Gezz, when I was a 70250B in the USAF messages were enough of a pain without having to worry about upper and lower case! Really that was the only up side; everything else was so particular. Ok, then again anything typed in my squadron was really particular now that I think about it!
I was a 30671 when I was in the AF. I remember reading msgs. in text, ITA-2, ASCII, and Hollerith.