(a) When a case is appealed, there shall be no
communication direct or indirect between the judge or judicial
officer who heard the case and any judge of the reviewing court
concerning the facts or merits of the case.
(b) When a petition for an original writ names a court as a party,
there shall be no communication direct or indirect between any judge
hearing the writ and the judge or judicial officer of the court
named as a party.
(c) The prohibitions of subdivisions (a) and (b) shall not apply
to a written communication if at the time the communication is
transmitted all the parties are sent a copy.