[arch] [hibernate-script] how to use hibernate-cleanup ?

[solsTiCe d'Hiver]

i installed suspend2 kernel and hibernate-script packages.
i have followed the suspend2 wiki entry for that 
http://wiki.archlinux.org/index.php/Suspend_to_Disk

but it did not mention hibernate-cleanup boot script. 

is that script mandatory ? optionnal ? 

where is its best place in DAEMONS list of /etc/rc.conf ?

before syslog-ng ? after it ? 

an installation message you'd be helpful