31 C.F.R. § 586.513 Certain transactions with respect to trade with blocked persons authorized.
Title 31 - Money and Finance: Treasury
(a) U.S. persons may trade in goods in which a person whose property and interests in property are blocked pursuant to §586.201 has an interest, provided that the payment for the goods is made in bank notes and coins of any currency or by barter. Any open account credit terms may not exceed 30 days. Transactions relating to services incident to this trade in goods, including payment for shipping and insurance to non-blocked entities, are authorized. (b) Example: A U.S. company located outside of Serbia may ship goods to Serbia in exchange for bank notes and coins or under a barter arrangement in exchange for Serbian goods, exchanged directly with the U.S. company or assigned to a third company in satisfaction of an obligation owed that party by the U.S. company. Except as provided in §586.408 or otherwise specifically authorized, however, the U.S. company may not establish or use an account at a financial institution within the territory of the Republic of Serbia in connection with any trade transaction described in this section.
Title 31: Money and Finance: Treasury
PART 586—FEDERAL REPUBLIC OF YUGOSLAVIA (SERBIA & MONTENEGRO) KOSOVO SANCTIONS REGULATIONS
Subpart E—Licenses, Authorizations, and Statements of Licensing Policy
§ 586.513 Certain transactions with respect to trade with blocked persons authorized.

