Gives an error when creating a guild

[TheCadl]

Hello! I want to create a guild, but for some reason it gives me an error. Can you fix this somehow?

CADL = The abbreviation of my name. Kostritsky Alexander Dmitrievich. L - because he was born in the month of the lion. I don't understand why I can't create a guild
Why in my name abbreviation illegal?

 

[TheCadl]

Thank you very much to the kind person Skyuper!