Where a witness is unable to meet the costs of his travel, he shall be issued, if he so requests and on presentation of an order made by the president of the judicial court of his place of residence, with a deposit on the compensation that will be due to him.
This advance payment may be equal to the price of a return ticket when the journey is made by a transport service that issues return tickets payable in full at the time of departure; in other cases, it must not exceed half the amount of the compensation.
The imprest administrator who pays this advance shall mention it in the margin or at the bottom of either the copy of the summons or the warning given to the witness.