the passport code is follow your parents then form an alliance. The months included are January, February, April, and September. aka 1, 2, 4, and 9. aka A, B, D, and I. 24 possible combinations.

abdi,abid,aidb,aibd,adbi,adib,
baid,badi,bida,biad,bdai,bdia,
dbai,dbia,diba,diab,daib,dabi,
iabd,iadb,ibad,ibda,idab,idba.

The order on the card is dabi, searching through google revealed nothing of great historical interest. If anyone comes up with something, let me know.