27 CFR 46.76: Supporting evidence.

The claimant must support the claim with any available evidence (such as inventories, statements, invoices, bills, records, stamps, and labels), relating to the tobacco products or cigarette papers or tubes on hand at the time of the disaster and claimed to have been lost, rendered unmarketable, or condemned as a result thereof. If the claim is for refund of duty, the claimant must furnish, if practicable, the customs entry number, date of entry, and the name of the port of entry.