http://inspire.ec.europa.eu/codelist/VoidReasonValue/UnknownINSPIRE Registry teamJRC-INSPIRE-SUPPORT@ec.europa.euhttp://inspire.ec.europa.eu/registry2015-08-18 18:25 PM CEST2015-08-18 18:25 PM CESTUnknownThe correct value for the specific spatial object is not known to, and not computable by, the data provider. However, a correct value may exist.EXAMPLE When the "elevation of the water body above the sea level" of a certain lake has not been measured, then the reason for a void value of this property would be 'Unknown'.\n \nNOTE 'Unknown' is applied on an object-by-object basis in a spatial data set.