An *event* refers to an application instance. When a distinct HTTP request is made to an application, it is accompanied by a value of *Event ID* or *Event Name*. In the Opendelight, an Event is uniquely identified by *Event ID* (available as `$APP->ID` within the application), or by *Event Name* (available as `$APP->IDN` within the application). The latter is usually employed for beautifying URL, and also for tagging event's ID for readability during development. An *event* can be defined for a *Controller* on the Opendelight IDE. You can add an event with the following information: 1. **Event Name, `$APP->IDN`:** This is any string of alphanumeric characters without any white space or special characters, but can have dashes or underscores. Event Name must be unique for an application. *Event ID* is automatically assigned to an event upon addition. 2. **Set as Default:** You can specify if this event is the default event; i.e., this