[cc-licenses] Request for feedback: compatibility mechanism in BY-SA, and possibility of one-way compatibility

Kat Walsh kat at creativecommons.org
Thu Feb 28 14:40:24 EST 2013

In this third compatibility prompt, we want to raise the issue of
compatibility with ShareAlike generally--and particularly, whether to
allow one-way compatibility from BY-SA such that contributions made to
adaptations may be licensed under other similarly-spirited licenses
even if there is no reciprocity.

The definition of "Creative Commons Compatible License" has been
revised in draft 3, removing the list of criteria for being
"essentially the equivalent of this Public License".

This has several purposes. One is that a fuller list of required
characteristics and description of the process really belongs outside
of the license text itself. The criteria were not originally intended
to be the only things used to make a decision on compatibility (that
is, not all licenses which met the minimum criteria in the license
text would be Compatible). Instead, they were some of the criteria CC
would use to determine which candidates to consider. (A discussion
from the time of version 3.0 raises some interesting points along
these lines: http://comments.gmane.org/gmane.org.creativecommons.licenses/3340)

The main reason, however, is that it opens up the possibility of CC
deciding in the future (after a full, rigorous community discussion)
to allow one-way compatibility with other licenses. This is not
something the licenses have previously allowed, due to the two-way
requirement that was explicitly in 3.0 and in previous drafts of 4.0.
Removing this language, as we have in draft 3, does not immediately
allow this. But do not want to foreclose the possibility, and unless
we make this change now, we would need to version again to make that
happen would like to pursue it, and we think it is important enough a
change that we need to raise it with this community first.

Earlier in this versioning process, we raised the possibility of
compatibility with other licenses, including the GPL. While working
toward this and figuring out what would be needed to achieve it, we've
come to a few conclusions.

* We do want to reduce legal uncertainty around combining CC-licensed
works with works under other copyleft licenses. For example, people
frequently ask how to combine BY-SA works with GPL works, and the
question is likely to come up more and more as works combining content
and code become more popular.

* There are some cases where it is unlikely that the CC licenses would
ever be compatible with another license with very similar but more
extensive terms, if compatibility were to require that the licenses be
compatible both ways. (For example, the GPL is one of the most popular
copyleft software licenses. Because it is designed for software, it
contains some sections that are unlikely to be included in the CC
licenses, such as a source code requirement.) Any such license that
would be considered would have to have all of the same requirements as
BY-SA, but would also contain some additional requirements that BY-SA
did not.

Because of this, we want to figure out if there is a way to pursue
one-way compatibility with the Share-Alike licenses.

For a quick explanation of how we see license compatibility: the basic
idea described in the previous message about BY and BY-NC is still
true here; when you create an adaptation of a work under a compatible
license, both licenses apply to the adaptation. You are permitted to
license the new material you contribute to an adaptation under the
terms of a compatible license if you wish, without any obligation to
license that material under the CC license. (When you are adapting a
ShareAlike work, there are currently no compatible licenses other than
ShareAlike itself, but this may change in the future.) However, the
original BY-SA work is always subject to the terms of BY-SA, and so
must be used in a way that respects its terms. There is slightly more
detail on this point in the previous message and on the wiki.

What this would mean is that it would be possible to create
adaptations of a work under CC-BY-SA and release them under a one-way
compatible license. The adaptation would be usable under the new
license, but use of the original work implicating the licensed rights
would always be subject to BY-SA--and so any user of the adaptation
would have to respect the requirements of both the adaptation license
and CC-BY-SA. But because of the license on the material added by the
author of the adaptation, the adaptation as a whole could not be used
under the terms of CC-BY-SA only: it would have be subject to the more
expansive terms of the adaptation license.

(Keep in mind that simply removing the criteria does not commit us to
anything.  We may decide after a full consultation that allowing
one-way compatibility is inadvisable.  Unless this change is made,
however, we foreclose that possibility until we version again--a
process that we at CC would like to avoid for the foreseeable future!)

The criteria for compatibility, the process for determining a
compatible license, and a commitment to uphold certain essential
principles for determining what is compatible have not yet been
established; we would want to have a fuller public discussion on
those, and then maintain them on a separate page outside the license
text itself; we hope to have a process and a set of standards that
respects the expectations of the CC license community as fully as
possible and to develop that with your participation. This discussion
is whether we should begin that process with one-way compatibility in
mind at all.

In that light, we have two questions to focus discussion:

1. Is one-way compatibility with BY-SA worth having a full
conversation on in the near future? (We would expect this to be a
discussion that did not have to finish before the 4.0 process
concluded: the text in the current draft of 4.0 does not prescribe
either decision.)

2. If not, why shouldn't such a discussion take place? Are there
important considerations that would need to be addressed before any
discussion should occur, such as the posting of a statement of
intention or description of a process? (We would expect many such
things to come out of such a discussion, but would some need to be
posted before?)


Kat Walsh, Counsel, Creative Commons
IM/IRC/@/etc: mindspillage * phone: please email first
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CC does not and cannot give legal advice. If you need legal advice,
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