No stipulation or agreement between the parties, with regard to any matter involved in any board proceeding shall be enforced unless it has been reduced to writing and agreed to by the parties or their authorized representatives, or unless it has been dictated into the record by them during the course of a State Office of Administrative Hearings (SOAH) hearing, deposition, or other proceeding of record, or incorporated in a motion bearing their written approval. This section does not limit a party's ability to waive, modify or stipulate any right or privilege.
22 Tex. Admin. Code § 187.4