The set of practices and techniques determining the rules of conduct, according to the specificities of each field, so that the works or providing a service are properly performed. This set of written rules (e.g. scientific and technical publication, manufacturer's guide, standards defined by certain specialized bodies, etc.) and of unwritten rules (e.g., generally recognized long standing practice, usage, etc.) constitute knowhow resulting from the achievements of practice. The failure of abiding thereto constitutes a fault that may engage the contractual civil liability of its author.
WHAT YOU SHOULD KNOW ! The concept of "rules of the trade" is in the law but is not defined therein. These rules are deemed to be implicit contractual obligations, as opposed to those which derive from the terms and conditions of a contract.