Procedure
To create a new message class from the ABAP Editor:
REPORT <Name> MESSAGE-ID <messageclass>.
Messages are visible systemwide. Your message ID (name of the message class) may therefore not already exist in the system.
If you specified a message ID that already exists, the system opens the Maintain Message dialog box. If this happens, you can simply enter another ID. If you entered a message ID that does not yet exist, a dialog box appears, in which you are asked whether you want to create a new message class.
The Maintain Message Class screen appears.
Result
If you choose Messages, you can add new messages to your message class. If you double-click the message ID in your program, you can return to the Maintain Message Class screen at any time.
See also
Adding Messages.