The license info in the footer of every Stack Exchange page contains a link to the blog post Attribution Required. In this post, Jeff Atwood explains what the attribution is required to contain.

However, that list misses an important part: CC BY-SA 3.0 also requires a reference to itself, the license.

The legal code says:

  • 4(a)

You must include a copy of, or the Uniform Resource Identifier (URI) for, this License with every copy of the Work You Distribute or Publicly Perform.

  • 4(b) (for adaptions of the work):

You must include a copy of, or the URI for, the Applicable License with every copy of each Adaptation You Distribute or Publicly Perform […]

As this post is linked in the license notice on every page, and contains this nicely formatted list of required things, it’s likely that many people follow it, not knowing that they must also include the license reference.

So I propose to either update the blog post (*) accordingly, or to replace the link with a link to a new separate page (hosted at stackexchange.com respectively in the Help area of every SE site (**)), as the format of a blog post (publication date, comments) doesn’t seem to be appropriate for such an important resource.

(*) And all other places this is missing, e.g.,

(**) For example /help/licensing, (thanks, Michael Hampton), but then it probably shouldn’t be categorized under "My Account".


2 Answers 2


In the new ToS (2018), the relevant section was changed.

So it’s no longer an issue in the ToS, but the footer should stop linking to the blog post, and/or the list in the blog post should clarify that, in addition to the attribution, also the license must be specified.

Relevant section in the old ToS

In the event that You post or otherwise use Subscriber Content outside of the Network or Services, with the exception of content entirely created by You, You agree that You will follow the attribution rules of the Creative Commons Attribution Share Alike license as follows:

  • a. You will ensure that any such use of Subscriber Content visually displays or otherwise indicates the source of the Subscriber Content as coming from the Stack Exchange Network. This requirement is satisfied with a discreet text blurb, or some other unobtrusive but clear visual indication.

  • b. You will ensure that any such Internet use of Subscriber Content includes a hyperlink directly to the original question on the source site on the Network (e.g., https://stackoverflow.com/questions/12345)

  • c. You will ensure that any such use of Subscriber Content visually display or otherwise clearly indicate the author names for every question and answer so used.

  • d. You will ensure that any such Internet use of Subscriber Content Hyperlink each author name directly back to his or her user profile page on the source site on the Network (e.g., https://stackoverflow.com/users/12345/username), directly to the Stack Exchange domain, in standard HTML (i.e. not through a Tinyurl or other such indirect hyperlink, form of obfuscation or redirection), without any “nofollow” command or any other such means of avoiding detection by search engines, and visible even with JavaScript disabled.

Relevant section in the new ToS (2018)

The CC-BY-SA Creative Commons license terms are explained in further detail by Creative Commons, but you should be aware that all Public Content you contribute is available for public copy and redistribution, and all such Public Content must have appropriate attribution.

  • The ToS are not a license, from a legal point of view. Commented Feb 26, 2020 at 12:23
  • @FedericoPoloni: I don’t think I suggested that. The problem was that the ToS explained (without it being legally necessary) how the attribution has to look like, but this explanation missed an important part, which is not ideal, and can easily lead to errors.
    – unor
    Commented Feb 27, 2020 at 18:53

This was fixed, AFAICS: the footer now has a link <a href="http://creativecommons.org/licenses/by-sa/3.0/" rel="license">cc by-sa 3.0</a>.

  • 1
    This link was always there, wasn’t it? Anyway, my post is about the second link, with the anchor "attribution required", which links to blog.stackoverflow.com/2009/06/attribution-required
    – unor
    Commented Jul 25, 2015 at 23:04
  • Ah, I thought you were saying the SE usage itself was not compliant with the licenses. So your concern is that the blog post is not a full-fledged guide to usage of Creative Commons content? «Please read the terms of service and the full legal text of the license carefully for more details on how your content can be used» is present on meta.stackoverflow.com/help/licensing , as noted: should it be added to the blog post as well?
    – Nemo
    Commented Jul 26, 2015 at 10:12
  • 1
    The blog post, the Terms of Service, the license.txt of data dumps, and probably more places -- they all specify how to attribute, but they all miss the mentioned requirement. /help/licensing is intended for authors (but it also links to the wrong blog post, with the anchor "Proper attribution is required"), but my issue is about people that want to make use of user-generated SE content (e.g., republish it) and follow the prominently linked guide for how to attribute it correctly.
    – unor
    Commented Jul 26, 2015 at 12:15
  • The attribution part is correct. Linking the license is not attribution, is one of the many other requirements of the license.
    – Nemo
    Commented Jul 26, 2015 at 13:04
  • How’s that? While version 4.0 of the license makes this more clear (it has a section "Attribution" which contains the requirement in question), version 3.0 does not contain a section labeled "Attribution", so I couldn’t tell what is or what is not part of the attribution, as this term is not defined or used as grouping/heading.
    – unor
    Commented Jul 26, 2015 at 13:22
  • Hah, finally we're reaching the bottom of the misunderstanding. Even if it's not explicitly defined, the term "attribution" has the same meaning in 3.0. Creative Commons is not listed among the "Attribution Parties" in 4(c), hence linking creativecommons.org is not an attribution requirement.
    – Nemo
    Commented Jul 26, 2015 at 14:53
  • 1
    The term "Attribution Parties" is used in 4(c)i, where it only refers to parties for which the original authors want to see attribution, too (i.e., in addition). Neither would Creative Commons typically be an "Attribution Party" (you don’t attribute Creative Commons as author, but you have to reference the used Creative Commons license), nor is 4(c)i the only kind of "attribution" needed: for example, the title of the work is required, too (as is the license notice, which this question is about), but it has nothing to do with "Attribution Parties".
    – unor
    Commented Jul 26, 2015 at 15:14

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