The PTO is held to MPEP.
USPTO n.d. [The United States Patent and Trademark Office, the federal agency for granting U.S. patents and registering trademarks; n.d.; The United States Patent and Trademark Office; "Using the Manual of Patent Examining Procedure"; https://www.uspto.gov/patents/laws/manual-patent-examining-procedure#:~:text=The%20Manual%20of%20Patent%20Examining%20Procedure%20or%20MPEP%20is%20published,patent%20applications%20before%20the%20USPTO] shiwen
The Manual of Patent Examining Procedure or MPEP is published to provide U.S. Patent and Trademark Office (USPTO) patent examiners, applicants, attorneys, agents, and representatives of applicants with a reference work on the practices and procedures relative to the prosecution of patent applications before the USPTO. It contains instructions to examiners, as well as other material in the nature of information and interpretation, and outlines the current procedures which the examiners are required or authorized to follow in appropriate cases in the normal examination of a patent application.