Mediation is an entirely voluntary process, everybody knows that. (newlawjournal.co.uk)
An informal, voluntary process allowing parties to work with a neutral third party (the «mediator») to develop a separation agreement. (divorcenet.com)
If this massive transfer were the outcome of a competitive voluntary process, economists could debate how efficient this outcome is, but otherwise there would be very little to complain about. (slaw.ca)