+ the device is not exposed as a systemd
+ unit (see above).</para>
+
+ <para>Note that systemd will only act
+ on <varname>Wants</varname>
+ dependencies when a device first
+ becomes active. It will not act on
+ them if they are added to devices that
+ are already active. Use
+ <varname>SYSTEMD_READY=</varname> (see
+ below) to influence on which udev
+ event to trigger the dependencies.
+ </para></listitem>