# Using the event reference

A typical event description includes:

Description | A brief description of the meaning of the event.
State transition | If the event signifies a call or line state transition, the transition is described here. If the event is informational, None appears here.
Associated function | If the event is solicited (occurs as a result of a function call), the associated function or functions are listed here. If the event is unsolicited, Unsolicited appears here.
Fields | Lists information returned with the event, such as line or call handles or values.
Reason codes | If the event returns a value field, possible values are listed here.
Details | Lists any further information about the event, such as capabilitymask or bit settings that regulate whether or not the event occurs.