Edit: so far every single vendor I've looked at (OK, just Linuxen: Gentoo, Debian, Ubuntu and CentOS) doesn't package the packlists. If someone could point me to one who does so I can look at their policy and build system, that would be enormously helpful already.
:) ActiveState has long included packlists .... I doubt they have an official documented policy
search engines and websites (centos.org .... ) are useless for getting this kind of information
The only policy I've ever seen is http://www.debian.org/doc/packaging-manuals/perl-policy/ch-module_packages.html