can you (theoretically) run only NFSv4 (without earlier versions)?

[Robert P. J. Day]

   a long, long time ago, i reported an apparent glitch with NFS on
fedora:

https://lists.fedoraproject.org/pipermail/users/2010-January/097465.html

in that, at the time, it *appeared* that you couldn't set up
NFS so that *only* version 4 was running. before i start messing
with this again, anyone know whether that's changed? that is,
is it possible to set up a network in which only NFSv4 is running,
and no earlier versions are supported? thanks.

rday