Re: Developer's Certificate of Origin

Florian,

On Friday, November 29, 2024 1:22:07 AM MST Florian Weimer wrote:
> * Soren Stoutner:
> > The GFDL with Invariant Section is not the right comparison.  The correct
> > comparison is to the GPL (which has the exact same wording).
> 
> The FSF gives permission to make modified versions of the GPL,
> though: <https://www.gnu.org/licenses/gpl-faq.html#ModifyGPL>

That is a good point.  Basically, that FAQ is a list of what your legal rights 
are under fair use of copyrighted material.

At the top of the GPL it states:

"Copyright © 2007 Free Software Foundation, Inc. <https://fsf.org/>

"Everyone is permitted to copy and distribute verbatim copies of this license 
document, but changing it is not allowed.”

Althought not explicitly stated in this text, the meaning is this:

"Everyone is permitted to copy and distribute verbatim copies of this license 
document, but changing it is not allowed, **except at fair use provisions of 
copyright law allows you to make changes without our permission**.”

The FAQ at the link you listed above explains when the FSF will not attempt to 
enforce their copyright claims and restrictions on changing the text.  One 
argument is that they are here granting you some rights you haven’t previously 
had.  But the other argument is that they are just explaining what rights you 
already have under fair use (these actually vary by jurisdictions, so aren’t 
necessarily the same in all parts of the world).

"You can legally use the GPL terms (possibly modified) in another license 
provided that you call your license by another name and do not include the GPL 
preamble, and provided you modify the instructions-for-use at the end enough 
to make it clearly different in wording and not mention GNU (though the actual 
procedure you describe may be similar).”

If you modify a copyrighted text under fair use, you have to distinguish it in 
such a way that nobody confuses it with the original text, and nobody thinks 
it was produced or endorsed by the original party.  One aspect of that is you 
must change the name.

Just like your ability to do this isn’t spelled out in the GPL itself, but is 
granted to you by copyright law’s fair use provisions anyway, these same fair 
use provisions also apply to the DCO, even though they aren’t spelled out 
there.

My purpose here is not to try to explain when you have a fair use to modify a 
copyrighted text without the permission of the copyright holder.  If someone 
wants to have that full discussion, I would recommend they start a new thread 
for that.  But as a starting point, I would recommend that you read over the 
Wikipedia page on the subject:

https://en.wikipedia.org/wiki/Fair_use

The rest of the text in the FAQ explains why they discourage you from doing 
this even though you can:

"It is possible to make modified versions of the GPL, but it tends to have 
practical consequences.”

"If you want to use our preamble in a modified license, please write to 
<[email protected]> for permission. For this purpose we would want to check 
the actual license requirements to see if we approve of them."

"Although we will not raise legal objections to your making a modified license 
in this way, we hope you will think twice and not do it. Such a modified 
license is almost certainly incompatible with the GNU GPL, and that 
incompatibility blocks useful combinations of modules. The mere proliferation 
of different free software licenses is a burden in and of itself."

"Rather than modifying the GPL, please use the exception mechanism offered by 
GPL version 3.”

There is one other paragraph that explains that you can request explicit 
copyright permission in a way that goes beyond fair use, but there is no 
guarantee they will grant it (handled on a case-by-case basis):

"If you want to use our preamble in a modified license, please write to 
<[email protected]> for permission. For this purpose we would want to check 
the actual license requirements to see if we approve of them."

-- 
Soren Stoutner
[email protected]

-----BEGIN PGP SIGNATURE-----
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=/uYp
-----END PGP SIGNATURE-----