[cc-community] An easy way to notify licensors about new license versions

Terry Hancock hancock at anansispaceworks.com
Mon Dec 10 09:26:23 EST 2007


drew Roberts wrote:
> I may indeed be being dense, but I don't see it as that easy yet. I would like 
> to have it explained to me step by step if it really is that easy.

Okay...

The only reason you know that a given license applies to the work in
question is because there's a license grant statement (which is
obviously not part of the license text -- but it's not a statement of
conditions outside of the text, it's a statement of what license applies).

The grant statement also determines which VERSION of that license
applies, and there is nothing to prevent it from granting several
licenses (or several versions) independently -- UNLESS one of the
licenses represents a promise of *exclusivity* (which none of the CC
licenses do).

> With dual licenses, I see it as easy because I would point to the other 
> license and say I am not using this one at all.

Which also works here. If you decide to use the work under the later
license, you aren't using the older one at all.

> However, if I am trying to use this one with modifications that are not 
> mutually agreed upon and in writing, then I would think that "This License 
> constitutes the entire agreement between the parties with respect to the Work 
> licensed here." might kick in and prevent that.

Yes, that's true. But that's not what's happening with an "or any later
version" clauses. You're not adding conditions or removing them from the
license. You are offering multiple licensing options in the license grant.

It's exactly as if I were to say (and this is common on Wikipedia, BTW),
"this work is available for use under the terms of the GFDL version 1,
CC-By-SA v1.0, CC-By-SA v2.0, CC-By-SA v2.5, or CC-By-SA 3.0, at your
option".

Each time you use the work, you may choose exactly one license to
follow. You are then bound by the terms of that license, and no external
statements (*that's* the effect of the "entire agreement" language).

The only difference is that, by not using explicit version numbers, the
"or any later version" clause can include versions of licenses that
haven't been written yet (this is of course, also the reason why it may
not always be a wise choice -- it depends on how much you trust the
license steward).

> I couldn't say I am not using this license but another one. Or what? Plus, in 
> the case of SA licenses, wouldn't modifications make mixing works with mods 
> and no mods or different mods not possible?

The SA licenses include the "or any later version" for derivatives IN
the license, so this problem doesn't arise.

There are no "mods" in the case we are discussing. Once you choose a
license, you are limited to that license's terms (of course in practice,
you can always change which license you say you were using it under
after the fact -- so long as everything you've done (along that
particular derivation chain) can be covered by one and only one of the
licenses).

Details of the license grant do not propagate through to derivatives. So
 if I give you both GFDL and CC-By-SA licenses on a work and you combine
it with GFDL work, the result must be GFDL (no CC-By-SA at all), and you
are clearly using it under GFDL. OTOH, if you combine it with CC-By-SA
work, the opposite situation applies.

You can't keep the dual licensing unless everything you use it with is
ALSO dual-licensed (or unless the licenses are altered to allow
conversion from one to the other, in which case the dual licensing
wasn't really necessary in the first place).

> I am happy to be wrong here, I would just like to understand things better if 
> so.

I think you are misunderstanding the scope of what is being done here. I
can't make any conditional statements in the grant statement, I can only
offer licenses. Once you choose one, you're limited to the terms of that
license.

It is important to realize that you can use the same work under
different licenses if you use them in completely unrelated ways. So, I
can take a GFDL+BySA work "A" and combine it with a GFDL work "B" to
make a GFDL work "C" and at the same time combine it with a BySA work
"D" to make a BySA work "E" -- but I can't then combine "C" and "E" into
another work (not unless something is done to allow conversion between
GFDL and BySA licenses).

Cheers,
Terry

-- 
Terry Hancock (hancock at AnansiSpaceworks.com)
Anansi Spaceworks http://www.AnansiSpaceworks.com




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