The input message is separated into request units. These request
units are simple requests for some entity or operation pair. Each
request unit is processed without validation. If an XPath expression
is found as a value for some node, then the corresponding value
from the previous response will be substituted. If no value is found, then
an empty value is returned. An invalid XPath expression returns
a corresponding exception. The following is an example of an
XPath expression:
<is:Status>${//crm:account.Create.Response/crm:EntityList/crm:Entity/crm:Status}</is: Status >
Note: XML
Path Language (XPath) version 1.0 is currently supported.