Comment 2 for bug 971710

From : http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=610429
and the reference : http://wiki.debian.org/LSBInitScripts/

"the problem its that rules [are] set to non default values due [to the] type of daemon...

and LSB header says different ...

must update LSB headers and change to:

# Default-Start: 1 2 3 4 5
# Default-Stop: 0 6

this change[s] are a clear mistake of the packager."

Sorting through this information, you have to modify the file /etc/init.d/apcupsd accordingly.
e.g. Use gedit in super user mode:

$ gksu gedit /etc/init.d/apcupsd

You will see the current (problematic) LSBInit

#!/bin/sh

### BEGIN INIT INFO
# Provides: apcupsd
# Required-Start: $remote_fs $syslog
# Required-Stop: $remote_fs $syslog
# Should-Start: $local_fs
# Should-Stop: $local_fs
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: Starts apcupsd daemon
# Description: apcupsd provides UPS power management for APC products.
### END INIT INFO

To make this script LSB (Linux Standards Base)-compliant, change it to look like this

#!/bin/sh

### BEGIN INIT INFO
# Provides: apcupsd
# Required-Start: $remote_fs $syslog
# Required-Stop: $remote_fs $syslog
# Should-Start: $local_fs
# Should-Stop: $local_fs
# Default-Start: 1 2 3 4 5
# Default-Stop: 0 6
# Short-Description: Starts apcupsd daemon
# Description: apcupsd provides UPS power management for APC products.
### END INIT INFO

I managed to rebuild this package with dpkg-deb -b dir-name

And there is no more warning while installing it :

$ sudo dpkg -i apcupsd_3.14.10-2_amd64.deb
(Reading database ... 1195394 files and directories currently installed.)
Preparing to replace apcupsd 3.14.10-2 (using apcupsd_3.14.10-2_amd64.deb) ...
Please check your configuration ISCONFIGURED in /etc/default/apcupsd
Unpacking replacement apcupsd ...
Please check your configuration ISCONFIGURED in /etc/default/apcupsd
Setting up apcupsd (3.14.10-2) ...
Please check your configuration ISCONFIGURED in /etc/default/apcupsd
Processing triggers for man-db ...
Processing triggers for ureadahead ...
$

Cheers :-)