Shirts must be tucked into pants so that the belt or waistline is clearly visible all the way around waist.
(Shirts; must be tucked; into pants; so that the belt or waistline is clearly visible all the way around waist) (the belt or waistline; is clearly; visible all the way around waist)
Shirts the belt or waistline
must be tucked is clearly
into pants so that the belt or waistline is clearly visible all the way around waist
visible all the way around waist