According to the article- "In a move the International Gymnastics Federation (FIG) has called “shocking,” Ivan Kuliak wore the letter Z, which has become an emblem of support for the Russian invasion, tacked on his uniform with white tape. Kuliak is among the many Russians using the Z to show where their allegiances lie. The symbol was first seen on tanks heading to the Ukraine border in late February, and initially, military experts speculated that it, along with other letters, including O and V, might have been used to identify different task forces or distinguish Russian tanks from similar Ukrainian ones. The letter has now spread across the country."