There is a wordpress theme I am modifying to create my own derived work. This original wordpress theme has the GPLv2 licence in it's root directory, so I assume that the entire theme is GPL code. There is a particular php file which has the following written in its first few lines: // This code is protected under Creative Commons License: http://creativecommons.org/licenses/by-nc-nd/3.0/ Is that legal for them to make a part of the code under a more restrictive license? The CC license referenced is more restrictive because it prohibits derivative work, but that is exactly what I am doing is making a derivative work. So here are my two questions: * By having the full GPL (version 2) licence in the root of the theme's directory, is that a legally binding way of saying that the code is licensed under the GPL2? * Is that legal for them to make that file licensed under that particular CC license? Ultimately, what I care about is this: I want to make sure that what I am doing is technically legal :) EDIT: None of the source files actually _say_ that it is under GPL; except the theme does include jQuery and jQuery plugins (under MIT and GPL2) as well as thumb.php which explicitly says it is under GPL2.