You must create a message definition file before
you can create the message model objects. The message definition file contains
the logical and physical model definitions of the objects in XML schema form.
To
create a new message definition file that is based on an existing
resource:
The new message definition file, with the name
that you have specified and a file extension of *.mxsd,
opens in the Message Definition editor; you can use the editor to create your
own message definitions. If you have chosen to use a target namespace, a directory
structure that is based on the URI that you have supplied is created. The
new message definition file is placed within this directory structure, which
appears in the Broker Development view, the Outline view, and the Overview
editor.