ADDRESS GUIDELINES
The United States Postal Service (USPS) is an agency of the United States government responsible for providing postal service in the United States; it is generally referred to within the United States as "the post office." For any letter addressed within the United States, the USPS requires two things on the envelope.
The first is the address of the recipient, to be placed in the center of the envelope. It is sometimes required to put the name of the addressee above the address. Another optional addition to the address is a ZIP+4 code.
The formatting of the address is as follows
Line 1: Name of recipient
Line 2: Street address or P.O. Box
Line 3: City and ZIP+4 code
Example
Mr. John Dan
1111 JOHNSON ST
NEW YORK NY 10036-4658
The USPS maintains a list of proper abbreviations.
The formatting of a return address is identical. A common myth is that a comma is required after the city name, but this is not true. The Post Office recommends use of all upper case block letters using the appropriate formats and abbreviations and leaving out all punctuation except for the hyphen in the ZIP+4 code to ease automated address reading and speed processing. USPS guidelines mention that all items in an address should be in all capital letters with no punctuation marks on an envelope. Also, ZIP codes must be used on all mails. Zip codes have 5 digits or 9 digits. In a 9-digit ZIP code, ZIP + 4 code, a hyphen is placed after the first 5 digits.
For example:
DENNIS RUSSO
PO BOX 6018
BABYLON NY