In the larger populated cities of the time, merchants found a way to cater to busy customers who had little time or energy to prepare food during the evening. The variation in Chinese cuisine from different regions led caterers to create a list or menu for their patrons.
ZIP Code began on July 1, 1963, as scheduled. Use of the new code was not mandatory at first for anyone, but, in 1967, the Post Office required mailers of second- and third-class bulk mail to presort by ZIP Code. Although the public and mailers alike adapted well to its use, it was not enough.
The Fast Lane Answer. A ZIP Code is a group of five or nine numbers that are added to a postal address to assist the sorting of mail. A complete, 9-digit ZIP Code, including its additional four digits (called a ZIP+4 Code), is the designation of a delivery route. In other words, regular ZIP Codes indicate which USPS employees will be servicing the address, while the ZIP+4 will tell you which delivery route it will be on.