Current license:
License
This document is licensed, as-per the LICENSE file, as derived from the MIT License. The original condition:
"The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software"
was changed to:
"The above copyright notice, a clear indication whether the content has been modified, and this permission notice shall be included in all copies or substantial portions of the Software".
In other words, MIT + tell everyone whether you simply copied the content or modified it.