Strange (to me) import statements

[Charles Fineman]

I've been asked to look over an integration toolkit that has a bunch
of schemas to specify message format. There are a couple of strange
things I noticed right off the bat and I wanted to get others'
thoughts on it (disclaimer, obviously I'm no XML expert so forgive
me if these are basic).

--------Exhibit A: The start of a response message-----------------
<xsd:schema targetNamespace="http://www.QQQ.com"
xmlns:QQQ="http://www.QQQ.com/datatypes"
xmlns="http://www.QQQ.com"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
elementFormDefault="unqualified">

<xsd:import namespace="http://www.QQQ.com/datatypes"
schemaLocation="../general/datatypes.xsd"/>

<xsd:import namespace="http://www.QQQ.com"
schemaLocation="../general/datatypes.xsd"/>
--------Exhibit B: The start of general/datatypes.xsd --------------

<xsd:schema targetNamespace="http://www.QQQ.com/datatypes"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns="http://www.QQQ.com/datatypes"
elementFormDefault="unqualified"
attributeFormDefault="unqualified">

--------------------------------------------------------------------

#1) Exhibit A seems to be following poor form by using such a generic
targetNamespace (the same one is used for all their top-level schema).
The convention I've seen is that the targetNamespace should be the
public URL of the document.

#2) Exhibit A defines both the default and QQQ namespace to point to
the same schema (namely, Exhibit B). I guess I don't have a problem
with it technically (sans #3) but it does seem bizarre. Seems like a
really bad idea in fact. Would you do this so you could normally refer
to a name X without qualification unless there were some ambiguity with
an X in the current document (and so you could refer to it as QQQ:X)?

#3) The namespace used in the 2nd import of Exhibit A does not match
the targetNamespace of Exhibit B. Why would someone do this?

#4) Please confirm/dispute my interpretation of the elementForDefault and
the attributeFormDefault: all these say is that I do not have to qualify
elements in the document but they are still implicitly part of the
default namespace for that document (and hence would be subject to the
appropriate validations).

If this is all just bad form, so be it (and I may have a chance to
get it fixed) but if there are plausible reasons for why one would
do things this way I sure would like to hear about them.

Thanks,

Charlie Fineman