The mediator shall summon the parties to be heard from the outset of the mediation.
He shall invite the parties to provide him with any clarifications he deems necessary and may hear any person whose hearing he deems useful. The parties may be assisted by a lawyer or by any person of their choice who has been approved by the mediator. Only persons summoned by the mediator may take part in meetings.
The mediator may not retain any fact, grievance, item of information or evidence without notifying the parties concerned under conditions that allow them to discuss the merits of the case.