As of tmux 3.5, this document is out of date; tmux now defaults to supporting extended-keys in a way similar to xterm. Normal ASCII or UTF-8 keys are sent as themselves (a is a). Ctrl with ASCII keys ...
Notifications are sent via libnotify, and visual bells are raised in the Tmux window. Visual bells can be mapped (in the terminal level) to the X11 urgency bit and handled by your window manager. When ...