+
+ <para>Optionally, a mount unit may be accompanied by
+ an automount unit, to allow on-demand or parallelized
+ mounting. See
+ <citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
+
+ <para>If a mount point is beneath another mount point
+ in the file system hierarchy, a dependency between both
+ units is created automatically.</para>
+
+ <para>Mount points created at runtime (independently of
+ unit files or <filename>/etc/fstab</filename>) will be
+ monitored by systemd and appear like any other mount
+ unit in systemd.</para>
+
+ <para>Some file systems have special semantics as API
+ file systems for kernel-to-userspace and
+ userspace-to-userpace interfaces. Some of them may not
+ be changed via mount units, and cannot be disabled.
+ For a longer discussion see <ulink
+ url="http://www.freedesktop.org/wiki/Software/systemd/APIFileSystems">API
+ File Systems</ulink>.</para>