What is the burden of proof for establishing distinctness in process and product claims?

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 burden of proof for establishing distinctness in process and product claims lies with the examiner. According to MPEP 806.05(f):

“Allegations of different processes or products need not be documented.”

This means that:

• The examiner must provide a logical reasoning for distinctness.
• The examiner is not required to provide documentary evidence.
• Hypothetical examples can be used to demonstrate distinctness.

However, the examples or reasoning provided by the examiner must be reasonable and based on the technology involved in the application. If the applicant challenges the examiner’s assertion of distinctness, they should provide evidence or arguments to refute the examiner’s reasoning.