I was wondering about the meaning of this term in CC BY-SA 4.0 (and others), with this context:

In addition to the conditions in Section 3(a), if You Share Adapted Material You produce, the following conditions also apply. The Adapter’s License You apply must be a Creative Commons license with the same License Elements, this version or later, or a BY-SA Compatible License.

In the most extreme but perhaps not unthinkable case, what if Creative Commons releases a "CC BY-SA 5.0" license in the future that removes the requirements for attribution and copyleft -- or maybe even the disclaimer of liability? (The title would then be a misnomer, but I hope that isn't a legal requirement.) Yes, such a license would be incompatible with BY-SA 4.0 if it came from a third party, but the requirement of compatibility doesn't seem to apply for licenses coming from Creative Commons.

Under my interpretation, a third party Bob could then 'adapt' my (or any BY-SA 4.0 author's) code in his BY-SA 5.0 (or 6.0, 7.0, etc.) project. Then, transitively, any other programmer could take Bob's 5.0 work (which is really just my work) without crediting me or disclosing source.

So, here are my questions:

  • Is my above interpretation correct?
  • Are there any measures in place that would protect me from this happening, either legally binding (in the license) or not (e.g. a mission statement from CC or other nonbinding promise)?
  • Is there a way for me to license my FLOSS works under CC-BY-SA 4.0 without allowing derivative works to be licensed under e.g. CC-BY-SA 5.0, like you can do with the GPL (by just saying 'v2 only')?

2 Answers 2


Your interpretation is correct, you are relying on the license steward (in this case Creative Commons) to continue to act in good faith and according to their vision and mission. You cannot add restrictions to CC licenses, you can only give more permissions. So you won't be able to restrict users from using a later license if the current license gives them that permission. (As a side note, a similar provision exists in CC BY-SA 3.0.)

Based on my observations (made since CC was formed) I think the specific scenario you suggest (dropping the BY clause) is incredibly unlikely. In fact, CC previously had a bunch of licenses without a BY clause. They stopped updating them because so few people used them.

And despite that change they still have a mechanism by which you can ask for your name to be removed from a derivative work. So even when "dropping" a license option, they have provided some way to get similar functionality.

Further, CC are focused on making sure the existing works remain shareable, rather than making arbitrary changes. For example, they spent some time addressing new sui generis database laws that threatened the ability to share works with older licenses:

As the steward of our licenses and one of several stewards of the greater commons (including the Free Software Foundation and the Open Knowledge Foundation), we remain mindful and take with utmost seriousness the risks associated with shifting course. We fully intend to (and expect to be held accountable for) strengthening our messaging to policymakers about the dangers of maintaining and expanding [sui generis database rights] within the EU and beyond, and of creating new related rights. From https://creativecommons.org/2011/11/03/copyright-experts-discuss-cc-license-version-4-0-at-the-global-summit/

In general copyleft "upgrades" rely on a decision by one of:

  • the sole author (who may die or otherwise be untraceable)
  • all collaborators (a coordination problem, plus one or more may be untraceable)
  • a proxy (same as the sole author, or if an organization, same as a steward)
  • the license steward (no searching for the author/s, the author puts their trust in the steward)

CC have gone with the option that puts the least burden on the author, and the least burden on recipients/contributors, to continue sharing works in the spirit that they were given.

  • 1
    Thank you for this answer. I feel like this system is especially problematic in the case where a (or group of) BY-SA licensed product becomes more 'valuable' than Creative Commons itself. Then, it would be a cheaper for a business adversary to buy out CC and release a license upgrade removing SA than to buy out the original product. Of course this hypothetical assumes a lot, but I wonder if creating a 'crayon license' that removes this clause would be possible.
    – habs
    Apr 10, 2018 at 16:56
  • 1
    crayon licenses are a barrier to anyone using or distributing your work, because they need to evaluate your non-standard license - it's easier to reject it and pick something else
    – lofidevops
    Apr 13, 2018 at 6:00
  • 1
    these nightmare scenarios are technically valid but imho unlikely, maybe worth researching what safety measures various stewards have in place?
    – lofidevops
    Apr 13, 2018 at 6:02

Is there a way for me to license my FLOSS works under CC-BY-SA 4.0 without allowing derivative works to be licensed under e.g. CC-BY-SA 5.0, like you can do with the GPL (by just saying 'v2 only')?

If you are really worried about this have you considered simply using an earlier CC-BY-SA license? The CC-BY-SA 1.0 license does not allow contributions at all under later CC-BY-SA licenses. The CC-BY-SA 2.0, 2.5 and 3.0 licenses do allow such contributions but do not allow downstream users to elect to comply with their license terms by only complying with the terms of the license chosen by contributer (such a provision is new in 4.0) and hence require that downstream users comply with both the original license AND the new (compatible) license(s) the contributor(s) chose. So while someone could say make an adaption of a CC-BY-SA 3.0 work by making a CC-BY-SA 5.0 contribution such a work would be licensed under the license stack of CC-BY-SA 3.0 + CC-BY-SA 5.0 and a user would still need to comply with all the terms of the CC-BY-SA 3.0 license including attribution and share-alike.

Relevant quote from Creative Commons:

In version 4.0, CC added a provision in the ShareAlike licenses that enables downstream licensees to refer only to the adapter’s license when using adapted material that contains the copyrightable contributions of multiple authors. This feature is designed to minimize complexity for reusers where they are using a later version of the ShareAlike license or a compatible license as their adapter's license. In 4.0, users need only refer to a single set of conditions contained in the last license applied to reuse adapted material, rather than parsing the conditions of the original and other adapter's licenses (to the extent the licenses differ).

In all cases, the licenses stack (the later license does not supplant all previously-applied licenses) when adapted material is created. In particular, the license originally applied to the material being remixed continues to apply once remixed, however permission is given in 4.0 for licensees to meet the conditions of the 4.0 license with reference to those in the adapter's license.

Prior to the 4.0 versioning process, CC had not always been clear that the ShareAlike licenses stacked just as they stack for the BY and BY-NC licenses, and reasonable minds do differ on this point. CC believes, however, that this is the best reading of its all of its licenses that permit adaptations prior to 4.0 and, now, has made that explicit in version 4.0.


Also, although you could no longer call it a CC-BY-SA 4.0 license you could modify the CC-BY-SA 4.0 license (stripping out share-alike compatibility mechanisms) and release your work under that new license).


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.