What is the difference between supplementary notes and ‘See or Search’ notes in USPC definitions?

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.

The United States Patent Classification (USPC) system includes two types of Definition Notes, as explained in MPEP 902.02(a):

1. Supplementary notes: These “supplement definitions by explaining terms or giving examples.” They provide additional context and clarification for the class or subclass definition.
2. ‘See or Search’ notes: These refer to “related disclosures located in other classes or subclasses.” They help users understand the relationships between different classifications and guide them in expanding their search to related areas.

The key difference is that supplementary notes focus on explaining the current classification, while ‘See or Search’ notes direct users to other relevant classifications. Both types of notes are crucial for understanding the scope of a classification and conducting thorough prior art searches.