b. Communications to which the privilege attaches

The privilege applies to a broad array of "mediation communications" including some communications that are not made during the course of a formal mediation session, such as those made for purposes of convening or continuing a mediation. See Reporter's Notes to Section 2(2) for further discussion.

c. Proceedings at which the privilege may be asserted.

The privilege under Section 4 applies in most legal "proceedings" that occur during or after a mediation covered by the Act. See Section 2(7). If the privilege is raised in a criminal felony proceeding, it is subject to a specialized treatment under Section 6(b)(1), and the Reporter's Notes to that Section should be consulted for further clarification.

3. Section 4(a). Description of effect of privilege.

The words "is not subject to discovery or admissible in evidence" in Section 4(a) make explicit that a court or other tribunal must exclude privileged communications that are protected under these sections, and may not compel discovery of them. Because the privilege is unfamiliar to many using mediation, this Section provides a description of the effect of the privilege provided in Sections 4(b), 5, and 6. It does not change the reach of the remainder of the Section.

4. Section 4(b). Operation of privilege.

As with other privileges, a mediation privilege operates to allow a person to refuse to disclose and to prevent another from disclosing particular communications. See generally Strong, supra, at Section 72; Developments in the Law - Privileged Communications, 98 Harv. L. Rev. 1450 (1985).

This blocking function is critical to the operation of the privilege. As discussed in more detail below, parties have the greatest blocking power and may block provision of testimony about or other evidence of mediation communications made by anyone in the mediation, including persons other than the mediator and parties. The evidence may be blocked whether the testimony is by another party, a mediator, or any other participant. However, if all parties agree that a party should testify about a party's mediation communications, no one else may block them from doing so, including a mediator or nonparty participant.

Mediators may block their own provision of evidence, including their own testimony and evidence provided by anyone else of the mediator's mediation communications, even if the parties consent.