What criteria are used to determine if information should be expunged?

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 primary criterion for determining if information should be expunged is whether it is material to patentability. The MPEP defines materiality in this context:

‘Materiality’ is defined as any information which the examiner considers as being important to a determination of patentability of the claims.

Additionally, the petition must establish one of the following:

• The information contains trade secret material, proprietary material, and/or material subject to a protective order that has not been made public.
• The information was unintentionally submitted, and failure to obtain its return would cause irreparable harm to the party who submitted it or to the party in interest on whose behalf it was submitted, and the information has not otherwise been made public.

The petitioner must also commit to retaining the expunged material for the life of any patent issued on the application.