evento			 todo	      journal	   fbrequest	    fbreply  busytime  timezone
	attach		 attach	      attach
	attendee	 attendee     attendee	   attendee	    attendee attendee
	categories	 categories   categories
	class		 class	      class
	comment		 comment      comment	   comment	    comment  comment   comment
			 completed
	contact		 contact      contact
	created		 created      created			    created
	description	 description  description
			 dtstamp      dtstamp
	dtend/duration	 due->dtend		   dtend [duration] dtend    dtend
	dtstart		 dtstart      dtstart	   dtstart	    dtstart  dtstart   dtstart
	exdate		 exdate	      exdate
	exrule		 exrule	      exrule
	geo		 geo
	last-mod	 last-mod     last-mod	   last-mod	    last-mod
	location	 location
	organizer	 organizer    organizer
			 percent
	priority	 priority
	rstatus		 rstatus      rstatus			    rstatus
	related		 related      related
	resources	 resources
	rdate		 rdate	      rdate					       [rdate/rrule]
	rrule		 rrule	      rrule
	dtstamp					   dtstamp	    dtstamp  dtstamp
	seq		 seq	      seq	   seq		    seq
	status		 status
	summary		 summary      summary
	transp
	uid		 uid	      uid	   uid		    uid
	url		 url	      url			    url	     url
	recurid		 recurid      recurid
								    freebusy freebusy
										       tzname
										       tzoffset-to
										       tzoffset-from