Java/jOOQ: Improve README

by-language/java-jooq/README.rst

@@ -63,13 +63,21 @@ directory has been generated like this.
 Caveats
 =======
 
+Contributions to resolve any of those items will be welcome.
+
 - `jOOQ's code generator`_ currently does not work with directly connecting to
   a real CrateDB database instance and reflecting the schema from there.
-  Because SQL DDL statements are usually maintained in form of multiple
-  incremental migration scripts anyway, this is considered to be not of a too
-  big concern, see above. With corresponding improvements to CrateDB, this
-  can be made work in the future, see `issue #10 - with reflection from the
-  database`_.
+  With corresponding improvements to CrateDB, this can be made work in the
+  future, see `issue #10 - with reflection from the database`_. Right now, this
+  example uses code generation based on SQL DDL files, which is also supported
+  by jOOQ.
+
+- Applying code generation based on the database schema (directly, or via SQL
+  DDL) is only supported for schema definitions which use field types
+  compatible with standard PostgreSQL, and understood by jOOQ. jOOQ does not
+  know anything about any other special data types supported by CrateDB, and
+  does not support it. When using special field types, like ``IP``, it will
+  trip the code generator.
 
 - Most of the jOOQ examples use uppercase letters for the database, table, and
   field names. Within this setup, we have only been able to make it work using