File:Cc-license-by.png

Summary
Creative Commons Public Copyright License Marks: CC-BY

Creative Commons licenses the use of its trademarked CC logo in the context of its Public Copyright License Marks (shown immediately to the right) on the condition that licensee use the mark solely to point to a Creative Commons license or Commons deed on the Creative Commons server or otherwise uses it to describe the Creative Commons license that applies to a particular work; and provided that, to the extent the licensee is using the mark in an online environment, licensee does not alter or remove the hyperlink embedded in such logo as made available on Creative Commons webpage. Creative Commons retains full, unfettered, and sole discretion to revoke this trademark license for any reason whatsoever or for no specified reason. Creative Commons is particularly likely to revoke said license if, in its full, unfettered, and sole discretion, it finds that licensee’s use of the mark is likely to bring disrepute to licensor or its mark.

See: http://creativecommons.org/policies