Architectural form-like validation with schemas?

Hello,
I need to validate documents with respect to multiple
models; each model provides a partial description or
view of a document instance; I guess archtiectural
form validation (with meta-dtds) is what I need, but I
am unaware of the status of architectural forms,
whether they  are still widely used or considered a
lost art.
Can you recommend me whether it's a good idea to use
architectural forms today, or whether they have been
superseded by some other mechanism developed in the
schema community? Is there any namespace aware
validating parser that can validate a document with
respect to several schemas?

Many thanks,

Helka F.


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