What proof must be included with the request for reinstatement?

In the context of a request for reinstatement of a trademark application or registration, it is crucial to provide proof of USPTO error. This is because if the trademark was canceled or allowed to expire due to an error made by the USPTO, demonstrating this error is necessary to warrant the reinstatement. The burden of proof lies in showing that the circumstances leading to the cancellation or expiration were not due to the applicant’s actions or omissions, but rather a mistake made by the Office.

The other options, while relevant to different scenarios in trademark handling, do not specifically pertain to the requirements for reinstatement. For instance, proof of prior registration validity may be necessary in other contexts, but not specifically for reinstatement requests. User compliance with regulations is also an important consideration, but it does not directly address the need for proving an error on the part of the USPTO. Lastly, while proof of payment for the filing fee is typically part of any application process, the focus in reinstatement is predominantly on demonstrating that an error occurred at the USPTO.