You found that it is catcheverest_options because it is used with the register_setting function, right ?
But how do you find out about the 3 subkeys ? Using a different theme I tried a bunch of things and nothing appeared in the strings translation tab.
I had to use PHP directly as succinctly described here. Upside is that you only have to register once, then it stays in the strings translation tab and you can remove the PHP, so no slowdown. I'm not sure it's the same with wpml-config.xml, which may have to be loaded each time. Or not... :)
