What are the implications of language in commercial agreements?

The traditional tests for implication of terms, namely the test of business efficacy stemming from Ship Moorcock, Re (1889), 14 P.D. 64 and the test of the obvious inference, judged by the officious bystander, who would answer “of course” to a question as to whether a particular arrangement not expressed was intended to be part of the arrangement (Shirlaw v. Southern Founderies Ltd., [1939] 2 K.B. 206) are, in a sense, manifestations of a desire to facilitate the achievement of the reasonable expectations of the parties, objectively determined from the language used in the context of their negotiations. It is, of course, not the subjective expectations of one party which should be protected: rather it is the reasonable expectations shared by the parties or held by one party and of which the other was aware or ought to have been aware was the basis of the conclusion of the transaction. This determination is judged on the basis of what reasonable persons in the contracting milieu facing the parties could be said to have expected.