211 May 2026

To ensure a "proper" post for mail delivery, Section 211 of the USPS Postal Addressing Standards requires a standardized format to match ZIP+4 and City State files:

Note: Use standardized abbreviations like "APT" or "STE" rather than the pound sign (#) if the specific designation is known. To ensure a "proper" post for mail delivery,

City, state (two-letter abbreviation), and ZIP code. state (two-letter abbreviation)

Full name of the individual or business. To ensure a "proper" post for mail delivery,

All uppercase letters are preferred for machine readability, and punctuation should be omitted except for the hyphen in the ZIP+4 code. 2. IBM POST Error Code 211