prerm is in nas 1.9.3-4.
This file is a maintainer script. It is executed when installing (*inst) or removing (*rm) the package.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21  | #!/bin/sh -e
if [ \( "$1" = "upgrade" -o "$1" = "remove" \) -a -L /usr/doc/nas ]; then
 	rm -f /usr/doc/nas
fi
case "$1" in
	remove|upgrade|remove-in-favour|deconfigure-in-favour)
		# Stop running nas
        if which invoke-rc.d >/dev/null 2>&1; then
            invoke-rc.d nas stop
        else
            /etc/init.d/nas stop
        fi
		;;
	failed-upgrade)
		;;
esac
 |