The import licence number and letter of credit number should be noted. Certificate of Origin None, unless specifically requested. No special form, but the data should conform to that contained in other documents. It should be signed by a responsible member of the exporting firm and certified by a Chamber of Commerce from which it is obtainable. No special form required.
Customs require an original and three copies.
All weights and other measurements should be specified in the metric system. Facsimile signatures are not accepted. There are special invoice requirements for parts and accessories of aircrafts. For most goods have been eliminated since April 1992. In all cases, it will facilitate customs clearance.