Under the recent reform of the law of contracts and in the context of arbitration, the distinction between mandatory and default rules is relative in two respects. It is so, first, from the perspective of the domestic law of contracts itself, where the room left for freedom of contract turns to be more limited than one might think. Second, the said distinction is made even more relative, before the international arbitrator, by the broad freedom that is given to the parties as regards the choice of the applicable rules of law