ABAP Keyword Documentation → ABAP - Reference → User Dialogs → Messages → Behavior of messages
Messages in HTTP Servers
Messages which are sent whilst an ABAP program is executed as an HTTP server of the Internet Communication Framework (ICF), behave just like in RFC processing.
Other versions: 7.31 | 7.40 | 7.54
Dialog processing or list processing can only occur for an HTTP server if the Service data → GUI connection setting for the service is set to "Yes" in the SICF transaction. By default, messages of the types "I", "S", and "W" are always ignored and messages of the types "A", "E", and "X" always lead to a termination in the processing and then a database rollback.