No stipulation or agreement between the parties, their attorneys, or representatives, with regard to any matter involved in any proceeding governed by this chapter, shall be enforced unless it shall have been reduced to writing and signed by the parties or the representatives authorized by this chapter to appear for them, or unless it shall have been dictated into the record by them during the course of a hearing or incorporated into an order bearing their written approval. This section does not limit a party's ability to waive, modify, or stipulate any right or privilege afforded by this chapter, unless precluded by law.