Still trying to figure out ^Ms in text files

I was still struggling with trying to figure out why Cygwin/Xemacs displays ^Ms in files on Windows. I guess I found the problem, but I'm wondering about exactly what I'm seeing. I noticed that I had hardcoded a setting of (for some reason lost in antiquity): (setq-default buffer-file-coding-system 'undecided-unix) In my "init.el". I thought that coding systems might have something to do with this. I tried commenting this out, and it appeared to fix the problem. Now, when I view either Windows-created files, or Unix-created files, they show with no ^Ms. What's curious is, when I had this hardcoded setting, in my mode line, I would always see "Auto---". Now that I removed the line, I see either "Raw---" or "Raw:T-". I see the "Raw:T" on files that have DOS eols. I don't know what the ":T" specifically means, but it seems odd to me that the notion of "Auto" and "Raw" seems opposite to what it appears to be doing. When it was showing "Auto", it felt like it was "raw", because it would show the file contents without parsing out the ^Ms. When it was showing "Raw", it did parse out the ^Ms.