Bernie wrote:

> I've ended up with two different FB translations of this C  
> structure. They both work but which one is the preferred translation?

Translation (1) is obsolete and should be killed off wherever it  
appears.
Translation (2) is the correct one. Callbacks are set like this:
  dbCallbacks.u.v1.itemDataCallback = fn NewDataBrowserItemDataUPP 
([ ....] )

Robert P.