It's right ALT+Space. After 'C-h b' it's first character at list 'Key translations' key: A-SPC. I tried with (global-unset-key (kbd "A-SPC")) or try to find it with (lookup-key (current-global-map) (kbd "A-SPC")) but it returns nil.

  • What does it say when you press C-h k and then press right Alt+Space?
    – Hubisan
    Commented Sep 8, 2022 at 19:55
  • "runs the command org-self-insert-command..."
    – slk500
    Commented Sep 8, 2022 at 19:59
  • and did it say A-SPC? nothing about that it was translated? you could try call global-unset-key interactively with M-x and then hit the A-SPC. Maybe you have to unbind it in a map mentionned here: gnu.org/software/emacs/manual/html_node/elisp/…
    – Hubisan
    Commented Sep 9, 2022 at 20:34
  • 2
    Consider updating your question with following info ... What OS are you using? What is the printed word on the keyboard key you are pressing. If you are on linux, post the result of xmodmap. Most likely the key in question is doing shifting the keyboard to the next input level or group. Open gnome-tweaks to inspect see how the keyboard system is configured.
    – user31220
    Commented Sep 11, 2022 at 1:28

1 Answer 1


I suspect your right Alt key is doing something outside of Emacs and sending Emacs a non-breaking space in that particular combination.

Test that outside of Emacs.

If this is the case, you'll have to resolve the issue outside of Emacs.

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