The validity of bills of exchange and promissory notes, and the requirements concerning the issue and form, the endorsement, and the acceptance or non-payment of these instruments, are all governed by national laws. Conflicting national laws may lead to different results as to the rights and obligations of the parties concerned in the event of a dispute relating to a bill or a note which has connections with more than one country. This adds a degree of uncertainty to international commercial transactions and may result in a grave injustice for one or more of the parties concerned.