20.7 Whenever, in terms of these Rules, it is required that notice be given of any step or proceeding by or to the Secretariat, the Registrar, or any party, the period of such notice shall, unless otherwise provided herein, be 7 calendar days.

ARTICLE 21: General

21.1 FEES PAYABLE PRO RATA

The fees payable to the Secretariat shall, as provided herein, be payable in equal shares by the claimant and by the defendant; provided that, if there is more than one claimant or defendant, such claimants or defendants shall pro rata to their numbers be liable to pay their share of the fee; and provided further that, if any party defaults in paying his share of such fee, any other party may pay the defaulting party's share to enable the arbitration to proceed, and may at any stage of the proceedings apply for an order for costs to recover the other party's share so paid. The arbitrator may make such order as to costs on such application as he deems just.

21.2 ARBITRATION TO BE PRIVATE

21.2.1 The arbitration proceedings shall be conducted in private, and a party shall be entitled to require the arbitrator to exclude therefrom any person whose presence is not reasonably required by another party.