155.Rule 28 is a default rule, that in the absence of agreement between the parties, the arbitrator can determine the procedure to be followed and evidential matters.
156.Rule 28(2) provides an illustrative, but not exhaustive, list of such powers for the tribunal. Arbitrators are for instance allowed to act inquisitorially (rule 28(2)(e)) and can generally disapply the law of evidence (rule 28(2)(h)).