Help with terms for kind of schema I'm building

["Karr, David" <david.karr@wamu.net>]

I'm trying to figure out appropriate terms to describe the kind of
schema I'm trying to build (and related terms).  Each time I have to
talk about this, I wave my hands a bit.  I'd like to find better terms
to describe this, that are "in the literature", as they say.

We have a downstream service that uses what I would call an
"application-specific" schema, simply that the types and elements are
named according to the semantics of what the information represents.  In
other words, a perfectly normal application schema.

I have to build a web service that interfaces with this service.  The
schema for my service should provide most of the information in the
other schema, although we're going to get some of the pieces for the
downstream service from other sources.  I've been told that we're going
to need a lot of flexibility in the messages matching this schema.  A
new "schema" has to be usable in minutes, not the days and weeks that
changing files in production in a bank would require.

So, I figure the best way to deal with this is to "dumb down" my service
schema, so instead of having a set of application-specific element
names, it will just be a list of key-value pairs.  I've referred to this
as "non-type-safe", but that isn't quite right.  Obviously, there are
specific disadvantages to this type of schema (the term of which I'm
looking for here), but it will probably be the best compromise for my
needs.

Again, I'm not looking for a critique of this approach, just useful
vocabulary to describe what I'm building, and also perhaps an opposite
term to describe my downstream service schema.