MPEP § 1876 — Notation of Errors and Informalities by the Examiner (Annotated Rules)

§1876 Notation of Errors and Informalities by the Examiner

USPTO MPEP version: BlueIron's Update: 2026-01-17

This page consolidates and annotates all enforceable requirements under MPEP § 1876, 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.

Notation of Errors and Informalities by the Examiner

This section addresses Notation of Errors and Informalities by the Examiner. Contains: 4 requirements, 3 permissions, and 2 other statements.

Key Rules

Topic

International Preliminary Examining Authority (IPEA)

4 rules
MPEP GuidanceRequiredAlways
[mpep-1876-8478ea8e1431ac92f75e0728]
International Preliminary Examining Authority Must Indelibly Mark Rectified Sheets
Note:
The International Preliminary Examining Authority must mark rectified sheets with the international application number, date received, and a clear indication that they are rectified under Rule 91.
(a) Where the International Preliminary Examining Authority authorizes a rectification of an obvious mistake under Rule 91, it shall:
  • (i) indelibly mark, in the upper right-hand corner of each replacement sheet, the international application number and the date on which that sheet was received;
  • (ii) indelibly mark, in the middle of the bottom margin of each replacement sheet, the words “RECTIFIED SHEET (RULE 91)” or their equivalent in the language of the demand as well as an indication of the International Preliminary Examining Authority as provided for in Section 107(b);
  • (iii) indelibly mark on the letter containing the rectification or accompanying any replacement sheet the date on which that letter was received;
  • (iv) keep in its files a copy of the letter containing the rectification or, when the rectification is contained in a replacement sheet, the replaced sheet, a copy of the letter accompanying the replacement sheet and a copy of the replacement sheet;
  • (v) annex to the copy of the international preliminary examination report which is transmitted to the International Bureau any replacement sheet and any letter as provided for under Rule 70.16;
  • (vi) annex to the copy of the international preliminary examination report which is transmitted to the applicant a copy of each replacement sheet and any letter as provided for under Rule 70.16.
Jump to MPEP SourceInternational Preliminary Examining Authority (IPEA)Competent Authority for RectificationObvious Mistakes
MPEP GuidancePermittedAlways
[mpep-1876-1a9da36bed82280b56795602]
Examiner Can Invite Applicant to Correct Obvious Errors Using Form PCT/IPEA/411
Note:
The examiner may ask the applicant to fix clear mistakes in the international application using a specific form.

Although the examiner is not responsible for discovering mistakes in the international application, if any mistakes come to the attention of the examiner, they may be noted and called to the applicant’s attention. The examiner may invite applicant to rectify obvious mistakes using Form PCT/IPEA/411. Mistakes that are not obvious may be called to applicant’s attention in Box VII of PCT/IPEA/408.

Jump to MPEP SourceInternational Preliminary Examining Authority (IPEA)Request Content and FormSignature Requirements
MPEP GuidancePermittedAlways
[mpep-1876-201bc222f1645694466872c2]
Non-Obvious Mistakes Noted in Box VII of PCT/IPEA/408
Note:
The examiner may note and call to the applicant's attention any non-obvious mistakes found during the international application examination process.

Although the examiner is not responsible for discovering mistakes in the international application, if any mistakes come to the attention of the examiner, they may be noted and called to the applicant’s attention. The examiner may invite applicant to rectify obvious mistakes using Form PCT/IPEA/411. Mistakes that are not obvious may be called to applicant’s attention in Box VII of PCT/IPEA/408.

Jump to MPEP SourceInternational Preliminary Examining Authority (IPEA)Request Content and FormSignature Requirements
MPEP GuidanceRequiredAlways
[mpep-1876-18755d3f29520ed9016cd6a8]
Examiners Must Sign PCT/IPEA Forms
Note:
Examiners with partial signatory authority must sign Form PCT/IPEA/408 and Form PCT/IPEA/411.

Form PCT/IPEA/408 and Form PCT/IPEA/411 must be signed by an examiner having at least partial signatory authority.

Jump to MPEP SourceInternational Preliminary Examining Authority (IPEA)Request Content and FormSignatory Authority Review
Topic

35 U.S.C. 103 – Obviousness

4 rules
MPEP GuidanceInformativeAlways
[mpep-1876-8faebcd02819e8ec93c16108]
Replacement Sheets and Letters Required for Obvious Mistakes
Note:
When the International Preliminary Examining Authority corrects an obvious mistake under Rule 91, it must include a copy of each replacement sheet and any related letter in the transmitted international preliminary examination report.

(a) Where the International Preliminary Examining Authority authorizes a rectification of an obvious mistake under Rule 91, it shall:

(vi) annex to the copy of the international preliminary examination report which is transmitted to the applicant a copy of each replacement sheet and any letter as provided for under Rule 70.16.

MPEP GuidanceRequiredAlways
[mpep-1876-2c3956130a3f5898dd714b59]
Rectified Sheet Not Considered for Report
Note:
When an obvious mistake is rectified but not considered by the International Preliminary Examining Authority, the words 'RECTIFIED SHEET (RULE 91) – NOT CONSIDERED FOR REPORT (Rule 66.4 bis)' must be marked.

(b) Where the rectification of an obvious mistake is not taken into account by the International Preliminary Examining Authority pursuant to Rule 66.4bis, and the Authority so indicates in the international preliminary examination report in accordance with Rule 70.2(e), it shall proceed as indicated under paragraph (a), provided that the words “RECTIFIED SHEET (RULE 91) – NOT CONSIDERED FOR REPORT (Rule 66.4 bis)” shall be used when marking in accordance with paragraph (a)(ii).

MPEP GuidanceRequiredAlways
[mpep-1876-96eab74cb9adbab067580a3d]
Rectification of Obvious Mistakes Must Be Forwarded to International Bureau
Note:
The International Preliminary Examining Authority must forward any replacement sheet and letter containing rectifications or accompanying replacement sheets to the International Bureau if an obvious mistake is not taken into account.

(c) Where the rectification of an obvious mistake is not taken into account by the International Preliminary Examining Authority pursuant to Rule 66.4bis, and the Authority is not able to so indicate in the international preliminary examination report in accordance with the second sentence of Rule 70.2(e), it shall proceed as indicated under paragraph (a)(i) to (iv) and forward any replacement sheet and any letter containing the rectification or accompanying any replacement sheet to the International Bureau. The International Bureau will promptly notify the elected Offices accordingly.

MPEP GuidanceInformativeAlways
[mpep-1876-213943ced173f7a5ff9ed890]
International Bureau Must Notify Elected Offices of Rectifications
Note:
The International Bureau is required to promptly inform the elected offices about any rectifications made due to obvious mistakes not addressed by the International Preliminary Examining Authority.

(c) Where the rectification of an obvious mistake is not taken into account by the International Preliminary Examining Authority pursuant to Rule 66.4bis, and the Authority is not able to so indicate in the international preliminary examination report in accordance with the second sentence of Rule 70.2(e), it shall proceed as indicated under paragraph (a)(i) to (iv) and forward any replacement sheet and any letter containing the rectification or accompanying any replacement sheet to the International Bureau. The International Bureau will promptly notify the elected Offices accordingly.

Topic

Signature Requirements

1 rules
MPEP GuidancePermittedAlways
[mpep-1876-ff10da5a790555b2848a09bf]
Mistakes Noted and Called to Applicant’s Attention by Examiner
Note:
If mistakes in the international application come to the examiner's attention, they must be noted and brought to the applicant’s attention. Obvious mistakes can be rectified using Form PCT/IPEA/411, while non-obvious mistakes are addressed through Box VII of PCT/IPEA/408.

Although the examiner is not responsible for discovering mistakes in the international application, if any mistakes come to the attention of the examiner, they may be noted and called to the applicant’s attention. The examiner may invite applicant to rectify obvious mistakes using Form PCT/IPEA/411. Mistakes that are not obvious may be called to applicant’s attention in Box VII of PCT/IPEA/408.

Jump to MPEP SourceSignature RequirementsPatent Cooperation TreatyInternational Preliminary Examining Authority (IPEA)

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: 2026-01-17