at my high school, administrators know that they cant do anything in order to keep students from bringing their phones- its going to happen! students text, take pictures and video record when the teacher isnt paying attention.
before the morning bell and during our lunch periods, we are able to use our phones with the admin. permitting.
our dress code isnt very strict. no tanks, shoulder width should be 3 fingers width, no midriff showing, hats, du rags, short shorts... anything of that sort.