In international law the term "soft law" has been referred to in order to indicate standards and principles contained in international acts that are deemed to lack legally binding force "per se". However, the concept of soft law underlies the evolution of the international community and of its process of law. Soft law does perform legally relevant functions in contemporary international law, travelling in tandem with hard law in some areas: particularly in international environmental law, human rights and economic law. First, it permits and facilitates the assessment customary rules or general principles of international law. Second, a soft-law stage is often anticipatory of the negotiation of a treaty. Third, soft law may also be a means of interpretation of international legally binding rules. Finally, soft enforcement procedures are also available to implement hard law and soft standards alike.