There is a messages manual.
Go to the TSM web site, look for the link on the right that says "product
manuals".

http://www.tivoli.com/products/index/storage_mgr/

However, the quickest way to find the message text for a client, is to ask
the client.
*       Start the COMMAND LINE version of the client (DSMC).
*       Follow the onscreen instructions EXACTLY (type D to scroll down).
*       All the messages are there, and they will be the correct version for
what you have installed.