united-states copyright internet licensing
Can I use my Stack Overflow profile to release the contents of my questions and answers under a secondary license?
<p>As I understand, when I post something on Stack Overflow (or other Stack Exchange sites), I have copyright on the contents of the post and I've licensed significant redistribution and re-licensing rights to Stack Overflow.</p>
<p>Stack Overflow then releases that content to other netizens under an <a href="https://creativecommons.org/licenses/by-sa/3.0/" rel="nofollow noreferrer">open license</a>, but <a href="https://stackoverflow.blog/2009/06/25/attribution-required/">requires attribution in the form of a link to the original answer</a>.</p>
<p>I have occasionally seen users on Stack Overflow who update the 'bio' section of their profile page to say something like 'I hereby release all of my contributions to Stack Overflow, past, present, and future, into the public domain.'.</p>
<p>Since those users <em>do</em> hold copyright, it seems to me this is valid. I.e., anyone using the content can choose to use it under the license offered by Stack Overflow (with attribution required) <em>or</em> as public domain content as offered by the user themself (without attribution required).</p>
<p>Is it valid to use the 'bio' section of your Stack Overflow profile to release your Stack Overflow contributions under a secondary license? Does the answer differ if releasing to the public domain rather than under a secondary license?</p>

<h2>You can licence your copyright under as many licences as you like to as many people as you like</h2>

<p>It's your copyright - you can do what you want with it.</p>

<p>What you can't do is give someone an <em>exclusive</em> licence and then give licences to others - that would be a breach of contract with the exclusive licensee.</p>

<p>How you let people know about the available licences is also up to you - your bio on Stack Exchange is fine.</p>
