> > M-S-LEFT (org-table-delete-column) > Kill the current column. > > But the keystroke combination doesn't work as expected, instead it > triggers the following info in the bottom minibuffer: > M-s is undefined. Which keys, exactly, are you pressing? M-S-Left in Emacs Key Notation ( https://www.emacswiki.org/emacs/EmacsKeyNotation) refers to Meta-Shift-Left, which in my testing works as expected, but the message you see, as posted, corresponds to what happens when you press Meta-s (the letter S) followed by "Left". Best, --Diego