In the EX-2 Fuselage Manual on page 75 there is a need to drill a floorboard hole to attach the front seat belt (Photo 132). There is also a parallel need to drill a hole from the underside through an attached nut for which the purpose is unclear. What is the purpose of this hole (Photo 137), perhaps in preparation for some later procedure, yet unidentified. Perhaps it is just another floorboard attachment, should the hole be left unfilled at this stage, any ideas or confirmation?