Whenever any person subject to this Code has been tried by a civil court, the registrar or clerk of such court shall, if required by the commanding officer of such person or by any other officer, transmit to him a certificate setting forth the offence for which such person was tried, the judgment and the sentence and any order of the court or, if he was acquitted, a statement to that effect, and such certificate shall for all purposes be proof of the conviction and the sentence, or of the order of the court or of the acquittal of such person.