[archy]

Social Security number? Surely the "serial number" isn't one's Social Security number?

It sure is, usually abbreviated *SSAN*. Since around 1970.

[visualops]

Wow I had no idea.

[Prodigal Son]

Whoops, I see archy has already answered that one.

Another interesting note, even the color of your medical records jacket is based upon your SSN. You commonly use the last four digits of the number for just about everything in the Army, but the medical records take it a step further. They use the next to the last digit of your SSN to asign you a specific color of folder.

My next to the last number was/is 7, so I always had a brown folder. The folders come as blanks with the 7 already filled in and the other three numbers blank (7 or whatever your next to last digit is)

When you go to the clinic, they ask you your last four and you would spout off '_ _ 7 _' and they'd know just what color folder to go looking for.

Sounds wild but it works very efficiently. Don't ask me what the reasoning is behind that one.