MPEP § 2173.01 — Interpreting the Claims (Annotated Rules)

§2173.01 Interpreting the Claims

USPTO MPEP version: BlueIron's Update: 2025-12-31

This page consolidates and annotates all enforceable requirements under MPEP § 2173.01, including statutory authority, regulatory rules, examiner guidance, and practice notes. It is provided as guidance, with links to the ground truth sources. This is information only, it is not legal advice.

Interpreting the Claims

This section addresses Interpreting the Claims. Primary authority: 35 U.S.C. 102, 35 U.S.C. 100, and 35 U.S.C. 112(b). Contains: 2 requirements, 1 guidance statement, 4 permissions, and 10 other statements.

Key Rules

Topic

Interpreting Claims (MPEP 2173.01)

7 rules
StatutoryInformativeAlways
[mpep-2173-01-97ecd681a70e82397d0d1801]
Claims Must Be Interpreted Broadly Consistent With Specification
Note:
The claims must be interpreted in their broadest reasonable interpretation consistent with the specification as it would be understood by one of ordinary skill in the art.

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

Jump to MPEP SourceInterpreting Claims (MPEP 2173.01)Appeal to Federal CircuitDetermining Level of Ordinary Skill
StatutoryInformativeAlways
[mpep-2173-01-5c59a497e44b6d4be109c13d]
Claims Must Be Given Broadest Reasonable Interpretation
Note:
During examination, claims must be interpreted as broadly as their terms allow, considering the specification and what would be reasonable to one of ordinary skill in the art.

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

Jump to MPEP SourceInterpreting Claims (MPEP 2173.01)Appeal to Federal CircuitDetermining Level of Ordinary Skill
StatutoryInformativeAlways
[mpep-2173-01-4506d780ee7f3156a6f47c1f]
Claims Must Be Interpreted Broadly Consistent With Specification
Note:
The claims must be interpreted in their broadest reasonable interpretation consistent with the specification as it would be understood by one of ordinary skill in the art.

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

Jump to MPEP SourceInterpreting Claims (MPEP 2173.01)Appeal to Federal CircuitDetermining Level of Ordinary Skill
StatutoryInformativeAlways
[mpep-2173-01-6140d84ed1e4cdcae67e04c0]
Claims Must Be Interpreted Broadly Consistent With Specification
Note:
The claims must be interpreted in their broadest reasonable sense as one of ordinary skill in the art would interpret them, consistent with the specification provided.

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

Jump to MPEP SourceInterpreting Claims (MPEP 2173.01)Appeal to Federal CircuitDetermining Level of Ordinary Skill
StatutoryInformativeAlways
[mpep-2173-01-bb851b135fd46721bec0aa10]
Claims Must Be Interpreted According to Ordinary Meaning
Note:
Claims must be interpreted based on the ordinary and customary meaning of terms used by those skilled in the art at the time of invention.

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

Jump to MPEP SourceInterpreting Claims (MPEP 2173.01)Description of EmbodimentsClaim Form Requirements
StatutoryPermittedAlways
[mpep-2173-01-53b3b3e31d555154eae73d3f]
Claim Term Special Definition Must Be Proven
Note:
Applicant must show the claim term has a special definition as it was given its plain meaning in an Office action.

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

Jump to MPEP SourceInterpreting Claims (MPEP 2173.01)Patent Application Content
StatutoryRequiredAlways
[mpep-2173-01-1a0e73262270944df4eafe68]
Claim Term Requires Special Definition
Note:
The applicant must point to a clear and intentional special definition in the specification for claim terms to be treated as having a special meaning.

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

Jump to MPEP SourceInterpreting Claims (MPEP 2173.01)Patent Application Content
Topic

Alternative Limitations (MPEP 2173.05(h))

6 rules
StatutoryInformativeAlways
[mpep-2173-01-d3c0b15a95800f116040c139]
Applicants Define Claim Terms
Note:
Applicants can define terms in claims as they see fit, provided the special meaning is clearly explained in the specification.

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

Jump to MPEP SourceAlternative Limitations (MPEP 2173.05(h))AIA vs Pre-AIA PracticeDisclosure Requirements
StatutoryPermittedAlways
[mpep-2173-01-777f47fb299cc61cd44bba61]
Inventor Can Define Claim Terms
Note:
The inventor can define claim terms in any way they choose as long as the special meaning is clearly explained in the specification.

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

Jump to MPEP SourceAlternative Limitations (MPEP 2173.05(h))Lack of Antecedent Basis (MPEP 2173.05(e))Patent Application Content
StatutoryPermittedAlways
[mpep-2173-01-06a18271b8c5f11ae20ec89f]
Applicant May Use Functional Language for Claims
Note:
The rule permits applicants to define the invention using various types of language, including functional descriptions and alternative expressions, to clearly delineate the subject matter seeking patent protection.

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

Jump to MPEP SourceAlternative Limitations (MPEP 2173.05(h))Lack of Antecedent Basis (MPEP 2173.05(e))Functional Limitations (MPEP 2173.05(g))
StatutoryRecommendedAlways
[mpep-2173-01-024affcf12ccfef986ec853a]
Claim Limitations Must Be Construed Accordingly
Note:
Examiners must determine if claim limitations invoke 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph and construe them accordingly.

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

Jump to MPEP SourceAlternative Limitations (MPEP 2173.05(h))Lack of Antecedent Basis (MPEP 2173.05(e))Interpreting Claims (MPEP 2173.01)
StatutoryRequiredAlways
[mpep-2173-01-ec7077c23e3d1ba0e6e92251]
Claim Limitation Must Cover Corresponding Structure
Note:
If a claim limitation invokes 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, it must be construed to cover the corresponding structure, material, or acts described in the specification and their equivalents.

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

Jump to MPEP SourceAlternative Limitations (MPEP 2173.05(h))Lack of Antecedent Basis (MPEP 2173.05(e))Interpreting Claims (MPEP 2173.01)
StatutoryInformativeAlways
[mpep-2173-01-7537ddd5c56f1a524c659874]
Claim Limitations Must Be Construed to Cover Corresponding Structure
Note:
Examiners must interpret claim limitations that invoke 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph to cover the corresponding structure described in the specification and its equivalents.

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

Jump to MPEP SourceAlternative Limitations (MPEP 2173.05(h))Lack of Antecedent Basis (MPEP 2173.05(e))When 112(f) Is Invoked (MPEP 2181)
Topic

Required Claim Content

3 rules
StatutoryRequiredAlways
[mpep-2173-01-313afef7a533a7d9ff96a6e5]
Claims Must Be Given Broadest Reasonable Interpretation Consistent With Specification
Note:
During examination, claims must be interpreted in the broadest reasonable way consistent with the specification as it would be understood by one of ordinary skill in the art.

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

Jump to MPEP SourceRequired Claim ContentInterpreting Claims (MPEP 2173.01)Statutory Authority for Examination
StatutoryRequiredAlways
[mpep-2173-01-8efd7dfa676a61b173b341ab]
Claims Must Be Interpreted Broadly During Examination
Note:
During patent examination, claims must be interpreted as broadly as their terms reasonably allow to avoid overly broad post-issuance interpretation.

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

Jump to MPEP SourceRequired Claim ContentInterpreting Claims (MPEP 2173.01)Statutory Authority for Examination
StatutoryRequiredAlways
[mpep-2173-01-e65fb6f9990ab68fb32db221]
Claims Must Be Interpreted Broadly
Note:
Claims must be interpreted according to their plain meaning unless the specification provides a different definition.

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

Jump to MPEP SourceRequired Claim ContentInterpreting Claims (MPEP 2173.01)
Topic

Composition of Matter Claims

2 rules
StatutoryInformativeAlways
[mpep-2173-01-6489a00c009c34543ba8bcb3]
Claims Must Be Interpreted Broadly Consistent With Specification
Note:
Patent claims must be interpreted in their broadest reasonable sense consistent with the specification, considering the subject matter disclosed and the boundaries of the invention.

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

Jump to MPEP SourceComposition of Matter ClaimsInterpreting Claims (MPEP 2173.01)
StatutoryInformativeAlways
[mpep-2173-01-8a2f94bdca5e61472f130e01]
Flexible vs Rigid Foam Mixtures Distinguished
Note:
Examiners must distinguish between flexible and rigid foam mixtures when interpreting claims in polyurethane foams, as experienced practitioners recognize these as distinct types.

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

Jump to MPEP SourceComposition of Matter ClaimsInterpreting Claims (MPEP 2173.01)Appeal to Federal Circuit
Topic

Claims

2 rules
StatutoryPermittedAlways
[mpep-2173-01-c3c07e45ad415855296d0419]
Specification as Glossary for Claim Terms
Note:
The specification is the best source for determining the meaning of claim terms, with priority given to its ordinary and customary meanings.

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

Jump to MPEP SourcePatent Application ContentInterpreting Claims (MPEP 2173.01)
StatutoryInformativeAlways
[mpep-2173-01-cefc0955044facfc7db50a88]
Claims Must Not Be Limited Solely by Specification
Note:
The court advises the PTO to avoid narrowing broad claim terms based solely on specification passages.

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

Jump to MPEP SourcePatent Application ContentInterpreting Claims (MPEP 2173.01)
Topic

Determining Whether Application Is AIA or Pre-AIA

1 rules
StatutoryInformativeAlways
[mpep-2173-01-961fae792176c6bb51b11013]
Effective Filing Date Determines Claimed Invention's Validity Under FITF Provision
Note:
The effective filing date of the claimed invention is used to determine its validity under the first inventor to file (FITF) provisions of the AIA, replacing the time of invention for pre-AIA applications.

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

Jump to MPEP SourceDetermining Whether Application Is AIA or Pre-AIADetermining AIA vs Pre-AIA Applicability (MPEP 2159)AIA vs Pre-AIA Practice
Topic

Optional Claim Content

1 rules
StatutoryProhibitedAlways
[mpep-2173-01-f220bc661aea3e92a813a804]
Claims Must Not Be Rejected Based on Language Type
Note:
Patent claims should not be rejected solely because of the type of language used to define the subject matter for which protection is sought.

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

Jump to MPEP SourceOptional Claim ContentProhibited Claim ContentLack of Antecedent Basis (MPEP 2173.05(e))
Topic

Determining Level of Ordinary Skill

1 rules
StatutoryInformativeAlways
[mpep-2173-01-19497deef5be6c1e66b8cc81]
Examine Claim Boundaries Consistently With Specification
Note:
Ensure claims are interpreted broadly and consistently with the application's disclosed invention, as understood by one of ordinary skill in the art.

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

Jump to MPEP SourceDetermining Level of Ordinary SkillDetermining Claim Definiteness (MPEP 2173.02)
Topic

Person of Ordinary Skill in the Art

1 rules
StatutoryRecommendedAlways
[mpep-2173-01-b1db821e15b3d7a6c78c19df]
Claim Meaning From Perspective of Person of Ordinary Skill in the Art
Note:
The focus when interpreting a claim is on what would be reasonable to someone with average skill in the relevant field.

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

Jump to MPEP SourcePerson of Ordinary Skill in the ArtInterpreting Claims (MPEP 2173.01)
Topic

Appeal to Federal Circuit

1 rules
StatutoryInformativeAlways
[mpep-2173-01-7182f320c394a0a0ae9bda4d]
Flexible Foam Not Equated to Crushed Rigid Foam
Note:
The Federal Circuit found that equating a flexible foam with a crushed rigid foam in a claim is not reasonable.

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

Jump to MPEP SourceAppeal to Federal CircuitJudicial Review of Board DecisionsPTAB Jurisdiction
Topic

Description of Embodiments

1 rules
StatutoryPermittedAlways
[mpep-2173-01-540a59bf9698ed38a410b30e]
Claim Term May Have Different Meaning Than Ordinary Usage
Note:
A claim term can have a different meaning than its ordinary usage if clearly defined in the specification.

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

Jump to MPEP SourceDescription of EmbodimentsDetailed Description
Topic

PTAB Jurisdiction

1 rules
StatutoryInformativeAlways
[mpep-2173-01-a4ca8521feb0888e923e6c04]
Claim Term Not Limited to Scalp Hairbrushes
Note:
The court upheld the Board’s refusal to limit a claim term 'hairbrush' to only scalp hairbrushes based on the specification.

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

Jump to MPEP SourcePTAB JurisdictionPatent Application ContentPTAB Contested Case Procedures
Topic

Claim Form Requirements

1 rules
StatutoryInformativeAlways
[mpep-2173-01-5cf9ca0c2aeb0dff013c4ccc]
Specification Must Clear Claim Scope
Note:
The specification must clearly guide claim language to ensure the claims' scope is easily determined and serves public notice.

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

Jump to MPEP SourceClaim Form RequirementsInterpreting Claims (MPEP 2173.01)
Topic

Components Required for Filing Date

1 rules
StatutoryProhibitedAlways
[mpep-2173-01-15a0f47116b07d32fc673e8c]
Specification Special Definitions Must Be Filed Before Filing Date
Note:
The specification must not contain special definitions added after the filing date, but applicants may explain where such definitions are present in the original specification.

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

Jump to MPEP SourceComponents Required for Filing DateFiling Date RequirementsPatent Application Content

Citations

Primary topicCitation
Determining Whether Application Is AIA or Pre-AIA35 U.S.C. § 100
Determining Whether Application Is AIA or Pre-AIA35 U.S.C. § 102
Alternative Limitations (MPEP 2173.05(h))
Optional Claim Content
35 U.S.C. § 112
Alternative Limitations (MPEP 2173.05(h))
Optional Claim Content
35 U.S.C. § 112(b)
Alternative Limitations (MPEP 2173.05(h))35 U.S.C. § 112(f)
Appeal to Federal Circuit
Composition of Matter Claims
Determining Level of Ordinary Skill
Interpreting Claims (MPEP 2173.01)
Person of Ordinary Skill in the Art
Required Claim Content
MPEP § 2111
Alternative Limitations (MPEP 2173.05(h))
Claim Form Requirements
Claims
Description of Embodiments
Interpreting Claims (MPEP 2173.01)
Optional Claim Content
PTAB Jurisdiction
Required Claim Content
MPEP § 2111.01
Determining Whether Application Is AIA or Pre-AIAMPEP § 2150
Alternative Limitations (MPEP 2173.05(h))MPEP § 2181
Claim Form Requirements
Claims
Description of Embodiments
Interpreting Claims (MPEP 2173.01)
PTAB Jurisdiction
Required Claim Content
In re Bigio, 381 F.3d 1320, 1325, 72 USPQ2d 1209, 1211 (Fed. Cir. 2004)
Appeal to Federal Circuit
Composition of Matter Claims
Determining Level of Ordinary Skill
Interpreting Claims (MPEP 2173.01)
Person of Ordinary Skill in the Art
Required Claim Content
In re Buszard, 504 F.3d 1364, 84 USPQ2d 1749 (Fed. Cir. 2007)
Claim Form Requirements
Claims
Description of Embodiments
Interpreting Claims (MPEP 2173.01)
PTAB Jurisdiction
Required Claim Content
In re Morris, 127 F.3d 1048, 1054, 44 USPQ2d 1023, 1028 (Fed. Cir. 1997)
Alternative Limitations (MPEP 2173.05(h))
Optional Claim Content
In re Swinehart, 439 F.2d 210, 160 USPQ 226 (CCPA 1971)
Appeal to Federal Circuit
Composition of Matter Claims
Determining Level of Ordinary Skill
Interpreting Claims (MPEP 2173.01)
Person of Ordinary Skill in the Art
Required Claim Content
In re Yamamoto, 740 F.2d 1569, 1571, 222 USPQ 934, 936 (Fed. Cir. 1984)
Appeal to Federal Circuit
Composition of Matter Claims
Determining Level of Ordinary Skill
Interpreting Claims (MPEP 2173.01)
Person of Ordinary Skill in the Art
Required Claim Content
In re Zletz, 893 F.2d 319, 321, 13 USPQ2d 1320, 1322 (Fed. Cir. 1989)

Source Text from USPTO’s MPEP

This is an exact copy of the MPEP from the USPTO. It is here for your reference to see the section in context.

BlueIron Last Updated: 2025-12-31