On Jan 27, 2017 3:37 PM, "Denenberg, Ray" <[log in to unmask]> wrote:


BIBFRAME supports the capability to provide information from an external (non bibframe) namespace.

A bibframe Title, for example, is a resource of type bf:Title. If it were intended that the object of property bf:title must always be in the bibframe namespace then the range of bf:title would be bf:Title.  The range of bf:title is unconstrained to allow its object to be some title resource defined in a different namespace.

Setting a range on bf:title of bf:Title would not require that any extensions used with that property must be defined in the bf:namespace. What it says is that any value of bf:title is an instance of bf:Title in addition to any other classes it might have. The type could be explicitly  defined as a subclass of bf:Title (in any namespace desired), but even if it weren't it would have to have all the properties of a bf:Title. 

To re-emphasize, subclasses and subproperties do not have to be in the same namespace as their parents.