2173.05(a) New Terminology [R-07.2022]

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

Courts have recognized that it is not only permissible, but often desirable, to use new terms that are frequently more precise in describing and defining the new invention. In reFisher, 427 F.2d 833, 166 USPQ 18 (CCPA 1970). Although it is difficult to compare the claimed invention with the prior art when new terms are used that do not appear in the prior art, this does not make the new terms indefinite.

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

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

2173.05(b) Relative Terminology [R-01.2024]

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

• (A) “R is halogen, for example, chlorine”;
• (B) “material such as rock wool or asbestos” Ex parteHall, 83 USPQ 38 (Bd. App. 1949);
• (C) “lighter hydrocarbons, such, for example, as the vapors or gas produced” Ex parteHasche, 86 USPQ 481 (Bd. App. 1949);
• (D) “normal operating conditions such as while in the container of a proportioner” Ex parteSteigerwald, 131 USPQ 74 (Bd. App. 1961); and
• (E) “coke, brick, or like material”. Ex parte Caldwell, 1906 C.D. 58 (Comm’r Pat. 1906).

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

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

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

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

The mere fact that a term or phrase used in the claim has no antecedent basis in the specification disclosure does not mean, necessarily, that the term or phrase is indefinite. There is no requirement that the words in the claim must match those used in the specification disclosure. Applicants are given a great deal of latitude in how they choose to define their invention so long as the terms and phrases used define the invention with a reasonable degree of clarity and precision.

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

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

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

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

2173.05(g) Functional Limitations [R-07.2022]

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

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

Other examples of permissible function language include the following.

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

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

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

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

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

2173.05(h) Alternative Limitations [R-01.2024]

A claim which recites a list of alternatives to define a limitation is an acceptable claim construction which should not necessarily be rejected as confusing under 35 U.S.C. 112(b) or as improper. See MPEP § 2117 for guidelines regarding the determination of whether a Markush grouping is improper.

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

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

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

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

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

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

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

2173.05(i) Negative Limitations [R-07.2022]

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

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

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

2173.05(j) Old Combination [R-11.2013]

With the passage of the 1952 Patent Act, the courts and the Board have taken the view that a rejection based on the principle of old combination is NO LONGER VALID. Claims should be considered proper so long as they comply with the provisions of 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph.

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

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

2173.05(k) Aggregation [R-08.2012]

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

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

2173.05(l) [Reserved]

2173.05(m) Prolix [R-08.2012]

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

2173.05(n) Multiplicity [R-11.2013]

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

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

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

2173.05(o) Double Inclusion [R-08.2012]

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

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

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

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

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

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

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

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

2173.05(q) “Use” Claims [R-10.2019]

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

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

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

It is appropriate to reject a claim that recites a use but fails to recite steps under 35 U.S.C. 101 and 35 U.S.C. 112(b) if the facts support both rejections. For failure to recite a claim within one of the statutory classes under 35 U.S.C. 101, the appropriate form paragraph is 7.05.01. For indefiniteness under 35 U.S.C. 112(b), the appropriate form paragraph is 7.34.01.

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

2173.05(r) Omnibus Claim [R-10.2019]

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

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

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

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

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

2173.05(t) Chemical Formula [R-11.2013]

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

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

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

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

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

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

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

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