Thanks to all suggestions, here is what is now running at my site, in
/etc/apt/apt.conf.d/local-recommends:
Dpkg::Pre-Install-Pkgs{
"xargs --max-args=1 dpkg -I|grep -e 'Package\|Suggests\|Recommends' "
}
gives out a list of installed packages and their Recommends or
Suggests-fields.
cheers
Uli