I'm reading over the tmux manual and as best I can tell, if
set is given with no flags, it's a "session option" by default, which I assume to mean that it only applies to that one session.
-g flag is provided, it's a "global session" option. Which I assume to mean it applies to all sessions.
Now, if I do
setw -g, that's a global window option, which I assume to mean that it applies to all windows in a session, which is the same as as
set with no flag.
Then there is the
-s flag, which means it applies across the entire server. This sounds like it would apply to all sessions, which sounds like the same thing as
set -g flag. But I don't think this can be right. That doesn't sound right, though, because then why have two flags that do the same thing?