The Tribunal’s timetable provided as follows:
(1) 16th October 2000: Further written submissions of Petitioners for amicus curiae status.
(2) 27th October 2000: Written submissions from the Claimant and the Respondent in respect of (1).
(3) 10th November 2000: Written submissions from Canada and Mexico as NonDisputing State Parties as provided for by Article 1128 of NAFTA.
(4) 22nd November 2000: Written submissions from the Claimant and the Respondent in respect of (3).
An "Amended Petition" was duly submined on 13th October 2000 by (i) Communities for a Better Environment, (ii) the Bluewater Network of Earth Island Institute and (iii) the Center for International Environmental Law (the "Communities/BIuewater/Center Petition"); on 16th October 2000, 'Final Submissions" were submitted by the International Institute for Sustainable Development (the "Institute Final Petition"); on 27th October 2000, the Claimant and the Respondent filed their written submissions; on 10th November 2000, Canada and Mexico each filed written submissions; and on 22nd November 2000, the Claimant and the Respondent filed their farther written submissions.
subject to the proviso that the parties be treated with equality and given a full opportunity of presenting their cases. This rule was sufficiently broad to encompass the authority to accept amicus briefs. The Respondent cited comments on the application of the UNCITRAL Arbitration Rules by the Iran-US Claims Tribunal in Baker & Davis, The UNCITRAL Arbitration Rules in Practice, 1992, pp. 76 and 98. The Respondent also relied on the practice of the Appellate Body of the WTO in finding that it had broad authority to adopt procedural rules that did not conflict with the express rules of the WTO Dispute Settlement Understanding, therefore allowing amicus submissions: see United States - Imposition of Countervailing Duties on Certain Hot-Rolled Lead and Bismuth Carbon Steel Products Originating in the United Kingdom, paragraph 39, [WT/DS138/AB/R], adopted on 7th June 2000.
Article 15(1) of the UNCITRAL Arbitration Rules grants to the Tribunal a broad discretion as to the conduct of this arbitration, subject always to the requirements of procedural equality and fairness towards the Disputing Parties. It provides, broken down into numbered sub-paragraphs for ease of reference below, as follows:
" Subject to these Rules,  the arbitral tribunal may conduct the arbitration in such manner as it considers appropriate,  provided that the parties are treated with equality and that at any stage in the proceedings each party is given a full opportunity of presenting its case."
This provision constitutes one of the essential "hallmarks" of an international arbitration under the UNCITRAL Arbitration Rules, according to the travaur preparatories. Article 15 has also been described as the "heart" of the UNCITRAL Arbitration Rules; and its terms have since been adopted in Articles 18 and 19(2) of the UNCITRAL Model Law on International Commercial Arbitration, where these provisions were considered as the procedural "Magna Carta" of international commercial arbitration. Article 15(1) is plainly a very important provision.
In addressing this issue, there are four principal matters to be considered:
(i) whether the Tribunal’s acceptance of amicus submissions falls within the general scope of the sub-paragraph numbered  of Article 15(1);
(ii) if so, whether the acceptance of amicus submissions could affect the equal treatment of the Disputing Parties and the opportunity of each fully to present its case, under the sub-paragraph numbered  of Article 15(1);
(iii) whether there are any provisions in Chapter 11, Section B, of NAFTA that modify the application of Article 15(1) for present purposes; and
(iv) whether other provisions of the UNCITRAL Arbitration Rules likewise modify the application of Article 15(1) in regard to thia particular case, given the introductory words of the sub-paragraph numbered  of Article 15(1).
It is convenient to consider each matter in turn.
Iran-US Claims Tribunal Note 5 of the Iran-US Claims Tribunal Notes to Article 15(1), of the UNCITRAL Arbitration Rules states;
"5. The arbitral tribunal may, having satisfied itself that the statement of one of the two Governments - or, under special circumstances, any other person - who is not an arbitrating party in a particular case is likely to assist the arbitral tribunal in carrying out its task, permit such Government or person to assist the arbitral tribunal by presenting written and [or] oral statements."
This provision was specifically drafted for the Iran-US Claims Tribunal as a supplementary guide. Although (so it appears from published commentaries) it was invoked by Iran or the US as non-arbitrating parties, it was also invoked by non-state third persons (albeit infrequently), such as the foreign banks submitting their own memorial to the Tribunal in Iran v United States, Case A/15-. see the Award No 63-A/15-FT made by the Full Tribunal (President Bockstiegel and Judges Briner, Virally. Bahrami, Holtzmann, Mostafavi, Aldrich, Ansari and Brower) 2 Iran-US C.T.R. 40, at p.43. For present purposes, the authoritative guide to the exercise of the Iran-US Claim Tribunal’s discretion under Article 15(1) and this award demonstrate that the receipt of written submissions from a non-party third person does not necessarily offend the philosophy of international arbitration involving states and non-state parties.
As to privacy, the Respondeat has accepted that, as a result of Article 25(4), hearings are to be held in camera unless both Disputing Parties consent otherwise. The Respondent has given such consent. The Claimant has given no such consent. The Tribunal must therefore apply Article 25(4); and it has no power (or inclination) to undermine the effect of its terms. It follows that the Tribunal must reject the Petitioners’ requests to attend oral hearings of the arbitration.