+ argument in the form VARIABLE=VALUE.
+ May be used to set default environment
+ variables to add to forked child processes.
+ May be used more than once to set multiple
+ variables.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>quiet</varname></term>
+
+ <listitem><para>Turn off
+ status output at boot, much like
+ <varname>systemd.show_status=false</varname>
+ would. Note that this option is also
+ read by the kernel itself and disables
+ kernel log output. Passing this option
+ hence turns off the usual output from
+ both the system manager and the kernel.
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>debug</varname></term>
+
+ <listitem><para>Turn on debugging
+ output. This is equivalent to
+ <varname>systemd.log_level=debug</varname>.
+ Note that this option is also read by
+ the kernel itself and enables kernel
+ debug output. Passing this option
+ hence turns on the debug output from
+ both the system manager and the
+ kernel.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>emergency</varname></term>
+ <term><varname>-b</varname></term>
+
+ <listitem><para>Boot into emergency
+ mode. This is equivalent to
+ <varname>systemd.unit=emergency.target</varname>
+ and provided for compatibility reasons
+ and to be easier to
+ type.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>rescue</varname></term>
+ <term><varname>single</varname></term>
+ <term><varname>s</varname></term>
+ <term><varname>S</varname></term>
+ <term><varname>1</varname></term>
+
+ <listitem><para>Boot into rescue
+ mode. This is equivalent to
+ <varname>systemd.unit=rescue.target</varname>
+ and provided for compatibility reasons
+ and to be easier to
+ type.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>2</varname></term>
+ <term><varname>3</varname></term>
+ <term><varname>4</varname></term>
+ <term><varname>5</varname></term>
+
+ <listitem><para>Boot into the
+ specified legacy SysV runlevel. These
+ are equivalent to
+ <varname>systemd.unit=runlevel2.target</varname>,
+ <varname>systemd.unit=runlevel3.target</varname>,
+ <varname>systemd.unit=runlevel4.target</varname>,
+ and <varname>systemd.unit=runlevel5.target</varname>, respectively,
+ and provided for compatibility reasons
+ and to be easier to
+ type.</para></listitem>