What evidence can be used to show possession of a claimed invention for priority purposes?

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 MPEP 2304.02(c) provides guidance on the types of evidence that can be used to show possession of a claimed invention for priority purposes:

• Written description: A detailed explanation of how the earlier application supports each claim element.
• Charts: Visual representations showing the correlation between claim elements and the earlier application’s disclosure.
• Additional evidence: This may include experimental data, drawings, or other documentation that demonstrates possession of the invention at the time of the earlier filing.

The MPEP states:

“The party seeking benefit may be required to provide a chart showing the written description for each claim in dispute, and/or an explanation of additional evidence showing possession of the claimed invention.”

It’s important to note that the specific evidence required may vary depending on the complexity of the invention and the nature of the priority claim.