Have you ever heard "Please tell me your registration number" at a hospital reception desk? One foreign student, reading out the number, asked, "Why is the first digit of the back part like this?" Let's take that number apart, one box at a time. ## The first 6 digits: date of birth If it's 050312, it means you were born on March 12, 2005. The year has only two digits, so these numbers alone can't tell you whether it's 1905 or 2005. ## First digit of the back part: gender and century This digit answers the question that came up earlier. This is how you read a foreigner registration number. - 5: a man born in the 1900s - 6: a woman born in the 1900s - 7: Male born in the 2000s - 8: Female born in the 2000s Koreans use 1 to 4. So just by looking at this number, you can tell whether someone is Korean or a foreigner. ## Why the remaining digits and numbers are asked for The remaining digits are numbers that are decided at the time of registration. The last digit is used to check that the number isn't wrong. In Korea, many people share the same name. Some even share the same birthday. That's why hospitals, banks, and phone stores look you up by number instead of by name. Here's a tip you can use right away. The number is on the front of your Alien Registration Card. Don't give it out unless it's absolutely necessary. Don't send a photo of your ID card to just anyone, either. That's because if the number leaks, someone else could use your name to carry out schemes.