Customary law is unwritten objective law based on a long, uninterrupted practice of law based on legal conviction. However, customary law cannot derogate written law. A precondition for the existence of customary law is the existence of a gap in written law and the need to want to fill this gap. The application of customary law to fill the gap therefore requires the continuous practice of the law throughout Switzerland and the existing legal conviction (conviction of the legal obligation).
German: Gewohnheitsrecht (388)
Source: LK-Lötscher, 11.05.2020