However, in some cases, earlier agreements may prevail, even if this agreement contains a full contractual clause under the doctrine of breach by convention.21The doctrine of Estoppels by convention means that a party is “set apart” from arguing that a contract is not modified by the conduct of the parties, although the treaty contains an “entire agreement” clause. `This instrument contains the entire agreement of the Parties on the subject matter of this Agreement and there are no other assurances, assurances, guarantees, uses or transactions which affect it.` 4. [Optional] Nothing in this clause limits or excludes liability for fraud. In addition, a generally designed comprehensive agreement does not affect the terms of a contract. This is due to the fact that the implicit conditions are not “before” the treaty. They are part of the contract itself.