This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.
USPC class and subclass definitions are detailed explanations of the subject matter covered by each class and subclass within the U.S. Patent Classification System (USPC). As stated in the MPEP, 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.
These definitions are essential for determining the proper classification of subject matter within the USPC.
The MPEP emphasizes the importance of these definitions: A study of the definitions is essential to determine the proper classification of subject matter within the U.S. Patent Classification System (USPC).