39 C.F.R. § 965.5 Submittals by parties.
Title 39 - Postal Service
Within 15 days after receipt of the Recorder's notice, each party shall file with the Recorder a sworn statement of the facts supporting its claim to receipt of the mail together with a copy of each document on which it relies in making such claim. All such submittals shall be in duplicate. Upon receipt of such evidence, the Recorder shall send a copy of each submittal to the opposing party.
Title 39: Postal Service
PART 965—RULES OF PRACTICE IN PROCEEDINGS RELATIVE TO MAIL DISPUTES
§ 965.5 Submittals by parties.

