Eli Zaretskii <eliz@gnu.org> 于2023年3月30日周四 13:33写道：
>
> I think there's a cleaner way: a defcustom can have a :set function,
> which is called each time the variable is customized; this setter
> function should be defined for a defcustom when changing its value has
> non-trivial effects.  So we can define such a setter function to
> rewrite the list, and document in the doc string of the defcustom that
> users should not just set the value with setq, but instead use either
> setopt or "M-x customize-variable".  WDYT?

OK, I think it is good. Please see the attached patch.