37 CFR 11.35 - Service of complaint.
(a) A complaint may be served on a respondent in any of the following methods:
(1) By delivering a copy of the complaint personally to the respondent, in which case the individual who gives the complaint to the respondent shall file an affidavit with the OED Director indicating the time and place the complaint was delivered to the respondent.
(2) By mailing a copy of the complaint by Priority Mail Express®, first-class mail, or any delivery service that provides ability to confirm delivery or attempted delivery to:
(b) If a copy of the complaint cannot be delivered to the respondent through any one of the procedures in paragraph (a) of this section, the OED Director shall serve the respondent by causing an appropriate notice to be published in the Official Gazette for two consecutive weeks, in which case, the time for filing an answer shall be thirty days from the second publication of the notice. Failure to timely file an answer will constitute an admission of the allegations in the complaint in accordance with paragraph (d) of § 11.36, and the hearing officer may enter an initial decision on default.
(c) If the respondent is known to the OED Director to be represented by an attorney under § 11.40(a), a copy of the complaint shall be served on the attorney in lieu of service on the respondent in the manner provided for in paragraph (a) or (b) of this section.