A postal code (aka 'ZIP code' (Zone Improvement Plan code) in the U.S.) is a series of letters and/or digits which is useful to identify a particular region or route. In some cases, they may identify company (eg, The Washington Post or a large university) or a post office (typically used for Post Office boxes). Postal codes areas are typically contiguous, but may not be mutually exclusive in the case of overlapping postal routes.
