15 U.S.C. § 1693l

No writing or other agreement between a consumer and any other person may contain any provision which constitutes a waiver of any right conferred or cause of action created by this subchapter. Nothing in this section prohibits, however, any writing or other agreement which grants to a consumer a more extensive right or remedy or greater protection than contained in this subchapter or a waiver given in settlement of a dispute or action.