BACKGROUND: Every day, more than 1.2 billion letters are posted for delivery within national borders, accounting for more than 430 billion letters each year. In addition, each day, close to 20 million pieces of mail cross international boundaries, accounting for nearly 7.4 billion items posted in international service (over a third of them by developing countries) and are swiftly and safely delivered to their destinations. To handle this traffic, postal services employ more than 6 million employees who work at or out of some 700,000 permanent post office outlets around the globe. The orderly and economical movement of international mail is made possible by the Constitution and Convention of the Universal Postal Union, the basic Acts under which the UPU operates. Since 189 countries now come under these Acts, the provisions affect virtually the entire world population. Under the Constitution, UPU member countries form a single postal...