> This is performed by emitting the runlevel(7) event, which includes the new runlevel in the RUNLEVEL
environment variable as well as the previous runlevel (obtained from the environment or from
/var/run/utmp) in the PREVLEVEL variable. An additional INIT_HALT variable may be set, this will con‐
tain the value HALT when bringing the system down for halt and POWEROFF when bringing the system down
for power off.