As of June 1998, the U.S. Postal Service changed the way delivery point digits are calculated for addresses involving high-rise buildings and apartment complexes. Delivery points are now calculated based on the apartment or suite number. The change derived from mail carriers' complaints that the old system didn't help them sort mail for delivery within large buildings.

For example, the delivery point for 715 Prospect Ave Apt 8 used to be 15 but is now 08.

As a result, the delivery point barcode (DPBC) for an apartment-type address CASS-certified in April of 98 will be slightly different than the barcode for the same address CASS-certified in June of 98.