What is the "prior art" date for a 102(f) rejection of a U.S. published application?

The "prior art" date for a 102(f) rejection of a U.S. published application is indeed the filing date of the application. In the context of patent law, specifically under Section 102(f), a rejection can be based on the grounds that the applicant did not invent the claimed subject matter. This typically involves the situation where the invention was previously made by another person.

The filing date serves as the crucial reference point because it establishes the circumstances under which the application is examined for prior art. Prior art includes any patents, publications, or public disclosures that existed before the filing date. Thus, if another individual had publicly disclosed the invention before the filing date, that prior disclosure could serve as the basis for a 102(f) rejection, indicating that the applicant did not have the right to claim that invention.

This understanding is key for patent applicants and patent examiners alike, as it shapes how prior art is evaluated relative to the filing date of a given patent application.