it's delimited by pipes... i mean, it is a standard, but it's far from ideal.
Having said that, it still seems to get data between all sorts of systems in the hospital.
[edit] and as for the XML v3, nobody uses it. Nobody.
All in all, very fun times :)
you could also say Cache (it's a post-relational database... whatever that means) is a standard database used in medical systems, but it sure isn't a postgres.