Perhaps something simple like "This function returns t if the file filename1 is newer than file filename2, as reported by your operating system."

On Tue, Oct 15, 2024 at 10:52 AM Eli Zaretskii <eliz@gnu.org> wrote:
> From: Drew Adams <drew.adams@oracle.com>
> CC: "73709@debbugs.gnu.org" <73709@debbugs.gnu.org>
> Date: Tue, 15 Oct 2024 14:20:21 +0000
>
> > So these are the conceptual difficulties we bump into when we go down
> > to this low level.
>
> There's no reason to go down to a low level
> to fix this doc bug for `file-newer-than-file-p'.

You are missing the point of my post.  The point was not to say this
should be in the doc string, the point was to explain why "time of the
last write" is still not accurate in some quite widespread cases.  The
low-level details were meant to explain the subtleties, so that if
someone has ideas how to describe that _without_ getting into details,
but also without being inaccurate, could understand the problem to
solve.