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  • From: Kat Walsh <kat AT>
  • To: Development of Creative Commons licenses <cc-licenses AT>
  • Subject: [cc-licenses] Developing a future compatibility process for ShareAlike (and thoughts about future versions)
  • Date: Mon, 23 Sep 2013 15:28:26 -0700

We've mentioned a few times on this list that we planned to talk more about the compatibility process and criteria after the launch of 4.0. However, several of the concerns around the treatment of BY-SA adaptations tie in closely to the way this process will operate, so while these are still fairly preliminary thoughts, they may be useful to the discussion in giving some idea of the ways CC intends to maintain the standards and meet the expectations of the license-using community.

Several years ago, CC published a statement of intent for the Attribution-ShareAlike licenses:

This was initially published so that we wouldn't need to ask for blind trust that CC will uphold certain standards--we don't ask it, and we don't expect it; we hope to have a good enough record of upholding our commitments that additional commitments aren't necessary, but part of the way you get such trust is by being willing to make public statements of what you will do and then stand behind them. And we also hope to have a common understanding both within CC and with our community as to what we're doing and what we won't do--what are fixed points and what is open to change.

For all of these reasons, we plan to have a similar commitment for compatible licenses as we have with Attribution-ShareAlike.

Currently, we don't have any compatible licenses outside the CC license suite--so if we don't have good criteria for them to determine what should and should not be considered, we may make inconsistent decisions that don't necessarily reflect a common understanding. While we've needed to have some of these understandings in order to develop the ported licenses, we haven't yet done this kind of consideration for non-CC licenses. We're committing to a lot when we name a license as compatible with SA, and we should have a good idea of the boundaries. While it is ultimately up to CC as a license steward to make these determinations, we don't think this can come from within the CC office alone--before we name any licenses compatible, there should be a public process, just as with license development.

The definition of compatibility in the license itself currently requires a compatible license to be "essentially the equivalent of" the CC license. In Version 3.0, the definition within the license continued: "(i) contains terms that have the same purpose, meaning and effect as the License Elements of this License; and, (ii) explicitly permits the relicensing of adaptations of works made available under that license under this License or a Creative Commons jurisdiction license with the same License Elements as this License". In 4.0, this is no longer within the license itself--and as CC never named any other licenses compatible with 3.0, it was never put into practice. But we envision the same sort of thoughts informing the criteria we settle on for compatibility with 4.0.

For example, we've taken a preliminary look at other licenses that are candidates for compatibility. The list so far is not long (primarily GPL and the Free Art License, which have been discussed on this list previously), and we expect that probably reflects the ultimate outcome. There simply are not likely to be many: we expect that most licensors and licensing communities who have the same aims (and don't have some fundamental, irreconcilable difference with the way our licenses work) will have chosen to adopt CC licenses, working with us through our license development processes to be sure their needs are addressed.

However, one reason to drop the reciprocity requirement from the earlier definition is that some of the most compelling cases for compatibility are where reciprocity does not make sense, often because the context of the intended use has different requirements or where it would not have been possible to use a CC license. For example, CC does not recommend its licenses for software--we go so far as to explicitly recommend licenses developed by the Free Software Foundation, particularly GPL, which is one of the sources of inspiration for CC BY-SA. The GPL's requirements include particular features that make a lot of sense for a software license but fit less well with artistic and textual works. But where it's necessary to mix CC-licensed content and software in a way that triggers the copyleft requirements, there is currently no solution we can recommend other than starting with content that is already dual-licensed (something done by a vanishingly small minority of the most informed and interested licensors).

We don't currently have a formal statement of intent for what future versions of BY-SA may contain, aside from the broad issues raised in the current statement of intent, but we will be developing one. While several of these issues have been discussed in the past (for example, during the 3.0 and 4.0 versioning processes) or held as common understandings, there's no single place where we lay out the particular criteria CC uses in developing new versions. We also don't yet know if future versions of the CC licenses would be considered under exactly the same constraints we would currently place on compatible licenses. A version that differed too greatly wouldn't be considered the same license, of course (as expressed in the existing statement), but we want to be able to adapt to future conditions (such as new legislation) in a way that makes sense, even if we can't yet see what we may need to do to ensure the licenses have essentially the same effect. The thoughts and expectations we'll be talking about with outside-CC compatibility will obviously apply to the development of this statement as well.

For some examples, here are a few things we're thinking about. (None of this is definite, and these may end up different from the way they are described here, depending on future discussions.)

* Requiring statements of intent from the license stewards of other licenses deemed compatible, such that they too promise to uphold principles we think are essential to our license community.

Naming a license as compatible is a big commitment; since the compatibility mechanism and requiring material to be "shared alike" is the heart of BY-SA, we would expect the stewards of compatible licenses to have the same idea of what their licenses do now and will do in the future as CC does. License stewards who hold the same values and concerns have expressed willingness to work with us and make this kind of commitment, to increase the trust of all of our communities, and we expect that to be true of others we might approach as well.

* Requiring certain characteristics of compatible licenses.

At a minimum, licenses deemed compatible should be copylefts, should require attribution, should be intended to broadly allow sharing, reusing, remixing, for any purpose (for BY-SA), or for all noncommercial purposes (for BY-NC-SA). There may be other basic characteristics that are non-negotiable for something to be considered "compatible" and in the same spirit as the CC license--we may want to only consider licenses with well-established stewards, or with wide adoption; certain terms and conditions of the license may also be essential.

* Having an open discussion process around any potential compatible license.

Even after criteria for determining a compatible license are established, the process would benefit from community input, especially those who are part of those license communities. There are also other questions to consider: how widely used the license is, whether it has been interpreted strangely and its community has different expectations than we might expect, whether we would be encouraging or discouraging license proliferation by acknowledging it.


It's our goal to uphold the trust licensors have placed in CC as a license steward by having a process that makes it hard to do otherwise, and we hope that this will both be informative as to what's coming and will help you evaluate whether the mechanism in draft 4 of 4.0 should stay as is.


Kat Walsh, Counsel, Creative Commons
IM/IRC/@/etc: mindspillage * phone: please email first
Help us support the commons:
California Registered In-House Counsel #801759
CC does not and cannot give legal advice. If you need legal advice, please consult your attorney.

  • [cc-licenses] Developing a future compatibility process for ShareAlike (and thoughts about future versions), Kat Walsh, 09/23/2013

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