(a) Filing; Number of Copies. Except as otherwise provided by the Judge or the Secretary, all documents or papers required or authorized by the rules in this part to be filed with the Hearing Clerk shall be filed in quadruplicate: Provided, That, where there are parties to the proceeding in addition to complainant and respondent, an additional copy shall be filed for each such additional party. Any document or paper, required or authorized under the rules in this part to be filed with the Hearing Clerk, shall, during the course of an oral hearing, be filed with the Judge.

(b) Service; proof of service. Copies of all such documents or papers required or authorized by the rules in this part to be filed with the Hearing Clerk, shall be served upon the parties by the Hearing Clerk, or by some other employee of the Department, or by a U.S. Marshal or his Deputy. Service shall be made either (1) by delivering a copy of the document or paper to the individual to be served or to a member of the partnership to be served, or to the president, secretary, or other executive officer or any director of the corporation or association to be served, or to the attorney or agent of record of such individual, partnership, corporation, organization, or association; or (2) by leaving a copy of the document or paper at the principal office or place of business or residence of such individual, partnership, corporation, organization, or association, or of his or its attorney or agent of record and mailing by regular mail another copy to each person at such address; or (3) by registering or certifying and mailing a copy of the document or paper, addressed to such individual, partnership, corporation, organization, or association, or to his or its attorney or agent of record, at his or its last known residence or principal office or place of business: Provided, That if the registered or certified document or paper is returned undelivered because the addressee refused or failed to accept delivery, the document or paper shall be served by remailing it by regular mail. Proof of service hereunder shall be made by the certification of the person who actually made the service: Provided, That if the service be made by mail, as outlined in paragraph (b)(3) of this section proof of service shall be made by the return post office receipt, in the case of registered or certified mail, or by the certificate of the person who mailed the matter by regular mail. The certificate and post office receipt contemplated herein shall be filed with the Hearing Clerk, and the fact of filing thereof shall be noted in the record of the proceeding.

(c) Extension of time. The time for the filing of any document or paper required or authorized under the rules in this part to be filed may be extended by the Judge prior to the filing of the certification of the transcript or recording if there is good reason for the extension. In all instances in which time permits, notice of the request for extension of the time shall be given to the other party with opportunity to submit views concerning the request.

(d) Effective date of filing. Any document or paper required or authorized under the rules in this part to be filed shall be deemed to be filed at the time when it reaches the Department of Agriculture in Washington, D.C.; or, if authorized to be filed with an officer or employee of the Department at any place outside the District of Columbia, it shall be deemed to be filed at the time when it reaches the office of such officer or employee.

(e) Computation of time. Saturdays, Sundays and Federal holidays shall be included in computing the time allowed for the filing of any document or paper: Provided, That when such time expires on a Saturday, Sunday or Federal holiday, such period shall be extended to include the next following business day.