This property cannot be extended with a datatype annotation (e.g."[[Has type::Page]]") as it is already predefined (see the special properties help page for more information).
MediaWiki:Smw-editpage-property-annotation-disabled
From dinoflaj2
This property cannot be extended with a datatype annotation (e.g."[[Has type::Page]]") as it is already predefined (see the special properties help page for more information).
