Quote Originally Posted by Jothki View Post
Out of curiosity, would it be a violation of copyright to publish an extensive set of errata for an existing system? Every single aspect of the publication (besides pages and line numbers, which seem unlikely to be copyrightable) would be your own original work, assuming that you didn't directly quote the passages that you are modifying.
That's basically what I did. Several times. I have yet to receive any communication from WotC.

Seriously folks, even if there is some legal jargon about using D&D terminology, WotC has zero incentive to take legal action against you. Unless you try to sell it. As long as you give it away for free, life is good.