Liftland Identification Citizen Numbering System

The Liftland Identification Citizen Numbering System is a unique identification number that was assigned to every citizen of Liftland. It was introduced in 6 March 1941.

Composition
The number is made up of 13 digits, LL-YYMMDD-GXXXQ (an old Liftland Identification Citizen Numbering System used from 1941 to 1984 has only 11 digits of LL-YYMMDD-III where III was the identification format and the last character was a letter). An example of a valid number is 15-991013-4159I.

The LL indicates the place of birth. See the table below. The YYMMDD represents the date of birth.

G indicates the gender of the person and birth century (1-2 19th, 3-4 20th, 5-6 21st).

XXX is a generic special random number given by the Liftland Identification System's computer.

Q, the 13th digit, is a check character, to make sure that the number is transcribed correctly. To calculate checksum, remove the dashes, the 14-digit number is doubled, then divided by 39. For remainders below 10, the remainder itself is the check character, otherwise, pick the corresponding character from the string '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ*#&', where A = 10, B = 11, … Y = 34, Z = 35, * = 36, # = 37, ending up with & = 38. For example, with 15-991013-4159x, 159910134159 plus 159910134159 is 319820268318 and then when divided by 39 it gives 8200519700 with remainder 18 so the check character is I.