What does the term "ex parte reexamination" refer to?

The term "ex parte reexamination" refers specifically to a procedure within the patent system that allows a party to request the United States Patent and Trademark Office (USPTO) to reexamine a patent's validity. This request must be based on prior art that raises questions about the patent's originality or novelty. This process is initiated by a third party, who provides evidence that they believe could influence the patent's validity.

In this context, it is important to understand that "ex parte" signifies that the reexamination process does not involve the participation of the patent holder's competitors or other interested parties during the reexamination phase. The USPTO examines the validity of the claims of the patent primarily based on the newly presented evidence without any back-and-forth interaction with the original patent owner, maintaining a one-sided nature in the proceedings.

The other options describe processes that do not align with the definition of ex parte reexamination. For instance, the appeals process for patent rejection involves active engagement from the applicant and is not a function of reexamination. Legal actions against infringement pertain to disputes in enforcement rather than questioning the validity of the patent itself, and requests for patent extension focus on prolonging the term of existing patents, which is