They are the five numbers that stand for home. Since 1963, ZIP codes have been a part of just about every piece of mail that travels through our system. But what do those numbers stand for?

A number is redacted if there are one to four cases in a zip code for privacy, said Nate Wardle, a spokesman for the state Department of Health. The department shares numbers that are five or higher.

ZIP codes were unveiled in 1962, but it was more than 20 years before the U.S. Postal Service announced nearly 100% compliance with the five-digit system.

A number is redacted if there are one to four cases in a zip code for privacy, said Nate Wardle, a spokesman for the state Department of Health. The department shares numbers that are five or higher.