I recently switched to Ubuntu 17.10 from Ubuntu 16.04.
So far, I used xmodmap to remove Caps_Lock and replace it with the backslash-symbol.
This doesn't seem to work under 17.10 (maybe because xmodmap is an X11 app and 17.10 uses Wayland?). Is there another way to get this done?
The answer is complicated and and evolving: see https://unix.stackexchange.com/questions/292868/how-to-customise-keyboard-mappings-with-wayland for a variety of approaches.
The GNOME Tweak Tool might be your best bet. https://unix.stackexchange.com/a/417708/108198
By the way, Ubuntu 18.04 LTS uses Xorg by default.
