-From within systemd network namespace, nat it to the outside. If given
--c, or if in the default network namespace, create a named network
-namepace natted to the current netns.
+From within a systemd network namespace, nat it to the outside. This
+would be called from ExecStartPre, and or subsequent units called with
+JoinsNamespaceOf= and PrivateNetwork=true.
+
+If given -c, or if in the default network namespace, create a named
+network namepace natted to the current netns.