Private mailbox and commercial mail receiving agency identification.
The United States Postal Service updates the CASS requirements for private mailbox (PMB) addresses and commercial mail receiving agency (CMRA) addresses in Cycle O. To meet the Cycle O standard,
Address Verification
adds PMB as a prefix before a private mailbox number in a CMRA address. If a pound sign (#) precedes a private mailbox number in the address,
Address Verification
converts the pound sign to PMB. To comply with the Cycle O standard,
Address Verification
does not use the PMB number to verify Delivery Point Validation (DPV) data for an address.
SuiteLink verification for default records.
The United States Postal Service updates the conditions that determine when CASS-certified software must query the SuiteLink reference data.
The address
verification
operation must compare high-rise default and street default addresses to the SuiteLink reference data. Additionally, if an address contains secondary information that does not match a DPV address, address
verification
must compare the address without the secondary information to the SuiteLink reference data.
If the SuiteLink data contains a match with the input address, the address
verification
operation must add any valid secondary information from the SuiteLink address to the address. The 11-digit bar code for the updated address must match the bar code for the SuiteLink address.
Post office box street address (PBSA) identification.
The United States Postal Service accepts post office box addresses in a street address format when the street address identifies the post office that contains the box. For example, the following address identifies box number 3094 at a post office on South Center Street:
131 S Center St Unit 3094 
Collierville TN 38027-0419
The Cycle O standard specifies "Unit" as the post office box descriptor in a PBSA.
The United States Postal Service adds the value PB as a Delivery Point Validation footnote to a PBSA.
Address Verification
writes the value as a DPV footnote.
R777 address identification.
The United States Postal Service assigns physical addresses that do not receive mail to carrier route R777. An R777 carrier route is known as a phantom carrier route.
Address Verification
writes the value R7 as a DPV footnote to any address with an R777 carrier route designation.
Form 3553 completion.
Address Verification
also adds a ZIP+4 3553 flag that indicates whether an address is valid for inclusion in the total address count on Form 3553.
Address Verification
returns N for any address that passes delivery point validation but does not include a valid ZIP+4 Code. For example,
Address Verification
returns N for an address on an R777 carrier route. When you compile Form 3553, omit any address with a ZIP+4 3553 value of N from the total count.
Verification of primary house or building numbers that include trailing alphabet characters.
If the primary house number or building number in a non-valid address includes a trailing alphabet character, CASS standards permit an address
verification
operation to check the address without the trailing character.

<InputData>
    <AddressElements>
        <Country Item="1" Type="NAME">UNITED STATES</Country>
        <Locality Item="1" Type="COMPLETE">ATHENS</Locality>
        <PostalCode Item="1" Type="UNFORMATTED">247121000</PostalCode>
        <Province Item="1" Type="COUNTRY_STANDARD">WV</Province>
    </AddressElements>
    <AddressLines>
        <DeliveryAddressLine Line="1">COLLEGE BOX C345</DeliveryAddressLine>
        <DeliveryAddressLine Line="2">PO BOX 1000</DeliveryAddressLine>
    </AddressLines>
</InputData>

Street descriptors
Directional values
Sub-building descriptors