Marsden, S, Stark, P, Sumerling, P 1990, Heritage of the City of Adelaide: an illustrated history, Corporation of the City of Adelaide, Adelaide, p219-20 +
"Has improper value for" is a predefined property to track input errors for irregular value annotations that was likely caused by type or allowed value restrictions.
"Has subobject" is a predefined property representing a container construct that allows to accumulate property-value assignments similar to that of a normal wiki page.