In hs-minor-mode, typing C-x @ C-e gives "C-x @ C-e is undefined" in the echo area. Section 26.7 of the manual (https://www.gnu.org/software/emacs/manual/html_node/emacs/Hideshow.html ), on the contrary, says that hs-toggle-hiding is bound to C-x @ C-e. (hs-toggle-hiding is bound to C-c @ C-e, so this is likely a typo in the manual.) In GNU Emacs 26.2 (build 2, x86_64-pc-linux-gnu, GTK+ Version 3.22.30) of 2019-04-12 built on lgw01-amd64-060 Windowing system distributor 'The X.Org Foundation', version 11.0.11906000 System Description: Ubuntu 18.04.2 LTS Recent messages: Loading /home/ricercar/.emacs.d/elpa/tabbar-20180726.1735/tabbar.el (source)...done Can’t guess python-indent-offset, using defaults: 4 Applying style hooks...done DocView: using cached files! Type C-c C-c to toggle between editing or viewing the document. Wrote /home/ricercar/.emacs.d/.emacs.desktop.lock Desktop: 1 frame, 10 buffers restored. For information about GNU Emacs and the GNU system, type C-h C-a. Undo! 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