The Authority will not consider any submission filed by any party other than those authorized under this part, provided however that the Authority may, in its discretion, grant permission to file an additional submission based on a written request showing extraordinary circumstances by any party. The additional submission must be filed either with the written request or no later than five (5) days after receipt of the Authority's order granting the request. Any opposition to the additional submission must be filed within fifteen (15) days after the date of the receipt of the additional submission. All documents filed under this section must be served in accord with §2424.2(g).