Can i Obsoletes core packages from extras package?

[Paul Howarth]

seth vidal wrote:
> On Tue, 2006-07-18 at 12:50 +0530, Parag N(पराग़) wrote:
>> Hi,
>>   I am planning to add Gutenprint package to Fedora-extras. Gutenprint
>> was formerly called Gimp-Print. So once this package is in
>> Fedora-extras it needs first to remove following packages
>> gimp-print
>> gimp-print-cups
>> gimp-print-devel
>> gimp-print-plugin
>> gimp-print-utils
>>  But is it allowed to do that?
>> I have opened a review request for this package. You can check it at
>> https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=199108
>>
> 
> No. Absolutely not.
> 
> Extras packages are not allowed to obsolete or explicitly conflict with
> core.

I was pretty sure this was the case, but I can't seem to find it 
documented anywhere in the packaging guidelines. Did I miss somewhere?

Paul.