+ <para>This target is started
+ automatically as soon as a
+ sound card is plugged in or
+ becomes available at
+ boot.</para>
+
+ <para>This may be used to pull
+ in audio management daemons
+ dynamically when audio
+ hardware is found.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Special Passive System Units </title>
+
+ <para>A number of special system targets are defined
+ that can be used to properly order boot-up of optional
+ services. These targets are generally not part of the
+ initial boot transaction, unless they are explicitly
+ pulled in by one of the implementing services. Note
+ specifically, that these <emphasis>passive</emphasis>
+ target units are generally not pulled in by the
+ consumer of a service, but by the provider of the
+ service. This means: a consuming service should order
+ itself after these targets (as appropriate), but not
+ pull it in. A providing service should order itself
+ before these targets (as appropriate) and pull it in
+ (via a <varname>Wants=</varname> type
+ dependency).</para>
+
+ <para>Note that these passive units cannot be started
+ manually, i.e. <literal>systemctl start
+ time-sync.target</literal> will fail with an
+ error. They can only be pulled in by dependency. This
+ is enforced since they exist for ordering purposes
+ only and thus are not useful as only unit within a
+ transaction.</para>
+
+ <variablelist>
+ <varlistentry>
+ <term><filename>local-fs-pre.target</filename></term>
+ <listitem>
+ <para>This target unit is
+ automatically ordered before
+ all local mount points marked
+ with <option>auto</option>
+ (see above). It can be used to
+ execute certain units before
+ all local mounts.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><filename>network.target</filename></term>
+ <listitem>
+ <para>This unit is supposed to
+ indicate when network
+ functionality is available,
+ but it is only very weakly
+ defined what that is supposed
+ to mean, with one exception:
+ at shutdown, a unit that is
+ ordered after
+ <filename>network.target</filename>
+ will be stopped before the
+ network -- to whatever level
+ it might be set up then -- is
+ shut down. Also see <ulink
+ url="http://www.freedesktop.org/wiki/Software/systemd/NetworkTarget">Running
+ Services After the Network is
+ up</ulink> for more
+ information. Also see
+ <filename>network-online.target</filename>
+ described above.</para>
+