How do i design messages?

 

Hi

 

I have been asked to create a set of xml messages for an existing system so the system can be exposed on a messaging bus. I know what the system does so how do I go about designing the format of the messages? Do I just start by thinking about what information my system needs? Should I get a book or look at a site which will tell me what to do and what to avoid? What is this book or site?

 

thanks - hope you can help.

 

Jason
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