Grounds for invalidating

A treaty is the official document which expresses that agreement in words; and it is also the objective outcome of a ceremonial occasion which acknowledges the parties and their defined relationships.

Since the late 19th century, most treaties have followed a fairly consistent format.

Modern preambles are sometimes structured as a single very long sentence formatted into multiple paragraphs for readability, in which each of the paragraphs begins with a gerund (desiring, recognizing, having, and so on).Originally, international law was unaccepting of treaty reservations, rejecting them unless all parties to the treaty accepted the same reservations.However, in the interest of encouraging the largest number of states to join treaties, a more permissive rule regarding reservations has emerged.Bilateral treaties are concluded between two states or entities.It is possible, however, for a bilateral treaty to have more than two parties; consider for instance the bilateral treaties between Switzerland and the European Union (EU) following the Swiss rejection of the European Economic Area agreement. These however are still bilateral, not multilateral, treaties.