I have a latin american keyboard and I'm trying to use the right alt key so I can write symbols like the backtip and others.
What I've tried is:
setxkbmap -option compose:ralt
I'm under Arch Linux.
A command I regurlarly use is
setxkbmap -option l3:ralt_switch us.
The symbols you want are mapped to the level 3 of your keyboard config, if you look at the definition files in /usr/share/X11/xkb/symbols/....