This section of the code stipulates that all disputes concerning child custody or visitation, including petitions for visitation from stepparents or grandparents, will be set by the court for mediation. It also states that natural or adoptive parents not a party to the dispute are not required to participate in the mediation, but if they do not, they waive their right to object to any resulting settlement.
California Family Code Section 3170-3173: Mediation of Custody and Visitation Issues; Availability of Mediation
Legislative Counsel of California. Jan. 1, 1970http://www.leginfo.ca.gov/cgi-bin/waisgate?WAISdocID=73034020264+0+0+0&WAISaction=retrieve