lines (ACS or UTF-8), double or heavy (UTF-8), simple (plain ASCII) or
number (the pane numbers). Lines that won't work on a non-UTF-8 terminal
are translated back into ACS when they are output.
terminal features, each of which are defined in one place and map to a
builtin set of terminfo(5) capabilities. Features can be specified based
on TERM with a new terminal-features option or with the -T flag when
running tmux. tmux will also detect a few common terminals from the DA
and DSR responses.
This is intended to make it easier to configure tmux's use of
terminfo(5) even in the presence of outdated ncurses(3) or terminfo(5)
databases or for features which do not yet have a terminfo(5) entry.
Instead of having to grok terminfo(5) capability names and what they
should be set to in the terminal-overrides option, the user can
hopefully just give tmux a feature name and let it do the right thing.
The terminal-overrides option remains both for backwards compatibility
and to allow tweaks of individual capabilities.
tmux already did much of this already, this makes it tidier and simpler
to configure.
it is present and zero. This is useful for users with terminals or fonts
that do not correctly support UTF-8 line drawing characters. GitHub
issue 927, reported by Hiroaki Yamazoe and Akinori Hattori.
terminals (I'm looking at you, putty) which disable the vt100 ACS mode
switching sequences in UTF-8 mode.
Also on terminals without ACS at all, use ASCII equivalents where
obvious.
nicm