Today, I received some swag (thanks!). One of the items was a cap, and I was puzzled by the logo on it. I've never seen it before, but it's related to the Stack Exchange logo as it seems to have the same colors. What is it, and is it used in other places?
(click to enlarge)
The logo is now also featured on the Winter Bash 2017 secret hat 'Ooh, Shiny!'
which was based on a Winter Bash 2013 secret hat which was awarded for the user being a ♦ moderator.