Mailing Standards of the United States Postal Service - International Mail Manual > 5 Nonpostal Export Regulations > 590 Exporting Wildlife and Protected Plants > 594 Marking Requirements for Wildlife Exports
All packages containing wildlife products must be marked clearly with the name and address of both the shipper and the recipient. Information identifying the contents as fish or wildlife and specifying the quantity and species involved must accompany the shipment. Federal regulations (50 CFR Part 14, Subpart H) explain how to comply with wildlife marking requirements. See 597.
