As has been stressed in the tutorial: Form is not to be underestimated! This is even more so for the memoranda prepared during the Vis Moot. As a competition, the Vis Moot has its own rules that i.a. contain formal requirements. Not adhering to these requirements can result in downgrading of your memorandum or even disqualification from the competition. Thus, have a good look at the Vis Moot Rules and stick to them.
Note that every year a new set of rules is published. The current one can be found here. Most of the formatting requirements have been unchanged for the last few years. Currently the following requirements set out in the rules are (emphasis added):
VII. Formatting of Memoranda
42. The formatting provisions listed in paragraphs 43, 44, 45, 48 and 49 are required to be followed. No memorandum that violates these provisions will be considered for award or honorable mention.
43. Paragraphs must be numbered and references to statements in either one’s own memorandum or, in the case of the memorandum for respondent, to statements in the opponent’s memorandum for claimant must be to the paragraph number.
44. The memoranda are intended to be of practical use to the arbitrators in deciding the dispute. They are not intended to be scholarly dissertations on the relevant law. Therefore, citations in the memorandum should be limited to those that advance the argument being made. The List of Authorities must reference to each paragraph in the memorandum where the case or doctrinal authority is cited. The use of passim in place of specific paragraph numbers is not sufficient.
45. Citations must be in the text of the memorandum and not in footnotes or endnotes. Citations in the text should be in a shortened form. The full citation should be given in a List of Authorities.
46. The List of Authorities should be in a form that is intelligible to all who will read the memorandum. That includes the members of the other teams, the arbitrators in the oral hearings and the members of the jury who will judge the written phase of the Moot. Most of the readers of the memorandum will be from other countries. Account should be taken that the style of citation of judicial decisions or articles in legal journals that is common in one country may not be intelligible to participants in the Moot (or in an arbitration) from other countries. Therefore, deviation from the standard style of citation in your country may be appropriate and desirable.
47. Care should be taken in the use of legal doctrines and terminology (including Latin maxims) common in some legal systems that are not found in the CISG, Model Law, New York Convention or the relevant arbitration rules and that may not be known to teams or arbitrators from other legal systems. Similarly, care should be taken to write in a formal English style that would be appropriate for submission to a court or arbitral tribunal. In particular, slang or contractions (aren’t, didn’t) should not be used. This tends to be a mistake made by non-Anglophone teams that may have been taught not to be too formal when using English.
48. Memoranda may be no longer than thirty five (35) 8½ x 11 inch or A4 typed pages, including any statement of facts, argument or discussion and any conclusion. Cover pages, tables of contents, indices, lists of authorities or other material that does not consist of facts, argument, discussion or conclusions may be in addition.
49. No type style smaller than 12 point may be used, including in quotations or other non-argument parts of the memorandum. The memorandum should be typed at 1½ line-spacing. All margins must be at least one inch or 2.5 cm.
50. The name of the team and whether the memorandum is for the claimant or for the respondent must appear prominently on the outside cover page so that it can easily be read without opening the memorandum.
Of course the only binding source of these rules are the official publication of the current Vis Rules on the official Vis Moot website at Pace University. Please double check the rules published there and do not rely on the reproduction here.