Have you read this befor you published your art? http://www.ubuntu.com/aboutus/trademarkpolicy http://creativecommons.org/licenses/by-sa/2.0/de/deed.en If you build your work up on an existing art, you couldn't change the license typ. So you should change the license to "CC-BY-SA license". You also should say who was the original artist. best wishes Achim