Call Event Blocks
Event blocks are processing blocks in an ABAP program that are executed when the corresponding event occurs in the ABAP runtime environment. The following statements can be used to trigger the events (program-driven) in two cases:
SET USER-COMMAND(classic list processing)
PUT(in logical databases)
If implemented, the event blocks are also called. Both statements are effectively obsolete. You can find more information about them in the relevant sections.