Patent Classification Definitions

About Patents
What is a Patent?| Basic Patent Facts| Patent Blogs|

Patent Search
Patent Search Process| U.S. Patent Databases| How to Search by Patent Number| U.S. Manual of Classification| Classification Definitions| U.S. Official Gazette| Prior Art|

Types of U.S. Patents
Utility Patents| Design Patents| Plant Patents|Utility Patent Applications| Design Patent Applications| Plant Patent Applications|

Patent Search Help
Patent Search Tutorials| Patent Books| How to Cite A Patent|

Patent Attorneys
How to Find a Patent Attorney|

Patent Agents
Patent Agents|

Patent Law
U.S. Code| CFR| Patent Law Organizations| Patent Journals|

USPTO
About the USPTO|
PTDLP (Patent and Trademark Depository Library Program)
About PTDLP| PTDL Library Directory| PTDLP Partnership Libraries|

Inventors
Help for Inventors| Inventor Associations| African-American Inventors|

Patent Information for Collectors
U.S. Patent Issue Years/Numbers| Patent Sites for Collectors| Tool Patents for Collectors|

About this Site
Sitemap|

U.S. Patent Classification Definitions

Patent Classification Definitions explain the scope of each patent class, what is included, and what is excluded. Patent subclasses are also defined.

Patent Classification Definitions also provide referrals to related classes and subclasses.
The use of Patent Classification Definitions is essential in selecting the correct class and subclass by which to search for relevant patents.

Sample Search Box to Obtain Classification Definitions

Sample Patent Classification Definition