The City of birth is one of the information reported in the tax code which, as a reminder, is used by the tax registry to register and check data relevant to the tax authorities.
The alphanumeric code that identifies the city of birth is found exactly after our day of birth and is made up of a letter and three digits (eg: those born in Milan will find the code F205). This code cannot be deduced through particular calculations since each City holds one deposited with the Revenue Agency.