When educational materials cross frontiers, they meet with trade obstacles, such as high postal charges or freight rates or limitations on packaging, [etc]. The task of removing, on a worldwide basis, these trade and other obstacles which hinder the free movement of educational, scientific and cultural materials remains to be accomplished. It may concern, for example, materials which move only temporarily from one country to another for the purpose of exhibitions, conferences, or as loans, in particular scientific instruments or apparatus. It may also concern safe and rapid transit of delicate scientific instruments.