Mercantile law
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
An expression substantially equivalent to the law-merchant or commercial law. It designates the system of rules, customs, and usages generally recognized and adopted by merchants and traders, and which, either in its simplicity or as modified by common law or statutes, constitutes the law for the regulation of their transactions and the solution of their controversies