(a) As used in this Code section, the term "guardian" means the guardian ad litem appointed by the probate court who may represent a single party or more than one party or a class of parties with common or nonadverse interests; provided, however, that the court may determine for the purpose of the particular proceeding that the natural guardian, if any, or the testamentary guardian, if any, or the duly constituted guardian of the property, if any, or the duly constituted guardian of the person, if any, has no conflict of interest and thus may represent for the purpose of the proceeding a party who is not sui juris, who is unborn, or who is unknown.

(b) When a party to a proceeding in the probate court is not sui juris, is unborn, or is unknown, that party shall be represented in the proceeding by a guardian. Service upon or notice to a guardian shall constitute service upon or notice to the party represented and no additional service upon or notice to such party shall be required. Waivers, acknowledgments, consents, answers, objections, or other documents executed by the guardian shall be binding upon the party represented.

(c) Whenever a guardian ad litem is appointed, the court may limit the appointment or may at any time for cause appoint a successor. Unless the appointment is limited by the court, the guardian ad litem first appointed with respect to any proceeding involving the administration of the estate shall continue to serve with respect to such proceeding on behalf of the party represented until a successor is appointed, the party represented becomes sui juris, or the court terminates the appointment.

(d) In every petition filed in the probate court, the petitioner shall specify the name of each party who requires a guardian and the name and address of any person who is acting as guardian of the party. A copy of the letters appointing the guardian shall be attached to the petition or the petition shall allege such facts as shall show the authority of such guardian to act; provided, however, that the probate court may take judicial notice of the issuance of such letters or of such authority.