What is Au Besoin?

Legal Definition
This is a French phrase, used in commercial law. When the drawer of a foreign bill of exchange wishes as a matter of precaution, and to-save expenses, he puts in the corner of the bill, " Au besoin chez Messieurs or, in other words, " In case of need, apply to Messrs. at __________ " ___________." 1 Bouv. Inst. n. 1133 Pardess Droit Com. 208.
-- Bouviers Law Dictionary
Legal Definition
In case of need. A French phrase sometimes incorporated in a bill of exchange, pointing out some person from whom payment may be sought in case the drawee fails or refuses to pay the bilL Story, Bills, § 65.
-- Black's Law Dictionary
Legal Definition
A designation in a bill of exchange of one of whom payment may be requested upon the drawee’s refusal.
-- Ballentine's Law Dictionary