(a) Copies. Unless the officer otherwise directs, the original and 10 copies of each exhibit of a documentary character should be furnished for the use of the Board. The original will be delivered to the reporter, and the copy to the officer. If the hearing is before a board, a copy of the exhibit should be furnished to each member of the board, unless the board otherwise directs. Unless the officer for cause directs otherwise, a reasonable number of copies should be furnished to counsel in attendance at the hearing.

(b) Interchange prior to hearing. Whenever practicable, the parties should interchange copies of exhibits or other pertinent material or matter before or at the commencement of the hearing; and the Board or presiding officer may so direct.

(c) When excluded how treated. When exhibit has been identified, objected to, and excluded, the officer will develop whether the party offering the exhibit withdraws the offer, and if so, permit the return of the exhibit to him. If the excluded exhibit is not withdrawn, it should be given an exhibit number for identification and be incorporated in the record. Exhibit numbers once used for identification will not be duplicated thereafter.