Available Keys
Look at man tmux, search / for KEY BINDINGS:
tmux allows a command to be bound to most keys, with or without a prefix key.
When specifying keys, most represent themselves (for example ‘A’ to ‘Z’).
Ctrl keys may be prefixed with ‘C-’ or ‘^’, and Alt (meta) with ‘M-’.
In addition, the following special key names are accepted:
Up, Down, Left, Right, BSpace, BTab, DC (Delete), End, Enter, Escape, F1 to F20,
Home, IC (Insert), NPage/PageDown/PgDn, PPage/PageUp/PgUp, Space, and Tab.
Note that to bind the ‘"’ or ‘'’ keys, quotation marks are necessary [...]
M-S-Left should be Alt+Shift+Left for example.
List all bound keys
To list all key bindings, simply press Ctrl-b then ? while in a tmux session.
This is also documented in man tmux in section EXAMPLES:
Typing ‘C-b ?’ lists the current key bindings in the current window; up and down may be used to navigate the list or ‘q’ to exit from it.
You can also list all key-bindings via tmux list-keys. If you want to check for already set keys, you can grep it's output to check, if it's already set.
Research
To find more via Google, search for Section names in man tmux - just type in tmux default key bindings for example :). But often man tmux is sufficient.
This site is a very good documentation about tmux and pops up, if you search for said string in Google.
Arch wiki is always good, too.
I have memorized tmux list-keys | less and tmux show -gw | less (I also check just -g, -w, and -s when I think I'm missing something).
That usually gives me anything I need to know, or set. I use man tmux then /OPTIONS for more.
Also remember that any command you would issue to Ctrl+b, : can also be passed to the tmux cli/cmd though tab-completion is a trick to set up there.
Best Answer
The
toecommand will show you the terminfo definitions on the current system. If you lack that command, you see the raw data in/usr/share/terminfoon most Linux systems.