Licensing Policy for existing files is?

Hi,

all the files of kdesdk/poxml do not have a copyright header, see 
http://websvn.kde.org/trunk/KDE/kdesdk/poxml

Now the reasoning is that after all there is a COPYING file in the toplevel 
dir of kdesdk, see http://websvn.kde.org/trunk/KDE/kdesdk/COPYING?view=markup
so that one would then apply to the files in the subfolder automatically.

Is that reasoning correct or flawed?

http://techbase.kde.org/Policies/Licensing_Policy only talks about "All _new_ 
source code" for which the requirement 2 is: 

	"All source files must contain a copyright header which identifies the
	 copyright holder(s) together with an e-mail address that can be used to
	 reach the copyright holder."

So, what is the policy for old/existing source code? Is a license file 
floating around in the toplevel dir enough? Or does each single file need a 
proper reference to the license?

Cheers
Friedrich