Incidents are most commonly created automatically through rules and rule sets (user-defined instructions that tell Incident Manager how to handle specific events when they occur). As shown in the preceding examples, incidents can also be created manually. Once an incident is raised, its severity is inherited from the worst severity of all events within the incident. The latest event Message, by default, becomes the Incident Summary. Beginning with Enterprise Manager 13c, you can also define customized messages for grouped incidents. Incidents can also be created manually. See "Creating an Incident Manually" for more information.