Alphanumeric Zip+4 in US?

[JaredWilliams1]

Hi all, I returned a zip+4 of "40ND".  USPS doesn't recognize anything but numbers for Zip+4.  However, I've seen some online feedback (and geocoders such as Navteq) that it can actually be alphanumeric (see full address below).  Does anyone know what the "ND" means?  I'm aware of the zip+4 history, but cannot find any information on an alphanumeric zip+4.  Thanks!! 

1725 STOUT FIELD EAST DR
INDIANAPOLIS IN 46241-40ND

[PaulDuggan]

I work for GreatData.com and was working on creating a ZIP+4 to Latitude/Longitude product based on the USPS ZIP+4 data that we license and found similar codes in Alaska, which totally surprised me, since I've worked with ZIP Codes and ZIP+4 data for a long time. I looked at the documentation that comes with the product and it doesn't indicate anywhere that it could include alphabetic characters (in fact it's always referred to as 'digits').

The best that I could find is that they split the +4 part of the code into a 2-digit sector and a 2-digit segment.

Unfortunately I couldn't find what 'ND' means.

[ShanaBritt]

Jared:

I looked up the address on the USPS Look up Zip code tool and received the following details for the address and it looks like the 'ND' that was returned could be some sort of Mailing Industry code for sorting the mail. Go to the following link and click the 'Show Mailing Industry Details'.

https://tools.usps.com/go/ZipLookupResultsAction!input.action?resultMode=1&companyName=&address1=172...

This link to the USPS Address Information Systems product goes over most of the headings that show in the Mailing Industry Details, https://ribbs.usps.gov/index.cfm?page=address_info_system

-Shana