I have a bind in vim for F5 key to trim whitespaces and I'm unable to use it in tmux. Instead of that letter "T" appears. Is there's any solution for that? Actually it was working in putty, now I've switched to Xshell4. Can this be TERM issue? inside tmux $TERM is screen
![How to use Fn keys in tmux?](https://cdn-ak-scissors.b.st-hatena.com/image/square/1903ece89af850aed3e9777e774c51491b959a61/height=288;version=1;width=512/https%3A%2F%2Fcdn.sstatic.net%2FSites%2Fsuperuser%2FImg%2Fapple-touch-icon%402.png%3Fv%3De869e4459439)