An Estonian Personal identification code consists of 11 digits, generally given without any whitespace or other delimiters. The form is GYYMMDDSSSC, where G shows the person's sex and century of birth (odd number male, even number female, 1-2 19th century, 3-4 20th century, 5-6 21st century), YYMMDD is the person's date of birth, SSS is a serial number separating persons born on the same date, and C is a checksum.
