A brief of anamicus curiae or of a guardian ad litem representing a minor who is not a partyto the appeal may be filed only by leave of court granted on motion or at the requestof the court. The motion for leave may be accompanied by a proposed amicusbrief, provided it complies with applicable rules and the number of copiesspecified by Rule 26(b) are submitted to the court. A motion for leave shallidentify the interest of the movant and shall state the reasons why a brief ofan amicus curiae or the guardian ad litem is desirable. Except for a motion forleave to participate in support of, or in opposition to, a petition for writ ofcertiorari filed pursuant to Rule 50(e), the motion for leave shall be filed atleast 21 days prior to the date on which the brief of the party whose positionas to affirmance or reversal the amicus curiae or guardian ad litem willsupport is due, unless the court for cause shown otherwise orders. Parties tothe proceeding may indicate their support for, or opposition to, the motion.Any response of a party to a motion for leave shall be filed within 7 days ofservice of the motion. If leave is granted, an amicus curiae or guardian adlitem shall file its brief within 7 days of the time allowed the party whoseposition the amicus curiae or guardian ad litem will support, unless the ordergranting leave otherwise indicates. The time for responsive briefs under Rule26(a) shall run from the timely service of the amicus or guardian ad litembrief or from the timely service of the brief of the party whose position theamicus curiae or guardian ad litem supports, whichever is later. A motion of anamicus curiae or guardian ad litem to participate in the oral argument will begranted when circumstances warrant in the court's discretion.