37 C.F.R. § 42.4 – Notice of trial.

(a) Institution of trial. The Board institutes the trial on behalf of the Director.
(b) Notice of a trial will be sent to every party to the proceeding. The entry of the notice institutes the trial.
(c) The Board may authorize additional modes of notice, including:
1. (1) Sending notice to another address associated with the party, or
2. (2) Publishing the notice in the Official Gazette of the United States Patent and Trademark Office or the Federal Register.