MPEP § 1823 — The Description (Annotated Rules)

§1823 The Description

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

This page consolidates and annotates all enforceable requirements under MPEP § 1823, 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.

The Description

This section addresses The Description. Primary authority: 37 CFR 1.435. Contains: 4 requirements, 3 guidance statements, 3 permissions, and 2 other statements.

Key Rules

Topic

PCT Description Requirements

6 rules
StatutoryRequiredAlways
[mpep-1823-96a56c8c73b075c407dafb1e]
Indications for Deposited Biological Material on Separate Sheet
Note:
Indications regarding deposited biological material not in the description may be provided on a separate sheet, preferably Form PCT/RO/134 and attached to the request at filing.

(a) To the extent that any indication with respect to deposited biological material is not contained in the description, it may be given on a separate sheet. Where any such indication is so given, it shall preferably be on Form PCT/RO/134 and, if furnished at the time of filing, the said Form shall, subject to paragraph (b), preferably be attached to the request and referred to in the check list referred to in Rule 3.3(a)(ii).

Jump to MPEP SourcePCT Description RequirementsRequest Content and FormPCT Description and Claims
StatutoryRequiredAlways
[mpep-1823-c2f6c11a433d08c119c9fc34]
Description Must Meet PCT Rules and Administrative Instructions
Note:
The application description must comply with the requirements set forth in PCT Rules 5, 9, 10, and 11, as well as sections 204 and 208 of the Administrative Instructions.

(a) The application must meet the requirements as to the content and form of the description set forth in PCT Rules 5, 9, 10, and 11 and sections 204 and 208 of the Administrative Instructions.

Jump to MPEP Source · 37 CFR 1.435PCT Description RequirementsRequest Content and FormPCT Description and Claims
StatutoryRequiredAlways
[mpep-1823-f4c6379179436a454ee2438b]
Description Must Be Clear and Complete for Skilled Person
Note:
The description must fully disclose the invention so a skilled person can carry it out, starting with the invention’s title.

The description must disclose the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art. It must start with the title of the invention as appearing in Box No. I of the request. PCT Rule 5 contains detailed requirements as to the manner and order of the description, which, generally, should be in six parts. Those parts should have the following headings: “Technical Field,” “Background Art,” “Disclosure of Invention,” “Brief Description of Drawings,” “Best Mode for Carrying Out the Invention” or, where appropriate, “Mode(s) for Carrying Out the Invention,” and “Industrial Applicability,” where applicable.

Jump to MPEP Source · 37 CFR 1.435PCT Description RequirementsRequest Content and FormPCT Description and Claims
StatutoryRecommendedAlways
[mpep-1823-ac2d92d2290065401b3d0f50]
PCT Description Must Follow Six Part Structure
Note:
The description must include six specific parts: Technical Field, Background Art, Disclosure of Invention, Brief Description of Drawings, Best Mode for Carrying Out the Invention, and Industrial Applicability if applicable.

The description must disclose the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art. It must start with the title of the invention as appearing in Box No. I of the request. PCT Rule 5 contains detailed requirements as to the manner and order of the description, which, generally, should be in six parts. Those parts should have the following headings: “Technical Field,” “Background Art,” “Disclosure of Invention,” “Brief Description of Drawings,” “Best Mode for Carrying Out the Invention” or, where appropriate, “Mode(s) for Carrying Out the Invention,” and “Industrial Applicability,” where applicable.

Jump to MPEP Source · 37 CFR 1.435PCT Description RequirementsPCT Description and ClaimsPatent Cooperation Treaty
StatutoryPermittedAlways
[mpep-1823-b853f2ab9bb4da500353b9a1]
Sequence Listing Allowed for PCT Descriptions After July 1, 2022
Note:
For international applications filed on or after July 1, 2022, the description may include a sequence listing as part of the requirements.

For international applications having an international filing date on or after July 1, 2022, the description may include a sequence listing. Where applicable, the sequence listing should be included as a separate part of the description complying with the standard provided for in the PCT Administrative Instructions.

Jump to MPEP Source · 37 CFR 1.435PCT Description RequirementsInternational Filing DatePCT Description and Claims
StatutoryRecommendedAlways
[mpep-1823-caa12ce442d2790b14900661]
Sequence Listing Must Be Included Separately
Note:
For international applications filed on or after July 1, 2022, a sequence listing must be included as a separate part of the description and comply with PCT Administrative Instructions.

For international applications having an international filing date on or after July 1, 2022, the description may include a sequence listing. Where applicable, the sequence listing should be included as a separate part of the description complying with the standard provided for in the PCT Administrative Instructions.

Jump to MPEP Source · 37 CFR 1.435PCT Description RequirementsPCT Description and ClaimsSequence Listing Format
Topic

Sequence Listing Format

2 rules
StatutoryRecommendedAlways
[mpep-1823-148391f7e9d39a700b6ac34a]
Sequence Listings Required for Pre-July 2022 Filing
Note:
For international applications filed before July 1, 2022, include sequence listings and free text descriptions where applicable.

For international applications having an international filing date before July 1, 2022, headings for “Sequence Listing” and “Sequence Listing Free Text” should also be used where applicable. See Section 204 of the Administrative Instructions (in effect before July 1, 2022), which may be found at: www.wipo.int/wipolex/en/text/584509.

Jump to MPEP Source · 37 CFR 1.435Sequence Listing FormatSequence Listing Requirements
StatutoryPermittedAlways
[mpep-1823-d82a69f08800105014f93595]
Sequence Listing Required for International Applications
Note:
For international applications with an international filing date before July 1, 2022, a sequence listing and its free text must be included where applicable.

For international applications having an international filing date before July 1, 2022, headings for “Sequence Listing” and “Sequence Listing Free Text” should also be used where applicable. See Section 204 of the Administrative Instructions (in effect before July 1, 2022), which may be found at: www.wipo.int/wipolex/en/text/584509.

Jump to MPEP Source · 37 CFR 1.435Sequence Listing FormatSequence Listing Requirements
Topic

Sequence Listing Content

2 rules
StatutoryInformativeAlways
[mpep-1823-0df3bcf131ed825856a002cb]
Information on Filing Sequence Listings Required
Note:
Provides guidance on how to file nucleotide and amino acid sequence listings as required.

For more information on filing nucleotide and/or amino acid sequence listings, see MPEP § 1823.02. For information on reference to deposited biological material, see MPEP § 1823.01.

Jump to MPEP Source · 37 CFR 1.435Sequence Listing ContentSequence Listing FormatSequence Listing Requirements
StatutoryInformativeAlways
[mpep-1823-0e1c682b4d69c4997990506f]
Requirement for Deposited Biological Material Reference
Note:
The rule requires that information on deposited biological material be referenced, as detailed in MPEP § 1823.01.

For more information on filing nucleotide and/or amino acid sequence listings, see MPEP § 1823.02. For information on reference to deposited biological material, see MPEP § 1823.01.

Jump to MPEP Source · 37 CFR 1.435Sequence Listing ContentSequence Listing FormatSequence Listing Requirements
Topic

Maintenance Fee Payment

2 rules
StatutoryRequiredAlways
[mpep-1823-074e0c8e4b9001a71d96f54f]
Description Must Align with U.S. National Practice
Note:
The description must align with the national practice in the United States to ensure it can be carried out by a skilled person and avoid potential amendments during the national phase.

The details required for the disclosure of the invention so that it can be carried out by a person skilled in the art depend on the practice of the national Offices. It is therefore recommended that due account be taken of national practice in the United States of America when the description is drafted. The need to amend the description during the national phase may thus be avoided.

Jump to MPEP Source · 37 CFR 1.435Maintenance Fee Payment
StatutoryPermittedAlways
[mpep-1823-f0911b8befadfdbf317f7a91]
Description Must Satisfy National Practice
Note:
The description must be drafted to satisfy national practice in the United States to avoid amendments during the national phase.

The details required for the disclosure of the invention so that it can be carried out by a person skilled in the art depend on the practice of the national Offices. It is therefore recommended that due account be taken of national practice in the United States of America when the description is drafted. The need to amend the description during the national phase may thus be avoided.

Jump to MPEP Source · 37 CFR 1.435Maintenance Fee Payment
Topic

Statutory Authority for Examination

1 rules
StatutoryRequiredAlways
[mpep-1823-889a5c3413a3a053bf37a776]
Description Must Fully Disclose Invention
Note:
The description must state the title, technical field, background art, and disclose the invention in detail, including best mode and advantageous effects.
(a) The description shall first state the title of the invention as appearing in the request and shall:
  • (i) specify the technical field to which the invention relates;
  • (ii) indicate the background art which, as far as known to the applicant, can be regarded as useful for the understanding, searching and examination of the invention, and, preferably, cite the documents reflecting such art;
  • (iii) disclose the invention, as claimed, in such terms that the technical problem (even if not expressly stated as such) and its solution can be understood, and state the advantageous effects, if any, of the invention with reference to the background art;
  • (iv) briefly describe the figures in the drawings, if any;
  • (v) set forth at least the best mode contemplated by the applicant for carrying out the invention claimed; this shall be done in terms of examples, where appropriate, and with reference to the drawings, if any; where the national law of the designated State does not require the description of the best mode but is satisfied with the description of any mode (whether it is the best contemplated or not), failure to describe the best mode contemplated shall have no effect in that State;
  • (vi) indicate explicitly, when it is not obvious from the description or nature of the invention, the way in which the invention is capable of exploitation in industry and the way in which it can be made and used, or, if it can only be used, the way in which it can be used; the term “industry” is to be understood in its broadest sense as in the Paris Convention for the Protection of Industrial Property.
Jump to MPEP SourceStatutory Authority for ExaminationExamination ProceduresObviousness
Topic

PCT Abstract Requirements

1 rules
StatutoryRecommendedAlways
[mpep-1823-92ad0f90cfccb7d5b233b2aa]
Description Must Include Six Parts
Note:
The description must include six parts: Technical Field, Background Art, Disclosure of Invention, Brief Description of Drawings, Best Mode for Carrying Out the Invention, and Industrial Applicability.

The description must disclose the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art. It must start with the title of the invention as appearing in Box No. I of the request. PCT Rule 5 contains detailed requirements as to the manner and order of the description, which, generally, should be in six parts. Those parts should have the following headings: “Technical Field,” “Background Art,” “Disclosure of Invention,” “Brief Description of Drawings,” “Best Mode for Carrying Out the Invention” or, where appropriate, “Mode(s) for Carrying Out the Invention,” and “Industrial Applicability,” where applicable.

Jump to MPEP Source · 37 CFR 1.435PCT Abstract RequirementsPCT Description RequirementsPCT Description and Claims

Citations

Primary topicCitation
Sequence Listing ContentMPEP § 1823.01
Sequence Listing ContentMPEP § 1823.02
PCT Description Requirements
Sequence Listing Format
Section 204 of the Administrative Instructions
PCT Abstract Requirements
PCT Description Requirements
PCT Rule 5

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