What are examples of universal facts that can be shown by non-prior art references?

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.

Non-prior art references can be used to show universal facts in patent examination. The MPEP 2124 provides several examples of such universal facts:

• Characteristics and properties of a material
• Scientific truisms
• Whether undue experimentation would have been required at the filing date
• Whether a parameter was critical or not
• The accuracy of statements in the specification
• Whether the invention was inoperative or lacked utility
• Whether a claim was indefinite
• Known characteristics of prior art products

These examples illustrate that non-prior art references can be used to establish facts that were true at the time of filing, even if the reference itself was published later. This allows for a more comprehensive evaluation of the patent application based on the state of knowledge at the relevant time.