What license should be used?

Under the GitHub terms of service, others can view and fork this repository within the GitHub site.  See:
- https://help.github.com/articles/open-source-licensing/
- https://help.github.com/articles/github-terms-of-service/

Are there additional permissions or a different license that could be used that would make it easier for people to use this non-normative AreaTree XML documentation?
