§ 100. Concurrence in joint tariffs. The names of the several carriers which are parties to any joint tariff shall be specified therein, and each of the parties thereto, other than the one filing the same, shall file with the commissioner such evidence of concurrence therein or acceptance thereof as may be required or approved by the commissioner; and where such evidence of concurrence or acceptance is filed, it shall not be necessary for the carriers filing the same also to file copies of the tariffs in which they are named as parties.