Sri Lanka
In Sri Lanka, all citizens over the age of 16 need to apply for a National Identity Card (NIC). Each NIC has a unique 10 digit number, in the format 000000000A (where 0 is a digit and A is a letter). The first two digits of the number are your year of birth (e.g.: 88xxxxxxxx for someone born in 1988). The final letter is generally a 'V' or 'X'. An NIC number is required to apply for a passport (over 16), driving license (over 18) and to vote (over 18). In addition, all citizens are required to carry their NIC on them at all times as proof of identity. NICs are not issued to non-citizens, but they too are required to carry some form of photo identification (such as a photocopy of their passport or foreign driving license) at all times.
Read more about this topic: National Identification Number