The IDOC domain processes messages that SAP R3 clients send to the broker across the MQSeries® link for R3.
A SAP IDoc message contains both SAP-defined and user-defined fields. The parser that is supplied with the IDOC domain creates a logical message tree from the SAP-defined fields, then automatically invokes the MRM domain parser to complete the tree from the user-defined fields. You must therefore model the user-defined content of the IDoc message using a message set that contains a Custom Wire Format (CWF) physical format.
One of the message definitions that are supplied with WebSphere Message Broker is a model of the SAP-defined fields. You can add the model to a message set using the New Message Definition file wizard. This addition enables other editors to make use of the SAP-defined fields; for example, the WebSphere Message Broker ESQL editor uses the model to provide code completion.