You can add messages to a message set by importing IBM supplied messages using the New Message Definition File From IBM supplied messages wizard.
Each IBM supplied message that you import results in a new message definition file within the message set. The name of the message definition file defaults to the name of the IBM supplied message, but the New Message Definition File From IBM supplied messages wizard allows you to choose a different file name.
See Importing from the command line for information about what IBM supplied messages can be imported.
When you import using the New Message Definition File From IBM supplied messages wizard, you can specify only one IBM supplied message definition for each import operation.
If the message definition file already exists, you must have permitted overwriting to occur for the import to proceed, in which case the existing content is deleted and recreated.
A report file is generated during the import operation that allows you to examine what occurred during the import process and check any errors that resulted.