RE: text/xml for SOAP is incorrect

I think application/soap+xml is better than application/xml
for different reasons than given by others. I think it's better
because SOAP messages do not allow arbitrary XML expressions.
For example, the SOAP specification restricts:

  A SOAP message MUST NOT contain a Document Type Declaration.
  A SOAP message MUST NOT contain Processing Instructions.

further, SOAP contains more restrictive rules for encoding
types than XML:

  XML allows very flexible encoding of data. SOAP defines a
  narrower set of rules for encoding. 

MIME labeling is a packaging technology, and the purpose of
packaging is not primarily 'routing' in this case (since the
URL and SOAPAction header do that) but mainly 'protection'.

Wrapping SOAP content with "content-type: application/soap+xml"
instead of "content-type: application/xml" protects the SOAP
content better from intermediaries that might translate
one "application/xml" body into an equivalent one (using XML
rules) but would leave application/soap+xml alone.

Received on Tuesday, 18 September 2001 14:26:06 UTC