Messages
Messages are the informational text you sometimes see at the bottom (status bar or status line) of an application or Environment form, such as "No records found to process" or "Field Is Required."
Application messages are grouped by product line and category. Typically, a category corresponds to a program. Within a category, each message has a unique number. For more information about messages, see the documentation on the Message Definition utility (msgmnt) in the System Utilities Reference Guide.