Under a broadest reasonable interpretation (BRI), words of the claim must be given their plain meaning, unless such meaning is inconsistent with the specification. The plain meaning of a term means the ordinary and customary meaning given to the term by those of ordinary skill in the art at the relevant time. The ordinary and customary meaning of a term may be evidenced by a variety of sources, including the words of the claims themselves, the specification, drawings, and prior art. However, the best source for determining the meaning of a claim term is the specification – the greatest clarity is obtained when the specification serves as a glossary for the claim terms. Phillips v. AWH Corp., 415 F.3d 1303, 1315, 75 USPQ2d 1321, 1327 (Fed. Cir. 2005) (en banc) (“[T]he specification ‘is always highly relevant to the claim construction analysis. Usually, it is dispositive; it is the single best guide to the meaning of a disputed term.’” (quoting Vitronics Corp. v. Conceptronic Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996)). The words of the claim must be given their plain meaning unless the plain meaning is inconsistent with the specification. In re Zletz, 893 F.2d 319, 321, 13 USPQ2d 1320, 1322 (Fed. Cir. 1989) (discussed below); Chef America, Inc. v. Lamb-Weston, Inc., 358 F.3d 1371, 1372, 69 USPQ2d 1857 (Fed. Cir. 2004) (Ordinary, simple English words whose meaning is clear and unquestionable, absent any indication that their use in a particular context changes their meaning, are construed to mean exactly what they say. Thus, “heating the resulting batter-coated dough to a temperature in the range of about 400 o F to 850 o F” required heating the dough, rather than the air inside an oven, to the specified temperature.). See also Salazar v. AT&T Mobility LLC, 64 F.4th 1311, 1317-1318, 2023 USPQ2d 412 (Fed. Cir. 2023) (While the claim language, “a microprocessor for generating…, said microprocessor creating…, a plurality of parameter sets retrieved by said microprocessor…, said microprocessor generating…,” does not require there be only one microprocessor, the limitations to "said microprocessor" require a singular element—“a microprocessor”—to be capable of performing all of the recited “generating,” “creating,” and “retrieving” functions. Similarly, “[f]or a dog owner to have ‘a dog that rolls over and fetches sticks,’ it does not suffice that he have two dogs, each able to perform just one of the tasks.” (quoting In re Varma, 816 F.3d 1352, 1363, 118 USPQ2d 1342, 1350 (Fed. Cir. 2016))).

“Though understanding the claim language may be aided by explanations contained in the written description, it is important not to import into a claim limitations that are not part of the claim. For example, a particular embodiment appearing in the written description may not be read into a claim when the claim language is broader than the embodiment.” Superguide Corp. v. DirecTV Enterprises, Inc., 358 F.3d 870, 875, 69 USPQ2d 1865, 1868 (Fed. Cir. 2004). See also Liebel-Flarsheim Co. v. Medrad Inc., 358 F.3d 898, 906, 69 USPQ2d 1801, 1807 (Fed. Cir. 2004) (discussing recent cases wherein the court expressly rejected the contention that if a patent describes only a single embodiment, the claims of the patent must be construed as being limited to that embodiment); E-Pass Techs., Inc. v. 3Com Corp., 343 F.3d 1364, 1369, 67 USPQ2d 1947, 1950 (Fed. Cir. 2003) (“Interpretation of descriptive statements in a patent’s written description is a difficult task, as an inherent tension exists as to whether a statement is a clear lexicographic definition or a description of a preferred embodiment. The problem is to interpret claims ‘in view of the specification’ without unnecessarily importing limitations from the specification into the claims.”); Altiris Inc. v. Symantec Corp., 318 F.3d 1363, 1371, 65 USPQ2d 1865, 1869-70 (Fed. Cir. 2003) (Although the specification discussed only a single embodiment, the court held that it was improper to read a specific order of steps into method claims where, as a matter of logic or grammar, the language of the method claims did not impose a specific order on the performance of the method steps, and the specification did not directly or implicitly require a particular order). See also subsection IV, below. When an element is claimed using language falling under the scope of 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, 6 th paragraph (often broadly referred to as means- (or step-) plus- function language), the specification must be consulted to determine the structure, material, or acts corresponding to the function recited in the claim, and the claimed element is construed as limited to the corresponding structure, material, or acts described in the specification and equivalents thereof. In re Donaldson, 16 F.3d 1189, 29 USPQ2d 1845 (Fed. Cir. 1994) (see MPEP § 2181 – MPEP § 2186).

“Though understanding the claim language may be aided by explanations contained in the written description, it is important not to import into a claim limitations that are not part of the claim. For example, a particular embodiment appearing in the written description may not be read into a claim when the claim language is broader than the embodiment.” Superguide Corp. v. DirecTV Enterprises, Inc., 358 F.3d 870, 875, 69 USPQ2d 1865, 1868 (Fed. Cir. 2004). See also Liebel-Flarsheim Co. v. Medrad Inc., 358 F.3d 898, 906, 69 USPQ2d 1801, 1807 (Fed. Cir. 2004) (discussing recent cases wherein the court expressly rejected the contention that if a patent describes only a single embodiment, the claims of the patent must be construed as being limited to that embodiment); E-Pass Techs., Inc. v. 3Com Corp., 343 F.3d 1364, 1369, 67 USPQ2d 1947, 1950 (Fed. Cir. 2003) (“Interpretation of descriptive statements in a patent’s written description is a difficult task, as an inherent tension exists as to whether a statement is a clear lexicographic definition or a description of a preferred embodiment. The problem is to interpret claims ‘in view of the specification’ without unnecessarily importing limitations from the specification into the claims.”); Altiris Inc. v. Symantec Corp., 318 F.3d 1363, 1371, 65 USPQ2d 1865, 1869-70 (Fed. Cir. 2003) (Although the specification discussed only a single embodiment, the court held that it was improper to read a specific order of steps into method claims where, as a matter of logic or grammar, the language of the method claims did not impose a specific order on the performance of the method steps, and the specification did not directly or implicitly require a particular order). See also subsection IV, below. When an element is claimed using language falling under the scope of 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, 6 th paragraph (often broadly referred to as means- (or step-) plus- function language), the specification must be consulted to determine the structure, material, or acts corresponding to the function recited in the claim, and the claimed element is construed as limited to the corresponding structure, material, or acts described in the specification and equivalents thereof. In re Donaldson, 16 F.3d 1189, 29 USPQ2d 1845 (Fed. Cir. 1994) (see MPEP § 2181 – MPEP § 2186).

In Sisvel Int’l S.A. v. Sierra Wireless, Inc., 81 F.4th 1231, 1236-37, 2023 USPQ2d 1030 (Fed. Cir. 2023), the court found that construing “connection rejection message” should be given its plain and ordinary meaning, and should not be construed in such a way as to improperly limit the claims to specific disclosed embodiments. The intrinsic evidence provided no basis to limit the claims to the preferred embodiments and a person of ordinary skill in the art would broadly interpret the claim language consistent with the broad statements in the specification.

Any meaning of a claim term taken from the prior art must be consistent with the use of the claim term in the specification and drawings. Moreover, when the specification is clear about the scope and content of a claim term, there is no need to turn to extrinsic evidence for claim interpretation. 3M Innovative Props. Co. v. Tredegar Corp., 725 F.3d 1315, 1326-28, 107 USPQ2d 1717, 1726-27 (Fed. Cir. 2013) (holding that “continuous microtextured skin layer over substantially the entire laminate” was clearly defined in the written description, and therefore, there was no need to turn to extrinsic evidence to construe the claim). See also Seabed Geosolutions (US) Inc. v. Magseis FF LLC, 8 F.4th 1285, 1290, 2021 USPQ2d 848 (Fed. Cir. 2021) (finding that where the intrinsic evidence (i.e., the claims, written description and prosecution history) clearly supports a claim interpretation, it is unnecessary to resort to extrinsic evidence.). However, in some instances where neither the claims, nor the specification, nor the prosecution history offer sufficient clarity on claim scope, extrinsic evidence may become a necessary part of claim interpretation. In Actelion, the claim language of “a pH of 13 or higher” was unclear after analysis of the intrinsic evidence. The court looked to the specification, which inconsistently described the level of specificity for a pH of 13. Finally, the court turned to the prosecution history, which also did not provide any clarity as to whether a pH of 13 includes values that round to 13, such as 12.5. The court found that in this case extrinsic evidence should be consulted to understand “the meaning of a term in the relevant art during the relevant time period”. Actelion Pharmaceuticals Ltd v. Mylan Pharmaceuticals Inc., 85 F.4th 1167, 1172-74, 2023 USPQ2d 1314 (Fed. Cir. 2023) (quoting Teva Pharmaceuticals USA, Inc v. Sandoz, Inc., 574 U.S. 318, 331, 135 S. Ct. 831, 841, 113 USPQ2d 1269, 1276 (2015)).

Any meaning of a claim term taken from the prior art must be consistent with the use of the claim term in the specification and drawings. Moreover, when the specification is clear about the scope and content of a claim term, there is no need to turn to extrinsic evidence for claim interpretation. 3M Innovative Props. Co. v. Tredegar Corp., 725 F.3d 1315, 1326-28, 107 USPQ2d 1717, 1726-27 (Fed. Cir. 2013) (holding that “continuous microtextured skin layer over substantially the entire laminate” was clearly defined in the written description, and therefore, there was no need to turn to extrinsic evidence to construe the claim). See also Seabed Geosolutions (US) Inc. v. Magseis FF LLC, 8 F.4th 1285, 1290, 2021 USPQ2d 848 (Fed. Cir. 2021) (finding that where the intrinsic evidence (i.e., the claims, written description and prosecution history) clearly supports a claim interpretation, it is unnecessary to resort to extrinsic evidence.). However, in some instances where neither the claims, nor the specification, nor the prosecution history offer sufficient clarity on claim scope, extrinsic evidence may become a necessary part of claim interpretation. In Actelion, the claim language of “a pH of 13 or higher” was unclear after analysis of the intrinsic evidence. The court looked to the specification, which inconsistently described the level of specificity for a pH of 13. Finally, the court turned to the prosecution history, which also did not provide any clarity as to whether a pH of 13 includes values that round to 13, such as 12.5. The court found that in this case extrinsic evidence should be consulted to understand “the meaning of a term in the relevant art during the relevant time period”. Actelion Pharmaceuticals Ltd v. Mylan Pharmaceuticals Inc., 85 F.4th 1167, 1172-74, 2023 USPQ2d 1314 (Fed. Cir. 2023) (quoting Teva Pharmaceuticals USA, Inc v. Sandoz, Inc., 574 U.S. 318, 331, 135 S. Ct. 831, 841, 113 USPQ2d 1269, 1276 (2015)).

Any meaning of a claim term taken from the prior art must be consistent with the use of the claim term in the specification and drawings. Moreover, when the specification is clear about the scope and content of a claim term, there is no need to turn to extrinsic evidence for claim interpretation. 3M Innovative Props. Co. v. Tredegar Corp., 725 F.3d 1315, 1326-28, 107 USPQ2d 1717, 1726-27 (Fed. Cir. 2013) (holding that “continuous microtextured skin layer over substantially the entire laminate” was clearly defined in the written description, and therefore, there was no need to turn to extrinsic evidence to construe the claim). See also Seabed Geosolutions (US) Inc. v. Magseis FF LLC, 8 F.4th 1285, 1290, 2021 USPQ2d 848 (Fed. Cir. 2021) (finding that where the intrinsic evidence (i.e., the claims, written description and prosecution history) clearly supports a claim interpretation, it is unnecessary to resort to extrinsic evidence.). However, in some instances where neither the claims, nor the specification, nor the prosecution history offer sufficient clarity on claim scope, extrinsic evidence may become a necessary part of claim interpretation. In Actelion, the claim language of “a pH of 13 or higher” was unclear after analysis of the intrinsic evidence. The court looked to the specification, which inconsistently described the level of specificity for a pH of 13. Finally, the court turned to the prosecution history, which also did not provide any clarity as to whether a pH of 13 includes values that round to 13, such as 12.5. The court found that in this case extrinsic evidence should be consulted to understand “the meaning of a term in the relevant art during the relevant time period”. Actelion Pharmaceuticals Ltd v. Mylan Pharmaceuticals Inc., 85 F.4th 1167, 1172-74, 2023 USPQ2d 1314 (Fed. Cir. 2023) (quoting Teva Pharmaceuticals USA, Inc v. Sandoz, Inc., 574 U.S. 318, 331, 135 S. Ct. 831, 841, 113 USPQ2d 1269, 1276 (2015)).

Any meaning of a claim term taken from the prior art must be consistent with the use of the claim term in the specification and drawings. Moreover, when the specification is clear about the scope and content of a claim term, there is no need to turn to extrinsic evidence for claim interpretation. 3M Innovative Props. Co. v. Tredegar Corp., 725 F.3d 1315, 1326-28, 107 USPQ2d 1717, 1726-27 (Fed. Cir. 2013) (holding that “continuous microtextured skin layer over substantially the entire laminate” was clearly defined in the written description, and therefore, there was no need to turn to extrinsic evidence to construe the claim). See also Seabed Geosolutions (US) Inc. v. Magseis FF LLC, 8 F.4th 1285, 1290, 2021 USPQ2d 848 (Fed. Cir. 2021) (finding that where the intrinsic evidence (i.e., the claims, written description and prosecution history) clearly supports a claim interpretation, it is unnecessary to resort to extrinsic evidence.). However, in some instances where neither the claims, nor the specification, nor the prosecution history offer sufficient clarity on claim scope, extrinsic evidence may become a necessary part of claim interpretation. In Actelion, the claim language of “a pH of 13 or higher” was unclear after analysis of the intrinsic evidence. The court looked to the specification, which inconsistently described the level of specificity for a pH of 13. Finally, the court turned to the prosecution history, which also did not provide any clarity as to whether a pH of 13 includes values that round to 13, such as 12.5. The court found that in this case extrinsic evidence should be consulted to understand “the meaning of a term in the relevant art during the relevant time period”. Actelion Pharmaceuticals Ltd v. Mylan Pharmaceuticals Inc., 85 F.4th 1167, 1172-74, 2023 USPQ2d 1314 (Fed. Cir. 2023) (quoting Teva Pharmaceuticals USA, Inc v. Sandoz, Inc., 574 U.S. 318, 331, 135 S. Ct. 831, 841, 113 USPQ2d 1269, 1276 (2015)).

Any meaning of a claim term taken from the prior art must be consistent with the use of the claim term in the specification and drawings. Moreover, when the specification is clear about the scope and content of a claim term, there is no need to turn to extrinsic evidence for claim interpretation. 3M Innovative Props. Co. v. Tredegar Corp., 725 F.3d 1315, 1326-28, 107 USPQ2d 1717, 1726-27 (Fed. Cir. 2013) (holding that “continuous microtextured skin layer over substantially the entire laminate” was clearly defined in the written description, and therefore, there was no need to turn to extrinsic evidence to construe the claim). See also Seabed Geosolutions (US) Inc. v. Magseis FF LLC, 8 F.4th 1285, 1290, 2021 USPQ2d 848 (Fed. Cir. 2021) (finding that where the intrinsic evidence (i.e., the claims, written description and prosecution history) clearly supports a claim interpretation, it is unnecessary to resort to extrinsic evidence.). However, in some instances where neither the claims, nor the specification, nor the prosecution history offer sufficient clarity on claim scope, extrinsic evidence may become a necessary part of claim interpretation. In Actelion, the claim language of “a pH of 13 or higher” was unclear after analysis of the intrinsic evidence. The court looked to the specification, which inconsistently described the level of specificity for a pH of 13. Finally, the court turned to the prosecution history, which also did not provide any clarity as to whether a pH of 13 includes values that round to 13, such as 12.5. The court found that in this case extrinsic evidence should be consulted to understand “the meaning of a term in the relevant art during the relevant time period”. Actelion Pharmaceuticals Ltd v. Mylan Pharmaceuticals Inc., 85 F.4th 1167, 1172-74, 2023 USPQ2d 1314 (Fed. Cir. 2023) (quoting Teva Pharmaceuticals USA, Inc v. Sandoz, Inc., 574 U.S. 318, 331, 135 S. Ct. 831, 841, 113 USPQ2d 1269, 1276 (2015)).

The only exceptions to giving the words in a claim their ordinary and customary meaning in the art are (1) when the applicant acts as their own lexicographer; and (2) when the applicant disavows or disclaims the full scope of a claim term in the specification. To act as their own lexicographer, the applicant must clearly set forth a special definition of a claim term in the specification that differs from the plain and ordinary meaning it would otherwise possess. CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d 1359, 1366, 62 USPQ2d 1658, 1662 (Fed. Cir. 2002). The specification may also include an intentional disclaimer, or disavowal, of claim scope. In both of these cases, “the inventor’s intention, as expressed in the specification, is regarded as dispositive.” Phillips v. AWH Corp., 415 F.3d 1303, 1316 (Fed. Cir. 2005) (en banc). See also Starhome GmbH v. AT&T Mobility LLC, 743 F.3d 849, 857, 109 USPQ2d 1885, 1890-91 (Fed. Cir. 2014) (holding that the term “gateway” should be given its ordinary and customary meaning of “a connection between different networks” because nothing in the specification indicated a clear intent to depart from that ordinary meaning); Thorner v. Sony Computer Entm’t Am. LLC, 669 F.3d 1362, 1367-68, 101 USPQ2d 1457, 1460 (Fed. Cir. 2012) (The asserted claims of the patent were directed to a tactile feedback system for video game controllers comprising a flexible pad with a plurality of actuators “attached to said pad.” The court held that the claims were not limited to actuators attached to the external surface of the pad, even though the specification used the word “attached” when describing embodiments affixed to the external surface of the pad but the word “embedded” when describing embodiments affixed to the internal surface of the pad. The court explained that the plain and ordinary meaning of “attached” includes both external and internal attachments. Further, there is no clear and explicit statement in the specification to redefine “attached” or disavow the full scope of the term.).

An applicant is entitled to be their own lexicographer and may rebut the presumption that claim terms are to be given their ordinary and customary meaning by clearly setting forth a definition of the term that is different from its ordinary and customary meaning(s) in the specification at the relevant time. See In re Paulsen, 30 F.3d 1475, 1480, 31 USPQ2d 1671, 1674 (Fed. Cir. 1994) (holding that an inventor may define specific terms used to describe invention, but must do so “with reasonable clarity, deliberateness, and precision” and, if done, must “‘set out his uncommon definition in some manner within the patent disclosure’ so as to give one of ordinary skill in the art notice of the change” in meaning) (quoting Intellicall, Inc. v. Phonometrics, Inc., 952 F.2d 1384, 1387-88, 21 USPQ2d 1383, 1386 (Fed. Cir. 1992)).

Where an explicit definition is provided by the applicant for a term, that definition will control interpretation of the term as it is used in the claim. Toro Co. v. White Consolidated Industries Inc., 199 F.3d 1295, 1301, 53 USPQ2d 1065, 1069 (Fed. Cir. 1999) (meaning of words used in a claim is not construed in a “lexicographic vacuum, but in the context of the specification and drawings”). Thus, if a claim term is used in its ordinary and customary meaning throughout the specification, and the written description clearly indicates its meaning, then the term in the claim has that meaning. Old Town Canoe Co. v. Confluence Holdings Corp., 448 F.3d 1309, 1317, 78 USPQ2d 1705, 1711 (Fed. Cir. 2006) (The court held that “completion of coalescence” must be given its ordinary and customary meaning of reaching the end of coalescence. The court explained that even though coalescence could theoretically be “completed” by halting the molding process earlier, the specification clearly intended that completion of coalescence occurs only after the molding process reaches its optimum stage.).

Where an explicit definition is provided by the applicant for a term, that definition will control interpretation of the term as it is used in the claim. Toro Co. v. White Consolidated Industries Inc., 199 F.3d 1295, 1301, 53 USPQ2d 1065, 1069 (Fed. Cir. 1999) (meaning of words used in a claim is not construed in a “lexicographic vacuum, but in the context of the specification and drawings”). Thus, if a claim term is used in its ordinary and customary meaning throughout the specification, and the written description clearly indicates its meaning, then the term in the claim has that meaning. Old Town Canoe Co. v. Confluence Holdings Corp., 448 F.3d 1309, 1317, 78 USPQ2d 1705, 1711 (Fed. Cir. 2006) (The court held that “completion of coalescence” must be given its ordinary and customary meaning of reaching the end of coalescence. The court explained that even though coalescence could theoretically be “completed” by halting the molding process earlier, the specification clearly intended that completion of coalescence occurs only after the molding process reaches its optimum stage.).

However, it is important to note that any special meaning assigned to a term “must be sufficiently clear in the specification that any departure from common usage would be so understood by a person of experience in the field of the invention.” Multiform Desiccants Inc. v. Medzam Ltd., 133 F.3d 1473, 1477, 45 USPQ2d 1429, 1432 (Fed. Cir. 1998). See also Process Control Corp. v. HydReclaim Corp., 190 F.3d 1350, 1357, 52 USPQ2d 1029, 1033 (Fed. Cir. 1999) and MPEP § 2173.05(a). In Apple Inc. v. Corephotonics, Ltd., 81 F.4th 1353, 1358-60, 2023 USPQ2d 1056 (Fed. Cir. 2023), the claim phrase “a point of view of the Wide camera” was held to only require a “Wide perspective point of view or Wide position point of view” after reviewing the specification. In particular, the court found that a reasonable reading of the specification defined two different types of Wide point of view – perspective and position, whereas the claim language was broad as to the point of view. The court also explained that claims should not be interpreted in a way that would omit a disclosed embodiment, absent evidence to the contrary. Thus, given the review of the intrinsic evidence, the court held that the claim language only required Wide perspective or Wide position point of view, but not both.

In some cases, the meaning of a particular claim term may be defined by implication, that is, according to the usage of the term in the context in the specification. See Phillips v. AWH Corp., 415 F.3d 1303, 1320-21, 75 USPQ2d 1321, 1332 (Fed. Cir. 2005) (en banc); Vitronics Corp. v. Conceptronic Inc., 90 F.3d 1576, 1583, 39 USPQ2d 1573, 1577 (Fed. Cir. 1996). But where the specification is ambiguous as to whether the inventor used claim terms inconsistent with their ordinary meaning, the ordinary meaning will apply. Merck & Co. v. Teva Pharms. USA, Inc., 395 F.3d 1364, 1370, 73 USPQ2d 1641, 1646 (Fed. Cir. 2005) (The Federal Circuit reversed the district court’s construction of the claim term “about” as “exactly.” The appellate court explained that a passage in the specification the district court relied upon for the definition of “about” was too ambiguous to redefine “about” to mean “exactly” in clear enough terms. The appellate court held that “about” should instead be given its plain and ordinary meaning of “approximately.”).

In some cases, the meaning of a particular claim term may be defined by implication, that is, according to the usage of the term in the context in the specification. See Phillips v. AWH Corp., 415 F.3d 1303, 1320-21, 75 USPQ2d 1321, 1332 (Fed. Cir. 2005) (en banc); Vitronics Corp. v. Conceptronic Inc., 90 F.3d 1576, 1583, 39 USPQ2d 1573, 1577 (Fed. Cir. 1996). But where the specification is ambiguous as to whether the inventor used claim terms inconsistent with their ordinary meaning, the ordinary meaning will apply. Merck & Co. v. Teva Pharms. USA, Inc., 395 F.3d 1364, 1370, 73 USPQ2d 1641, 1646 (Fed. Cir. 2005) (The Federal Circuit reversed the district court’s construction of the claim term “about” as “exactly.” The appellate court explained that a passage in the specification the district court relied upon for the definition of “about” was too ambiguous to redefine “about” to mean “exactly” in clear enough terms. The appellate court held that “about” should instead be given its plain and ordinary meaning of “approximately.”).

Applicant may also rebut the presumption of plain meaning by clearly disavowing the full scope of the claim term in the specification. Disavowal, or disclaimer of claim scope, is only considered when it is clear and unmistakable. See SciMed Life Sys., Inc. v. Advanced Cardiovascular Sys., Inc., 242 F.3d 1337, 1341, 58 USPQ2d 1059, 1063 (Fed. Cir. 2001) (“Where the specification makes clear that the invention does not include a particular feature, that feature is deemed to be outside the reach of the claims of the patent, even though the language of the claims, read without reference to the specification, might be considered broad enough to encompass the feature in question.”); see also In re Am. Acad. Of Sci. Tech Ctr., 367 F.3d 1359, 1365-67, 70 USPQ2d 1827, 1831-33 (Fed. Cir. 2004) (refusing to limit claim term “user computer” to only “single-user computers” even though “some of the language of the specification, when viewed in isolation, might lead a reader to conclude that the term… is meant to refer to a computer that serves only a single user, the specification as a whole suggests a construction that is not so narrow”). But, in some cases, disavowal of a broader claim scope may be made by implication, such as where the specification contains only disparaging remarks with respect to a feature and every embodiment in the specification excludes that feature. In re Abbott Diabetes Care Inc., 696 F.3d 1142, 1149-50, 104 USPQ2d 1337, 1342-43 (Fed. Cir. 2012) (holding that the broadest reasonable interpretation of the claim term “electrochemical sensor” does not include a sensor having “external connection cables or wires” because the specification “repeatedly, consistently, and exclusively depict[s] an electrochemical sensor without external cables or wires while simultaneously disparaging sensors with external cables or wires”). But see In re Clarke, 809 Fed. Appx. 787, 794, 2020 USPQ2d 10253 (Fed. Cir. 2020) (“The doctrine of prosecution history estoppel is inapplicable during prosecution. Instead the doctrine is applicable only to issued patents.”) (emphasis in the original). If the examiner believes that the broadest reasonable interpretation of a claim is narrower than what the words of the claim otherwise suggest as the result of implicit disavowal in the specification, then the examiner should make the interpretation clear on the record.

Applicant may also rebut the presumption of plain meaning by clearly disavowing the full scope of the claim term in the specification. Disavowal, or disclaimer of claim scope, is only considered when it is clear and unmistakable. See SciMed Life Sys., Inc. v. Advanced Cardiovascular Sys., Inc., 242 F.3d 1337, 1341, 58 USPQ2d 1059, 1063 (Fed. Cir. 2001) (“Where the specification makes clear that the invention does not include a particular feature, that feature is deemed to be outside the reach of the claims of the patent, even though the language of the claims, read without reference to the specification, might be considered broad enough to encompass the feature in question.”); see also In re Am. Acad. Of Sci. Tech Ctr., 367 F.3d 1359, 1365-67, 70 USPQ2d 1827, 1831-33 (Fed. Cir. 2004) (refusing to limit claim term “user computer” to only “single-user computers” even though “some of the language of the specification, when viewed in isolation, might lead a reader to conclude that the term… is meant to refer to a computer that serves only a single user, the specification as a whole suggests a construction that is not so narrow”). But, in some cases, disavowal of a broader claim scope may be made by implication, such as where the specification contains only disparaging remarks with respect to a feature and every embodiment in the specification excludes that feature. In re Abbott Diabetes Care Inc., 696 F.3d 1142, 1149-50, 104 USPQ2d 1337, 1342-43 (Fed. Cir. 2012) (holding that the broadest reasonable interpretation of the claim term “electrochemical sensor” does not include a sensor having “external connection cables or wires” because the specification “repeatedly, consistently, and exclusively depict[s] an electrochemical sensor without external cables or wires while simultaneously disparaging sensors with external cables or wires”). But see In re Clarke, 809 Fed. Appx. 787, 794, 2020 USPQ2d 10253 (Fed. Cir. 2020) (“The doctrine of prosecution history estoppel is inapplicable during prosecution. Instead the doctrine is applicable only to issued patents.”) (emphasis in the original). If the examiner believes that the broadest reasonable interpretation of a claim is narrower than what the words of the claim otherwise suggest as the result of implicit disavowal in the specification, then the examiner should make the interpretation clear on the record.

Moving back to the first question, if a claim term does not have an ordinary and customary meaning, the examiner should check the specification to determine whether it provides a meaning to the claim term. If no reasonably clear meaning can be ascribed to the claim term after considering the specification and prior art, the examiner should apply the broadest reasonable interpretation to the claim term as it can be best understood. Also, the claim should be rejected under 35 U.S.C. 112(b) and the specification objected to under 37 CFR 1.75(d).

Under a broadest reasonable interpretation (BRI), words of the claim must be given their plain meaning, unless such meaning is inconsistent with the specification. The plain meaning of a term means the ordinary and customary meaning given to the term by those of ordinary skill in the art at the relevant time. The ordinary and customary meaning of a term may be evidenced by a variety of sources, including the words of the claims themselves, the specification, drawings, and prior art. However, the best source for determining the meaning of a claim term is the specification – the greatest clarity is obtained when the specification serves as a glossary for the claim terms. Phillips v. AWH Corp., 415 F.3d 1303, 1315, 75 USPQ2d 1321, 1327 (Fed. Cir. 2005) (en banc) (“[T]he specification ‘is always highly relevant to the claim construction analysis. Usually, it is dispositive; it is the single best guide to the meaning of a disputed term.’” (quoting Vitronics Corp. v. Conceptronic Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996)). The words of the claim must be given their plain meaning unless the plain meaning is inconsistent with the specification. In re Zletz, 893 F.2d 319, 321, 13 USPQ2d 1320, 1322 (Fed. Cir. 1989) (discussed below); Chef America, Inc. v. Lamb-Weston, Inc., 358 F.3d 1371, 1372, 69 USPQ2d 1857 (Fed. Cir. 2004) (Ordinary, simple English words whose meaning is clear and unquestionable, absent any indication that their use in a particular context changes their meaning, are construed to mean exactly what they say. Thus, “heating the resulting batter-coated dough to a temperature in the range of about 400 o F to 850 o F” required heating the dough, rather than the air inside an oven, to the specified temperature.). See also Salazar v. AT&T Mobility LLC, 64 F.4th 1311, 1317-1318, 2023 USPQ2d 412 (Fed. Cir. 2023) (While the claim language, “a microprocessor for generating…, said microprocessor creating…, a plurality of parameter sets retrieved by said microprocessor…, said microprocessor generating…,” does not require there be only one microprocessor, the limitations to "said microprocessor" require a singular element—“a microprocessor”—to be capable of performing all of the recited “generating,” “creating,” and “retrieving” functions. Similarly, “[f]or a dog owner to have ‘a dog that rolls over and fetches sticks,’ it does not suffice that he have two dogs, each able to perform just one of the tasks.” (quoting In re Varma, 816 F.3d 1352, 1363, 118 USPQ2d 1342, 1350 (Fed. Cir. 2016))).

Under a broadest reasonable interpretation (BRI), words of the claim must be given their plain meaning, unless such meaning is inconsistent with the specification. The plain meaning of a term means the ordinary and customary meaning given to the term by those of ordinary skill in the art at the relevant time. The ordinary and customary meaning of a term may be evidenced by a variety of sources, including the words of the claims themselves, the specification, drawings, and prior art. However, the best source for determining the meaning of a claim term is the specification – the greatest clarity is obtained when the specification serves as a glossary for the claim terms. Phillips v. AWH Corp., 415 F.3d 1303, 1315, 75 USPQ2d 1321, 1327 (Fed. Cir. 2005) (en banc) (“[T]he specification ‘is always highly relevant to the claim construction analysis. Usually, it is dispositive; it is the single best guide to the meaning of a disputed term.’” (quoting Vitronics Corp. v. Conceptronic Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996)). The words of the claim must be given their plain meaning unless the plain meaning is inconsistent with the specification. In re Zletz, 893 F.2d 319, 321, 13 USPQ2d 1320, 1322 (Fed. Cir. 1989) (discussed below); Chef America, Inc. v. Lamb-Weston, Inc., 358 F.3d 1371, 1372, 69 USPQ2d 1857 (Fed. Cir. 2004) (Ordinary, simple English words whose meaning is clear and unquestionable, absent any indication that their use in a particular context changes their meaning, are construed to mean exactly what they say. Thus, “heating the resulting batter-coated dough to a temperature in the range of about 400 o F to 850 o F” required heating the dough, rather than the air inside an oven, to the specified temperature.). See also Salazar v. AT&T Mobility LLC, 64 F.4th 1311, 1317-1318, 2023 USPQ2d 412 (Fed. Cir. 2023) (While the claim language, “a microprocessor for generating…, said microprocessor creating…, a plurality of parameter sets retrieved by said microprocessor…, said microprocessor generating…,” does not require there be only one microprocessor, the limitations to "said microprocessor" require a singular element—“a microprocessor”—to be capable of performing all of the recited “generating,” “creating,” and “retrieving” functions. Similarly, “[f]or a dog owner to have ‘a dog that rolls over and fetches sticks,’ it does not suffice that he have two dogs, each able to perform just one of the tasks.” (quoting In re Varma, 816 F.3d 1352, 1363, 118 USPQ2d 1342, 1350 (Fed. Cir. 2016))).

The presumption that a term is given its ordinary and customary meaning may be rebutted by the applicant by clearly setting forth a different definition of the term in the specification. In re Morris, 127 F.3d 1048, 1054, 44 USPQ2d 1023, 1028 (Fed. Cir. 1997) (the USPTO looks to the ordinary use of the claim terms taking into account definitions or other “enlightenment” contained in the written description); But c.f. In re Am. Acad. of Sci. Tech. Ctr., 367 F.3d 1359, 1369, 70 USPQ2d 1827, 1834 (Fed. Cir. 2004) (“We have cautioned against reading limitations into a claim from the preferred embodiment described in the specification, even if it is the only embodiment described, absent clear disclaimer in the specification.”). When the specification sets a clear path to the claim language, the scope of the claims is more easily determined and the public notice function of the claims is best served.

The ordinary and customary meaning of a term may be evidenced by a variety of sources, including the words of the claims themselves, the specification, drawings, and prior art. However, the best source for determining the meaning of a claim term is the specification – the greatest clarity is obtained when the specification serves as a glossary for the claim terms. See, e.g., In re Abbott Diabetes Care Inc., 696 F.3d 1142, 1149-50, 104 USPQ2d 1337, 1342-43 (Fed. Cir. 2012) (construing the term “electrochemical sensor” as “devoid of external connection cables or wires to connect to a sensor control unit” to be consistent with “the language of the claims and the specification”); In re Suitco Surface, Inc., 603 F.3d 1255, 1260-61, 94 USPQ2d 1640, 1644 (Fed. Cir. 2010) (construing the term “material for finishing the top surface of the floor” to mean “a clear, uniform layer on the top surface of a floor that is the final treatment or coating of a surface” to be consistent with “the express language of the claim and the specification”); Vitronics Corp. v. Conceptronic Inc., 90 F.3d 1576, 1583, 39 USPQ2d 1573, 1577 (Fed. Cir. 1996) (construing the term “solder reflow temperature” to mean “peak reflow temperature” of solder rather than the “liquidus temperature” of solder in order to remain consistent with the specification); Malvern Panalytical Inc. v. TA Instruments-Waters LLC, 85 F.4th 1365, 1374-75, 2023 USPQ2d 1297 (Fed. Cir. 2023) (the court construed “pipette guiding mechanism” as a mechanism that guides the pipette assembly either manually or automatically, and stated that the plain and ordinary meaning can be ascertained by examining the claim language, specification, and the prosecution history).

The only exceptions to giving the words in a claim their ordinary and customary meaning in the art are (1) when the applicant acts as their own lexicographer; and (2) when the applicant disavows or disclaims the full scope of a claim term in the specification. To act as their own lexicographer, the applicant must clearly set forth a special definition of a claim term in the specification that differs from the plain and ordinary meaning it would otherwise possess. CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d 1359, 1366, 62 USPQ2d 1658, 1662 (Fed. Cir. 2002). The specification may also include an intentional disclaimer, or disavowal, of claim scope. In both of these cases, “the inventor’s intention, as expressed in the specification, is regarded as dispositive.” Phillips v. AWH Corp., 415 F.3d 1303, 1316 (Fed. Cir. 2005) (en banc). See also Starhome GmbH v. AT&T Mobility LLC, 743 F.3d 849, 857, 109 USPQ2d 1885, 1890-91 (Fed. Cir. 2014) (holding that the term “gateway” should be given its ordinary and customary meaning of “a connection between different networks” because nothing in the specification indicated a clear intent to depart from that ordinary meaning); Thorner v. Sony Computer Entm’t Am. LLC, 669 F.3d 1362, 1367-68, 101 USPQ2d 1457, 1460 (Fed. Cir. 2012) (The asserted claims of the patent were directed to a tactile feedback system for video game controllers comprising a flexible pad with a plurality of actuators “attached to said pad.” The court held that the claims were not limited to actuators attached to the external surface of the pad, even though the specification used the word “attached” when describing embodiments affixed to the external surface of the pad but the word “embedded” when describing embodiments affixed to the internal surface of the pad. The court explained that the plain and ordinary meaning of “attached” includes both external and internal attachments. Further, there is no clear and explicit statement in the specification to redefine “attached” or disavow the full scope of the term.).

An applicant is entitled to be their own lexicographer and may rebut the presumption that claim terms are to be given their ordinary and customary meaning by clearly setting forth a definition of the term that is different from its ordinary and customary meaning(s) in the specification at the relevant time. See In re Paulsen, 30 F.3d 1475, 1480, 31 USPQ2d 1671, 1674 (Fed. Cir. 1994) (holding that an inventor may define specific terms used to describe invention, but must do so “with reasonable clarity, deliberateness, and precision” and, if done, must “‘set out his uncommon definition in some manner within the patent disclosure’ so as to give one of ordinary skill in the art notice of the change” in meaning) (quoting Intellicall, Inc. v. Phonometrics, Inc., 952 F.2d 1384, 1387-88, 21 USPQ2d 1383, 1386 (Fed. Cir. 1992)).

Where an explicit definition is provided by the applicant for a term, that definition will control interpretation of the term as it is used in the claim. Toro Co. v. White Consolidated Industries Inc., 199 F.3d 1295, 1301, 53 USPQ2d 1065, 1069 (Fed. Cir. 1999) (meaning of words used in a claim is not construed in a “lexicographic vacuum, but in the context of the specification and drawings”). Thus, if a claim term is used in its ordinary and customary meaning throughout the specification, and the written description clearly indicates its meaning, then the term in the claim has that meaning. Old Town Canoe Co. v. Confluence Holdings Corp., 448 F.3d 1309, 1317, 78 USPQ2d 1705, 1711 (Fed. Cir. 2006) (The court held that “completion of coalescence” must be given its ordinary and customary meaning of reaching the end of coalescence. The court explained that even though coalescence could theoretically be “completed” by halting the molding process earlier, the specification clearly intended that completion of coalescence occurs only after the molding process reaches its optimum stage.).

However, it is important to note that any special meaning assigned to a term “must be sufficiently clear in the specification that any departure from common usage would be so understood by a person of experience in the field of the invention.” Multiform Desiccants Inc. v. Medzam Ltd., 133 F.3d 1473, 1477, 45 USPQ2d 1429, 1432 (Fed. Cir. 1998). See also Process Control Corp. v. HydReclaim Corp., 190 F.3d 1350, 1357, 52 USPQ2d 1029, 1033 (Fed. Cir. 1999) and MPEP § 2173.05(a). In Apple Inc. v. Corephotonics, Ltd., 81 F.4th 1353, 1358-60, 2023 USPQ2d 1056 (Fed. Cir. 2023), the claim phrase “a point of view of the Wide camera” was held to only require a “Wide perspective point of view or Wide position point of view” after reviewing the specification. In particular, the court found that a reasonable reading of the specification defined two different types of Wide point of view – perspective and position, whereas the claim language was broad as to the point of view. The court also explained that claims should not be interpreted in a way that would omit a disclosed embodiment, absent evidence to the contrary. Thus, given the review of the intrinsic evidence, the court held that the claim language only required Wide perspective or Wide position point of view, but not both.

In some cases, the meaning of a particular claim term may be defined by implication, that is, according to the usage of the term in the context in the specification. See Phillips v. AWH Corp., 415 F.3d 1303, 1320-21, 75 USPQ2d 1321, 1332 (Fed. Cir. 2005) (en banc); Vitronics Corp. v. Conceptronic Inc., 90 F.3d 1576, 1583, 39 USPQ2d 1573, 1577 (Fed. Cir. 1996). But where the specification is ambiguous as to whether the inventor used claim terms inconsistent with their ordinary meaning, the ordinary meaning will apply. Merck & Co. v. Teva Pharms. USA, Inc., 395 F.3d 1364, 1370, 73 USPQ2d 1641, 1646 (Fed. Cir. 2005) (The Federal Circuit reversed the district court’s construction of the claim term “about” as “exactly.” The appellate court explained that a passage in the specification the district court relied upon for the definition of “about” was too ambiguous to redefine “about” to mean “exactly” in clear enough terms. The appellate court held that “about” should instead be given its plain and ordinary meaning of “approximately.”).

In some cases, the meaning of a particular claim term may be defined by implication, that is, according to the usage of the term in the context in the specification. See Phillips v. AWH Corp., 415 F.3d 1303, 1320-21, 75 USPQ2d 1321, 1332 (Fed. Cir. 2005) (en banc); Vitronics Corp. v. Conceptronic Inc., 90 F.3d 1576, 1583, 39 USPQ2d 1573, 1577 (Fed. Cir. 1996). But where the specification is ambiguous as to whether the inventor used claim terms inconsistent with their ordinary meaning, the ordinary meaning will apply. Merck & Co. v. Teva Pharms. USA, Inc., 395 F.3d 1364, 1370, 73 USPQ2d 1641, 1646 (Fed. Cir. 2005) (The Federal Circuit reversed the district court’s construction of the claim term “about” as “exactly.” The appellate court explained that a passage in the specification the district court relied upon for the definition of “about” was too ambiguous to redefine “about” to mean “exactly” in clear enough terms. The appellate court held that “about” should instead be given its plain and ordinary meaning of “approximately.”).

In some cases, the meaning of a particular claim term may be defined by implication, that is, according to the usage of the term in the context in the specification. See Phillips v. AWH Corp., 415 F.3d 1303, 1320-21, 75 USPQ2d 1321, 1332 (Fed. Cir. 2005) (en banc); Vitronics Corp. v. Conceptronic Inc., 90 F.3d 1576, 1583, 39 USPQ2d 1573, 1577 (Fed. Cir. 1996). But where the specification is ambiguous as to whether the inventor used claim terms inconsistent with their ordinary meaning, the ordinary meaning will apply. Merck & Co. v. Teva Pharms. USA, Inc., 395 F.3d 1364, 1370, 73 USPQ2d 1641, 1646 (Fed. Cir. 2005) (The Federal Circuit reversed the district court’s construction of the claim term “about” as “exactly.” The appellate court explained that a passage in the specification the district court relied upon for the definition of “about” was too ambiguous to redefine “about” to mean “exactly” in clear enough terms. The appellate court held that “about” should instead be given its plain and ordinary meaning of “approximately.”).

Applicant may also rebut the presumption of plain meaning by clearly disavowing the full scope of the claim term in the specification. Disavowal, or disclaimer of claim scope, is only considered when it is clear and unmistakable. See SciMed Life Sys., Inc. v. Advanced Cardiovascular Sys., Inc., 242 F.3d 1337, 1341, 58 USPQ2d 1059, 1063 (Fed. Cir. 2001) (“Where the specification makes clear that the invention does not include a particular feature, that feature is deemed to be outside the reach of the claims of the patent, even though the language of the claims, read without reference to the specification, might be considered broad enough to encompass the feature in question.”); see also In re Am. Acad. Of Sci. Tech Ctr., 367 F.3d 1359, 1365-67, 70 USPQ2d 1827, 1831-33 (Fed. Cir. 2004) (refusing to limit claim term “user computer” to only “single-user computers” even though “some of the language of the specification, when viewed in isolation, might lead a reader to conclude that the term… is meant to refer to a computer that serves only a single user, the specification as a whole suggests a construction that is not so narrow”). But, in some cases, disavowal of a broader claim scope may be made by implication, such as where the specification contains only disparaging remarks with respect to a feature and every embodiment in the specification excludes that feature. In re Abbott Diabetes Care Inc., 696 F.3d 1142, 1149-50, 104 USPQ2d 1337, 1342-43 (Fed. Cir. 2012) (holding that the broadest reasonable interpretation of the claim term “electrochemical sensor” does not include a sensor having “external connection cables or wires” because the specification “repeatedly, consistently, and exclusively depict[s] an electrochemical sensor without external cables or wires while simultaneously disparaging sensors with external cables or wires”). But see In re Clarke, 809 Fed. Appx. 787, 794, 2020 USPQ2d 10253 (Fed. Cir. 2020) (“The doctrine of prosecution history estoppel is inapplicable during prosecution. Instead the doctrine is applicable only to issued patents.”) (emphasis in the original). If the examiner believes that the broadest reasonable interpretation of a claim is narrower than what the words of the claim otherwise suggest as the result of implicit disavowal in the specification, then the examiner should make the interpretation clear on the record.

Applicant may also rebut the presumption of plain meaning by clearly disavowing the full scope of the claim term in the specification. Disavowal, or disclaimer of claim scope, is only considered when it is clear and unmistakable. See SciMed Life Sys., Inc. v. Advanced Cardiovascular Sys., Inc., 242 F.3d 1337, 1341, 58 USPQ2d 1059, 1063 (Fed. Cir. 2001) (“Where the specification makes clear that the invention does not include a particular feature, that feature is deemed to be outside the reach of the claims of the patent, even though the language of the claims, read without reference to the specification, might be considered broad enough to encompass the feature in question.”); see also In re Am. Acad. Of Sci. Tech Ctr., 367 F.3d 1359, 1365-67, 70 USPQ2d 1827, 1831-33 (Fed. Cir. 2004) (refusing to limit claim term “user computer” to only “single-user computers” even though “some of the language of the specification, when viewed in isolation, might lead a reader to conclude that the term… is meant to refer to a computer that serves only a single user, the specification as a whole suggests a construction that is not so narrow”). But, in some cases, disavowal of a broader claim scope may be made by implication, such as where the specification contains only disparaging remarks with respect to a feature and every embodiment in the specification excludes that feature. In re Abbott Diabetes Care Inc., 696 F.3d 1142, 1149-50, 104 USPQ2d 1337, 1342-43 (Fed. Cir. 2012) (holding that the broadest reasonable interpretation of the claim term “electrochemical sensor” does not include a sensor having “external connection cables or wires” because the specification “repeatedly, consistently, and exclusively depict[s] an electrochemical sensor without external cables or wires while simultaneously disparaging sensors with external cables or wires”). But see In re Clarke, 809 Fed. Appx. 787, 794, 2020 USPQ2d 10253 (Fed. Cir. 2020) (“The doctrine of prosecution history estoppel is inapplicable during prosecution. Instead the doctrine is applicable only to issued patents.”) (emphasis in the original). If the examiner believes that the broadest reasonable interpretation of a claim is narrower than what the words of the claim otherwise suggest as the result of implicit disavowal in the specification, then the examiner should make the interpretation clear on the record.

The first question is to determine whether a claim term has an ordinary and customary meaning to those of ordinary skill in the art. If so, then the examiner should check the specification to determine whether it provides a special definition for the claim term. If the specification does not provide a special definition for the claim term, the examiner should apply the ordinary and customary meaning to the claim term. If the specification provides a special definition for the claim term, the examiner should use the special definition. However, because there is a presumption that claim terms have their ordinary and customary meaning and the specification must provide a clear and intentional use of a special definition for the claim term to be treated as having a special definition, an Office action should acknowledge and identify the special definition in this situation.

The first question is to determine whether a claim term has an ordinary and customary meaning to those of ordinary skill in the art. If so, then the examiner should check the specification to determine whether it provides a special definition for the claim term. If the specification does not provide a special definition for the claim term, the examiner should apply the ordinary and customary meaning to the claim term. If the specification provides a special definition for the claim term, the examiner should use the special definition. However, because there is a presumption that claim terms have their ordinary and customary meaning and the specification must provide a clear and intentional use of a special definition for the claim term to be treated as having a special definition, an Office action should acknowledge and identify the special definition in this situation.

Moving back to the first question, if a claim term does not have an ordinary and customary meaning, the examiner should check the specification to determine whether it provides a meaning to the claim term. If no reasonably clear meaning can be ascribed to the claim term after considering the specification and prior art, the examiner should apply the broadest reasonable interpretation to the claim term as it can be best understood. Also, the claim should be rejected under 35 U.S.C. 112(b) and the specification objected to under 37 CFR 1.75(d).

If the specification provides a meaning for the claim term, the examiner should use the meaning provided by the specification. It may be appropriate for an Office action to acknowledge and identify the meaning provided by the specification in this situation.

Under a broadest reasonable interpretation (BRI), words of the claim must be given their plain meaning, unless such meaning is inconsistent with the specification. The plain meaning of a term means the ordinary and customary meaning given to the term by those of ordinary skill in the art at the relevant time. The ordinary and customary meaning of a term may be evidenced by a variety of sources, including the words of the claims themselves, the specification, drawings, and prior art. However, the best source for determining the meaning of a claim term is the specification – the greatest clarity is obtained when the specification serves as a glossary for the claim terms. Phillips v. AWH Corp., 415 F.3d 1303, 1315, 75 USPQ2d 1321, 1327 (Fed. Cir. 2005) (en banc) (“[T]he specification ‘is always highly relevant to the claim construction analysis. Usually, it is dispositive; it is the single best guide to the meaning of a disputed term.’” (quoting Vitronics Corp. v. Conceptronic Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996)). The words of the claim must be given their plain meaning unless the plain meaning is inconsistent with the specification. In re Zletz, 893 F.2d 319, 321, 13 USPQ2d 1320, 1322 (Fed. Cir. 1989) (discussed below); Chef America, Inc. v. Lamb-Weston, Inc., 358 F.3d 1371, 1372, 69 USPQ2d 1857 (Fed. Cir. 2004) (Ordinary, simple English words whose meaning is clear and unquestionable, absent any indication that their use in a particular context changes their meaning, are construed to mean exactly what they say. Thus, “heating the resulting batter-coated dough to a temperature in the range of about 400 o F to 850 o F” required heating the dough, rather than the air inside an oven, to the specified temperature.). See also Salazar v. AT&T Mobility LLC, 64 F.4th 1311, 1317-1318, 2023 USPQ2d 412 (Fed. Cir. 2023) (While the claim language, “a microprocessor for generating…, said microprocessor creating…, a plurality of parameter sets retrieved by said microprocessor…, said microprocessor generating…,” does not require there be only one microprocessor, the limitations to "said microprocessor" require a singular element—“a microprocessor”—to be capable of performing all of the recited “generating,” “creating,” and “retrieving” functions. Similarly, “[f]or a dog owner to have ‘a dog that rolls over and fetches sticks,’ it does not suffice that he have two dogs, each able to perform just one of the tasks.” (quoting In re Varma, 816 F.3d 1352, 1363, 118 USPQ2d 1342, 1350 (Fed. Cir. 2016))).

Under a broadest reasonable interpretation (BRI), words of the claim must be given their plain meaning, unless such meaning is inconsistent with the specification. The plain meaning of a term means the ordinary and customary meaning given to the term by those of ordinary skill in the art at the relevant time. The ordinary and customary meaning of a term may be evidenced by a variety of sources, including the words of the claims themselves, the specification, drawings, and prior art. However, the best source for determining the meaning of a claim term is the specification – the greatest clarity is obtained when the specification serves as a glossary for the claim terms. Phillips v. AWH Corp., 415 F.3d 1303, 1315, 75 USPQ2d 1321, 1327 (Fed. Cir. 2005) (en banc) (“[T]he specification ‘is always highly relevant to the claim construction analysis. Usually, it is dispositive; it is the single best guide to the meaning of a disputed term.’” (quoting Vitronics Corp. v. Conceptronic Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996)). The words of the claim must be given their plain meaning unless the plain meaning is inconsistent with the specification. In re Zletz, 893 F.2d 319, 321, 13 USPQ2d 1320, 1322 (Fed. Cir. 1989) (discussed below); Chef America, Inc. v. Lamb-Weston, Inc., 358 F.3d 1371, 1372, 69 USPQ2d 1857 (Fed. Cir. 2004) (Ordinary, simple English words whose meaning is clear and unquestionable, absent any indication that their use in a particular context changes their meaning, are construed to mean exactly what they say. Thus, “heating the resulting batter-coated dough to a temperature in the range of about 400 o F to 850 o F” required heating the dough, rather than the air inside an oven, to the specified temperature.). See also Salazar v. AT&T Mobility LLC, 64 F.4th 1311, 1317-1318, 2023 USPQ2d 412 (Fed. Cir. 2023) (While the claim language, “a microprocessor for generating…, said microprocessor creating…, a plurality of parameter sets retrieved by said microprocessor…, said microprocessor generating…,” does not require there be only one microprocessor, the limitations to "said microprocessor" require a singular element—“a microprocessor”—to be capable of performing all of the recited “generating,” “creating,” and “retrieving” functions. Similarly, “[f]or a dog owner to have ‘a dog that rolls over and fetches sticks,’ it does not suffice that he have two dogs, each able to perform just one of the tasks.” (quoting In re Varma, 816 F.3d 1352, 1363, 118 USPQ2d 1342, 1350 (Fed. Cir. 2016))).

Under a broadest reasonable interpretation (BRI), words of the claim must be given their plain meaning, unless such meaning is inconsistent with the specification. The plain meaning of a term means the ordinary and customary meaning given to the term by those of ordinary skill in the art at the relevant time. The ordinary and customary meaning of a term may be evidenced by a variety of sources, including the words of the claims themselves, the specification, drawings, and prior art. However, the best source for determining the meaning of a claim term is the specification – the greatest clarity is obtained when the specification serves as a glossary for the claim terms. Phillips v. AWH Corp., 415 F.3d 1303, 1315, 75 USPQ2d 1321, 1327 (Fed. Cir. 2005) (en banc) (“[T]he specification ‘is always highly relevant to the claim construction analysis. Usually, it is dispositive; it is the single best guide to the meaning of a disputed term.’” (quoting Vitronics Corp. v. Conceptronic Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996)). The words of the claim must be given their plain meaning unless the plain meaning is inconsistent with the specification. In re Zletz, 893 F.2d 319, 321, 13 USPQ2d 1320, 1322 (Fed. Cir. 1989) (discussed below); Chef America, Inc. v. Lamb-Weston, Inc., 358 F.3d 1371, 1372, 69 USPQ2d 1857 (Fed. Cir. 2004) (Ordinary, simple English words whose meaning is clear and unquestionable, absent any indication that their use in a particular context changes their meaning, are construed to mean exactly what they say. Thus, “heating the resulting batter-coated dough to a temperature in the range of about 400 o F to 850 o F” required heating the dough, rather than the air inside an oven, to the specified temperature.). See also Salazar v. AT&T Mobility LLC, 64 F.4th 1311, 1317-1318, 2023 USPQ2d 412 (Fed. Cir. 2023) (While the claim language, “a microprocessor for generating…, said microprocessor creating…, a plurality of parameter sets retrieved by said microprocessor…, said microprocessor generating…,” does not require there be only one microprocessor, the limitations to "said microprocessor" require a singular element—“a microprocessor”—to be capable of performing all of the recited “generating,” “creating,” and “retrieving” functions. Similarly, “[f]or a dog owner to have ‘a dog that rolls over and fetches sticks,’ it does not suffice that he have two dogs, each able to perform just one of the tasks.” (quoting In re Varma, 816 F.3d 1352, 1363, 118 USPQ2d 1342, 1350 (Fed. Cir. 2016))).

Under a broadest reasonable interpretation (BRI), words of the claim must be given their plain meaning, unless such meaning is inconsistent with the specification. The plain meaning of a term means the ordinary and customary meaning given to the term by those of ordinary skill in the art at the relevant time. The ordinary and customary meaning of a term may be evidenced by a variety of sources, including the words of the claims themselves, the specification, drawings, and prior art. However, the best source for determining the meaning of a claim term is the specification – the greatest clarity is obtained when the specification serves as a glossary for the claim terms. Phillips v. AWH Corp., 415 F.3d 1303, 1315, 75 USPQ2d 1321, 1327 (Fed. Cir. 2005) (en banc) (“[T]he specification ‘is always highly relevant to the claim construction analysis. Usually, it is dispositive; it is the single best guide to the meaning of a disputed term.’” (quoting Vitronics Corp. v. Conceptronic Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996)). The words of the claim must be given their plain meaning unless the plain meaning is inconsistent with the specification. In re Zletz, 893 F.2d 319, 321, 13 USPQ2d 1320, 1322 (Fed. Cir. 1989) (discussed below); Chef America, Inc. v. Lamb-Weston, Inc., 358 F.3d 1371, 1372, 69 USPQ2d 1857 (Fed. Cir. 2004) (Ordinary, simple English words whose meaning is clear and unquestionable, absent any indication that their use in a particular context changes their meaning, are construed to mean exactly what they say. Thus, “heating the resulting batter-coated dough to a temperature in the range of about 400 o F to 850 o F” required heating the dough, rather than the air inside an oven, to the specified temperature.). See also Salazar v. AT&T Mobility LLC, 64 F.4th 1311, 1317-1318, 2023 USPQ2d 412 (Fed. Cir. 2023) (While the claim language, “a microprocessor for generating…, said microprocessor creating…, a plurality of parameter sets retrieved by said microprocessor…, said microprocessor generating…,” does not require there be only one microprocessor, the limitations to "said microprocessor" require a singular element—“a microprocessor”—to be capable of performing all of the recited “generating,” “creating,” and “retrieving” functions. Similarly, “[f]or a dog owner to have ‘a dog that rolls over and fetches sticks,’ it does not suffice that he have two dogs, each able to perform just one of the tasks.” (quoting In re Varma, 816 F.3d 1352, 1363, 118 USPQ2d 1342, 1350 (Fed. Cir. 2016))).

The presumption that a term is given its ordinary and customary meaning may be rebutted by the applicant by clearly setting forth a different definition of the term in the specification. In re Morris, 127 F.3d 1048, 1054, 44 USPQ2d 1023, 1028 (Fed. Cir. 1997) (the USPTO looks to the ordinary use of the claim terms taking into account definitions or other “enlightenment” contained in the written description); But c.f. In re Am. Acad. of Sci. Tech. Ctr., 367 F.3d 1359, 1369, 70 USPQ2d 1827, 1834 (Fed. Cir. 2004) (“We have cautioned against reading limitations into a claim from the preferred embodiment described in the specification, even if it is the only embodiment described, absent clear disclaimer in the specification.”). When the specification sets a clear path to the claim language, the scope of the claims is more easily determined and the public notice function of the claims is best served.

“Though understanding the claim language may be aided by explanations contained in the written description, it is important not to import into a claim limitations that are not part of the claim. For example, a particular embodiment appearing in the written description may not be read into a claim when the claim language is broader than the embodiment.” Superguide Corp. v. DirecTV Enterprises, Inc., 358 F.3d 870, 875, 69 USPQ2d 1865, 1868 (Fed. Cir. 2004). See also Liebel-Flarsheim Co. v. Medrad Inc., 358 F.3d 898, 906, 69 USPQ2d 1801, 1807 (Fed. Cir. 2004) (discussing recent cases wherein the court expressly rejected the contention that if a patent describes only a single embodiment, the claims of the patent must be construed as being limited to that embodiment); E-Pass Techs., Inc. v. 3Com Corp., 343 F.3d 1364, 1369, 67 USPQ2d 1947, 1950 (Fed. Cir. 2003) (“Interpretation of descriptive statements in a patent’s written description is a difficult task, as an inherent tension exists as to whether a statement is a clear lexicographic definition or a description of a preferred embodiment. The problem is to interpret claims ‘in view of the specification’ without unnecessarily importing limitations from the specification into the claims.”); Altiris Inc. v. Symantec Corp., 318 F.3d 1363, 1371, 65 USPQ2d 1865, 1869-70 (Fed. Cir. 2003) (Although the specification discussed only a single embodiment, the court held that it was improper to read a specific order of steps into method claims where, as a matter of logic or grammar, the language of the method claims did not impose a specific order on the performance of the method steps, and the specification did not directly or implicitly require a particular order). See also subsection IV, below. When an element is claimed using language falling under the scope of 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, 6 th paragraph (often broadly referred to as means- (or step-) plus- function language), the specification must be consulted to determine the structure, material, or acts corresponding to the function recited in the claim, and the claimed element is construed as limited to the corresponding structure, material, or acts described in the specification and equivalents thereof. In re Donaldson, 16 F.3d 1189, 29 USPQ2d 1845 (Fed. Cir. 1994) (see MPEP § 2181 – MPEP § 2186).

In Sisvel Int’l S.A. v. Sierra Wireless, Inc., 81 F.4th 1231, 1236-37, 2023 USPQ2d 1030 (Fed. Cir. 2023), the court found that construing “connection rejection message” should be given its plain and ordinary meaning, and should not be construed in such a way as to improperly limit the claims to specific disclosed embodiments. The intrinsic evidence provided no basis to limit the claims to the preferred embodiments and a person of ordinary skill in the art would broadly interpret the claim language consistent with the broad statements in the specification.

The ordinary and customary meaning of a term may be evidenced by a variety of sources, including the words of the claims themselves, the specification, drawings, and prior art. However, the best source for determining the meaning of a claim term is the specification – the greatest clarity is obtained when the specification serves as a glossary for the claim terms. See, e.g., In re Abbott Diabetes Care Inc., 696 F.3d 1142, 1149-50, 104 USPQ2d 1337, 1342-43 (Fed. Cir. 2012) (construing the term “electrochemical sensor” as “devoid of external connection cables or wires to connect to a sensor control unit” to be consistent with “the language of the claims and the specification”); In re Suitco Surface, Inc., 603 F.3d 1255, 1260-61, 94 USPQ2d 1640, 1644 (Fed. Cir. 2010) (construing the term “material for finishing the top surface of the floor” to mean “a clear, uniform layer on the top surface of a floor that is the final treatment or coating of a surface” to be consistent with “the express language of the claim and the specification”); Vitronics Corp. v. Conceptronic Inc., 90 F.3d 1576, 1583, 39 USPQ2d 1573, 1577 (Fed. Cir. 1996) (construing the term “solder reflow temperature” to mean “peak reflow temperature” of solder rather than the “liquidus temperature” of solder in order to remain consistent with the specification); Malvern Panalytical Inc. v. TA Instruments-Waters LLC, 85 F.4th 1365, 1374-75, 2023 USPQ2d 1297 (Fed. Cir. 2023) (the court construed “pipette guiding mechanism” as a mechanism that guides the pipette assembly either manually or automatically, and stated that the plain and ordinary meaning can be ascertained by examining the claim language, specification, and the prosecution history).

Any meaning of a claim term taken from the prior art must be consistent with the use of the claim term in the specification and drawings. Moreover, when the specification is clear about the scope and content of a claim term, there is no need to turn to extrinsic evidence for claim interpretation. 3M Innovative Props. Co. v. Tredegar Corp., 725 F.3d 1315, 1326-28, 107 USPQ2d 1717, 1726-27 (Fed. Cir. 2013) (holding that “continuous microtextured skin layer over substantially the entire laminate” was clearly defined in the written description, and therefore, there was no need to turn to extrinsic evidence to construe the claim). See also Seabed Geosolutions (US) Inc. v. Magseis FF LLC, 8 F.4th 1285, 1290, 2021 USPQ2d 848 (Fed. Cir. 2021) (finding that where the intrinsic evidence (i.e., the claims, written description and prosecution history) clearly supports a claim interpretation, it is unnecessary to resort to extrinsic evidence.). However, in some instances where neither the claims, nor the specification, nor the prosecution history offer sufficient clarity on claim scope, extrinsic evidence may become a necessary part of claim interpretation. In Actelion, the claim language of “a pH of 13 or higher” was unclear after analysis of the intrinsic evidence. The court looked to the specification, which inconsistently described the level of specificity for a pH of 13. Finally, the court turned to the prosecution history, which also did not provide any clarity as to whether a pH of 13 includes values that round to 13, such as 12.5. The court found that in this case extrinsic evidence should be consulted to understand “the meaning of a term in the relevant art during the relevant time period”. Actelion Pharmaceuticals Ltd v. Mylan Pharmaceuticals Inc., 85 F.4th 1167, 1172-74, 2023 USPQ2d 1314 (Fed. Cir. 2023) (quoting Teva Pharmaceuticals USA, Inc v. Sandoz, Inc., 574 U.S. 318, 331, 135 S. Ct. 831, 841, 113 USPQ2d 1269, 1276 (2015)).

However, it is important to note that any special meaning assigned to a term “must be sufficiently clear in the specification that any departure from common usage would be so understood by a person of experience in the field of the invention.” Multiform Desiccants Inc. v. Medzam Ltd., 133 F.3d 1473, 1477, 45 USPQ2d 1429, 1432 (Fed. Cir. 1998). See also Process Control Corp. v. HydReclaim Corp., 190 F.3d 1350, 1357, 52 USPQ2d 1029, 1033 (Fed. Cir. 1999) and MPEP § 2173.05(a). In Apple Inc. v. Corephotonics, Ltd., 81 F.4th 1353, 1358-60, 2023 USPQ2d 1056 (Fed. Cir. 2023), the claim phrase “a point of view of the Wide camera” was held to only require a “Wide perspective point of view or Wide position point of view” after reviewing the specification. In particular, the court found that a reasonable reading of the specification defined two different types of Wide point of view – perspective and position, whereas the claim language was broad as to the point of view. The court also explained that claims should not be interpreted in a way that would omit a disclosed embodiment, absent evidence to the contrary. Thus, given the review of the intrinsic evidence, the court held that the claim language only required Wide perspective or Wide position point of view, but not both.

However, it is important to note that any special meaning assigned to a term “must be sufficiently clear in the specification that any departure from common usage would be so understood by a person of experience in the field of the invention.” Multiform Desiccants Inc. v. Medzam Ltd., 133 F.3d 1473, 1477, 45 USPQ2d 1429, 1432 (Fed. Cir. 1998). See also Process Control Corp. v. HydReclaim Corp., 190 F.3d 1350, 1357, 52 USPQ2d 1029, 1033 (Fed. Cir. 1999) and MPEP § 2173.05(a). In Apple Inc. v. Corephotonics, Ltd., 81 F.4th 1353, 1358-60, 2023 USPQ2d 1056 (Fed. Cir. 2023), the claim phrase “a point of view of the Wide camera” was held to only require a “Wide perspective point of view or Wide position point of view” after reviewing the specification. In particular, the court found that a reasonable reading of the specification defined two different types of Wide point of view – perspective and position, whereas the claim language was broad as to the point of view. The court also explained that claims should not be interpreted in a way that would omit a disclosed embodiment, absent evidence to the contrary. Thus, given the review of the intrinsic evidence, the court held that the claim language only required Wide perspective or Wide position point of view, but not both.

Any meaning of a claim term taken from the prior art must be consistent with the use of the claim term in the specification and drawings. Moreover, when the specification is clear about the scope and content of a claim term, there is no need to turn to extrinsic evidence for claim interpretation. 3M Innovative Props. Co. v. Tredegar Corp., 725 F.3d 1315, 1326-28, 107 USPQ2d 1717, 1726-27 (Fed. Cir. 2013) (holding that “continuous microtextured skin layer over substantially the entire laminate” was clearly defined in the written description, and therefore, there was no need to turn to extrinsic evidence to construe the claim). See also Seabed Geosolutions (US) Inc. v. Magseis FF LLC, 8 F.4th 1285, 1290, 2021 USPQ2d 848 (Fed. Cir. 2021) (finding that where the intrinsic evidence (i.e., the claims, written description and prosecution history) clearly supports a claim interpretation, it is unnecessary to resort to extrinsic evidence.). However, in some instances where neither the claims, nor the specification, nor the prosecution history offer sufficient clarity on claim scope, extrinsic evidence may become a necessary part of claim interpretation. In Actelion, the claim language of “a pH of 13 or higher” was unclear after analysis of the intrinsic evidence. The court looked to the specification, which inconsistently described the level of specificity for a pH of 13. Finally, the court turned to the prosecution history, which also did not provide any clarity as to whether a pH of 13 includes values that round to 13, such as 12.5. The court found that in this case extrinsic evidence should be consulted to understand “the meaning of a term in the relevant art during the relevant time period”. Actelion Pharmaceuticals Ltd v. Mylan Pharmaceuticals Inc., 85 F.4th 1167, 1172-74, 2023 USPQ2d 1314 (Fed. Cir. 2023) (quoting Teva Pharmaceuticals USA, Inc v. Sandoz, Inc., 574 U.S. 318, 331, 135 S. Ct. 831, 841, 113 USPQ2d 1269, 1276 (2015)).

The only exceptions to giving the words in a claim their ordinary and customary meaning in the art are (1) when the applicant acts as their own lexicographer; and (2) when the applicant disavows or disclaims the full scope of a claim term in the specification. To act as their own lexicographer, the applicant must clearly set forth a special definition of a claim term in the specification that differs from the plain and ordinary meaning it would otherwise possess. CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d 1359, 1366, 62 USPQ2d 1658, 1662 (Fed. Cir. 2002). The specification may also include an intentional disclaimer, or disavowal, of claim scope. In both of these cases, “the inventor’s intention, as expressed in the specification, is regarded as dispositive.” Phillips v. AWH Corp., 415 F.3d 1303, 1316 (Fed. Cir. 2005) (en banc). See also Starhome GmbH v. AT&T Mobility LLC, 743 F.3d 849, 857, 109 USPQ2d 1885, 1890-91 (Fed. Cir. 2014) (holding that the term “gateway” should be given its ordinary and customary meaning of “a connection between different networks” because nothing in the specification indicated a clear intent to depart from that ordinary meaning); Thorner v. Sony Computer Entm’t Am. LLC, 669 F.3d 1362, 1367-68, 101 USPQ2d 1457, 1460 (Fed. Cir. 2012) (The asserted claims of the patent were directed to a tactile feedback system for video game controllers comprising a flexible pad with a plurality of actuators “attached to said pad.” The court held that the claims were not limited to actuators attached to the external surface of the pad, even though the specification used the word “attached” when describing embodiments affixed to the external surface of the pad but the word “embedded” when describing embodiments affixed to the internal surface of the pad. The court explained that the plain and ordinary meaning of “attached” includes both external and internal attachments. Further, there is no clear and explicit statement in the specification to redefine “attached” or disavow the full scope of the term.).

The only exceptions to giving the words in a claim their ordinary and customary meaning in the art are (1) when the applicant acts as their own lexicographer; and (2) when the applicant disavows or disclaims the full scope of a claim term in the specification. To act as their own lexicographer, the applicant must clearly set forth a special definition of a claim term in the specification that differs from the plain and ordinary meaning it would otherwise possess. CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d 1359, 1366, 62 USPQ2d 1658, 1662 (Fed. Cir. 2002). The specification may also include an intentional disclaimer, or disavowal, of claim scope. In both of these cases, “the inventor’s intention, as expressed in the specification, is regarded as dispositive.” Phillips v. AWH Corp., 415 F.3d 1303, 1316 (Fed. Cir. 2005) (en banc). See also Starhome GmbH v. AT&T Mobility LLC, 743 F.3d 849, 857, 109 USPQ2d 1885, 1890-91 (Fed. Cir. 2014) (holding that the term “gateway” should be given its ordinary and customary meaning of “a connection between different networks” because nothing in the specification indicated a clear intent to depart from that ordinary meaning); Thorner v. Sony Computer Entm’t Am. LLC, 669 F.3d 1362, 1367-68, 101 USPQ2d 1457, 1460 (Fed. Cir. 2012) (The asserted claims of the patent were directed to a tactile feedback system for video game controllers comprising a flexible pad with a plurality of actuators “attached to said pad.” The court held that the claims were not limited to actuators attached to the external surface of the pad, even though the specification used the word “attached” when describing embodiments affixed to the external surface of the pad but the word “embedded” when describing embodiments affixed to the internal surface of the pad. The court explained that the plain and ordinary meaning of “attached” includes both external and internal attachments. Further, there is no clear and explicit statement in the specification to redefine “attached” or disavow the full scope of the term.).

The only exceptions to giving the words in a claim their ordinary and customary meaning in the art are (1) when the applicant acts as their own lexicographer; and (2) when the applicant disavows or disclaims the full scope of a claim term in the specification. To act as their own lexicographer, the applicant must clearly set forth a special definition of a claim term in the specification that differs from the plain and ordinary meaning it would otherwise possess. CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d 1359, 1366, 62 USPQ2d 1658, 1662 (Fed. Cir. 2002). The specification may also include an intentional disclaimer, or disavowal, of claim scope. In both of these cases, “the inventor’s intention, as expressed in the specification, is regarded as dispositive.” Phillips v. AWH Corp., 415 F.3d 1303, 1316 (Fed. Cir. 2005) (en banc). See also Starhome GmbH v. AT&T Mobility LLC, 743 F.3d 849, 857, 109 USPQ2d 1885, 1890-91 (Fed. Cir. 2014) (holding that the term “gateway” should be given its ordinary and customary meaning of “a connection between different networks” because nothing in the specification indicated a clear intent to depart from that ordinary meaning); Thorner v. Sony Computer Entm’t Am. LLC, 669 F.3d 1362, 1367-68, 101 USPQ2d 1457, 1460 (Fed. Cir. 2012) (The asserted claims of the patent were directed to a tactile feedback system for video game controllers comprising a flexible pad with a plurality of actuators “attached to said pad.” The court held that the claims were not limited to actuators attached to the external surface of the pad, even though the specification used the word “attached” when describing embodiments affixed to the external surface of the pad but the word “embedded” when describing embodiments affixed to the internal surface of the pad. The court explained that the plain and ordinary meaning of “attached” includes both external and internal attachments. Further, there is no clear and explicit statement in the specification to redefine “attached” or disavow the full scope of the term.).

Where an explicit definition is provided by the applicant for a term, that definition will control interpretation of the term as it is used in the claim. Toro Co. v. White Consolidated Industries Inc., 199 F.3d 1295, 1301, 53 USPQ2d 1065, 1069 (Fed. Cir. 1999) (meaning of words used in a claim is not construed in a “lexicographic vacuum, but in the context of the specification and drawings”). Thus, if a claim term is used in its ordinary and customary meaning throughout the specification, and the written description clearly indicates its meaning, then the term in the claim has that meaning. Old Town Canoe Co. v. Confluence Holdings Corp., 448 F.3d 1309, 1317, 78 USPQ2d 1705, 1711 (Fed. Cir. 2006) (The court held that “completion of coalescence” must be given its ordinary and customary meaning of reaching the end of coalescence. The court explained that even though coalescence could theoretically be “completed” by halting the molding process earlier, the specification clearly intended that completion of coalescence occurs only after the molding process reaches its optimum stage.).

However, it is important to note that any special meaning assigned to a term “must be sufficiently clear in the specification that any departure from common usage would be so understood by a person of experience in the field of the invention.” Multiform Desiccants Inc. v. Medzam Ltd., 133 F.3d 1473, 1477, 45 USPQ2d 1429, 1432 (Fed. Cir. 1998). See also Process Control Corp. v. HydReclaim Corp., 190 F.3d 1350, 1357, 52 USPQ2d 1029, 1033 (Fed. Cir. 1999) and MPEP § 2173.05(a). In Apple Inc. v. Corephotonics, Ltd., 81 F.4th 1353, 1358-60, 2023 USPQ2d 1056 (Fed. Cir. 2023), the claim phrase “a point of view of the Wide camera” was held to only require a “Wide perspective point of view or Wide position point of view” after reviewing the specification. In particular, the court found that a reasonable reading of the specification defined two different types of Wide point of view – perspective and position, whereas the claim language was broad as to the point of view. The court also explained that claims should not be interpreted in a way that would omit a disclosed embodiment, absent evidence to the contrary. Thus, given the review of the intrinsic evidence, the court held that the claim language only required Wide perspective or Wide position point of view, but not both.

In some cases, the meaning of a particular claim term may be defined by implication, that is, according to the usage of the term in the context in the specification. See Phillips v. AWH Corp., 415 F.3d 1303, 1320-21, 75 USPQ2d 1321, 1332 (Fed. Cir. 2005) (en banc); Vitronics Corp. v. Conceptronic Inc., 90 F.3d 1576, 1583, 39 USPQ2d 1573, 1577 (Fed. Cir. 1996). But where the specification is ambiguous as to whether the inventor used claim terms inconsistent with their ordinary meaning, the ordinary meaning will apply. Merck & Co. v. Teva Pharms. USA, Inc., 395 F.3d 1364, 1370, 73 USPQ2d 1641, 1646 (Fed. Cir. 2005) (The Federal Circuit reversed the district court’s construction of the claim term “about” as “exactly.” The appellate court explained that a passage in the specification the district court relied upon for the definition of “about” was too ambiguous to redefine “about” to mean “exactly” in clear enough terms. The appellate court held that “about” should instead be given its plain and ordinary meaning of “approximately.”).

The only exceptions to giving the words in a claim their ordinary and customary meaning in the art are (1) when the applicant acts as their own lexicographer; and (2) when the applicant disavows or disclaims the full scope of a claim term in the specification. To act as their own lexicographer, the applicant must clearly set forth a special definition of a claim term in the specification that differs from the plain and ordinary meaning it would otherwise possess. CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d 1359, 1366, 62 USPQ2d 1658, 1662 (Fed. Cir. 2002). The specification may also include an intentional disclaimer, or disavowal, of claim scope. In both of these cases, “the inventor’s intention, as expressed in the specification, is regarded as dispositive.” Phillips v. AWH Corp., 415 F.3d 1303, 1316 (Fed. Cir. 2005) (en banc). See also Starhome GmbH v. AT&T Mobility LLC, 743 F.3d 849, 857, 109 USPQ2d 1885, 1890-91 (Fed. Cir. 2014) (holding that the term “gateway” should be given its ordinary and customary meaning of “a connection between different networks” because nothing in the specification indicated a clear intent to depart from that ordinary meaning); Thorner v. Sony Computer Entm’t Am. LLC, 669 F.3d 1362, 1367-68, 101 USPQ2d 1457, 1460 (Fed. Cir. 2012) (The asserted claims of the patent were directed to a tactile feedback system for video game controllers comprising a flexible pad with a plurality of actuators “attached to said pad.” The court held that the claims were not limited to actuators attached to the external surface of the pad, even though the specification used the word “attached” when describing embodiments affixed to the external surface of the pad but the word “embedded” when describing embodiments affixed to the internal surface of the pad. The court explained that the plain and ordinary meaning of “attached” includes both external and internal attachments. Further, there is no clear and explicit statement in the specification to redefine “attached” or disavow the full scope of the term.).

The only exceptions to giving the words in a claim their ordinary and customary meaning in the art are (1) when the applicant acts as their own lexicographer; and (2) when the applicant disavows or disclaims the full scope of a claim term in the specification. To act as their own lexicographer, the applicant must clearly set forth a special definition of a claim term in the specification that differs from the plain and ordinary meaning it would otherwise possess. CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d 1359, 1366, 62 USPQ2d 1658, 1662 (Fed. Cir. 2002). The specification may also include an intentional disclaimer, or disavowal, of claim scope. In both of these cases, “the inventor’s intention, as expressed in the specification, is regarded as dispositive.” Phillips v. AWH Corp., 415 F.3d 1303, 1316 (Fed. Cir. 2005) (en banc). See also Starhome GmbH v. AT&T Mobility LLC, 743 F.3d 849, 857, 109 USPQ2d 1885, 1890-91 (Fed. Cir. 2014) (holding that the term “gateway” should be given its ordinary and customary meaning of “a connection between different networks” because nothing in the specification indicated a clear intent to depart from that ordinary meaning); Thorner v. Sony Computer Entm’t Am. LLC, 669 F.3d 1362, 1367-68, 101 USPQ2d 1457, 1460 (Fed. Cir. 2012) (The asserted claims of the patent were directed to a tactile feedback system for video game controllers comprising a flexible pad with a plurality of actuators “attached to said pad.” The court held that the claims were not limited to actuators attached to the external surface of the pad, even though the specification used the word “attached” when describing embodiments affixed to the external surface of the pad but the word “embedded” when describing embodiments affixed to the internal surface of the pad. The court explained that the plain and ordinary meaning of “attached” includes both external and internal attachments. Further, there is no clear and explicit statement in the specification to redefine “attached” or disavow the full scope of the term.).

Applicant may also rebut the presumption of plain meaning by clearly disavowing the full scope of the claim term in the specification. Disavowal, or disclaimer of claim scope, is only considered when it is clear and unmistakable. See SciMed Life Sys., Inc. v. Advanced Cardiovascular Sys., Inc., 242 F.3d 1337, 1341, 58 USPQ2d 1059, 1063 (Fed. Cir. 2001) (“Where the specification makes clear that the invention does not include a particular feature, that feature is deemed to be outside the reach of the claims of the patent, even though the language of the claims, read without reference to the specification, might be considered broad enough to encompass the feature in question.”); see also In re Am. Acad. Of Sci. Tech Ctr., 367 F.3d 1359, 1365-67, 70 USPQ2d 1827, 1831-33 (Fed. Cir. 2004) (refusing to limit claim term “user computer” to only “single-user computers” even though “some of the language of the specification, when viewed in isolation, might lead a reader to conclude that the term… is meant to refer to a computer that serves only a single user, the specification as a whole suggests a construction that is not so narrow”). But, in some cases, disavowal of a broader claim scope may be made by implication, such as where the specification contains only disparaging remarks with respect to a feature and every embodiment in the specification excludes that feature. In re Abbott Diabetes Care Inc., 696 F.3d 1142, 1149-50, 104 USPQ2d 1337, 1342-43 (Fed. Cir. 2012) (holding that the broadest reasonable interpretation of the claim term “electrochemical sensor” does not include a sensor having “external connection cables or wires” because the specification “repeatedly, consistently, and exclusively depict[s] an electrochemical sensor without external cables or wires while simultaneously disparaging sensors with external cables or wires”). But see In re Clarke, 809 Fed. Appx. 787, 794, 2020 USPQ2d 10253 (Fed. Cir. 2020) (“The doctrine of prosecution history estoppel is inapplicable during prosecution. Instead the doctrine is applicable only to issued patents.”) (emphasis in the original). If the examiner believes that the broadest reasonable interpretation of a claim is narrower than what the words of the claim otherwise suggest as the result of implicit disavowal in the specification, then the examiner should make the interpretation clear on the record.

Applicant may also rebut the presumption of plain meaning by clearly disavowing the full scope of the claim term in the specification. Disavowal, or disclaimer of claim scope, is only considered when it is clear and unmistakable. See SciMed Life Sys., Inc. v. Advanced Cardiovascular Sys., Inc., 242 F.3d 1337, 1341, 58 USPQ2d 1059, 1063 (Fed. Cir. 2001) (“Where the specification makes clear that the invention does not include a particular feature, that feature is deemed to be outside the reach of the claims of the patent, even though the language of the claims, read without reference to the specification, might be considered broad enough to encompass the feature in question.”); see also In re Am. Acad. Of Sci. Tech Ctr., 367 F.3d 1359, 1365-67, 70 USPQ2d 1827, 1831-33 (Fed. Cir. 2004) (refusing to limit claim term “user computer” to only “single-user computers” even though “some of the language of the specification, when viewed in isolation, might lead a reader to conclude that the term… is meant to refer to a computer that serves only a single user, the specification as a whole suggests a construction that is not so narrow”). But, in some cases, disavowal of a broader claim scope may be made by implication, such as where the specification contains only disparaging remarks with respect to a feature and every embodiment in the specification excludes that feature. In re Abbott Diabetes Care Inc., 696 F.3d 1142, 1149-50, 104 USPQ2d 1337, 1342-43 (Fed. Cir. 2012) (holding that the broadest reasonable interpretation of the claim term “electrochemical sensor” does not include a sensor having “external connection cables or wires” because the specification “repeatedly, consistently, and exclusively depict[s] an electrochemical sensor without external cables or wires while simultaneously disparaging sensors with external cables or wires”). But see In re Clarke, 809 Fed. Appx. 787, 794, 2020 USPQ2d 10253 (Fed. Cir. 2020) (“The doctrine of prosecution history estoppel is inapplicable during prosecution. Instead the doctrine is applicable only to issued patents.”) (emphasis in the original). If the examiner believes that the broadest reasonable interpretation of a claim is narrower than what the words of the claim otherwise suggest as the result of implicit disavowal in the specification, then the examiner should make the interpretation clear on the record.

Applicant may also rebut the presumption of plain meaning by clearly disavowing the full scope of the claim term in the specification. Disavowal, or disclaimer of claim scope, is only considered when it is clear and unmistakable. See SciMed Life Sys., Inc. v. Advanced Cardiovascular Sys., Inc., 242 F.3d 1337, 1341, 58 USPQ2d 1059, 1063 (Fed. Cir. 2001) (“Where the specification makes clear that the invention does not include a particular feature, that feature is deemed to be outside the reach of the claims of the patent, even though the language of the claims, read without reference to the specification, might be considered broad enough to encompass the feature in question.”); see also In re Am. Acad. Of Sci. Tech Ctr., 367 F.3d 1359, 1365-67, 70 USPQ2d 1827, 1831-33 (Fed. Cir. 2004) (refusing to limit claim term “user computer” to only “single-user computers” even though “some of the language of the specification, when viewed in isolation, might lead a reader to conclude that the term… is meant to refer to a computer that serves only a single user, the specification as a whole suggests a construction that is not so narrow”). But, in some cases, disavowal of a broader claim scope may be made by implication, such as where the specification contains only disparaging remarks with respect to a feature and every embodiment in the specification excludes that feature. In re Abbott Diabetes Care Inc., 696 F.3d 1142, 1149-50, 104 USPQ2d 1337, 1342-43 (Fed. Cir. 2012) (holding that the broadest reasonable interpretation of the claim term “electrochemical sensor” does not include a sensor having “external connection cables or wires” because the specification “repeatedly, consistently, and exclusively depict[s] an electrochemical sensor without external cables or wires while simultaneously disparaging sensors with external cables or wires”). But see In re Clarke, 809 Fed. Appx. 787, 794, 2020 USPQ2d 10253 (Fed. Cir. 2020) (“The doctrine of prosecution history estoppel is inapplicable during prosecution. Instead the doctrine is applicable only to issued patents.”) (emphasis in the original). If the examiner believes that the broadest reasonable interpretation of a claim is narrower than what the words of the claim otherwise suggest as the result of implicit disavowal in the specification, then the examiner should make the interpretation clear on the record.

The presumption that a term is given its ordinary and customary meaning may be rebutted by the applicant by clearly setting forth a different definition of the term in the specification. In re Morris, 127 F.3d 1048, 1054, 44 USPQ2d 1023, 1028 (Fed. Cir. 1997) (the USPTO looks to the ordinary use of the claim terms taking into account definitions or other “enlightenment” contained in the written description); But c.f. In re Am. Acad. of Sci. Tech. Ctr., 367 F.3d 1359, 1369, 70 USPQ2d 1827, 1834 (Fed. Cir. 2004) (“We have cautioned against reading limitations into a claim from the preferred embodiment described in the specification, even if it is the only embodiment described, absent clear disclaimer in the specification.”). When the specification sets a clear path to the claim language, the scope of the claims is more easily determined and the public notice function of the claims is best served.

“Though understanding the claim language may be aided by explanations contained in the written description, it is important not to import into a claim limitations that are not part of the claim. For example, a particular embodiment appearing in the written description may not be read into a claim when the claim language is broader than the embodiment.” Superguide Corp. v. DirecTV Enterprises, Inc., 358 F.3d 870, 875, 69 USPQ2d 1865, 1868 (Fed. Cir. 2004). See also Liebel-Flarsheim Co. v. Medrad Inc., 358 F.3d 898, 906, 69 USPQ2d 1801, 1807 (Fed. Cir. 2004) (discussing recent cases wherein the court expressly rejected the contention that if a patent describes only a single embodiment, the claims of the patent must be construed as being limited to that embodiment); E-Pass Techs., Inc. v. 3Com Corp., 343 F.3d 1364, 1369, 67 USPQ2d 1947, 1950 (Fed. Cir. 2003) (“Interpretation of descriptive statements in a patent’s written description is a difficult task, as an inherent tension exists as to whether a statement is a clear lexicographic definition or a description of a preferred embodiment. The problem is to interpret claims ‘in view of the specification’ without unnecessarily importing limitations from the specification into the claims.”); Altiris Inc. v. Symantec Corp., 318 F.3d 1363, 1371, 65 USPQ2d 1865, 1869-70 (Fed. Cir. 2003) (Although the specification discussed only a single embodiment, the court held that it was improper to read a specific order of steps into method claims where, as a matter of logic or grammar, the language of the method claims did not impose a specific order on the performance of the method steps, and the specification did not directly or implicitly require a particular order). See also subsection IV, below. When an element is claimed using language falling under the scope of 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, 6 th paragraph (often broadly referred to as means- (or step-) plus- function language), the specification must be consulted to determine the structure, material, or acts corresponding to the function recited in the claim, and the claimed element is construed as limited to the corresponding structure, material, or acts described in the specification and equivalents thereof. In re Donaldson, 16 F.3d 1189, 29 USPQ2d 1845 (Fed. Cir. 1994) (see MPEP § 2181 – MPEP § 2186).

“Though understanding the claim language may be aided by explanations contained in the written description, it is important not to import into a claim limitations that are not part of the claim. For example, a particular embodiment appearing in the written description may not be read into a claim when the claim language is broader than the embodiment.” Superguide Corp. v. DirecTV Enterprises, Inc., 358 F.3d 870, 875, 69 USPQ2d 1865, 1868 (Fed. Cir. 2004). See also Liebel-Flarsheim Co. v. Medrad Inc., 358 F.3d 898, 906, 69 USPQ2d 1801, 1807 (Fed. Cir. 2004) (discussing recent cases wherein the court expressly rejected the contention that if a patent describes only a single embodiment, the claims of the patent must be construed as being limited to that embodiment); E-Pass Techs., Inc. v. 3Com Corp., 343 F.3d 1364, 1369, 67 USPQ2d 1947, 1950 (Fed. Cir. 2003) (“Interpretation of descriptive statements in a patent’s written description is a difficult task, as an inherent tension exists as to whether a statement is a clear lexicographic definition or a description of a preferred embodiment. The problem is to interpret claims ‘in view of the specification’ without unnecessarily importing limitations from the specification into the claims.”); Altiris Inc. v. Symantec Corp., 318 F.3d 1363, 1371, 65 USPQ2d 1865, 1869-70 (Fed. Cir. 2003) (Although the specification discussed only a single embodiment, the court held that it was improper to read a specific order of steps into method claims where, as a matter of logic or grammar, the language of the method claims did not impose a specific order on the performance of the method steps, and the specification did not directly or implicitly require a particular order). See also subsection IV, below. When an element is claimed using language falling under the scope of 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, 6 th paragraph (often broadly referred to as means- (or step-) plus- function language), the specification must be consulted to determine the structure, material, or acts corresponding to the function recited in the claim, and the claimed element is construed as limited to the corresponding structure, material, or acts described in the specification and equivalents thereof. In re Donaldson, 16 F.3d 1189, 29 USPQ2d 1845 (Fed. Cir. 1994) (see MPEP § 2181 – MPEP § 2186).

“Though understanding the claim language may be aided by explanations contained in the written description, it is important not to import into a claim limitations that are not part of the claim. For example, a particular embodiment appearing in the written description may not be read into a claim when the claim language is broader than the embodiment.” Superguide Corp. v. DirecTV Enterprises, Inc., 358 F.3d 870, 875, 69 USPQ2d 1865, 1868 (Fed. Cir. 2004). See also Liebel-Flarsheim Co. v. Medrad Inc., 358 F.3d 898, 906, 69 USPQ2d 1801, 1807 (Fed. Cir. 2004) (discussing recent cases wherein the court expressly rejected the contention that if a patent describes only a single embodiment, the claims of the patent must be construed as being limited to that embodiment); E-Pass Techs., Inc. v. 3Com Corp., 343 F.3d 1364, 1369, 67 USPQ2d 1947, 1950 (Fed. Cir. 2003) (“Interpretation of descriptive statements in a patent’s written description is a difficult task, as an inherent tension exists as to whether a statement is a clear lexicographic definition or a description of a preferred embodiment. The problem is to interpret claims ‘in view of the specification’ without unnecessarily importing limitations from the specification into the claims.”); Altiris Inc. v. Symantec Corp., 318 F.3d 1363, 1371, 65 USPQ2d 1865, 1869-70 (Fed. Cir. 2003) (Although the specification discussed only a single embodiment, the court held that it was improper to read a specific order of steps into method claims where, as a matter of logic or grammar, the language of the method claims did not impose a specific order on the performance of the method steps, and the specification did not directly or implicitly require a particular order). See also subsection IV, below. When an element is claimed using language falling under the scope of 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, 6 th paragraph (often broadly referred to as means- (or step-) plus- function language), the specification must be consulted to determine the structure, material, or acts corresponding to the function recited in the claim, and the claimed element is construed as limited to the corresponding structure, material, or acts described in the specification and equivalents thereof. In re Donaldson, 16 F.3d 1189, 29 USPQ2d 1845 (Fed. Cir. 1994) (see MPEP § 2181 – MPEP § 2186).

In Zletz, supra, the examiner and the Board had interpreted claims reading “normally solid polypropylene” and “normally solid polypropylene having a crystalline polypropylene content” as being limited to “normally solid linear high homopolymers of propylene which have a crystalline polypropylene content.” The court ruled that limitations, not present in the claims, were improperly imported from the specification. See also In re Marosi, 710 F.2d 799, 802, 218 USPQ 289, 292 (Fed. Cir. 1983) (“'[C]laims are not to be read in a vacuum, and limitations therein are to be interpreted in light of the specification in giving them their ‘broadest reasonable interpretation.'” (quoting In re Okuzawa, 537 F.2d 545, 548, 190 USPQ 464, 466 (CCPA 1976)). The court looked to the specification to construe “essentially free of alkali metal” as including unavoidable levels of impurities but no more.).

In Zletz, supra, the examiner and the Board had interpreted claims reading “normally solid polypropylene” and “normally solid polypropylene having a crystalline polypropylene content” as being limited to “normally solid linear high homopolymers of propylene which have a crystalline polypropylene content.” The court ruled that limitations, not present in the claims, were improperly imported from the specification. See also In re Marosi, 710 F.2d 799, 802, 218 USPQ 289, 292 (Fed. Cir. 1983) (“'[C]laims are not to be read in a vacuum, and limitations therein are to be interpreted in light of the specification in giving them their ‘broadest reasonable interpretation.'” (quoting In re Okuzawa, 537 F.2d 545, 548, 190 USPQ 464, 466 (CCPA 1976)). The court looked to the specification to construe “essentially free of alkali metal” as including unavoidable levels of impurities but no more.).

In Zletz, supra, the examiner and the Board had interpreted claims reading “normally solid polypropylene” and “normally solid polypropylene having a crystalline polypropylene content” as being limited to “normally solid linear high homopolymers of propylene which have a crystalline polypropylene content.” The court ruled that limitations, not present in the claims, were improperly imported from the specification. See also In re Marosi, 710 F.2d 799, 802, 218 USPQ 289, 292 (Fed. Cir. 1983) (“'[C]laims are not to be read in a vacuum, and limitations therein are to be interpreted in light of the specification in giving them their ‘broadest reasonable interpretation.'” (quoting In re Okuzawa, 537 F.2d 545, 548, 190 USPQ 464, 466 (CCPA 1976)). The court looked to the specification to construe “essentially free of alkali metal” as including unavoidable levels of impurities but no more.).

In Zletz, supra, the examiner and the Board had interpreted claims reading “normally solid polypropylene” and “normally solid polypropylene having a crystalline polypropylene content” as being limited to “normally solid linear high homopolymers of propylene which have a crystalline polypropylene content.” The court ruled that limitations, not present in the claims, were improperly imported from the specification. See also In re Marosi, 710 F.2d 799, 802, 218 USPQ 289, 292 (Fed. Cir. 1983) (“'[C]laims are not to be read in a vacuum, and limitations therein are to be interpreted in light of the specification in giving them their ‘broadest reasonable interpretation.'” (quoting In re Okuzawa, 537 F.2d 545, 548, 190 USPQ 464, 466 (CCPA 1976)). The court looked to the specification to construe “essentially free of alkali metal” as including unavoidable levels of impurities but no more.).

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

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

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

The only exceptions to giving the words in a claim their ordinary and customary meaning in the art are (1) when the applicant acts as their own lexicographer; and (2) when the applicant disavows or disclaims the full scope of a claim term in the specification. To act as their own lexicographer, the applicant must clearly set forth a special definition of a claim term in the specification that differs from the plain and ordinary meaning it would otherwise possess. CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d 1359, 1366, 62 USPQ2d 1658, 1662 (Fed. Cir. 2002). The specification may also include an intentional disclaimer, or disavowal, of claim scope. In both of these cases, “the inventor’s intention, as expressed in the specification, is regarded as dispositive.” Phillips v. AWH Corp., 415 F.3d 1303, 1316 (Fed. Cir. 2005) (en banc). See also Starhome GmbH v. AT&T Mobility LLC, 743 F.3d 849, 857, 109 USPQ2d 1885, 1890-91 (Fed. Cir. 2014) (holding that the term “gateway” should be given its ordinary and customary meaning of “a connection between different networks” because nothing in the specification indicated a clear intent to depart from that ordinary meaning); Thorner v. Sony Computer Entm’t Am. LLC, 669 F.3d 1362, 1367-68, 101 USPQ2d 1457, 1460 (Fed. Cir. 2012) (The asserted claims of the patent were directed to a tactile feedback system for video game controllers comprising a flexible pad with a plurality of actuators “attached to said pad.” The court held that the claims were not limited to actuators attached to the external surface of the pad, even though the specification used the word “attached” when describing embodiments affixed to the external surface of the pad but the word “embedded” when describing embodiments affixed to the internal surface of the pad. The court explained that the plain and ordinary meaning of “attached” includes both external and internal attachments. Further, there is no clear and explicit statement in the specification to redefine “attached” or disavow the full scope of the term.).
CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d 1359, 1366, 62 USPQ2d 1658, 1662 (Fed. Cir. 2002) The specification may also include an intentional disclaimer, or disavowal, of claim scope.

Applicant may also rebut the presumption of plain meaning by clearly disavowing the full scope of the claim term in the specification. Disavowal, or disclaimer of claim scope, is only considered when it is clear and unmistakable. See SciMed Life Sys., Inc. v. Advanced Cardiovascular Sys., Inc., 242 F.3d 1337, 1341, 58 USPQ2d 1059, 1063 (Fed. Cir. 2001) (“Where the specification makes clear that the invention does not include a particular feature, that feature is deemed to be outside the reach of the claims of the patent, even though the language of the claims, read without reference to the specification, might be considered broad enough to encompass the feature in question.”); see also In re Am. Acad. Of Sci. Tech Ctr., 367 F.3d 1359, 1365-67, 70 USPQ2d 1827, 1831-33 (Fed. Cir. 2004) (refusing to limit claim term “user computer” to only “single-user computers” even though “some of the language of the specification, when viewed in isolation, might lead a reader to conclude that the term… is meant to refer to a computer that serves only a single user, the specification as a whole suggests a construction that is not so narrow”). But, in some cases, disavowal of a broader claim scope may be made by implication, such as where the specification contains only disparaging remarks with respect to a feature and every embodiment in the specification excludes that feature. In re Abbott Diabetes Care Inc., 696 F.3d 1142, 1149-50, 104 USPQ2d 1337, 1342-43 (Fed. Cir. 2012) (holding that the broadest reasonable interpretation of the claim term “electrochemical sensor” does not include a sensor having “external connection cables or wires” because the specification “repeatedly, consistently, and exclusively depict[s] an electrochemical sensor without external cables or wires while simultaneously disparaging sensors with external cables or wires”). But see In re Clarke, 809 Fed. Appx. 787, 794, 2020 USPQ2d 10253 (Fed. Cir. 2020) (“The doctrine of prosecution history estoppel is inapplicable during prosecution. Instead the doctrine is applicable only to issued patents.”) (emphasis in the original). If the examiner believes that the broadest reasonable interpretation of a claim is narrower than what the words of the claim otherwise suggest as the result of implicit disavowal in the specification, then the examiner should make the interpretation clear on the record.

Applicant may also rebut the presumption of plain meaning by clearly disavowing the full scope of the claim term in the specification. Disavowal, or disclaimer of claim scope, is only considered when it is clear and unmistakable. See SciMed Life Sys., Inc. v. Advanced Cardiovascular Sys., Inc., 242 F.3d 1337, 1341, 58 USPQ2d 1059, 1063 (Fed. Cir. 2001) (“Where the specification makes clear that the invention does not include a particular feature, that feature is deemed to be outside the reach of the claims of the patent, even though the language of the claims, read without reference to the specification, might be considered broad enough to encompass the feature in question.”); see also In re Am. Acad. Of Sci. Tech Ctr., 367 F.3d 1359, 1365-67, 70 USPQ2d 1827, 1831-33 (Fed. Cir. 2004) (refusing to limit claim term “user computer” to only “single-user computers” even though “some of the language of the specification, when viewed in isolation, might lead a reader to conclude that the term… is meant to refer to a computer that serves only a single user, the specification as a whole suggests a construction that is not so narrow”). But, in some cases, disavowal of a broader claim scope may be made by implication, such as where the specification contains only disparaging remarks with respect to a feature and every embodiment in the specification excludes that feature. In re Abbott Diabetes Care Inc., 696 F.3d 1142, 1149-50, 104 USPQ2d 1337, 1342-43 (Fed. Cir. 2012) (holding that the broadest reasonable interpretation of the claim term “electrochemical sensor” does not include a sensor having “external connection cables or wires” because the specification “repeatedly, consistently, and exclusively depict[s] an electrochemical sensor without external cables or wires while simultaneously disparaging sensors with external cables or wires”). But see In re Clarke, 809 Fed. Appx. 787, 794, 2020 USPQ2d 10253 (Fed. Cir. 2020) (“The doctrine of prosecution history estoppel is inapplicable during prosecution. Instead the doctrine is applicable only to issued patents.”) (emphasis in the original). If the examiner believes that the broadest reasonable interpretation of a claim is narrower than what the words of the claim otherwise suggest as the result of implicit disavowal in the specification, then the examiner should make the interpretation clear on the record.

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

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

Under a broadest reasonable interpretation (BRI), words of the claim must be given their plain meaning, unless such meaning is inconsistent with the specification. The plain meaning of a term means the ordinary and customary meaning given to the term by those of ordinary skill in the art at the relevant time. The ordinary and customary meaning of a term may be evidenced by a variety of sources, including the words of the claims themselves, the specification, drawings, and prior art. However, the best source for determining the meaning of a claim term is the specification – the greatest clarity is obtained when the specification serves as a glossary for the claim terms. Phillips v. AWH Corp., 415 F.3d 1303, 1315, 75 USPQ2d 1321, 1327 (Fed. Cir. 2005) (en banc) (“[T]he specification ‘is always highly relevant to the claim construction analysis. Usually, it is dispositive; it is the single best guide to the meaning of a disputed term.’” (quoting Vitronics Corp. v. Conceptronic Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996)). The words of the claim must be given their plain meaning unless the plain meaning is inconsistent with the specification. In re Zletz, 893 F.2d 319, 321, 13 USPQ2d 1320, 1322 (Fed. Cir. 1989) (discussed below); Chef America, Inc. v. Lamb-Weston, Inc., 358 F.3d 1371, 1372, 69 USPQ2d 1857 (Fed. Cir. 2004) (Ordinary, simple English words whose meaning is clear and unquestionable, absent any indication that their use in a particular context changes their meaning, are construed to mean exactly what they say. Thus, “heating the resulting batter-coated dough to a temperature in the range of about 400 o F to 850 o F” required heating the dough, rather than the air inside an oven, to the specified temperature.). See also Salazar v. AT&T Mobility LLC, 64 F.4th 1311, 1317-1318, 2023 USPQ2d 412 (Fed. Cir. 2023) (While the claim language, “a microprocessor for generating…, said microprocessor creating…, a plurality of parameter sets retrieved by said microprocessor…, said microprocessor generating…,” does not require there be only one microprocessor, the limitations to "said microprocessor" require a singular element—“a microprocessor”—to be capable of performing all of the recited “generating,” “creating,” and “retrieving” functions. Similarly, “[f]or a dog owner to have ‘a dog that rolls over and fetches sticks,’ it does not suffice that he have two dogs, each able to perform just one of the tasks.” (quoting In re Varma, 816 F.3d 1352, 1363, 118 USPQ2d 1342, 1350 (Fed. Cir. 2016))).

Under a broadest reasonable interpretation (BRI), words of the claim must be given their plain meaning, unless such meaning is inconsistent with the specification. The plain meaning of a term means the ordinary and customary meaning given to the term by those of ordinary skill in the art at the relevant time. The ordinary and customary meaning of a term may be evidenced by a variety of sources, including the words of the claims themselves, the specification, drawings, and prior art. However, the best source for determining the meaning of a claim term is the specification – the greatest clarity is obtained when the specification serves as a glossary for the claim terms. Phillips v. AWH Corp., 415 F.3d 1303, 1315, 75 USPQ2d 1321, 1327 (Fed. Cir. 2005) (en banc) (“[T]he specification ‘is always highly relevant to the claim construction analysis. Usually, it is dispositive; it is the single best guide to the meaning of a disputed term.’” (quoting Vitronics Corp. v. Conceptronic Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996)). The words of the claim must be given their plain meaning unless the plain meaning is inconsistent with the specification. In re Zletz, 893 F.2d 319, 321, 13 USPQ2d 1320, 1322 (Fed. Cir. 1989) (discussed below); Chef America, Inc. v. Lamb-Weston, Inc., 358 F.3d 1371, 1372, 69 USPQ2d 1857 (Fed. Cir. 2004) (Ordinary, simple English words whose meaning is clear and unquestionable, absent any indication that their use in a particular context changes their meaning, are construed to mean exactly what they say. Thus, “heating the resulting batter-coated dough to a temperature in the range of about 400 o F to 850 o F” required heating the dough, rather than the air inside an oven, to the specified temperature.). See also Salazar v. AT&T Mobility LLC, 64 F.4th 1311, 1317-1318, 2023 USPQ2d 412 (Fed. Cir. 2023) (While the claim language, “a microprocessor for generating…, said microprocessor creating…, a plurality of parameter sets retrieved by said microprocessor…, said microprocessor generating…,” does not require there be only one microprocessor, the limitations to "said microprocessor" require a singular element—“a microprocessor”—to be capable of performing all of the recited “generating,” “creating,” and “retrieving” functions. Similarly, “[f]or a dog owner to have ‘a dog that rolls over and fetches sticks,’ it does not suffice that he have two dogs, each able to perform just one of the tasks.” (quoting In re Varma, 816 F.3d 1352, 1363, 118 USPQ2d 1342, 1350 (Fed. Cir. 2016))).

In some cases it is also appropriate to look to how the claim term is used in the prior art, which includes prior art patents, published applications, trade publications, and dictionaries. Phillips v. AWH Corp., 415 F.3d 1303, 1317, 75 USPQ2d 1321, 1329 (Fed. Cir. 2005) (“Although we have emphasized the importance of intrinsic evidence in claim construction, we have also authorized district courts to rely on extrinsic evidence, which “consists of all evidence external to the patent and prosecution history, including expert and inventor testimony, dictionaries, and learned treatises.”)

In some cases it is also appropriate to look to how the claim term is used in the prior art, which includes prior art patents, published applications, trade publications, and dictionaries. Phillips v. AWH Corp., 415 F.3d 1303, 1317, 75 USPQ2d 1321, 1329 (Fed. Cir. 2005) (“Although we have emphasized the importance of intrinsic evidence in claim construction, we have also authorized district courts to rely on extrinsic evidence, which “consists of all evidence external to the patent and prosecution history, including expert and inventor testimony, dictionaries, and learned treatises.”)

The first question is to determine whether a claim term has an ordinary and customary meaning to those of ordinary skill in the art. If so, then the examiner should check the specification to determine whether it provides a special definition for the claim term. If the specification does not provide a special definition for the claim term, the examiner should apply the ordinary and customary meaning to the claim term. If the specification provides a special definition for the claim term, the examiner should use the special definition. However, because there is a presumption that claim terms have their ordinary and customary meaning and the specification must provide a clear and intentional use of a special definition for the claim term to be treated as having a special definition, an Office action should acknowledge and identify the special definition in this situation.

The first question is to determine whether a claim term has an ordinary and customary meaning to those of ordinary skill in the art. If so, then the examiner should check the specification to determine whether it provides a special definition for the claim term. If the specification does not provide a special definition for the claim term, the examiner should apply the ordinary and customary meaning to the claim term. If the specification provides a special definition for the claim term, the examiner should use the special definition. However, because there is a presumption that claim terms have their ordinary and customary meaning and the specification must provide a clear and intentional use of a special definition for the claim term to be treated as having a special definition, an Office action should acknowledge and identify the special definition in this situation.

The only exceptions to giving the words in a claim their ordinary and customary meaning in the art are (1) when the applicant acts as their own lexicographer; and (2) when the applicant disavows or disclaims the full scope of a claim term in the specification. To act as their own lexicographer, the applicant must clearly set forth a special definition of a claim term in the specification that differs from the plain and ordinary meaning it would otherwise possess. CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d 1359, 1366, 62 USPQ2d 1658, 1662 (Fed. Cir. 2002). The specification may also include an intentional disclaimer, or disavowal, of claim scope. In both of these cases, “the inventor’s intention, as expressed in the specification, is regarded as dispositive.” Phillips v. AWH Corp., 415 F.3d 1303, 1316 (Fed. Cir. 2005) (en banc). See also Starhome GmbH v. AT&T Mobility LLC, 743 F.3d 849, 857, 109 USPQ2d 1885, 1890-91 (Fed. Cir. 2014) (holding that the term “gateway” should be given its ordinary and customary meaning of “a connection between different networks” because nothing in the specification indicated a clear intent to depart from that ordinary meaning); Thorner v. Sony Computer Entm’t Am. LLC, 669 F.3d 1362, 1367-68, 101 USPQ2d 1457, 1460 (Fed. Cir. 2012) (The asserted claims of the patent were directed to a tactile feedback system for video game controllers comprising a flexible pad with a plurality of actuators “attached to said pad.” The court held that the claims were not limited to actuators attached to the external surface of the pad, even though the specification used the word “attached” when describing embodiments affixed to the external surface of the pad but the word “embedded” when describing embodiments affixed to the internal surface of the pad. The court explained that the plain and ordinary meaning of “attached” includes both external and internal attachments. Further, there is no clear and explicit statement in the specification to redefine “attached” or disavow the full scope of the term.).