(a) Testimony. Where appropriate, the Presiding officer may direct that the testimony of witnesses be prepared in written exhibit form and shall be served at designated dates in advance of the hearing. Evidence as to events occurring after the exhibit-exchange dates shall be presented by a revision of exhibits. Witnesses sponsoring exhibits shall be made available for cross-examination. However, unless authorized by the presiding officer, witnesses will not be permitted to read prepared testimony into the record. The evidentiary record shall be limited to factual and expert opinion testimony. Argument will not be received in evidence but rather should be presented in opening and/or closing statements of counsel and in briefs to the presiding officer subsequently filed.

(b) Exhibits. All exhibits and responses to requests for evidence shall be numbered consecutively by the party submitting same and appropriately indexed as to number and title and shall be exchanged on dates prior to the hearing prescribed in the prehearing rulings. Written testimony should be identified alphabetically. Two copies shall be sent to each party and two to the presiding officer. No response to a request for evidence will be received into the record unless offered and received as an exhibit at the hearing. The exhibits, other than the written testimony, shall include appropriate footnotes or narrative material explaining the source of the information used and the methods employed in statistical compilations and estimates and shall contain a short commentary explaining the conclusions which the offeror draws from the data. Rebuttal exhibits should refer specifically to the exhibits being rebutted. Where one part of a multipage exhibit is based upon another part, appropriate cross-reference should be made. The principal title of each exhibit should state precisely what it contains and may also contain a statement of the purpose for which the exhibit is offered. However, such explanatory statement, if phrased in an argumentative fashion, will not be considered as a part of the evidentiary record. Additional exhibits pertinent to the issues may be submitted in a proceeding with the approval of the presiding officer.

(c) Cooperation on basic data. Parties having like interests are specifically encouraged to cooperate with each other in joint presentations particularly in such items as basic passenger, cargo, and scheduling data compiled from official or semiofficial sources, and any other evidence susceptible to joint presentation. Duplicate presentation of the same evidence should be avoided wherever possible.

(d) Authenticity. The authenticity of all documents submitted as proposed exhibits in advance of the hearing shall be deemed admitted unless written objection thereto is filed prior to the hearing, except that a party will be permitted to challenge such authenticity at a later time upon a clear showing of good cause for failure to have filed such written objection.

(e) Statement of position and trial briefs. A written statement of position should be exchanged by all counsel with copies to all other parties prior to the beginning of the hearing: Provided, however, That Public Counsel or counsel for a public body which has intervened as its interests may appear, may offer his statement of position at the conclusion of the evidentiary hearing, unless such is impracticable. This statement should include a showing of the theory of the case of the party submitting the statement and will not be subject to cross-examination. Trial briefs are acceptable but will not be required.