I am not sure about the difference between sub-collections and just
having different collections with a cross-collection search. I would
always want searches to be across all collections, so would want the
fact of their being separate collections behind the initial screen to
not be evident to users.

I'd appreciate comments - or advice as to where in the documentation the
difference between sub and cross - collections is explained. Do any of
the demonstration collections illustrate these?

Thanks
Ed Robinson