The clause often goes unheeded in the contract, but at least it is necessary to check whether there are other documents relating to the contract, such as a previous confidentiality agreement, which must remain in effect, or an agreement on the level of service that continues to fulfill the obligations of the supplier. Whether this measure also applies to trade agreements has been controversial for some time. Previous judgments have shown that trade agreements between professional parties, advised by contracting legal advisers, have decisive weight for the most obvious language declaration of the agreement. Especially when the parties have used a so-called “comprehensive agreement” clause. How a written agreement governs relations between the parties is determined on the basis of the Haviltex scale. Under this measure, which dates back to 1981, it is not enough to consider only the linguistic meaning of the text, but it must also be considered: “It should be noted that a “comprehensive agreement clause” is not in itself an explanatory provision. The clause has a particular origin and function in the Anglo-American legal field and is of no particular importance in Dutch law. It is often intended to ensure that the parties are not bound by previous agreements relating to the agreement which are contrary to it if these agreements are not included in the agreement and it does not concern them. However, the clause does not necessarily apply beforehand, namely that the interpretation of the provisions contained in the agreement takes into account statements or practices made in the pre-agreement phase. Under Dutch law, contrary to Anglo-American law, the intention of the parties is the starting point for the declaration of the treaties. The Supreme Court set a benchmark in Haviltex. On the basis of this measure, the interpretation of the contractual provisions is decisive in explaining the sentence the parties have given to these provisions in the present circumstances and in what they could reasonably have hoped for from each other.

The Haviltex measure leaves room, to explain the agreement, to take into account the statements or practices of the parties before the conclusion of the agreement. Subsequent Supreme Court decisions show that, in certain circumstances, the interpretation of the most obvious linguistic meaning of this provision may be more important than the party`s intent. Indeed, there is a slippery scale in which, on the one hand, the party`s (subjective) intention and, on the other hand, the (objective, linguistic explanation) of the treaty text. If, on this slippery scale, the judge is determined, among other things, by the following circumstances: This agreement contains all the parties` understanding of the transactions and cases envisaged, since and after the entry into force, and replaces all previous agreements between the parties concerning them.