Practice as a Basis of Forming International Custom

The point of view that "practice" is one of the main elements of customary international law is the most widespread in the doctrine of international law, activities of states and other subjects of international law. However, there is no consensus on the characterization of customary practices, as well as mandatory requirements to it, giving such practice a special quality. Not any practice in the relations between subjects of international law can become a prototype of the customary rule of international law. The article presents the peculiarities of customary practice and constituting the contest of the practice relationships between subjects of international law, its types and forms, as well as types of activities of state bodies forming the basis of the practice. The authors detail on the requirements for the customary practice without which the custom cannot be formed. The article also clarifies the list of such requirements and proposes to include them: commonality; uniformity and certainty; sustainability (stability) and permanence (continuity); compliance with laws of social development, needs of the development of interstate relations, common interests of states. These requirements, according to the authors, are systemic, interrelated, inseparable and constitute a coherent whole. The progressiveness of practice is proposed to be referred to its important requirements, which are optional. According to the author's position the duration in time shouldn't be attributed to a number of requirements to the customary practice, it is only its characteristic. The author analyses the concept of "instant custom" and the possibility of its application. A customary rule, corresponding to practices in any new area of interstate relations is formed in a short period of time. The completion of the formation of customary practice is characterized by the presence of its certainty, stability at a particular stage of development of the society. However, a long-term sustainable practice is the best proof of the existence of customary practice. The article pays attention to the formation of local customary practice. It is concluded that the general practice, as a rule, passes the stage of practice of two states or a group of states. In the future, such limited practice can expand because of its positivity and conformity with the vital interests of States.