some non-written terms were intended to be part of the contract, the parol evidence rule would never exclude them. In order to clarify this apparent confusion, the general approach utilised in practice is that where one party is reasonably entitled to assume that the writing does contain all the terms of the contract, the other party will not be allowed to give evidence that it does not. J Evans & Son (Portsmouth) Ltd v Andrea Merzario Ltd [1976] 1 WLR 1078 FACTS: The plaintiffs, importers of machines, regularly contracted with the defendant forwarding agents. On every occasion the machines were carried below deck in crates or trailers so as to avoid the risk of corrosion. In 1967, the defendants proposed to change to containerised transportation to enable them to carry goods both above and below deck. However, in discussions with the plaintiffs, the defendants gave them an oral assurance that their machines would be packed in containers but would always be carried below deck. About a year later, such a container was inadvertently carried on deck and was lost overboard. HELD by the Court of Appeal: The oral promise did have contractual force, principally on the basis that the defendant attached great importance to the carriage of his goods under deck and also on the basis that he would not have agreed to the new mode of carriage but for the promise. According to Roskill and Geoffrey Lane LJJ, the oral assurance was an express term of the contract and, as the contract was partly oral and partly written, evidence of the oral term was admissible. This was also the result in Couchman v Hill [1947] KB 554 where the documents in the case were held to form not the whole but only part of the contract; the oral assurance could be laid side-by-side with them so as to constitute a single and binding transaction.