intention

CONT: The related rules concerning the intention of the parties proceed from the capital principle that it is to the intention of the parties at the time the instrument was concluded, and in particular the meaning attached by them to words and phrases at the time, that primary regard must be paid. Hence, it is legitimate to consider what was the ""purpose"" or ""plan"" of the parties in negotiating the treaty. Nor should a treaty be interpreted so as to restrict unduly the rights intended to be protected by it. What must be ascertained is the ostensible intention of the parties, as disclosed in the four corners of the actual text; only in exceptional circumstances is it permissible to investigate other material to discover this intention. Moreover, a special meaning must be given to a particular term, if it is established that the party so intended.