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.
An affidavit or declaration under 37 CFR 1.131(a) serves to establish that the inventor or at least one joint inventor had possession of the subject matter of the rejected claim before the effective date of the reference or activity on which the rejection is based. The MPEP states:
‘The purpose of a 37 CFR 1.131(a) affidavit or declaration is to overcome a prior art rejection by proving invention of the claimed subject matter by the inventor or at least one joint inventor prior to the effective date of the reference or activity relied upon in the rejection.’
This process is commonly known as ‘swearing behind’ a reference and is used to demonstrate that the inventor’s work predates the cited prior art, thus potentially negating its use in a rejection.