According to BP 1.0 and Ivan's notes p.59
"A SOAP Envelope must not contain any soap:encodingStyle attributes on any child element
of the SOAP <Body> element."
But on Ivan's notes p.50, there is an example:
Obviously, this example shows that the soap:encodingStyle is used by the child element <add> of the soap:Body.
Does it conflict with the BP 1.0 ?