Parties on whom order of Court shall be binding.

An order of the Court shall be binding on— (a) all parties to the complaint; (b) all parties who were summoned to appear as parties to the complaint, whether they appear or not, unless the Court is of opinion that they were improperly made parties; (c) in the case of an employer who is a party to the complaint before such Court in respect of the undertaking to which the complaint relates, his heirs, successors or assigns in respect of the undertaking to which the complaint relates; and (d) where the party referred to in clause (a) or clause (b) is composed of employees, all persons, who on the date of the complaint, are employed in the undertaking to which the complaint relates and all persons who may be subsequently employed in the undertaking.