What is the Classification Challenge Procedure in CPC?

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 Classification Challenge Procedure in CPC is a process where patent examiners can challenge the designated CPC (Cooperative Patent Classification) symbols on a nonprovisional utility patent application if they believe the classifications are incorrect. According to MPEP 909.01(d):

“When, in the opinion of the assigned examiner, the C* designated CPC symbol(s) on a nonprovisional utility patent application are incorrect, they must initiate a C* challenge through the Classification Allocation Tool (CAT) and complete the C* challenge form indicating any and all challenges to any C* designations including suggested additions of C* designations.”

This procedure ensures that patent applications are properly classified, which is crucial for efficient searching and examination.