The "Achievements" menu on Skeptics shows me Russian text near my achievements:
The Russian text is:
Узнайте больше об этом в Справке
Learn more about it in Help.
I have checked my profile, and nowhere have I seen any country information or language preference. The help center doesn't to have any information about changing the language of achievements.
I'm located in Germany, and https://www.myip.com/ agrees that my IP address is located in Germany. I don't speak Russian, and my browser doesn't have anything set to "Russian". Thus, I don't see why this text is in Russian. Also, even if Stack Exchange thought I was in Russia, it's a bit weird to have half of the text in Russian and the other half in English...