Different types of diesel

I remember before ULSD, the loading rack would have HS burner, and I think it was 2000 or 5000 ppm max? Then LS was 500 ppm max? Then came along ULSD. Maybe the old fuel haulers will chime in. Yes, I read part of the thread, but I was still in my morning haze, so if this was mentioned already, sorry. But I remember loading HS burner and it was designated off road dyed. So I always would go fill my service tank from the pumps from where we hauled it to. My old 7.3 loved it.