> From: Spencer Baugh <sbaugh@janestreet.com>
> Cc: emacs-devel@gnu.org
> Date: Mon, 23 Sep 2024 15:36:10 -0400
>
> Eli Zaretskii <eliz@gnu.org> writes:
> >> Date: Sat, 14 Sep 2024 11:47:42 +0300
> >> From: Eli Zaretskii <eliz@gnu.org>
> >> Cc: emacs-devel@gnu.org
> >>
> >> > Date: Fri, 06 Sep 2024 13:23:19 -0400
> >> > From:  Spencer Baugh via "Emacs development discussions." <emacs-devel@gnu.org>
> >> > Eli Zaretskii <eliz@gnu.org> writes:
> >> > > Spencer, would you please take care of these gotchas?
> >> >
> >> > The attached patch does so.
> >>
> >> Thanks, installed.  But the new single-or-list feature should be
> >> documented in the ELisp manual.
> >
> > Ping! single-or-list is still undocumented, AFAICT.  We should
> > document it ASAP, as it is not good to have on the master branch
> > features which are not reflected in the documentation.
> >
> > TIA
>
> I started writing documentation, but I came to the conclusion that most
> users other than completion-styles should use the "group" widget
> instead.  And documenting single-or-list would encourage using it
> instead of group, which I don't think is correct.
>
> Maybe this widget should just be moved to minibuffer.el?
>
> Alternatively, if there are any other customizable variables or values
> in Emacs which are sometimes a single value, and sometimes a list, then
> this widget would be useful for those.  If we can think of any such
> variables, then that would help justify the existence of single-or-list
> (and I would convert their defcustoms to use single-or-list).  That
> would help in writing documentation about when exactly to use it.

I'm not sure I understand: are you saying that your change to
minibuffer.el can be rewritten to not use single-or-list?  If so, I'm
okay with that, and in that case we should simply remove
single-or-list, until there are some users of it.