Any party may file a posthearing brief concerning the information adduced at or after the hearing with the Secretary within a time specified in the notice of scheduling or by the presiding official at the hearing. No such posthearing brief shall exceed fifteen (15) pages of textual material, double spaced and single sided, on stationery measuring 81/2 × 11 inches. In addition, the presiding official may permit persons to file answers to questions or requests made by the Commission at the hearing within a specified time. The Secretary shall not accept for filing posthearing briefs or answers which do not comply with this section.