- <varname>Type=forking</varname> is set,
- the process started via this command
- line will be considered the main
- process of the
- daemon.</para></listitem>
+ <varname>Type=forking</varname> is
+ set, the process started via this
+ command line will be considered the
+ main process of the daemon. The
+ command line accepts % specifiers as
+ described in
+ <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. On
+ top of that basic environment variable
+ substitution is supported, where
+ <literal>$(FOO)</literal> is replaced
+ by the value of the environment
+ variable of the same
+ name.</para></listitem>