There does not appear to be a "shell" tag! I realize that AskUbuntu is fairly GUI and newbie oriented but having no tag for one of the landmarks of Unix and Linux systems is frankly ridiculous. I realize that there is a tag for gnome-shell but that does not cover somebody talking generically about sh, csh, bash and zsh in a generic sense, or talking about shells in general and certainly does not cover somebody working purely from a CLI.