RE: key to yank text at point into minibuffer?

[Drew Adams]

    I hit the "control", the "meta", and the "backspace" keys
    simultaneously.  [On my keyboard, the physical key
    is actually labelled "Delete", and generates an ascii DEL character,
    but apparently in some contexts (with modifier key?) it is interpreted
    to mean backspace.]

     > FWIW, in my own customization, I have `C-M-DEL' (Backspace)
     > bound globally (all modes) to `backward-kill-sexp'.

    Heh; since meta is commonly mapped to "Alt", that one sound
    potentially awkward as well... C-Alt-Del   :-)

So, on X Window (at least your setup of it), Control-Alt-Backspace (or ASCII
DEL) kills the X server. And on MS Windows, Control-Alt-Delete (not ASCII
DEL) reboots or displays the login screen or Task Manager. It seems that
whichever is chosen as an Emacs binding, Backspace or Delete with
Control-Alt will present problems for one or the other platform. Too bad
they couldn't at least agree on which key to use for interference with Emacs
;-).