Just being a bit pedantic:

On 16 May 2013, at 12:16, "Meehan, Thomas" <[log in to unmask]> wrote:

> bf:1234 a bf:Work .
> bf:1234 bf:label "Requiem" .
> bf:1234 bf:creator bf:9999 .
> 
> bf:9999 a bf:Authority .
> bf:9999 bf:label "Mozart" .

I think these would all be

bf:9999 a bf:Person .
bf:9999 bf:label "Mozart" .

(i.e. there is no suggestion you'd use the Authorities class in preference to the more specific sub-classes?)