More: Now some feedback on Header v0-63

[David RR Webber <Gnosis_@compuserve.com>]

Message text written by Joe Lapp
>The BizTalk/SOAP approach is to require that every child element belong to
some XML namespace (that every header entry belong to some namespace).
That way a middleware app can identify its own headers by namespace and
ignore everything else.
<<<<<<<<<<<<<<<

Joe, this is a very dangerous mechanism if not controlled and used
correctly.  The way Microsoft uses it in XDR is rightly labelled as
highly dangerous.

The reason being is that there is NO master message definition, since
the namespace used as an included which is itself part of the XML means
it is impossible to know what the actual header construct is, without 
inspecting an message header document instance!

In GUIDE this is explicitly excluded by using the GUIDE structure layer
to explicitly define the structure, and therefore avoiding any nested 
parsing complexities due to unresolved content.

Therefore a GUIDE structure defining the message header would be
extensible but in a predetermined and controlled way - and of course
that is exactly the guarantee we need for interoperability.

Thanks, DW.

p.s. More info' on the GUIDE structure layer mechanism for 
        http://www.bizcodes.org/GUIDE/