Thanks Eugene. I misinterpreted your post and though that the NORAC rules used a form of what we called DTC on the SP. It sounds more like the Form D is simply another name for Track Warrant, and that the Form D and Track Warrant system are similar (but not necessarily the same). And Direct Traffic Control is something different, and apparently disappeared on major railroads when SP and CNW merged into UP. In rereading your original post that should have been obvious to me, but I was focused on DTC.