The content of the MQSeries request can be anything. The content for a BizTalk request for example differs from a SOAP request. The content template defines the XML structure of the content of the MQSeries request message. In the content template one can include references to keys in the DID. It depends on the kind of XML messages that the server, which gets the XML messages from MQSeries, can process how one should define the content template.
The format of the content template must obey some rules.