Editor's note: This story has been updated to reflect details on the Court of Arbitration for Sport's ruling on Feb. 13, which upheld the disqualification. Wearing a helmet commemorating Ukrainian athletes killed by Russia is not allowed, the  International Olympic Committee (IOC) ruled on Feb. 12. Vladyslav Heraskevych, Ukraine's skeleton racer, was scheduled to compete in his third Olympic Games on Feb. 12. He was barred from taking part in the competition after refusing to change his helmet