IBM® MQ message content
The IBM® MQ message data content can be any content type. Under some conditions, message data contains a message header known as an IBM® MQ Message Descriptor structure. For example, if you use the IBM® MQ Link for R/3, the input message data always contains a header and a header must be created for an output message.
Use the IBM® MQ adapter to include the message header in the data using the optional Header adapter command (-HDR). When the command is specified for an input message, the message header appears before the message content. If the command is specified for an output message, the adapter assumes that the first block of data supplied for the target consists of the appropriate size and values of a valid IBM® MQ Message Descriptor structure. When the Header adapter command (-HDR) is specified, any of the message header components can be included in mapping rules.
For mapping purposes, definitions for the message descriptors and the IBM® MQ Link for the R/3 header are provided in the mq.mtt schema, located in the examples\adapters\mq folder.