MPEP § 2173.05(a) — New Terminology (Annotated Rules)

§2173.05(a) New Terminology

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

This page consolidates and annotates all enforceable requirements under MPEP § 2173.05(a), 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.

New Terminology

This section addresses New Terminology. Primary authority: 35 U.S.C. 112(b), 35 U.S.C. 112, and 37 CFR 2111.01. Contains: 4 requirements, 1 prohibition, 2 guidance statements, 1 permission, and 4 other statements.

Key Rules

Topic

Alternative Limitations (MPEP 2173.05(h))

5 rules
StatutoryInformativeAlways
[mpep-2173-05-a-c2d467a220a74e434f8b50d7]
Clarity and Precision for New Terms
Note:
The use of new terms in rapidly evolving technologies must be clear and precise, but not necessarily perfect. Examiners should provide reasons if the language is deemed insufficient.

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

Jump to MPEP SourceAlternative Limitations (MPEP 2173.05(h))New Terminology (MPEP 2173.05(a))35 U.S.C. 112(b) – Definiteness (MPEP 2171-2173)
StatutoryInformativeAlways
[mpep-2173-05-a-0292dcdf45cfa5c24145c546]
Claims Must Reasonably Apprise Artists of Invention Utilization and Scope
Note:
The claims must clearly describe the invention's use and scope to those skilled in the art, using precise language as much as the subject matter allows.

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

Jump to MPEP SourceAlternative Limitations (MPEP 2173.05(h))Lack of Antecedent Basis (MPEP 2173.05(e))AIA vs Pre-AIA Practice
StatutoryPermittedAlways
[mpep-2173-05-a-0d140ce93e09e74b4c20f71c]
Patentee Can Define Own Terms
Note:
A patentee can use terms in a manner contrary to their ordinary meanings if the written description clearly redefines them, putting competitors on notice of the intended meaning.

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

Jump to MPEP SourceAlternative Limitations (MPEP 2173.05(h))Lack of Antecedent Basis (MPEP 2173.05(e))New Terminology (MPEP 2173.05(a))
StatutoryRequiredAlways
[mpep-2173-05-a-91fd11371408f8103e1bf95e]
Written Description Must Clarify Claim Terms
Note:
The written description must clearly redefine claim terms when they have multiple meanings to inform a skilled artisan of the specific definition intended by the patentee.

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

Jump to MPEP SourceAlternative Limitations (MPEP 2173.05(h))Lack of Antecedent Basis (MPEP 2173.05(e))New Terminology (MPEP 2173.05(a))
StatutoryInformativeAlways
[mpep-2173-05-a-c6e4b52bb4a4632a30a1bf75]
Claim Terms Must Be Clearly Defined
Note:
Patent claims must clearly define terms used, and their meaning should be ascertained from the written description or technical dictionaries if ambiguous.

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

Jump to MPEP SourceAlternative Limitations (MPEP 2173.05(h))Lack of Antecedent Basis (MPEP 2173.05(e))AIA vs Pre-AIA Practice
Topic

Lack of Antecedent Basis (MPEP 2173.05(e))

3 rules
StatutoryRequiredAlways
[mpep-2173-05-a-63a624167b3596a163d6923d]
Precision Requirement for New Terminology
Note:
The claims must use language as precise as the subject matter permits, balancing clarity with the limitations of the language and science.

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

Jump to MPEP SourceLack of Antecedent Basis (MPEP 2173.05(e))New Terminology (MPEP 2173.05(a))35 U.S.C. 112(b) – Definiteness (MPEP 2171-2173)
StatutoryRequiredAlways
[mpep-2173-05-a-fde0d80b622de8a0f17b1547]
Clarity and Precision of Language Required
Note:
The claims must be described with reasonable precision, considering the science and language limitations, without requiring more than what is permitted by the subject matter.

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

Jump to MPEP SourceLack of Antecedent Basis (MPEP 2173.05(e))Use Claims (MPEP 2173.05(q))Assignee as Applicant Signature
StatutoryRecommendedAlways
[mpep-2173-05-a-987ff13aaaace3d3d46f67b3]
Examiner Must Provide Reasons for Indefiniteness and Suggest Alternatives
Note:
The examiner must provide reasons if the language is not precise enough and suggest clearer alternatives that would not be rejected.

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

Jump to MPEP SourceLack of Antecedent Basis (MPEP 2173.05(e))New Terminology (MPEP 2173.05(a))35 U.S.C. 112(b) – Definiteness (MPEP 2171-2173)
Topic

Claims

3 rules
MPEP GuidanceRecommendedAlways
[mpep-2173-05-a-d3fcbf500ddaaae659d0f041]
Claim Terms Must Be Clear From Specification
Note:
Claims must define terms using language from the prior art or specification to ensure clarity and coherence.

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

Jump to MPEP Source · 37 CFR 2111.01Patent Application ContentClaim Form Requirements
MPEP GuidanceRequiredAlways
[mpep-2173-05-a-98ef5dba2c67e4c723b1af45]
Claim Terms Must Be Clear and Precise
Note:
Applicants must define the terms used in claims clearly and precisely so that the scope of the invention can be determined.

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

Jump to MPEP Source · 37 CFR 2111.01Claim Form RequirementsRequired Claim Content
MPEP GuidanceInformativeAlways
[mpep-2173-05-a-e43d7ca3e7d684a10b4ff1dd]
Claims Examined Using Specified Term Meanings
Note:
When the specification defines a term in the claim, the claim is examined using that meaning to fully explore the invention and its relation to prior art.

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

Jump to MPEP Source · 37 CFR 2111.01Patent Application ContentClaim Form Requirements
Topic

Claim Form Requirements

1 rules
MPEP GuidanceProhibitedAlways
[mpep-2173-05-a-f5593ae6d055c73bf837430e]
Claims Must Be Clear and Precise
Note:
Patent claims must be described in a way that is clear, precise, and free from ambiguity to ensure the metes and bounds of the invention can be understood.

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

Jump to MPEP Source · 37 CFR 2111.01Claim Form RequirementsRequired Claim Content
Topic

Required Claim Content

1 rules
MPEP GuidanceRequiredAlways
[mpep-2173-05-a-671508093142a66061b3cfd2]
Pending Claims Must Be Given Broadest Reasonable Interpretation Consistent with Specification
Note:
During patent examination, claims must be interpreted in the broadest reasonable way that aligns with the specification to ensure a complete exploration of the applicant’s invention.

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

Jump to MPEP Source · 37 CFR 2111.01Required Claim ContentInterpreting Claims (MPEP 2173.01)Statutory Authority for Examination

Citations

Primary topicCitation
Alternative Limitations (MPEP 2173.05(h))
Lack of Antecedent Basis (MPEP 2173.05(e))
35 U.S.C. § 112
Alternative Limitations (MPEP 2173.05(h))
Lack of Antecedent Basis (MPEP 2173.05(e))
35 U.S.C. § 112(b)
Claim Form Requirements
Claims
Required Claim Content
37 CFR § 2111.01
Claim Form Requirements
Claims
Required Claim Content
MPEP § 2111
Alternative Limitations (MPEP 2173.05(h))MPEP § 2111.01
Alternative Limitations (MPEP 2173.05(h))Hormone Research Foundation Inc. v. Genentech Inc., 904 F.2d 1558, 15 USPQ2d 1039 (Fed. Cir. 1990)
Alternative Limitations (MPEP 2173.05(h))In re Barr, 444 F.2d 588, 170 USPQ 330 (CCPA 1971)
In re Fisher, 427 F.2d 833, 166 USPQ 18 (CCPA 1970)
Claim Form Requirements
Claims
Required Claim Content
In re Morris, 127 F.3d 1048, 1054, 44 USPQ2d 1023, 1027 (Fed. Cir. 1997)
Claim Form Requirements
Claims
Required Claim Content
In re Packard, 751 F.3d 1307, 1311, 110 USPQ2d 1785, 1787 (Fed. Cir. 2014)
Claim Form Requirements
Claims
Required Claim Content
In re Prater, 415 F.2d 1393, 162 USPQ 541 (CCPA 1969)
Claim Form Requirements
Claims
Required Claim Content
In re Zletz, 893 F.2d 319, 13 USPQ2d 1320 (Fed. Cir. 1989)
Alternative Limitations (MPEP 2173.05(h))Process Control Corp. v. HydReclaim Corp., 190 F.3d 1350, 1357, 52 USPQ2d 1029, 1033 (Fed. Cir. 1999)

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