Use
Create a long text whenever the message text itself is not fully self-explanatory.
Prerequisites
You must already have created the message for which you want to create the long text, and not flagged it as self-explanatory.
Procedure
To enter a long text for a message in the message maintenance transaction (SE91):
Result
When you send a message that has a long text, the message is displayed with a yellow question mark symbol.
Depending on the SAPgui settings, the message is displayed:
If you then click the message line or the Help pushbutton, the long text is displayed.