"Terms of Use" statement in a markup library

Bruce Cox wrote:

    If the [markup library] creators don't provide a "terms of use" statement 
    (or the equivalent) , the acceptance of which is a least implied, then the
     consumers should demand one.

I don't think I have ever seen a "terms of use" statement in an XML Schema, DTD, Relax NG schema, or Schematron schema. I am interested to see what should go into a "terms of use" statement. Would someone provide an actual "terms of use" statement please?

/Roger