I have always thought that the horizontal rebar used as a concrete encased electrode had to be "near the bottom" of the footing or foundation. Now it has brought to my attention that the "near the bottom" part went away in the 2011 NEC. I haven't had a chance yet to go dig for the substantiation. Does anyone know why they removed the wording? And would tying on to rebar in the top of a foundation wall really suffice?