129. Notice shall be sent to the parties within reasonable time before the hearing or within the time fixed by law, stating
(1) the purpose, date, time and place of the hearing;
(2) that the parties have the right to be assisted or represented, and listing the classes of persons authorized by law to assist or represent a party before the Tribunal;
(3) that the Tribunal has the authority to proceed, without further delay or notice, despite the failure of a party to appear at the time and place fixed if no valid excuse is provided.