Component/Property Presence
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METHOD 1 MUST be "CANCEL"
VTODO 1
ATTENDEE 0+ include all "Attendees" being removed from
the todo. MUST include all "Attendees" if
the entire todo is cancelled.
UID 1 MUST echo original UID
DTSTAMP 1
ORGANIZER 1
SEQUENCE 1
ATTACH 0+
CATEGORIES 0 or 1 This property MAY contain a list of values
CLASS 0 or 1
COMMENT 0 or 1
CONTACT 0+
CREATED 0 or 1
DESCRIPTION 0 or 1
DTSTART 0 or 1
DUE 0 or 1 If present DURATION MUST NOT be present
DURATION 0 or 1 If present DUE MUST NOT be present
EXDATE 0+
EXRULE 0+
GEO 0 or 1
LAST-MODIFIED 0 or 1
LOCATION 0 or 1
PERCENT-COMPLETE 0 or 1
RDATE 0+
RECURRENCE-ID 0 or 1 MUST only if referring to one or more
instances of a recurring calendar
component. Otherwise it MUST NOT be
present.
RELATED-TO 0+
RESOURCES 0 or 1 This property MAY contain a list of values
RRULE 0+
PRIORITY 0 or 1
STATUS 0 or 1 If present it MUST be set to "CANCELLED".
MUST NOT be used if purpose is to remove
"ATTENDEES" rather than cancel the entire
VTODO.
URL 0 or 1
X-PROPERTY 0+
REQUEST-STATUS 0
VTIMEZONE 0 or 1 MUST be present if any date/time refers to
a timezone
X-COMPONENT 0+
VALARM 0
VEVENT 0
VFREEBUSY 0