[Fedora-packaging] Guidelines#DuplicateFiles clarification

[Michael Schwendt]

>  http://fedoraproject.org/wiki/Packaging/Guidelines#DuplicateFiles:
>
>  A Fedora package must not contain any duplicate files in the %files
>  listing. 
What exactly does that refer to?

Only the rpmbuild "warning: File listed twice ..."?
Or actual files included in multiple %files sections for (sub-)packages?

The latter is not detected by rpmbuild.