+ of system suspend/hibernation and resume, there are
+ much nicer interfaces available.</para>
+
+ <para>Note that
+ <filename>systemd-suspend.service</filename>,
+ <filename>systemd-hibernate.service</filename>, and
+ <filename>systemd-hybrid-sleep.service</filename>
+ should never be executed directly. Instead, trigger
+ system sleep states with a command such as
+ <literal>systemctl suspend</literal> or
+ similar.</para>
+
+ <para>Internally, this service will echo a string like
+ <literal>mem</literal> into
+ <filename>/sys/power/state</filename>, to trigger the
+ actual system suspend. What exactly is written
+ where can be configured in the <literal>[Sleep]</literal>
+ section of <filename>/etc/systemd/sleep.conf</filename>.
+ See <citerefentry><refentrytitle>systemd-sleep.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
+ </para>
+ </refsect1>