Package: grep Version: 3.8-5 In Debian 12 stable, open an xterm in gnome on xorg and run: $ grep "[[:ascii:]]" /etc/services grep: Ungültiger Name für eine Zeichenklasse $ LC_ALL=en_US.utf8 grep "[[:ascii:]]" /etc/services grep: Invalid character class name The same error comes up with [:nonascii:]. However, both are listed in https://www.gnu.org/software/emacs/manual/html_node/elisp/Char-Classes.html https://www.gnu.org/software/emacs/manual/html_node/elisp/Char-Classes.html.
