Dating direct postal address
it was chosen to suggest that the mail travels more efficiently and quickly (zipping along) when senders use the code in the postal address. An extended 'ZIP 4' code was introduced in 1983 which includes the five digits of the ZIP Code, followed by a hyphen and four additional digits that determine a more specific location.The term ZIP Code was originally registered as a servicemark by the U. Postal Service, but its registration has since expired.The SCF sorts mail to all post offices with those first three digits in their ZIP Codes.The mail is sorted according to the final two digits of the ZIP Code and sent to the corresponding post offices in the early morning.The early history and context of postal codes began with postal district/zone numbers.The United States Post Office Department (USPOD) implemented postal zones for numerous large cities in 1943.The add-on code is often one of the following: the last four digits of the box number (e.g.PO Box 107050, Albany, NY 12201-7050), zero plus the last three digits of the box number (e.g., PO Box 17727, Eagle River, AK 99577-0727), or, if the box number consists of fewer than four digits, enough zeros are attached to the front of the box number to produce a four-digit number (e.g., PO Box 77, Juneau, AK 99750-0077).
The USPS publishes the rules for calculating the delivery point in a document called the CASS Technical Guide.Sectional centers do not deliver mail and are not open to the public (though the building may include a post office open to the public), and most of their employees work night shift.Mail picked up at post offices is sent to their own SCF in the afternoon, where the mail is sorted overnight.In 1971 Elmira (NY) Star Gazette reporter Dick Baumbach found out the White House was not using a zip code on its envelopes. A ZIP 4 Code uses the basic five-digit code plus four additional digits to identify a geographic segment within the five-digit delivery area, such as a city block, a group of apartments, an individual high-volume receiver of mail, a post office box, or any other unit that could use an extra identifier to aid in efficient mail sorting and delivery.Herb Klein, special assistant to President Nixon, responded by saying the next printing of envelopes would include the zip code. But initial attempts to promote universal use of the new format met with public resistance and today the plus-four code is not required.