in graph ical

Subject	Object
?:ACTION	"TEXT"
?:ATTACH	"URI"
?:ATTENDEE	"CAL-ADDRESS"
?:Any property name with a "X-" prefix	"TEXT"
?:CALSCALE	"TEXT"
?:CATEGORIES	"TEXT"
?:CLASS	"TEXT"
?:COMMENT	"TEXT"
?:COMPLETED	"DATE-TIME"
?:CONTACT	"TEXT"
?:CREATED	"DATE-TIME"
?:DESCRIPTION	"TEXT"
?:DTEND	"DATE-TIME"
?:DTSTAMP	"DATE-TIME"
?:DTSTART	"DATE-TIME"
?:DUE	"DATE-TIME"
?:DURATION	"DURATION"
?:EXDATE	"DATE-TIME"
?:EXRULE	"RECUR"
?:FREEBUSY	"PERIOD"
?:LAST-MODIFIED	"DATE-TIME"
?:LOCATION	"TEXT"
?:METHOD	"TEXT"
?:ORGANIZER	"CAL-ADDRESS"
?:PERCENT-COMPLETE	"INTEGER"
?:PRIORITY	"INTEGER"
?:PRODID	"TEXT"
?:RDATE	"DATE-TIME"
?:RECURRENCE-ID	"DATE-TIME"
?:RELATED-TO	"TEXT"
?:REPEAT	"INTEGER"
?:REQUEST-STATUS	"TEXT"
?:RESOURCES	"TEXT"
?:RRULE	"RECUR"
?:SEQUENCE	"integer"
?:STATUS	"TEXT"
?:SUMMARY	"TEXT"
?:TRANSP	"TEXT"
?:TRIGGER	"DURATION"
?:TZID	"TEXT"
?:TZNAME	"TEXT"
?:TZOFFSETFROM	"UTC-OFFSET"
?:TZOFFSETTO	"UTC-OFFSET"
?:TZURL	"URI"
?:UID	"TEXT"
?:URL	"URI"
?:VERSION	"TEXT"