Section A assumes you have a classification that you are looking for. For example, you may be looking at a patent and want to understand the nature of the classification schedule and definitions for classification symbols on the patent.

The Home page provides links to the Class Numbers list page and the Class Number plus Title pages. The List of Class Numbers page assumes you have knowledge of a particular class number and want to go to the top of the schedule or definition. The class numbers with titles listing shows the class titles for every class. This page is very useful for getting an understanding of the US Patent Classification system. Use browser Find (CTRL+F in Microsoft Windows browsers) to find a term on the Class Numbers with Titles page.

• Class Number links to top of Class Definition
• Subclass Number links to corresponding subclass defintion
• "P" icon searches for patents in the class/subclass in Patent on the Web
• "A" icon searches published applications in the class in Applications on the Web. Note: there are very few published applications at this time. Projection of the Number of Applications to be Published Per Week Under Eighteen-Month Publication. Therefore, applications are only looked for at the class level. In the future the "A" icon will be added to every subclass.

Excerpt of Classification Schedule for Class 482 EXERCISE DEVICES

2A & 2B. I am unfamiliar with Patent Classification. Where should I start?

Adapted from "The 7-Step Strategy for Conducting a Patent Search at a Patent and Trademark Depository Library (PTDL)"
a. Begin with the alphabetical subject Index to the U.S. Patent Classification system (Manual of Classification). Look for common terms describing the invention and its function, effect, end-product, structure, and use. Note class and subclass numbers. The class numbers in the Index to USPC on this web site link to the top of the corresponding classification schedule. The subclass number in the Index to USPC on this web site link to the subclass in the corresponding class schedule.

A Patent Classification is a code which provides a method for categorizing the invention. Classification are typically expressed as "482/1". The first number, 482, represents the class of invention. The number following the slash is the subclass of invention within the class. There are about 450 Classes of invention and about 150,000 subclasses of invention in the USPC.

Classes and subclasses have titles which provide a short description of the class or subclass. Classes and subclasses also have definitions which provide a more detailed explanation. Many Classes and subclasses have explicitly defined relationships to one another. Subclasses contain patents. In a sense, classes also contain patents but for classificaiton purposes patents are always classified at the subclass level. That isone or more classifications (i.e., class/subclass designations) are assigned to each granted patent and each published application.

A patent classification also represents a searchable collection of patents grouped together according to similarly claimed subject matter.

A classification is used both as a tool for finding patents (patentability searches), and for assisting in the assignment of patent applications to examiners for examination purposes. Classifications have definitions. Classifications have hierarchical relationships to one another.

The Index to USPC often referred to simply as "THE INDEX", is intended as an initial entry point for users unfamiliar with the USPC and is used by experienced searchers trying to locate an unfamiliar topic. It is a subject matter index like one finds at the back of a book.

The Index to the U.S. Patent Classification System is an alphabetic listing of technical and common terms. References to actual Classes and Subclasses of the USPC appear next to each term. Note, the Index should not be considered exhaustive. Patent Classifiers can update the index when they submit a Classificaiton Order.

Subject headings in the Index are not an alphabetical inversion of the Manual of Classification. They are a subjective determination of relevant terms, phrases, synonyms, acronyms, and occasionally even trademarks that have been selected over the years [during reclass activity] as the best identifying description of products, processes, and apparatus of patent disclosures. The Index contains product-related entries, whereas the Manual of Classification is descriptive or nonspecific. For example, the Index entry for phonograph record molding apparatus is reflected in the Manual of Classification as a "press forming apparatus having opposed press members." Some effort has been made to index current vocabulary usage when the classification system may contain technically general language; e.g., "water bed" or "air mattress" for the concept "fluid-containing mattress."

A Classification Schedule is the arrangement of subclasses for a class. The Schedule details the relationship between the Class and its subclasses, relationships between the subclasses, and relationships between the class and other classes and subclasses.

10. What is a subclass definition?

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