Thanks for the response Adam. I am referring to the version 3 license (I know that phpBB is released under the version 2 license). I have read the license and believe that I am clear on it. Obviously I can't remove the copyright because, of course, the script wasn't coded by me. I am just interested in editing the front and back end of an open source CMS software for a client who wants more of a white label solution.
Although phpBB isn't released under exactly the same license, I was hoping that some of you here would have some knowledge of the 3rd version
Anyways, I do thank you for the response Adam.