(a) Copies of all documents filed in any proceeding described in this part and copies of all notices pertinent to such proceeding shall be served by the filing party on all other persons made parties to the proceeding under § 44.3 . If a request for hearing has been filed by any party, a copy of all subsequent documents filed shall be served upon the Mine Safety and Health Administration through its representative, the Office of the Solicitor, Department of Labor.(b) All documents filed subsequent to a petition for modification may be served personally or by first class mail to the last known address of the party. Service may also be completed by telecopier or other electronic means.(c) Whenever a party is represented by an attorney who has signed any document filed on behalf of such party or otherwise entered an appearance on behalf of such party, service thereafter shall be made upon the attorney.(d) Any party filing a petition for modification under these rules shall file proof of service in the form of a return receipt where service is by registered or certified mail or an acknowledgment by the party served or a verified return where service is made personally. A certificate of service shall accompany all other documents filed by a party under these rules.(e) Service by mail shall be complete upon mailing. Service by telecopier or other electronic means shall be complete upon receipt.(f) Whenever a party has the right to do some act within a prescribed period after the service of a document or other material upon the party and the document or other material is served upon the party by mail, 5 days shall be added to the prescribed period: Provided, that specific provisions may, for good cause, be made otherwise by an order of an administrative law judge or the Assistant Secretary in a particular proceeding pending before that person.43 FR 29518, July 7, 1978, as amended at 55 FR 53440, Dec. 28, 1990