Delivery point
From Wikipedia, the free encyclopedia
In a postal system, a delivery point (sometimes DP) is a single mailbox or other place at which mail is delivered. It differs from a street address, in that each address may in fact have several delivery points, such as an apartment flat, office department, or other room. Such a building (mainly only residential) is often called a multiple-dwelling unit (MDU) by the USPS.
[edit] United States Postal Service usage
In the US Postal System, a delivery point is a specific set of digits between 00 and 99 assigned to every address. Combined with the ZIP + 4 code, the delivery point provides a unique identifier for every deliverable address served by the USPS.
The delivery point is almost never printed on mail in human-readable form; instead it is encoded in the POSTNET delivery point barcode (DPBC). The DPBC makes automated mail sorting possible, inlcuding ordering the mail according to how the the carrier delivers it (walk sequence).
The two-digit delivery point number is combined with an additional check digit in the DPBC. This digit is used by Barcode Sorters (BCS) to check if the ZIP, ZIP + 4, or Delivery Point ZIP codes contain an error. In a database, storing the ZIP + 4 code in a 10 character field (with the hyphen) allows easy output in the address block, and storing the check digit in a 3-digit field (instead of calculating it) can allow you to check if the ZIP code and delivery point have been changed independently. In order to receive the appropriate barcode discount, the delivery point digits and the sub-ZIP (the "+ 4" part) should always be verified using an up-to-date, CASS-certified program
Since each city block or section of a rural route has a different sub-ZIP, and address numbers generally increase by 100 per block, the delivery point is typically the last two digits of the address. It may also be the last two digits of a suite number, or the floor number. The delivery point is usually redundant for post office boxes, since they are typically assigned their own ZIP + 4 code.
