On Jan 3, 2005, at 4:42 PM, Ray Denenberg, Library of Congress wrote:

> The suggestion is to restructure the schema so that it will enforce
> the rule that the authority, variants, and relateds are all the same
> type. (Actually the suggestion was to use another language that can
> enforce this, but it's easy enough to do with XML schema.)

I definitely think the authority and variants should be validated of
the same type.  Otherwise, it makes no sense.

> I'm informed however, we really can't enforce this because there are
> actually records where the types are different.   Rebecca showed me an
> example of a name authority with a geographic reference. ("Clinton,
> Bill,
> 1946-" with a reference from "United States".  Rebecca can elaborate if
> necessary.)

I have no problem (I think) with leaving related more flexible.  In the
above example, "United States" is surely not a geographic variant of
the name "Bill Clinton"; is it?

> If we were to successfully enumerate the cases where this could
> happen (doubtful) and try to force validation, the schema complexity
> would
> be out-of-control, don't you think?

But, how complex it is all depends on how the data model is structured;
doesn't it?  I demonstrated how reworking the structure makes designing
the validation simpler.

> So perhaps leaving this unvalidated is
> best?

I'd say no.  I think it opens up more problems than it solves.

And I still think an authority name coded as "Clinton, Bill, 1946-"
only makes sense to librarians ;-)