The first 5 digits of your NJDL are known as your family code. Every member of your family, with the same last name (and I BELIEVE with the same home address), will have this same number. The first digit, a letter, is obviously your last initial. The rest of the numbers are assigned in sequential order based on the 2nd letter of your last name. What this means is, if your last name is Jackson, your family code may be J0062, or something like that (since A is the first letter of the alphabet, the number is low). If its Lucas, your family code may be something along the lines of L8493 (since you is close to the end of the alphabet, the number is high).