Evid Code § 1119 and 1126 say all writings and oral agreements cannot be used in Court to prove what was said.
Simmons v. Ghaderi (2008) 44 Cal.4th 570
Foxgate Homeowners' Assn. v. Bramalea California, Inc. (2001) 26 Cal.4th 1
A written settlement agreement achieved through mediation generally contains a provision waiving the confidentially provisions of the Evidence Code and provides that the court has jurisdiction to enforce its terms.
I am licensed in California only and my answers on Avvo assume California law. Answers provided by me are for general information only. They are not legal advice. Answers must not be relied upon. Legal advice must be based on the interplay between specific exact facts and the law. This forum does not allow for the discussion of that interplay. My answer to any specific question would likely be different if that interplay were explored during an attorney-client relationship. I provide legal advice during the course of an attorney-client relationship only. The exchange of information through this forum does not establish such a relationship. That relationship is established only by personal and direct consultation with me followed by the execution of a written attorney-client agreement signed by each of us. The communications on this website are not privileged or confidential and I assume no duty to anyone by my participation on Avvo or because I have answered or commented on a question. All legal proceedings involve deadlines and time limiting statutes. So that legal rights are not lost for failure to timely take appropriate action and because I do not provide legal advice in answer to any question, if you are an interested party you should promptly and personally consult with an attorney for legal advice. Also, see Avvo's terms and conditions of use, specifically item 9, incorporated by this reference
If parties settle during mediation, they sign an agreement which is enforceable in court-- meaning if one of the parties breaches the other party can sue for damages, etc. (depending on the specific terms of the agreement/contract different remedies are provided). Most agreements also waive all confidentiality in case of a breach.