902 Search Tools and Classification Information [R-07.2022]
There are multiple classification systems used throughout the international patent system. These include the Cooperative Patent Classification System (CPC), U.S. Patent Classification System (USPC), the International Patent Classification System (IPC), and the Locarno International Classification (Locarno). As of January 1, 2013, the USPTO moved from using the USPC system to the CPC system for classification of pending utility applications. All U.S. utility patents and U.S. utility Patent Application Publications published after December 31, 2014 no longer receive classifications within the USPC. The USPC is now a static searchable database for all utility areas. Only U.S. design and plant patents and U.S. plant patent application publications continue to receive classification within the USPC.
902.01 Classification Manual for the U.S. Patent Classification System [R-07.2022]
The U.S. Patent Classification System is a static system and is no longer updated for the utility classes. The USPC remains active for the plant and design classes.
The United States Patent Office (the Office) maintains an electronic classification manual for the U.S. Patent Classification System (USPC). The complete manual is available to USPTO personnel from the Classification Home Page (https://ptoweb.uspto.gov/patents/classification-resources/), which is accessible from the desktop via the Patent Examiner’s Toolkit. The Manual of Classification is also available via the Internet at www.uspto.gov/SearchClassification, however The Manual of Classification will no longer be updated after December 31, 2014. See MPEP § 905et seq. for information regarding the Cooperative Patent Classification System.
Each class has a title descriptive of its subject matter, is identified by a class number, and is subdivided into a number of subclasses. Each subclass also has a descriptive title, is identified by a subclass number, and the subclass number is an integral number that may contain a decimal portion and/or alpha characters. A complete identification of a subclass requires both the class and subclass number and any alpha or decimal designations; e.g., 417/161.1A identifies Class 417, Subclass 161.1A.
The Manual of Classification for the USPC system contains ordered arrangements of all class and subclass titles, the ordered arrangements are referred to as class schedules. The class and subclass titles are brief and are as suggestive as possible of the subject matter included. Therefore, it is best not to depend exclusively upon titles to explain the subject matter encompassed by a class and subclass but to refer also to the respective definitions and notes. If a search is to be expeditious, accurate, and complete, the Manual of Classification should be used only as a key to the class or subclass definition and appended notes.
The Manual of Classification for the USPC system has the following parts:
- (A) Overview of the U.S. Patent Classification System.
- (B) Classes Within the U.S. Classification System Arranged by Related Subject Matter: A hierarchical arrangement of class titles organized into four main groups by related subject matter. Only as a last resort should this hierarchical arrangement of class titles, be used to determine document placement, i.e., when none of the other classification criteria, such as comprehensiveness, etc., allow placement. This part also includes an exact hierarchical listing of the synthetic resin and chemical compound classes.
- (C) Classes Arranged by Art Unit (CAAU): A list, in numerical order, by art unit indicating the classification(s) assigned to each.
- (D) Classes Arranged Numerically With Art Unit and Search Room Locations (CAN): A list of classifications in numerical order by class number giving the class title, the art unit to which the art is assigned, and the examiner search room in which the art can be found.
- (E) Classes Arranged in Alphabetical Order (CAA): A list of classes in alphabetical order by class title with associated class numbers.
- (F) Class Schedules: Class schedules for utility patent, design, and plant classes.
902.01(a) Index to the U.S. Patent Classification System [R-08.2012]
The Index to the U.S. Patent Classification System (USPC) is an alphabetic listing of technical and common terms referring to specific classes and subclasses of the USPC. The index is used as an initial entry into the system and should not be considered exhaustive. All appropriate class schedules should be scanned for specifically related subclasses, and the definitions and associated notes of the pertinent classifications should also be reviewed, even when the citation found in the Index appears to be restricted to a specific subject matter area.
The Index is regularly updated. Suggestions or changes to the Index are encouraged and should be directed to the Technology Center (TC) classification contact in the TCs.
The Index is available online to USPTO personnel from the Classification Home Page – USPC Index. The Classification Home Page (http://ptoweb:8081/) is accessible from the desktop via the Patent Examiner’s Toolkit.
902.02 Class and Subclass Definitions in USPC [R-01.2024]
All of the classes within USPC have definitions.
Definitions state the subject matter of the classes and subclasses in much more detail than it is possible to state in the brief class and subclass titles. A study of the definitions is essential to determine the proper classification of subject matter within the U.S. Patent Classification System (USPC).
All classes and subclasses (class definitions) in the USPC are available online to USPTO personnel from the Classification Home Page under the heading Search Classification Data. The Classification Home Page (https://ptoweb.uspto.gov/patents/ classification-resources/) is accessible from the desktop via the Patent Examiner’s Toolkit.
It should be noted that classification orders frequently affect existing definitions. Personal sets of definitions used by examiners should be periodically revised to reflect these changes. Classification Orders are available online to USPTO personnel from the Classification Home Page under the heading Orders. The Classification Home Page is accessible from the desktop via the Patent Examiner’s Toolkit.
902.02(a) Definition Notes in USPC [R-07.2015]
Many of the definitions have accompanying notes. These notes are of two types: (A) notes that supplement definitions by explaining terms or giving examples, and (B) notes referring to related disclosures located in other classes or subclasses.
The latter notes are termed “See or Search” notes and are helpful in explaining the limits of a class or subclass. They generally state the relationship to, and difference from, other identified subject matter collections. Each “See or Search” note helps a user reach a decision either to include or exclude an area containing relevant subject matter.
Search notes are not exhaustive and do not limit the search but suggest additional fields of search. Additionally, since a search note that applies to a particular subclass is rarely repeated for subclasses indented thereunder, it is advisable to review the search notes of all parent subclasses.
902.02(b) [Reserved]
902.03 Classification Information [R-07.2022]
U.S. utility patents and U.S. utility patent application publications published after December 31, 2014, do not receive a designated U.S. patent classification. U.S. design and plant patents and U.S. plant patent application publications receive a designated U.S. patent classification. Current classification information for U.S. patents is available from the sources indicated below.
902.03(a) Patent Classification Home Page on the Internet [R-01.2024]
The Office of Patent Classification Home Page address on the internet is www.uspto.gov/Classification. The site is the clearinghouse for classification information. The site includes the following: (A) links to the Cooperative Patent Classification (CPC) system; (B) United States Classification (USPC) system resources including class definitions, the USPC index, and the Handbook for Classification; and (C) additional classification resources related to international classification.
902.03(b) Patent Classification Home Page on the USPTO Intranet [R-01.2024]
The address for the Patent Classification Home Page on the USPTO intranet is https://ptoweb.uspto.gov/ patents/classification-resources/. The Classification Home Page is also accessible from the desktop via the Patent Examiner’s Toolkit. The site is the clearinghouse for classification information by the U.S. Patent and Trademark Office (USPTO). Examiners and the public are provided with access to identical information for the Index, schedules, and definitions.
The Intranet Classification Home Page site also includes links to international information such as CPC schedules, IPC Concordance, IPC Schedules, IPC Catchword Index, WIPO Handbook on Industrial Property Information and Documentation, and to national (U.S.) information such as Overview of the Classification System, Classification Guides and Bulletins, and the Patent Classification Search Page.
902.03(c) [Reserved]
902.03(d) [Reserved]
902.03(e) Automated Search Tools: PE2E SEARCH [R-01.2024]
The automated search tool on examiners’ desktop computers is the Patents End-to-End (PE2E) Search tool (SEARCH). PE2E SEARCH provides examiners with access to the: (A) full text of U.S. published applications since 2001; (B) full text of U.S. patents granted since 1970; and (C) optically scanned full text of U.S. patents granted 1920-1970. Additionally, PE2E SEARCH provides current classification information and images for all U.S. published applications and patents. Images are available for foreign patent documents, and English language abstracts are available for many foreign patent documents published since 1978 using PE2E SEARCH. Specific instructions for gaining access to the various documents can be found on the PE2E SEARCH webpage on the intranet, available on examiners’ desktop computers.
The Patent Public Search tool (PPUBS) is available at www.uspto.gov/PatentPublicSearch.
