The Sun event registry is the central repository of all class names, ereports, faults, defects, upsets and suspect lists (list.suspect) events. The event registry also contains the current definitions of all event member payloads, as well as important non-payload information like internal documentation, suspect lists, dictionaries, and knowledge articles. For example, ereport.io and fault.io are two of the base class names that are of particular importance to I/O driver developers.
The FMA event protocol defines a base set of payload members that is supplied with each of the registered events. Developers can also define additional events that help diagnosis engines (or eft rules) to narrow a suspect list down to a specific fault.