All notices by a Department official, and all written motions, requests, petitions, memoranda, pleadings, exceptions, briefs, decisions, and correspondence to a Department official from a party, or vice versa, relating to a proceeding after its commencement shall be filed and served on all parties. Parties shall supply the original and two copies of documents submitted for filing. Filings shall be made with the Civil Rights hearing clerk at the address stated in the notice of hearing or notice of opportunity for hearing, during regular business hours. Regular business hours are every Monday through Friday (legal holidays in the District of Columbia excepted) from 9 a.m. to 5:30 p.m., eastern standard or daylight saving time, whichever is effective in the District of Columbia at the time. Originals only on exhibits and transcripts of testimony need be filed. For requirements of service on amici curiae, see §81.107.