config files management in maintscripts

["bilibop project" <quidame@Safe-mail.net>]

Hi,

I've built a package supplying:
- a udev rules file (in /lib/udev/rules.d)
- a helper script to build a custom rules file (in /etc/udev/rules.d) to override the previous one.
  This script is run manually by the admin.

Of course, when the package is removed, the custom rules file is not removed.
My question is: what to do when the package is PURGED ? Should the prerm or postrm script
remove this configuration' file even if it is not directly provided by the package ? Or should I
let the admin do as she wants ?

Thanks,
quidame