A unilateral statement formulated by a State or an international organization at the time when that State or that organization expresses its consent to be bound by a treaty by which its author purports to limit the obligations imposed on it by the treaty constitutes a reservation.
一国或一国际组织在表示同意接受条约约束时提出单方面声明，意图藉此限制该条约施加于它的义务，此项声明即构成保留。