Just a word about CAPS.
I had a customer who was emailing me about a flight in All Caps. The first thing that came to mind was, what a jerk, I really don't want to deal with him. Then he asked me to call him and I braced myself for someone who was just going to yell and scream. First thing he said was that I am really old so I write in all caps because I can see the words much better. He turned out to be a real nice guy.