After an exchange of comments on the Emacs wiki, that left me
wondering...
Is there any place in the Emacs documentation that explains that you
*can* type C-M-@, C-@, C-M-\, C-\ and C-] on an AltGr-challenged
keyboard, *provided* that you use the right order, i.e., AltGr, right
Ctrl, and then the modified key?
For example, on my Spanish keyboard:
C-M-@ => AltGr RCtrl Alt 2
C-@ => AltGr RCtrl 2
C-M-\ => AltGr RCtrl Alt º
C-\ => AltGr RCtrl º
C-] => AltGr RCtrl +
It is non-obvious: it doesn't work if you press other key before
AltGr, or if you use left control.