what is the last 4 digits of a zip code called
plus - four codes
-1
Section::::History.:ZIP+4.

ZIP Code
51550
add - on codes
-1
Section::::History.:ZIP+4.

ZIP Code
51550
add - ons
-1
Section::::History.:ZIP+4.

ZIP Code
51550
12859106570347899859
NONE
Section::::History.:ZIP+4.

ZIP Code
51550