TAEHO'S US LIFE

ND =>Notice Date (You can find on notice you get after filing I-140/485)
PD => Priority Date
AD=>Approved Date
RD=>Received Date(You can find on notice you get after filing I-140/485,Date when USCIS received yr application)
LUD=>Last Updated Date(Once you receive yr notice,you can check yr status online on uscis website,you can also check last updated date on website,it normally gets updated if someone works on yr applications,which in case of NSC rarely happens )