In Bank Information there is only one thing that i couldn'T find out, it is "city code"

Bank code / number: Maximum 12 numbers. Format: 4 Bank code digits + 5 branch code digits + 3 city code digits. In case codes are shorter, prefix with zeros to match format.
I asked to my bank and searched forum and web but couldn't find out exactly. There are traffic and telephone codes as city code but i don't know which one and their relation with bank information.
My bank do not have something as "city code".
Is "city code" traffic code or phone code or something else?