Created attachment 859290 [details]
Main boot menu: Some "lines" open a sub-menu, while others boot a kernel

There is quite some confusion what happens when you hit enter on a line
displayed in GRUB's boot menu:
Some lines are boot entries that boot a kernel, while other lines are submenus
that open another menu.

I suggest to add additional hints indicating that the line actually opens
another menu.
GUIs typically add "���������" at the end of an entry indicating that another dialog
(or menu) will open.
As an alternative add an arrow mark like "������" or "���������" at the beginning of a menu
line that opens another sub-menu.

To increase the confusion the Xen "advanced" boot entry contains nested
submenus.

I'm attaching some examples from SLES15 SP3, but they'll apply to Leap also, I
guess.