Where is it stated the ranger roll is unauthorized?

I've searched AR 670-1 repeatedly looking for the standard on wear of the patrol cap. Now that we have switched back the CSM is all about making sure us NCO's ensure soldiers are wearing it right, which includes keeping soldiers from utilizing the "ranger roll" and whatnot. The only thing I found is that the bottom must go around the largest part of the head and be parallel to the ground with no bunching or gaps. Can anyone explain this better?