From Law wiki, the wiki for law research

This case (Hillas v Arcos (1932) 38 Com Cas 23) demonstrates that a court has the option to infer terms in a Contract from the parties' previous dealings, rather than allow a contract to be voided. Courts do not usually like to do this if the wording or intention is vague, but it may be better than to allow a party to renege on a contract on a technicality.

The contract was to buy 22,000 standards of softwood of fair specification. The court ruled that fair specification was not sufficiently vague to void the contract, as the companies had done business before and each would have known the others' intentions.