Objects, other than personal effects, which are moved across frontiers are subject to customs regulations. The complexity of such regulations, particularly when objects have to be moved through several countries in succession, creates considerable obstacles to legitimate movement and may cause considerable delay. This aggravates problems of trade but also seriously hinders the movement of educational, scientific and cultural materials into the country in question.
All modes of transport are now going through a period of technological change, notably in the areas of air freight and containerization. Consequently goods are being moved much more quickly than hitherto, so much so that in an increasing number of cases they are arriving at critical points in the movement cycle, such as airports or customs clearance centres, before the necessary formalities required to release them can, under present circumstances, be completed. Frustrating and costly delays then result. In addition, quite apart from the regular procedures and documentation connected with the levying of duties on goods across frontiers, there are still a number of onerous formalities and requirements such as special customs invoices or declarations demanded by some countries which may also be discriminatory .