On Feb 3, 2005, at 11:14 AM, Andrew E Switala wrote:

> The gist of it is that type attributes don't mean anything with respect
> to validation. <genre authority="marcgt">abstract or summary</genre> is
> valid, but so are <genre authority="marcgt">abstract</genre>, and
> <genre
> authority="marcgt">marcgt my foot!</genre>.

There are two issues with attributes:

1)  They are really inflexible (you cannot extend them)
2)  neither XSD nor DTD are smart about attributes (they are basically
second-class xml structures in comparison to elements)

I think the content of these elements should be validated based on the
attribute values, where one could basically have sort of plug-in lists
for different genre authorities, for example.  I'm not sure how to do
that in XSD, or if it's even possible (??).

I've said before that both MODS and MADS are pretty much wide-open
schemas, leaving room for all kinds of mistakes.  They could stand to
offer much tighter validation.

Bruce