The 180-day rule is a statutory restriction prohibiting any vessel that enters a port or place in Cuba to engage in the trade of goods or the purchase or provision of services there from entering any U.S. port for the purpose of loading or unloading freight for 180 days after leaving Cuba, unless authorized by OFAC. This restriction is applied even if a vessel has stopped in Cuba solely to purchase services unrelated to the trade of goods, such as planned ship maintenance. The 180-day rule is separate from a second statutory restriction – the goods/passengers-on-board rule – which prohibits any vessel carrying goods or passengers to or from Cuba or carrying goods in which Cuba or a Cuban national has an interest from entering a U.S. port with such goods or passengers on board, unless authorized or exempt. There are certain exceptions to these rules. For a complete description of the 180-day rule, the goods/passengers-on-board rule, and the general licenses and exemptions that apply, see 31 CFR §§ 515.206, 515.207, and 515.550.