Except as provided in § 3–1804 of this subtitle, a mediator or any person present or otherwise participating in a mediation at the request of a mediator: Shall maintain the confidentiality of all mediation communications; and May not disclose or be compelled to disclose mediation communications in any judicial, administrative, or other proceeding. Except as provided in § 3–1804 of this subtitle: A party to a mediation and any person present or otherwise participating in the mediation at the request of a party may not disclose or be compelled to disclose mediation communications in any judicial, administrative, or other proceeding; and The parties may enter into a written agreement to maintain the confidentiality of all mediation communications and may require any person present or otherwise participating in the mediation at the request of a party to maintain the confidentiality of all mediation communications.