A few days ago, the new (3rd) version of the Scrum Guide was released by Jeff Sutherland and Ken Schwaber, the inventors of Scrum.
The only modification is the addition of a paragraph concerning the Scrum Values.
You can find a great article by Gunther Verheyen explaining the additions here.
It's also great fun to watch Ken and Jeff explain the additions.
You can download the latest version at scrumguides.org.