When a database event occurs in your application (such as creating a record or assigning a field), OpenEdge checks whether the CRC of the corresponding trigger procedure matches the CRC in the trigger metaschema record. If it matches, OpenEdge executes the procedure. Otherwise, OpenEdge returns a run-time error.
Trigger CRC validation works for both r-code and source versions of a trigger procedure. For source versions, OpenEdge calculates the CRC during the session compile.