[ Version ( since = "0.5.0" ) ]
public string po_box { get; set; }
Covers actual P.
O. boxes, drawers, locked bags, etc. This is usually but not always mutually exclusive with street.
For more information, see the <ulink type="http" url="http://code.google.com/apis/gdata/docs/2.0/elements.html#gdStructuredPostalAddress">GData specification</ulink>.