On Tue, Oct 25, 2022 at 01:01:14PM -0400, Stefan Monnier via Users list for the GNU Emacs text editor wrote:
> tomas@tuxteam.de [2022-10-21 19:00:56] wrote:
> >> file-remote-p works only when you use a special file name syntax. This
> >> is not clear from the docstring.
> > I think it's not about the syntax per se, but about whether Emacs handles
> > the remoteness itself or it is the operating system's job.
> 
> There's also the question of it means to be "remote".
> Is a file accessed via /su:... remote?
> What about a file accessed via NFS to a virtual machine running on the
> same physical machine?

Definitely. The closer you look at it the more elusive the thing
becomes :)

For the OP, I think the takeaway is that file-remote-p can only be
about remoteness Emacs "knows about", i.e. where Emacs handles the
protocol "bringing over" the file. So no NFS, no CIFS etc.

Cheers
-- 
t