No, I'm sorry I can't. I was taking for granted that a couple of acorn clamps on the #6 from the coil extension passing the rebar cage being a de facto practice—but shoulda’ figured it as a “regional variation." It would be a waste not to take every advantage of a ready-made attribute that comes with cages and concrete. In my experience, that detail seems to show up in a lot of municipal-specification boilerplate, but then again I've not worked in Detroit, Michigan or Muleshoe, Texas.
The ‘coil’ has probably been adapted from the long-standing utility practice for wood-pole butt grounding. The hippest in-the-know electrical experts call it a microUfer matrix. ;-)