When selecting which badge to track, there is now one that I haven't seen before:
If I select it and click "Go Get It", I get a 404 page. What is this badge for? Is it for the new Documentation part of Stack Overflow and not supposed to be shown yet?
I have seen it on Stack Overflow, Electrical Engineering, and MSE, but is not listed on the "Badges" page for those sites, or here: List of all badges with full descriptions