How should parent subclass Search Notes be considered in USPC searches?

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.

When conducting searches using the United States Patent Classification (USPC) system, it’s crucial to consider the Search Notes of parent subclasses. The MPEP 902.02(a) provides important guidance on this matter:

“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.”

This means that when searching in a specific subclass, you should:

• Review the Search Notes of the immediate subclass
• Look at the Search Notes of all parent subclasses
• Consider how the parent subclass notes might apply to the more specific subclass you’re searching

This approach ensures a more comprehensive search and helps prevent overlooking relevant prior art that might be classified in related areas.