9.1.2 Damaged in Customer’s Possession
Stamps that are damaged or otherwise unusable for postage (because of humidity,
moisture, or other causes) while in a customer’s possession may be exchanged only
for an equal number of stamps of the same denomination. Unusable stamps
accepted from a customer under these conditions must be those on sale at Post
Offices within 12 months before the transaction. Quantities of the same
denomination over $10 must be returned in the same configuration as when bought
(i.e., sheets, coils, booklets). Each such transaction is limited to $100 worth of
postage from each customer.
9.1.3 Condition and Quantity
The stamps presented for exchange must be in substantially whole condition, with the denomination evident.