IMHO,
People who believe all keys should be natural ARE WRONG.
People who believe all keys should be surrogates ARE WRONG.
Often the pragmatic solution is a combination and I'd suggest that the majority of databases are implemented in this way. Back to being pragmatic, I've implemented numerous files with correctly defined natural keys but with a surrogate to force uniqueness (via a secondary access path) so I can easily extend that entity with a generic piece of functionality, like a memo or a diary note.
I do like the point about prejudices though George.
As always, Crispin is right. The 'Denoted By' was never implemented, although it does show up in the odd prompt screen. Must people only discover it by accident when they start to get interested in the underlying model files and template files in particular.
Nice thread.
Lee.
p.s. Natural keys do make the model definitions a little easier to understand IMHO, however, if you do have your master driving file(s) as surrogates it is sometimes a lot easier to implement parallel processing in a generic fashion.