RE: Got a question about SOAP: can anybody recommend a good tutorial on understanding the XML?

To understand SOAP you need to understand XML Schema. Google XML Schema for lots of good references. 

In your example, nil="true" defines the value of the element when no value is passed.

<div>-------- Original message --------</div><div>From: "James H. H. Lampert" <jamesl@xxxxxxxxxxxxxxxxx> </div><div>Date:07/22/2014 4:33 PM (GMT-06:00) </div><div>To: Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx> </div><div>Subject: Got a question about SOAP: can anybody recommend a good tutorial
on understanding the XML? </div><div>
</div>Working on a project involving the use of RXS to consume a suite of SOAP
web services. SOAP web services with lots and lots of parameters (the
RXS templates for them run over 100 lines each). It's a project I've
worked on before; this time, I'm having to port the calls from one
server to another, with different server software, and (near as I can
tell) minor changes in the parameter tags (mostly capitalization changes).

It occurs to me that this would go a lot easier if I actually had an
adequate understanding of the syntax and low-level sematics of SOAP. For
example, one of the most puzzling things I see is that on the nulled-out
parameters in the RXS templates I have, it looks like each invocation of
nil is in its own namespace, e.g.,:

<ns1:foo xmlns:ns2="http://www.w3.org/2001/XMLSchema-instance"; ns2:nil="true"/>
<ns1:bar>.:bar:.</ns1:bar>
<ns1:baz xmlns:ns4="http://www.w3.org/2001/XMLSchema-instance"; ns4:nil="true"/>

(the names have been changed, to protect the innocent).

I'm hoping that the more I know about SOAP, the less it's going to leave
me with a bad taste in my mouth, craving some REST.

Can somebody recommend a reference and/or tutorial that will make all
this a bit more comprehensible to me?

--
JHHL