On Monday, Russian gymnast Ivan Kuliak was facing disciplinary proceedings by the International Gymnastics Federation (FIG) for displaying the letter "Z" on the podium next to a Ukrainian rival in Qatar.
In the past two weeks, Z has gone from a military marking to the main symbol of public support for Russia’s invasion of Ukraine.
Although Z is not a part of the Cyrillic alphabet, Russian military vehicles participating in the invasion have donned the letter, and its use has spread to supporters of the operation.
It has been sported by politicians, seen on the sides of cars, vans and advertising hoardings - as well as daubed on bus shelters. It has even been used by Serbs at pro-Russian demonstration in Belgrade. Photographs have been widely shared on social media.
Open source analysts and military experts first spotted the mysterious Z-shaped letter hand-painted on Russian tanks and military trucks massed on the Ukrainian border on 19 February, leading to widespread speculation among western experts as to what the letter meant.
The most popular theory used by military experts to explain the letters is that they were written according to the respective areas where the Russian troops are usually stationed, with Z potentially standing for Zapad (west). Others believe the letters were drawn in an attempt to avoid friendly fire.
Russian warplanes fly too quickly to see the daubed white markings, US Air Force Lt Col Tyson Wetzel - a senior Air Force fellow with The Atlantic Council think tank - told the Task and Purpose website. But he agreed the "Zs" were a "de-confliction measure to help prevent fratricide" - friendly fire from Russian attack helicopters or artillery.
Just three days after the invasion, the Kremlin-funded state network RT announced on its social media channels that it was selling Z merchandise, including T-shirts and hoodies, to show support for Russian troops.
Since then, countless flashmobs across the country have been organised by the authorities, in which young Russians are seen wearing a Z shirt while displaying their support for the war. The Z letter has also been painted on large Soviet-era apartment blocks and posted on street advertisement signs.
