For the assignment to be effective, the assignee must, in most cases, express its acceptance. This is done automatically where, as is generally the case, the assignee has contemplated the assignment (i.e., there is a contract between the assignor and the assignee in which the assignment is the assignor`s consideration) and the assignment is not revocable without the agreement of the assignee. As a rule, problems of acceptance arise only if the Zdiger intends the assignment as a gift. In order for the assignment to be irrevocable, either the assignee must express its acceptance or the zödner must inform the assignee in writing. The assignment of contractual rights is judicious and prohibitions are generally not preferred. Many contracts contain a general language that prohibits the assignment of rights or “contracts”. .