Term: Coutume de Paris
literally "Paris customs" but meaning more specifically the legal methods and laws of France, as opposed to American law.
From Wisconsin: comprising sketches of counties, towns, events, institutions, and persons, arranged in cyclopedic form, ed. by Ex-Gov. Geo. W. Peck (Madison, Wis., Western Historical Association, 1906).
"Prior to the passing of what is now Wisconsin from French control under British jurisdiction the only law enforced, and that only in a few settlements, was the Coutume de Paris, the ordinances of Paris. This was enforced by the only civil officer located at the posts, a notary commissioned by the governor [see: Reaume, Charles] He was supposed to be conversant with the provisions of the Coutume, but those to whom it was applied were not."
[Source: McDermott, John Francis. A glossary of Mississippi Valley French, 1673-1850 (St. Louis: 1941).]