Gianluigi Donnarumma has chosen to wear the unorthodox number 99 shirt at Manchester City following his deadline day move from Paris St-Germain.
The Italy international goalkeeper wears that number because he was born in 1999, and has sported it during his time in Paris and at his boyhood club AC Milan.
The 26-year-old wears the number one shirt at international level, but that squad number is already occupied at City by goalkeeper James Trafford.
Nobody has worn the number 99 shirt before in a Premier League game.
Players in England can wear any number between 1-99, but there are some restrictions on squad numbers in other leagues.
Donnarumma wore numbers 1, 50 and 99 in France but was prevented from wearing the latter until 2022-23 when Ligue 1 scrapped rules dictating that clubs could only use numbers 1-30.
Under those rules, goalkeepers were restricted to either 1, 16 or 30, meaning the Italian had to get special dispensation to wear the number 50 shirt for the 2021-22 season.
Players in Spain’s top flight can still only select a number between 1-25. Those rules prevented Trent Alexander-Arnold from wearing 66 at Real Madrid.
This article is the latest from BBC Sport’s Ask Me Anything team.