# iTIP: only the organizer may update or cancel an event

# Organizer invites two attendees (1)
> put a@example.com sender-role@example.com
BEGIN:VCALENDAR
PRODID:-//Example/ExampleCalendarClient//EN
VERSION:2.0
BEGIN:VEVENT
UID:sender-role@example.com
SEQUENCE:0
ORGANIZER:mailto:a@example.com
ATTENDEE;ROLE=CHAIR;PARTSTAT=ACCEPTED:mailto:a@example.com
ATTENDEE;RSVP=TRUE:mailto:b@example.com
ATTENDEE;RSVP=TRUE:mailto:c@example.com
SUMMARY:Planning
DTSTART:20270104T180000Z
DTEND:20270104T190000Z
DTSTAMP:20261027T120000Z
STATUS:CONFIRMED
END:VEVENT
END:VCALENDAR

# Organizer invites two attendees (2)
> send

# An attendee cancels the event for another attendee, posing as the organizer
> itip c@example.com b@example.com
BEGIN:VCALENDAR
PRODID:-//Example/ExampleCalendarClient//EN
METHOD:CANCEL
VERSION:2.0
BEGIN:VEVENT
UID:sender-role@example.com
SEQUENCE:1
ORGANIZER:mailto:a@example.com
ATTENDEE;ROLE=CHAIR;PARTSTAT=ACCEPTED:mailto:a@example.com
ATTENDEE:mailto:b@example.com
ATTENDEE:mailto:c@example.com
DTSTAMP:20261027T130000Z
STATUS:CANCELLED
END:VEVENT
END:VCALENDAR

> send
SenderIsNotOrganizer("c@example.com")

# An attendee reschedules the event for another attendee, posing as the organizer
> itip c@example.com b@example.com
BEGIN:VCALENDAR
PRODID:-//Example/ExampleCalendarClient//EN
METHOD:REQUEST
VERSION:2.0
BEGIN:VEVENT
UID:sender-role@example.com
SEQUENCE:2
ORGANIZER:mailto:a@example.com
ATTENDEE;ROLE=CHAIR;PARTSTAT=ACCEPTED:mailto:a@example.com
ATTENDEE:mailto:b@example.com
ATTENDEE:mailto:c@example.com
SUMMARY:Planning (moved)
DTSTART:20270105T030000Z
DTEND:20270105T040000Z
DTSTAMP:20261027T140000Z
STATUS:CONFIRMED
END:VEVENT
END:VCALENDAR

> send
SenderIsNotOrganizer("c@example.com")