Sec. 1.337  Return of service.

    (a) If service of the subpena is made by a person other than a 
United States marshal or his deputy such person shall make affidavit 
thereof, stating the date, time, and manner of service.
    (b) In case of failure to make service, the reasons for the failure 
shall be stated on the original subpena by the person who attempted to 
make service.
    (c) The original subpena, bearing or accompanied by the required 
return affidavit or statement, shall be returned forthwith to the 
Secretary of the Commission or, if so directed on the subpena, to the 
official before whom the person named in the subpena is required to 
appear.