(1) The Tribunal shall be the judge ofthe admissibility ofany evi- dence adduced and of its probative value.
(2) The Tribunal may,if it deems it necessary at any stage of the proceeding, call upon the parties to produce documents, witnesses and experts.
(3) After consulting both parties,the Tribunal may allow a person or entity that is not a party to the dispute (in this Article called the “non-disputing party”) to file a written submission with the Tribunal regarding a matter within the scope of the dispute. In determining whether to allow such a filing, the Tribunal shall consider, among other things,the extent to which:
a)
the non-disputing party submission would assist the Tri- bunal in the determination of a factual or legal issue related to the proceeding by bringing a perspective, par- ticular knowledge or insight that is different from that of the disputing parties; (b)the non-disputing party submission would address a matter within the scope of the dispute;
c)
the non-disputing party has a significant interest in the proceeding.
The Tribunal shall ensure that the non-disputing party submis- sion does not disrupt the proceeding or unduly burden or unfairly prejudice either party,and that both parties are given an opportunity to present their observations on the non-disputing party submission.