Aurélie Brès, Lise Chatain, Pierre Mousseron

This on-line course is the result of a collaboration which has developed since 2010 within the Centre du Droit de l’Entreprise and since 2015 within the Institut des usages de
la Faculté de Droit de Montpellier. It is a part of the project « Valuing usages » sponsored by the MUSE consortium (Montpellier UniverSité d’Excellence).

It is written for lawyers, students or practitioners who understand Law as being not only a set of rules with court sanctions but also rules organizing human relationships. This course follows 2 main goals:

• The first one is to remind us that usages belong to Law which drives us to our second objective…
• Which is to offer a new and simple method of presentation of Customary Law based on the study of the formation, application and termination of usages.

Facing most legal questions, it seems to us necessary to complement the classic legal analysis based on statutes and cases with a reference to usages. Ignoring Customary
Law, i.e. this law based on usages, creates a worrying blind spot for the documentation and a gold mine of arguments. On the contrary, paying attention to it improves the legal services on a national and even more on an international level.

Customary Law analyses and enriches legal work. On top of that, usages are evidence of professionalism from lawyers whether they work as negotiator, attorney, drafter, counsel, mediator, arbitrator or consultant.

Contents

Introduction

A – Definition of Customary Law
B – Opportunity of Customary Law
C – Legal Regime of Customary Law

I – Formation of customary rules
A – Objective requirements
B – Subjective requirements

II – Application of customary rules
A – Legal nature of customary rules
B – Evidence of customary rules
C – Effects of customary rules
D – Transfer of customary rules
E– Modification of customary rules

III – Termination of customary rules
A – Causes of termination
B – Consequences of termination