[Name] event [Required] false [Attribute Constraints] This attribute is mandatory if "type" is 'scxml'. [Type] Value expression [Default Value] none [Description] 
A value expression which returns a character string that indicates the type of message being generated. See 8.3 Legal Data Values and Value Expressions for details. The message type may include alphanumeric characters and the "." (dot) character. The first character may not be a dot or a digit. Message type names are case-insensitive. If neither the event attribute or in-line content is specified, an error.fetch event will be thrown. If used in conjunction with the inline content, an error.fetch will be thrown.