[Fedora-packaging] Do we allow arch specific Requires: in spec?

[Parag N(पराग़)]

Hi all,
    Just found one old bugzilla link
https://bugzilla.redhat.com/show_bug.cgi?id=235755 which tells rpm in
rawhide allows arch specific Requires: in spec.
    Just want to know is it possible in Fedora and since which rpm
version? I found link from comment #19 is not working. Is there any
package in fedora currently using this? Just curious to know what will
be the case where one really need arch specific Requires?
   I can't find anything related to this written in
http://fedoraproject.org/wiki/Packaging/Guidelines#Requires

Regards,
Parag.