In fiscal year 1991 and thereafter, when a Senator disseminates information under the frank by a mass mailing (as defined in ), the Senator shall register quarterly with the Secretary of the Senate such mass mailings. Such registration shall be made by filing with the Secretary a copy of the matter mailed and providing, on a form supplied by the Secretary, a description of the group or groups of persons to whom the mass mailing was mailed and the number of pieces mailed.section 3210(a)(6)(E) of title 39