How do Definition Notes in USPC help in conducting prior art 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.

Definition Notes in the United States Patent Classification (USPC) system play a crucial role in conducting effective prior art searches. According to MPEP 902.02(a), these notes help in several ways:

1. Clarifying scope: Supplementary notes “supplement definitions by explaining terms or giving examples,” helping searchers understand the exact scope of a classification.
2. Guiding to related areas: ‘See or Search’ notes point to “related disclosures located in other classes or subclasses,” expanding the search scope.
3. Decision-making: Each ‘See or Search’ note “helps a user reach a decision either to include or exclude an area containing relevant subject matter.”
4. Suggesting additional fields: Search notes “suggest additional fields of search,” encouraging a more comprehensive search.

By utilizing these notes, patent examiners and attorneys can conduct more thorough and accurate prior art searches, potentially uncovering relevant references that might otherwise be overlooked.