An arbitration clause contained in an agency contract which refers to the arbitration rules established by an association representing a category of economic operators must be interpreted restrictively, with reference to the scope of jurisdiction expressly delimited by the arbitral body established. It follows that, where such body limits its jurisdiction to disputes between members and the association itself, disputes relating to direct contractual relations between the parties, such as those concerning the determination or unilateral modification of remuneration by one of the contracting parties, are excluded from arbitral jurisdiction.