What is a “cross-reference art collection” in patent searching?

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.

A “cross-reference art collection” in patent searching refers to a grouping of patent documents that are relevant to a particular subject matter but do not fit neatly into a single classification. The MPEP 904.02(a) states:

“Cross-reference art collections, if any, associated with the class or subclass are also included in the search (MPEP § 903.07).”

These collections allow examiners to find relevant prior art that may be classified in multiple areas, enhancing the thoroughness of the search process. When conducting a classified search, it’s important to consider these cross-reference collections to ensure a comprehensive review of potential prior art.