What is the most appropriate examiner action when an applicant demands proof of an officially noticed fact?

The correct approach in this scenario is to cite a reference that teaches the noticed fact and make the next action final. This action acknowledges the applicant's demand for proof while reinforcing the validity of the previously noticed fact. By referencing external documentation or evidence that supports the fact taken as official notice, the examiner provides a basis for the rejection and fulfills the requirement for demonstrable support.

This method also indicates to the applicant that their concerns were considered, but it holds firm on the rejection due to the existing sufficiently corroborated evidence. Making the next action final signifies that this is a conclusive step in the examination process, which can help streamline proceedings and provide clarity to both the examiner and the applicant.

Other options do not adequately address the applicant's demand for proof. Simply vacating the rejection without providing justification would leave the determination unfounded, while reaffirming the rejection without additional evidence fails to substantiate the examiner’s position. Accepting the applicant's challenge without further inquiry would imply a lack of due diligence in considering the established facts, which undermines the integrity of the examination process.