In cases where the contract must be written to be in place, the Parol evidention rule applies. While this indicates that the document cannot be corrected by court order, the Meyer/Merchants Trust case shows that such a document has been corrected as it can. The insult clause in this case is that obligations can also be terminated by law, as in the case of compensation, mergers that exceed the impossibility of benefit, prescription, insolvency and death. The parties themselves may impose formalities regarding the conclusion, modification or revocation of their contract, as well as the waiver of all rights arising from their contract. If the parties agree that their agreement must be written, they may have one of two possible intentions. (The first is presumed if no clear intention is obvious.) Either the agreement is reduced to the letter only to facilitate proof of its terms, in which case the contract is immediately binding, or their agreement has legal value only when it has been reduced to the letter and signed by the parties. It is now firmly established that a derogation clause can protect against liability in the event of a “fundamental breach of contract.” Exception clauses often call into question the issues of justice between large corporations and the ordinary person: for example, as one patient cites in his complaint against an Afrox Healthcare hospital against Strydom (unsuccessfully). The fact that derogation clauses are generally considered effective does not mean that a specific exclusion clause cannot be declared contrary to public policy and, as such, unenforceable. The principle of the rule is that the courts do not enforce agreements deemed contrary to public policy. When a person enters into a contract because of misrepresentation or undue coercion or influence of the other party, the agreement is nevertheless valid because there is no disagreement. But because the consensus was wrongly reached, the treatise on The Case of the Innocent Party can be overturned. The remedy to cancel an annulable contract is the dissolution of restitution (called “restitutio” in the integrum) and is available both as a remedy and as a defence. Of course, the innocent party can also maintain the treaty.
The facts of a particular case can fit into both classes. Hutchison and Du Bois argue that “this classification is only a matter of comfort and not of actual meaning.”  Whether the exemption or restriction is part of a document or communication, which is also due, depends on the interpretation of the relevant document, in accordance with the above principles. In the absence of genuine consent, the question is essentially whether it was reasonable, given the nature and appearance of the document in question and the conduct of the parties, that the party based on the clause considered that the other party had accepted the clause or was prepared to be bound by the provisions of the document. It doesn`t matter what they were. It depends mainly on the integration rule, but the integration rule is just a backstop; it comes into force in the absence of a more dominant rule. It does not work when an aggrieved party accuses of fraud, misrepresentation, error, inappropriate influence, coercion or illegality, since in such cases it is the basis of the document that is problematic and not its interpretation.