An attribute is a special information defined inside an entry of the iCalendar. It contains further information in order to explain better or add more information to the entry...there can be many attributes for one entry! Actually, it's only implemented in the case of a RRULE.
This method is called when the parser recognise a component begin. Actually, in the OutlookEmitter, this happens only for the VEVENT component (rfc2445)
This method is called when a resource has been finished to been parsed. Actually it's only used in case of a RRULE (ends the job of the currently RecurrenceEmitter).
An ID is the main keyword identifying the iCalendar entry, as defined in the Parser class in the iCalendar parser project. It's used only in the case we're analyzing a VEVENT
A value property it's the value of an entry, when within the entry there are also some attributes defined. At the moment, it's defined only for VEVENT components.