In compliance with the United States Postal Service requirements,
matches the information in a single sub-building element with the reference data. If the Sub-building_1 information does not match,
compares the Sub-building_2 information. If the Sub-building_2 information does not match, Address Verification compares the Sub-building_3 information. Address Verification copies the unmatched sub-building information from the input address to the output address.