U.S. Department of Transportation ("DOT") statements of authorization allowing foreign carriers to display the codes of a U.S. air carrier partners contain a condition that a foreign operating carrier "shall not permit the code of its U.S. code-sharing partner to be carried on any flight that enters, departs or transits the airspace of any area for whose airspace the Federal Aviation Administration has issued a flight prohibition."  On March 19, 2015, "giving the growing concerns about regional conflict zones around the world," the DOT issued a notice to remind carriers of this condition and that a carrier's failure to adhere to the above condition would render the carrier liable to DOT enforcement action.