Oral arguments shall be made only before the hearing officer and shall be included in the record of the hearing. Such oral arguments may, in the discretion of the hearing officer, be curtailed, provided that a party shall be given an opportunity to submit his argument in writing. Briefs as to facts or law shall be received and may be requested to be submitted. The hearing officer may fix the time within which briefs shall be filed. Briefs received subsequent to such time need not be considered.