The Common Law has identified three types of errors in the treaty: frequent errors, reciprocal errors and unilateral errors. The second classification of contracts is an explicit and implicit contract. The parties establish an explicit contract when they clearly specify the terms of their agreement, orally or in a written document. This is more common than the case of a contract concluded, in which a court finds that the parties have concluded a contract concluded on the basis of the conduct of the parties or the facts of a situation, even if the parties have not concluded a clear verbal agreement or written document on the subject. The constitution of a legally binding contract must not be an intentional act. It can happen, even if you didn`t intend to enter into a contract. Trade agreements assume that the parties intend to be legally bound, unless the parties explicitly state otherwise as in an agreement document. . . .