postal code
The official locator number used by the national postal service for any address.
The postal code is a string of numerals, letters, and/or symbols officially designated by a national government or postal system which facilitates mail delivery by identifying locations systematically. In some areas no postal codes are available.
Postal codes may include optional extensions for greater specificity. When the level of specificity is smaller than a particular property, then that property may not be listed with the extension. For example, if a large building houses multiple units with different postcode extensions, then the building itself should be listed without any extension.
The code identifies a postal location for delivery rather than necessarily following an administrative boundary. A more specific extension can identify only part of a property, which is why it cannot always describe the whole property.