GPLv3's secretive Additional Terms

Chris Travers chris at
Thu Apr 22 17:00:54 UTC 2010

On Wed, Apr 21, 2010 at 11:55 PM, Luis Villa <luis.villa at> wrote:
> Two requests for clarification inline:

>> Unfortunately, there are a lot of things which aren't entirely black
>> and white here.  IANAL, etc.
>> For example, suppose I incorporate a BSD-licensed file into a GPL
>> v3-licensed work.  Pretty much everyone agrees I can do this, or even
>> if they don't they at least concede that this was a goal of the GPL
>> v3.
>> However, you run into a problem here trying to read the BSD license as
>> basically the GPL v3 plus additional permissions.  In essence, I don't
>> think you can simply chance the copyright on the otherwise-unchanged
>> BSD-licensed file by invoking section 7 of the GPL v3 (and Richard
>> Fontana from the SFLC has, in the past, opined as much on this list),
>> but that relicensing restriction is not in line with the additional
>> restrictions section either.
> Which relicensing restriction are you referring to here?

The question is, can I take, say, FreeBSD, distribute it verbatim
except for changing the license to the GPL v3?  I don't think so.  If
not, then the BSD license used by that project is not simply GPL v3 +
additional permissions since I can't remove those additional
permissions without making changes first and creating a derivative
work in the process.

Now, this is a key issue because the additional restrictions do not
allow for permissions which cannot be removed except in this way.  It
does allow for a copyright statement, which could be expanded to
include original licensing information, but one can still not
effectively relicense the software without changing it substantially
first.  Therefore the BSD license effectively has a restriction which
says that if you distribute the source code verbatim you cannot change
the license.

>> A very strict reading of section 7 of
>> the GPL v3 would therefore render it incompatible with the BSD
>> license.
>> But this ends up creating a great deal of difficulty.  If the
>> restriction that, absent significant changes, a file cannot be
>> relicensed is an implied exception,
> Implied exception to...?

the fact that only enumerated additional restrictions are allowed.

If I cannot remove additional copyright permissions on a BSD-licensed
file, then the additional permissions are restricted in ways not
officially allowed by the GPL.  Since everyone agrees these licenses
are compatible, this means:

if I include a verbatim BSD-licensed file in my project, there is an
implied restriction on the ability to remove additional permissions.
This is not officially allowed under the GPL so an implied exception
would have to be recognized.

Hope this helps,
Chris Travers

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