WebSphere MQ message format

Each WebSphere MQ message consists of two parts: a header and the application data.

There are five types of header, as shown in the following table

MQMD	The message descriptor. Created by the application at message create time.
MQXQH	The Transmission Queue header, which contains delivery information in remote queuing.
MQDLH	The dead letter header, which identifies conditions that prevent delivery to a destination queue.
MQRMH	Reference message header, which contains information to assist in delivery of reference messages.
IMSrtm	Information header (MQIIH), which is carried with the message using the IMS hierarchical database bridge facility.

Let's look at the MQMD header in more detail. The following figure shows how the MQMD is made up:

The following table shows the meaning of each MQMD entry in the preceding figure:

1	The queue name for reply messages.
2	If we cannot deliver this message, put it in the DLQ or discard (DLQ is the default).
3	Is the...