MPEP § 2171 — Two Separate Requirements for Claims Under 35 U.S.C. 112(b) or Pre-AIA 35 U.S.C. 112, Second Paragraph (Annotated Rules)

§2171 Two Separate Requirements for Claims Under 35 U.S.C. 112(b) or Pre-AIA 35 U.S.C. 112, Second Paragraph

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

This page consolidates and annotates all enforceable requirements under MPEP § 2171, 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.

Two Separate Requirements for Claims Under 35 U.S.C. 112(b) or Pre-AIA 35 U.S.C. 112, Second Paragraph

This section addresses Two Separate Requirements for Claims Under 35 U.S.C. 112(b) or Pre-AIA 35 U.S.C. 112, Second Paragraph. Primary authority: 35 U.S.C. 112(b), 35 U.S.C. 112, and 37 CFR 1.41(a). Contains: 1 requirement, 2 guidance statements, and 4 other statements.

Key Rules

Topic

Assignee as Applicant Signature

2 rules
StatutoryInformativeAlways
[mpep-2171-66ec5886f079824160e3174a]
Specification Must Describe Invention Subjectively
Note:
The specification must describe the inventor's or joint inventors' conception of their invention, reflecting a subjective perspective.

The first requirement is a subjective one because it is dependent on what the inventor or a joint inventor for a patent regards as his or her invention. Note that although pre-AIA 35 U.S.C. 112, second paragraph, uses the phrase “which applicant regards as his invention,” pre-AIA 37 CFR 1.41(a) provides that a patent is applied for in the name or names of the actual inventor or inventors.

Jump to MPEP Source · 37 CFR 1.41(a)Assignee as Applicant SignatureApplicant and Assignee Filing Under AIAAIA vs Pre-AIA Practice
StatutoryInformativeAlways
[mpep-2171-076a41963e22aadc79f9c0c5]
Patent Applied for Inventors Only
Note:
A patent application must be filed in the name of the actual inventor, as per pre-AIA 37 CFR 1.41(a).

The first requirement is a subjective one because it is dependent on what the inventor or a joint inventor for a patent regards as his or her invention. Note that although pre-AIA 35 U.S.C. 112, second paragraph, uses the phrase “which applicant regards as his invention,” pre-AIA 37 CFR 1.41(a) provides that a patent is applied for in the name or names of the actual inventor or inventors.

Jump to MPEP Source · 37 CFR 1.41(a)Assignee as Applicant SignatureApplicant and Assignee Filing Under AIAAIA vs Pre-AIA Practice
Topic

Statutory Authority for Examination

2 rules
StatutoryInformativeAlways
[mpep-2171-e45cc4ea9d80c4441fc5f83a]
Precision Requirement for Claims
Note:
The claims must be precise, clear, correct, and unambiguous to remove uncertainties in their scope during the examination process.

Although an essential purpose of the examination process is to determine whether or not the claims define an invention that is both novel and nonobvious over the prior art, another essential purpose of patent examination is to determine whether or not the claims are precise, clear, correct, and unambiguous. The uncertainties of claim scope should be removed, as much as possible, during the examination process.

Jump to MPEP SourceStatutory Authority for ExaminationExamination Procedures
StatutoryRecommendedAlways
[mpep-2171-22785878f11efcb4646f5b54]
Claims Must Be Precise and Unambiguous During Examination
Note:
During the examination process, uncertainties in claim scope must be resolved to ensure claims are precise, clear, correct, and unambiguous.

Although an essential purpose of the examination process is to determine whether or not the claims define an invention that is both novel and nonobvious over the prior art, another essential purpose of patent examination is to determine whether or not the claims are precise, clear, correct, and unambiguous. The uncertainties of claim scope should be removed, as much as possible, during the examination process.

Jump to MPEP SourceStatutory Authority for ExaminationExamination ProceduresClaim Scope and Breadth
Topic

Claims

2 rules
StatutoryInformativeAlways
[mpep-2171-eeb57425c66164cb9ea33ce2]
Claims Must Particularly Point Out Invention
Note:
The claims must distinctly and particularly describe the invention as the inventor regards it, otherwise they will be rejected under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph.

The inquiry during examination is patentability of the invention as the inventor or a joint inventor regards it. If the claims do not particularly point out and distinctly claim that which the inventor or a joint inventor regards as his or her invention, the appropriate action by the examiner is to reject the claims under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph. In re Zletz, 893 F.2d 319, 13 USPQ2d 1320 (Fed. Cir. 1989). If a rejection is based on 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph, the examiner should further explain whether the rejection is based on indefiniteness or on the failure to claim what the inventor or a joint invention regards as the invention. Ex parte Ionescu, 222 USPQ 537, 539 (Bd. Pat. App. & Inter. 1984).

Jump to MPEP SourceAIA vs Pre-AIA PracticeDisclosure Requirements
StatutoryRecommendedAlways
[mpep-2171-d8bd0180cefb5ccdc048d7f8]
Requirement for Clarifying Indefiniteness or Invention Scope in 112(b) Rejections
Note:
The examiner must specify if a 112(b) rejection is due to indefiniteness or failure to claim the inventor's invention.

The inquiry during examination is patentability of the invention as the inventor or a joint inventor regards it. If the claims do not particularly point out and distinctly claim that which the inventor or a joint inventor regards as his or her invention, the appropriate action by the examiner is to reject the claims under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph. In re Zletz, 893 F.2d 319, 13 USPQ2d 1320 (Fed. Cir. 1989). If a rejection is based on 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph, the examiner should further explain whether the rejection is based on indefiniteness or on the failure to claim what the inventor or a joint invention regards as the invention. Ex parte Ionescu, 222 USPQ 537, 539 (Bd. Pat. App. & Inter. 1984).

Jump to MPEP SourceAIA vs Pre-AIA PracticeDisclosure Requirements
Topic

35 U.S.C. 112 – Disclosure Requirements

1 rules
StatutoryRequiredAlways
[mpep-2171-61ae553a3b5eae16eb05c497]
Claims Must Particularly Point Out Invention
Note:
The claims must clearly define the boundaries of the invention as perceived by the inventor, ensuring that the scope of protection is distinctly defined.
Two separate requirements are set forth in 35 U.S.C. 112(b) and pre-AIA 35 U.S.C. 112, second paragraph, namely that:
  • (A) the claims must set forth the subject matter that the inventor or a joint inventor regards as the invention; and
  • (B) the claims must particularly point out and distinctly define the metes and bounds of the subject matter to be protected by the patent grant.
Jump to MPEP SourceDisclosure RequirementsAlternative Limitations (MPEP 2173.05(h))Lack of Antecedent Basis (MPEP 2173.05(e))
Topic

Lack of Antecedent Basis (MPEP 2173.05(e))

1 rules
StatutoryRequiredAlways
[mpep-2171-e6ef68bfa7c92113badf5d2f]
Claims Must Define Subject Matter Clearly
Note:
The claims must clearly and distinctly define the boundaries of the invention to be protected by the patent grant.

Two separate requirements are set forth in 35 U.S.C. 112(b) and pre-AIA 35 U.S.C. 112, second paragraph, namely that:

(B) the claims must particularly point out and distinctly define the metes and bounds of the subject matter to be protected by the patent grant.

Jump to MPEP SourceLack of Antecedent Basis (MPEP 2173.05(e))Patent Grant and Document Format35 U.S.C. 112(b) – Definiteness (MPEP 2171-2173)
Topic

Patent Application Content

1 rules
StatutoryInformativeAlways
[mpep-2171-498331ae53c7e037d0847430]
Claims Must Specifically Describe Invention as Regarded by Inventor
Note:
The claims must distinctly and specifically claim the invention as perceived by the inventor, otherwise they may be rejected under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph.

The inquiry during examination is patentability of the invention as the inventor or a joint inventor regards it. If the claims do not particularly point out and distinctly claim that which the inventor or a joint inventor regards as his or her invention, the appropriate action by the examiner is to reject the claims under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph. In re Zletz, 893 F.2d 319, 13 USPQ2d 1320 (Fed. Cir. 1989). If a rejection is based on 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph, the examiner should further explain whether the rejection is based on indefiniteness or on the failure to claim what the inventor or a joint invention regards as the invention. Ex parte Ionescu, 222 USPQ 537, 539 (Bd. Pat. App. & Inter. 1984).

Jump to MPEP SourcePatent Application ContentAIA vs Pre-AIA Practice

Citations

Primary topicCitation
35 U.S.C. 112 – Disclosure Requirements
Assignee as Applicant Signature
Claims
Lack of Antecedent Basis (MPEP 2173.05(e))
Patent Application Content
35 U.S.C. § 112
35 U.S.C. 112 – Disclosure Requirements
Claims
Lack of Antecedent Basis (MPEP 2173.05(e))
Patent Application Content
35 U.S.C. § 112(b)
Assignee as Applicant Signature37 CFR § 1.41(a)
Claims
Patent Application Content
In re Zletz, 893 F.2d 319, 13 USPQ2d 1320 (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