On July 1, 2021, the US Patent & Trademark Office (PTO) issued a notice reminding patent applicants that when their applications contain both prophetic and working examples, they must make a clear distinction between the two.

Prophetic examples illustrate reasonably expected results or anticipated results. They stem from experiments that have not been actually performed and are instead hypothetical simulations. In contrast, working examples result from experiments that were actually performed. In order to aid in distinguishing between the two example types within a patent application, prophetic examples should be written only in the future or present tense—not in the past tense. Prophetic examples cannot be used to meet the written description and enablement requirements for a patent application.

The PTO’s recent notice underscores the importance of the applicant’s duty to clearly distinguish between prophetic and working examples: “[k]nowingly asserting in a patent application that a certain result ‘was run’ or an experiment ‘was conducted’ when, in fact, the experiment was not conducted or the result was not obtained is fraud.”