The CustomEvent interface is the recommended interface for application-specific event types. Unlike the Event interface, it allows applications to provide contextual information about the event type. Application-specific event types should use a prefix string on the event type name to avoid clashes with future general-purpose event types.
|Specifies some detail information about the Event.|
|Initializes attributes of a CustomEvent object.|
DOM Core reference
DOM Core specification defines the Interface CustomEvent in 4.2 Interface CustomEvent.