YAST License, is redistribution permitted?

["Marcelo E. Magallon" <mmagallo@debian.org>]

Hi guys,

 please keep mmagallo@debian.org in the Cc:

 I'm seeking the opinion of -legal regarding an issue I've been
 discussing on another mailing list.  It pertains the YAST license as
 found in:

          ftp://ftp.suse.com/pub/suse/i386/8.1/COPYRIGHT.yast

 To make this clear from the start: I do not intent to package a program
 under this license.  I'm interested in this issue merely as a) Debian
 Developer trying to gain some insight into a particular aspect of
 copyright/contractual law; b) Application Manager who presents
 copyright-related questions to new maintainers.  If someone considers
 this discussion off-topic for this list, I apologize beforehand, *I*
 don't think that's the case.

 From the English translation of license (original is in German):

    3. Dissemination
       It is forbidden to reproduce or distribute data carriers which
       have been reproduced without authorisation for payment without
       the prior written consent of SuSE Linux AG or SuSE Linux.
       Distribution of the YaST 2 programme, its sources, whether
       amended or unamended in full or in part thereof, and the works
       derived thereof for a charge require the prior written consent of
       SuSE Linux AG.

       All programmes derived from YaST 2, and all works derived thereof
       as a whole or parts thereof may only be disseminated with the
       amended sources and this licence in accordance with 2b).  Making
       YaST 2 or works derived thereof available free of charge together
       with SuSE Linux on FTP Servers and mailboxes is permitted if the
       licences on the software are observed.

 The point of contention is whether or not redistribution of SuSE Linux
 CDs is permitted by this license.  My reading of the above is as
 follows: this bit stablishes two modes of redistribution, for charge
 and free of charge.  If you want to redistribute the program for
 charge, you have to get permission from SuSE Linux.  If you want to
 redistribute the software free of charge, you have two options: FTP
 servers or "mailboxes".  Any other option is forbidden.  Ergo, you
 can't redistribute copies of the SuSE Linux demo CDs (the ones with
 mostly free stuff -- modulo things like Acrobat Reader and its kind).

 Does this interpretation sound right to you?

 [ the "mailboxes" thing is something that isn't clear to me either.
   The original in German says "Mailboxen" IIRC, which according to the
   dictionary sitting near my desk is not a German word.  They _might_
   mean AOL-style distribution. ]

 During the discussion, another argument _for_ the redistribution of CDs
 has surfaced.  The other partner in this argument holds that in
 contractual law there's a principle called "Contrario Senso" (rough
 translation from Latin: opposed sense, contrary sense) which states
 that if an action is explicitly forbidden by a contract, the opposite
 action is implicitly permitted.  Even if this was to hold true for
 software licenses, I still think it's irrelevant for this case, but my
 question is precisely that: does such a principle hold true for
 software licenses?  How do you stablish what the "opposite action" is?
 Do you know of _any_ cases (relevant to software licensing) where such
 a principle has been applied?

 Thanks for your time,

 Marcelo