Property:Has improper value for

Has improper value for is a special property in Semantic MediaWiki with a built-in meaning: it helps to keep track of input errors in a wiki when values that are assigned to some property are invalid. This special property is available since SMW 1.4.2.

The property connects a page where some invalid input was given to the property to which this value was assigned. Thus, it can also be used in inline queries or on Special:SearchByProperty to find all pages where an error occurred for a particular property. Also note that even errors that appeared when using some SMW special property are recorded. As a simple example, we provide some erroneous input on this page:

Trying to assign "not a date" as value to Property:News date which requires a valid date: not a datewarning.pngThe date "not a date" was not understood.

Has improper value for can be used for wiki gardening and maintenance, and it is also employed by SMW for automatically repairing its records after the datatype of some property was changed.