+ <term><filename>sysinit.target</filename></term>
+ <listitem>
+ <para>A special target unit
+ covering early boot-up scripts.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><filename>syslog.socket</filename></term>
+ <listitem>
+ <para>The socket unit
+ syslog implementations should
+ listen on. All userspace log
+ messages will be made
+ available on this socket. For
+ more information about syslog
+ integration, please consult
+ the <ulink
+ url="http://www.freedesktop.org/wiki/Software/systemd/syslog">Syslog
+ Interface</ulink>
+ document.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><filename>system-update.target</filename></term>
+ <listitem>
+ <para>A special target unit
+ that is used for off-line
+ system updates.
+ <citerefentry><refentrytitle>systemd-system-update-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ will redirect the boot process
+ to this target if
+ <filename>/system-update</filename>
+ exists. For more information
+ see the <ulink
+ url="http://freedesktop.org/wiki/Software/systemd/SystemUpdates">System
+ Updates
+ Specification</ulink>.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><filename>timers.target</filename></term>
+ <listitem>
+ <para>A special target unit
+ that sets up all timer
+ units (see
+ <citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ for details) that shall be
+ active after boot.</para>
+
+ <para>It is recommended that
+ timer units installed by
+ applications get pulled in via
+ <varname>Wants=</varname>
+ dependencies from this
+ unit. This is best configured
+ via
+ <varname>WantedBy=timers.target</varname>
+ in the timer unit's
+ <literal>[Install]</literal>
+ section.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><filename>umount.target</filename></term>
+ <listitem>
+ <para>A special target unit
+ that umounts all mount and
+ automount points on system
+ shutdown.</para>
+
+ <para>Mounts that shall be
+ unmounted on system shutdown
+ shall add Conflicts
+ dependencies to this unit for
+ their mount unit, which is
+ implicitly done when
+ <varname>DefaultDependencies=yes</varname>
+ is set (the default).</para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Special System Units for Devices</title>
+
+ <para>Some target units are automatically pulled in as
+ devices of certain kinds show up in the system. These
+ may be used to automatically activate various services
+ based on the specific type of the available
+ hardware.</para>
+
+ <variablelist>
+ <varlistentry>
+ <term><filename>bluetooth.target</filename></term>
+ <listitem>
+ <para>This target is started
+ automatically as soon as a
+ Bluetooth controller is
+ plugged in or becomes
+ available at boot.</para>
+
+ <para>This may be used to pull
+ in Bluetooth management
+ daemons dynamically when
+ Bluetooth hardware is
+ found.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><filename>printer.target</filename></term>
+ <listitem>
+ <para>This target is started
+ automatically as soon as a
+ printer is plugged in or
+ becomes available at
+ boot.</para>
+
+ <para>This may be used to pull
+ in printer management
+ daemons dynamically when
+ printer hardware is
+ found.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><filename>smartcard.target</filename></term>
+ <listitem>
+ <para>This target is started
+ automatically as soon as a
+ smartcard controller is
+ plugged in or becomes
+ available at boot.</para>
+
+ <para>This may be used to pull
+ in smartcard management
+ daemons dynamically when
+ smartcard hardware is
+ found.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><filename>sound.target</filename></term>
+ <listitem>
+ <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>