@item :group
If this is specified, the value should be the customization group for
-this mode. (Not all major modes have one.) Only the (still
-experimental and unadvertised) command @code{customize-mode} currently
-uses this. @code{define-derived-mode} does @emph{not} automatically
-define the specified customization group.
+this mode. (Not all major modes have one.) The command
+@code{customize-mode} uses this. @code{define-derived-mode} does
+@emph{not} automatically define the specified customization group.
@item :after-hook
This optional keyword specifies a single Lisp form to evaluate as the