [top] 

 

 

 
 

 
 

 

 

 

 
 
 
 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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 03/09/2026 20:50:42