Summary of IBM article on SOAP / WSDL / XML Encoding / Schema styles

Russell Butek has an excellent article on the IBM web site about the various options for declaring SOAP services with WSDL.  Though he goes through many of the combinations, I wanted a much shorter cheat sheet table.

There are 3 main factors, which give a total of 8 possible combinations (though in reality some are not valid).

1. RPC vs. Document
2. Encoded vs. Literal
3. Unwrapped vs. Wrapped

This is the summary table I came up with (last row is the commonly used combination):

State	Combo			Used	Note
0:	RPC	Encoded	Unwrapped:	Seldom	Used with special data / graphs that need true references, and where a reference to an object can appear more than once.
1:	RPC	Encoded	Wrapped:	Never	Wrapped implies Literal
2:	RPC	Literal	Unwrapped:	Seldom	In the very rare case: Used if you have overloaded methods AND different methods with same args.  Example: Have A(i), A(f,f) and B(f,f); two methods called A, and two methods with args (f,f).  Maybe bad idea to overload anyway.
3:	RPC	Literal	Wrapped:	Never	Although Wrapped implies Literal, in practice, Wrapped only used with Doc / Literal (wasteful w RPC / Literal)
4:	Document	Encoded	Unwrapped:	Never	Nobody follows this style. It is not WS-I compliant.
5:	Document	Encoded	Wrapped:	Never	Wrapped implies Literal
6:	Document	Literal	Unwrapped:	Seldom	Used if you have overloaded methods (two methods with same name but different args).  Maybe bad idea to overload anyway.
7:	Document	Literal	Wrapped:	Most Common	Loved by Microsoft and WS-I (disambiguation committee).  Also gives a soap:body with one node, which also gives the name of the method.  The tradeoff is a more complex wsdl

A really helpful article.  I found the link to it from Jive's Clearspace Web Services Dev Guide.