SOAP Syntax
SOAP Building Blocks
A SOAP message is a regular XML document, containing the following elements:
The required Envelope element, which identifies this XML document as a SOAP message
The optional Header element, which contains header information
The required Body element, which contains all the call and response information
The optional Fault element, which provides information about errors that occurred while processing this message
All the above elements are declared in the default namespace for SOAP encapsulation:
http://www.w3.org/2001/12/soap-envelope
And the default namespace for SOAP encoding and data types:
http://www.w3.org/2001/12/soap-encoding
Syntax Rules
Here are some important syntax rules:
SOAP messages must be encoded in XML
SOAP messages must use the SOAP Envelope namespace
SOAP messages must use the SOAP Encoding namespace
SOAP messages must not contain DTD references
SOAP messages must not contain XML processing instructions