is this an enforceable restriction?

[Arnoud Engelfriet]

mr wrote:
> is released under the GPL however they have an added restriction that
> you are not allowed to remove the code that displays "Powered By:
> Snitz Forums 2000". Is this even enforceable if I also am granted all
> the rights as defined by the GPL?

This is a hard question. On the one hand, a copyright holder can set
whatever restrictions he wants when he licenses others to distribute
and modify his work. If he wants to use a license similar but not
entirely like the GPL, that's his choice. It does make it impossible
for him to combine the work with pure GPL software though. If you
follow this reasoning, you can modify & distribute the work but you
must comply with the restriction on the "Powered by" notice.

On the other hand, the GPL claims it is self-contained (section 0)
so the author contradicts himself when he says "GPL with this
additional restriction". You could conclude from this that there
is no valid license for you to distribute or modify, since you
cannot comply with a self-contained license and an additional restriction
at the same time.

On the third hand, some have argued that this kind of restriction
is in fact a proper implementation of GPLv2 section 2c, the
copyright notice at startup. The PHP-Nuke team holds this view, for
example. According to
http://phpnuke.org/modules.php?name=News&file=article&sid=6966
this view is in line with the FSF's intent of GPLv2 2(c).
Personally I'm not convinced; does web forum software "read commands
interactively when run"? 

Kind regards,

Arnoud Engelfriet

-- 
Arnoud Engelfriet, Dutch & European patent attorney - Speaking only for myself
Patents, copyright and IPR explained for techies: http://www.iusmentis.com/
              Arnoud blogt nu ook: http://blog.iusmentis.com/