RE: vertical fido-mode

[Drew Adams]

> > Please don't add any bindings for C-n/C-p to any
> > standard minibuffer keymaps.
> 
> What keys would be better for vertical completions navigation?
> Maybe M-up and M-down like in web browsers?

Don't know/care.  Whatever keys you choose, please
just don't bind them in a standard minibuffer keymap
(`minibuffer-local-*').