On Fri, 10 Dec 2004 12:54:33 +0100 (MET), Kein Ende said:
is it allowed to make changes in the GPL down the GPL-Copyright preamble in a licence-file?
No.
Copyright (C) 1989, 1991 Free Software Foundation, Inc. 675 Mass Ave, Cambridge, MA 02139, USA. Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.
^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^
It is pretty clear that you you don't have the right to change the text of the GPL at all or even use parts of it for writing your own license or for any other work.
Shalom-Salam,
Werner