author and iconoclast
posted 6 years ago
-r or -R stand for "raw", and they tell less to pass control characters through unchanged. The default is to display them textually -- not as "garbage", really, but for example to show the three ASCII letters "ESC" instead of the control character named "escape". "-r" means to do this for all characters, while "-R" means to do this only for those characters that control coloring and highlighting in a terminal, the so called "ANSI escape sequences."