International Bureau of Expositions. An international organization established by the Paris Convention of 1928 to regulate the conduct and scheduling of international expositions in which foreign nations are officially invited to participate. The BIE divides international expositions into different categories and types and requires each member nation to observe specified minimum time intervals in scheduling each of these categories and types of operations. Under BIE rules, member nations may not ordinarily participate in an international exposition unless the exposition has been approved by the BIE. The U.S. became a member of the BIE in April 1968. Federal participation in a recognized international exposition requires specific authorization by the Congress, based on the president’s finding that participation is in the national interest.