JDBC 2.0 Compatibility?

Is there a document somewhere that describes the level of conformance of the
PostgreSQL JDBC driver? Specifically, I'd like to know if/how the more
advanced features of JDBC are implemented -- e.g. scrollable/updatable
result sets, fetchSize, prepared statements, batch updates, etc.

I guess some of these features can only be correctly implemented by the JDBC
driver if the underlying database connector supports them. Is that
documented? I'm using PG 7.3. I already went through the manual, maybe I've
missed it?

Thanks for any pointers!