The "CANCEL" method in a "VEVENT" calendar component is used to send
a cancellation notice of an existing event request to the
"Attendees". The message is sent by the "Organizer" of the event. For
a recurring event, either the whole event or instances of an event
may be cancelled. To cancel the complete range of recurring event,
the "UID" property value for the event MUST be specified and a
"RECURRENCE-ID" MUST NOT be specified in the "CANCEL" method. In
order to cancel an individual instance of the event, the
"RECURRENCE-ID" property value for the event MUST be specified in the
"CANCEL" method.
There are two options for canceling a sequence of instances of a
recurring "VEVENT" calendar component:
(a) the "RECURRENCE-ID" property for an instance in the sequence MUST
be specified with the "RANGE" property parameter value of
THISANDPRIOR (or THISANDFUTURE) to indicate cancellation of the
specified "VEVENT" calendar component and all instances before
(or after); or
(b) individual recurrence instances may be cancelled by specifying
multiple "RECURRENCE-ID" properties corresponding to the
instances to be cancelled.
When a "VEVENT" is cancelled, the "SEQUENCE" property value MUST be
incremented.
This method type is an iCalendar object that conforms to the
following property constraints:
Component/Property Presence
------------------- ----------------------------------------------
METHOD 1 MUST be "CANCEL"
VEVENT 1+ All must have the same UID
ATTENDEE 0+ MUST include all "Attendees" being removed
the event. MUST include all "Attendees" if
the entire event is cancelled.
DTSTAMP 1
ORGANIZER 1
SEQUENCE 1
UID 1 MUST be the UID of the original REQUEST
COMMENT 0 or 1
ATTACH 0+
CATEGORIES 0 or 1 This property may contain a list of values
CLASS 0 or 1
CONTACT 0+
CREATED 0 or 1
DESCRIPTION 0 or 1
DTEND 0 or 1 if present DURATION MUST NOT be present
DTSTART 0 or 1
DURATION 0 or 1 if present DTEND MUST NOT be present
EXDATE 0+
EXRULE 0+
GEO 0 or 1
LAST-MODIFIED 0 or 1
LOCATION 0 or 1
PRIORITY 0 or 1
RDATE 0+
RECURRENCE-ID 0 or 1 MUST be present if referring to one or
more or more recurring instances.
Otherwise it MUST NOT be present
RELATED-TO 0+
RESOURCES 0 or 1
RRULE 0+
STATUS 0 or 1 MUST be set to CANCELLED. If uninviting
specific "Attendees" then MUST NOT be
included.
SUMMARY 0 or 1
TRANSP 0 or 1
URL 0 or 1
X-PROPERTY 0+
REQUEST-STATUS 0
VTIMEZONE 0+ MUST be present if any date/time refers to
a timezone
X-COMPONENT 0+
VTODO 0
VJOURNAL 0
VFREEBUSY 0
VALARM 0
3.2.6 REFRESH
The "REFRESH" method in a "VEVENT" calendar component is used by
"Attendees" of an existing event to request an updated description
from the event "Organizer". The "REFRESH" method must specify the
"UID" property of the event to update. A recurrence instance of an
event may be requested by specifying the "RECURRENCE-ID" property
corresponding to the associated event. The "Organizer" responds with
the latest description and version of the event.
This method type is an iCalendar object that conforms to the
following property constraints:
Component/Property Presence
------------------- ----------------------------------------------
METHOD 1 MUST be "REFRESH"
VEVENT 1
ATTENDEE 1 MUST be the address of requestor
DTSTAMP 1
ORGANIZER 1
UID 1 MUST be the UID associated with original
REQUEST
COMMENT 0 or 1
RECURRENCE-ID 0 or 1 MUST only if referring to an instance of a
recurring calendar component. Otherwise
it must NOT be present.
X-PROPERTY 0+
ATTACH 0
CATEGORIES 0
CLASS 0
CONTACT 0
CREATED 0
DESCRIPTION 0
DTEND 0
DTSTART 0
DURATION 0
EXDATE 0
EXRULE 0
GEO 0
LAST-MODIFIED 0
LOCATION 0
PRIORITY 0
RDATE 0
RELATED-TO 0
REQUEST-STATUS 0
RESOURCES 0
RRULE 0
SEQUENCE 0
STATUS 0
SUMMARY 0
TRANSP 0
URL 0
X-COMPONENT 0+
VTODO 0
VJOURNAL 0
VFREEBUSY 0
VTIMEZONE 0
VALARM 0
3.2.7 COUNTER
The "COUNTER" method for a "VEVENT" calendar component is used by an
"Attendee" of an existing event to submit to the "Organizer" a
counter proposal to the event description. The "Attendee" sends this
message to the "Organizer" of the event.
The counter proposal is an iCalendar object consisting of a VEVENT
calendar component describing the complete description of the
alternate event.
The "Organizer" rejects the counter proposal by sending the
"Attendee" a VEVENT "DECLINECOUNTER" method. The "Organizer" accepts
the counter proposal by rescheduling the event as described in
section 3.2.2.1 Rescheduling an Event.
This method type is an iCalendar object that conforms to the
following property constraints:
Component/Property Presence
------------------- ----------------------------------------------
METHOD 1 MUST be "COUNTER"
VEVENT 1
DTSTAMP 1
DTSTART 1
ORGANIZER 1 MUST be the "Organizer" of the original
event
SEQUENCE 1 MUST be present if value is greater than 0,
MAY be present if 0
SUMMARY 1 Can be null
UID 1 MUST be the UID associated with the REQUEST
being countered
ATTACH 0+
ATTENDEE 0+ Can also be used to propose other
"Attendees"
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
DTEND 0 or 1 if present DURATION MUST NOT be present
DURATION 0 or 1 if present DTEND MUST NOT be present
EXDATE 0+
EXRULE 0+
GEO 0 or 1
LAST-MODIFIED 0 or 1
LOCATION 0 or 1
PRIORITY 0 or 1
RDATE 0+
RECURRENCE-ID 0 or 1 MUST only if referring to an instance of a
recurring calendar component. Otherwise it
MUST NOT be present.
RELATED-TO 0+
REQUEST-STATUS 0+
RESOURCES 0 or 1 This property may contain a list of values
RRULE 0+
STATUS 0 or 1 Value must be one of CONFIRMED/TENATIVE/
CANCELLED
TRANSP 0 or 1
URL 0 or 1
X-PROPERTY 0+
VALARM 0+
VTIMEZONE 0+ MUST be present if any date/time refers to
a timezone
X-COMPONENT 0+
VTODO 0
VJOURNAL 0
VFREEBUSY 0
3.2.8 DECLINECOUNTER
The "DECLINECOUNTER" method in a "VEVENT" calendar component is used
by the "Organizer" of an event to reject a counter proposal submitted
by an "Attendee". The "Organizer" must send the "DECLINECOUNTER"
message to the "Attendee" that sent the "COUNTER" method to the
"Organizer".
This method type is an iCalendar object that conforms to the
following property constraints:
Component/Property Presence
------------------- ----------------------------------------------
METHOD 1 MUST be "DECLINECOUNTER"
VEVENT 1
DTSTAMP 1
ORGANIZER 1
UID 1 MUST, same UID specified in original
REQUEST and subsequent COUNTER
COMMENT 0 or 1
RECURRENCE-ID 0 or 1 MUST only if referring to an instance of a
recurring calendar component. Otherwise it
MUST NOT be present.
REQUEST-STATUS 0+
SEQUENCE 0 OR 1 MUST be present if value is greater than 0,
MAY be present if 0
X-PROPERTY 0+
ATTACH 0
ATTENDEE 0
CATEGORIES 0
CLASS 0
CONTACT 0
CREATED 0
DESCRIPTION 0
DTEND 0
DTSTART 0
DURATION 0
EXDATE 0
EXRULE 0
GEO 0
LAST-MODIFIED 0
LOCATION 0
PRIORITY 0
RDATE 0
RELATED-TO 0
RESOURCES 0
RRULE 0
STATUS 0
SUMMARY 0
TRANSP 0
URL 0
X-COMPONENT 0+
VTODO 0
VJOURNAL 0
VFREEBUSY 0
VTIMEZONE 0
VALARM 0
3.3 Methods For VFREEBUSY Components
This section defines the property set for the methods that are
applicable to the "VFREEBUSY" calendar component. Each of the methods
is defined using a restriction table.
This document only addresses the transfer of busy time information.
Applications desiring free time information MUST infer this from
available busy time information.
The busy time information within the iCalendar object MAY be grouped
into more than one "VFREEBUSY" calendar component. This capability
allows busy time periods to be grouped according to some common
periodicity, such as a calendar week, month, or year. In this case,
each "VFREEBUSY" calendar component MUST include the "ATTENDEE",
"DTSTART" and "DTEND" properties in order to specify the source of
the busy time information and the date and time interval over which
the busy time information covers.
The "FREEBUSY" property value MAY include a list of values, separated
by the COMMA character ([US-ASCII] decimal 44). Alternately, multiple
busy time periods MAY be specified with multiple instances of the
"FREEBUSY" property. Both forms MUST be supported by implementations
conforming to this document. Duplicate busy time periods SHOULD NOT
be specified in an iCalendar object. However, two different busy time
periods MAY overlap.
"FREEBUSY" properties should be sorted such that their values are in
ascending order, based on the start time, and then the end time, with
the earliest periods first. For example, today's busy time
information should appear after yesterday's busy time information.
And the busy time for this half-hour should appear after the busy
time for earlier today.
Since events may span a day boundary, free busy time period may also
span a day boundary. Individual "A" requests busy time from
individuals "B", "C" and "D". Individual "B" and "C" replies with
busy time data to individual "A". Individual "D" does not support
busy time requests and does not reply with any data. If the transport
binding supports exception messages, then individual "D" returns an
"unsupported capability" message to individual "A4.34.3".
The following summarizes the methods that are defined for the
"VFREEBUSY" calendar component.
|================|==================================================|
| Method | Description |
|================|==================================================|
| PUBLISH | Publish unsolicited busy time data. |
| REQUEST | Request busy time data. |
| REPLY | Reply to a busy time request. |
|================|==================================================|
3.3.1 PUBLISH
The "PUBLISH" method in a "VFREEBUSY" calendar component is used to
publish busy time data. The method may be sent from one CU to any
other. The purpose of the method is to provide a message for sending
unsolicited busy time data. That is, the busy time data is not being
sent as a "REPLY" to the receipt of a "REQUEST" method.
The "ATTENDEE" property must be specified in the busy time
information. The value is the CU address of the originator of the
busy time information.
This method type is an iCalendar object that conforms to the
following property constraints:
Component/Property Presence
------------------- ----------------------------------------------
METHOD 1 MUST be "PUBLISH"
VFREEBUSY 1+
DTSTAMP 1
DTSTART 1 DateTime values must be in UTC
DTEND 1 DateTime values must be in UTC
FREEBUSY 1+ MUST be BUSYTIME. Multiple instances are
allowed. Multiple instances must be sorted
in ascending order
ORGANIZER 1 MUST contain the address of originator of
busy time data.
COMMENT 0 or 1
CONTACT 0+
X-PROPERTY 0+
URL 0 or 1 Specifies busy time URL
ATTENDEE 0
DURATION 0
REQUEST-STATUS 0
UID 0
X-COMPONENT 0+
VEVENT 0
VTODO 0
VJOURNAL 0
VTIMEZONE 0
VALARM 0
3.3.2 REQUEST
The "REQUEST" method in a "VFREEBUSY" calendar component is used to
ask a "Calendar User" for their busy time information. The request
may be for a busy time information bounded by a specific date and
time interval.
This message only permits requests for busy time information. The
message is sent from a "Calendar User" requesting the busy time
information to one or more intended recipients.
If the originator of the "REQUEST" method is not authorized to make a
busy time request on the recipient's calendar system, then an
exception message SHOULD be returned in a "REPLY" method, but no busy
time data need be returned.
This method type is an iCalendar object that conforms to the
following property constraints:
Component/Property Presence
------------------- ----------------------------------------------
METHOD 1 MUST be "REQUEST"
VFREEBUSY 1
ATTENDEE 1+ contain the address of the calendar store
DTEND 1 DateTime values must be in UTC
DTSTAMP 1
DTSTART 1 DateTime values must be in UTC
ORGANIZER 1 MUST be the request originator's address
UID 1
COMMENT 0 or 1
CONTACT 0+
X-PROPERTY 0+
FREEBUSY 0
DURATION 0
REQUEST-STATUS 0
URL 0
X-COMPONENT 0+
VALARM 0
VEVENT 0
VTODO 0
VJOURNAL 0
VTIMEZONE 0
3.3.3 REPLY
The "REPLY" method in a "VFREEBUSY" calendar component is used to
respond to a busy time request. The method is sent by the recipient
of a busy time request to the originator of the request.
The "REPLY" method may also be used to respond to an unsuccessful
"REQUEST" method. Depending on the "REQUEST-STATUS" value, no busy
time information may be returned.
This method type is an iCalendar object that conforms to the
following property constraints:
Component/Property Presence
------------------- ----------------------------------------------
METHOD 1 MUST be "REPLY"
VFREEBUSY 1
ATTENDEE 1 (address of recipient replying)
DTSTAMP 1
DTEND 1 DateTime values must be in UTC
DTSTART 1 DateTime values must be in UTC
FREEBUSY 1+ (values MUST all be of the same data
type. Multiple instances are allowed.
Multiple instances MUST be sorted in
ascending order. Values MAY NOT overlap)
ORGANIZER 1 MUST be the request originator's address
UID 1
COMMENT 0 or 1
CONTACT 0+
REQUEST-STATUS 0+
URL 0 or 1 (specifies busy time URL)
X-PROPERTY 0+
DURATION 0
SEQUENCE 0
X-COMPONENT 0+
VALARM 0
VEVENT 0
VTODO 0
VJOURNAL 0
VTIMEZONE 0
3.4 Methods For VTODO Components
This section defines the property set for the methods that are
applicable to the "VTODO" calendar component. Each of the methods is
defined using a restriction table that specifies the property
constraints that define the particular method.
The following summarizes the methods that are defined for the "VTODO"
calendar component.
+================+==================================================+
| Method | Description |
|================+==================================================|
| PUBLISH | Post notification of a VTODO. Used primarily as |
| | a method of advertising the existence of a VTODO.|
| | |
| REQUEST | Assign a VTODO. This is an explicit assignment to|
| | one or more Calendar Users. The REQUEST method |
| | is also used to update or change an existing |
| | VTODO. Clients that cannot handle REQUEST MAY |
| | degrade the method to treat it as a PUBLISH. |
| | |
| REPLY | Reply to a VTODO request. Attendees MAY set |
| | PARTSTAT to ACCEPTED, DECLINED, TENTATIVE, |
| | DELEGATED, PARTIAL, and COMPLETED. |
| | |
| ADD | Add one or more instances to an existing to-do. |
| | |
| CANCEL | Cancel one or more instances of an existing |
| | to-do. |
| | |
| REFRESH | A request sent to a VTODO Organizer asking for |
| | the latest version of a VTODO. |
| | |
| COUNTER | Counter a REQUEST with an alternative proposal. |
| | |
| DECLINECOUNTER | Decline a counter proposal by an Attendee. |
+================+==================================================+
3.4.1 PUBLISH
The "PUBLISH" method in a "VTODO" calendar component has no
associated response. It is simply a posting of an iCalendar object
that maybe added to a calendar. It MUST have an "Organizer". It MUST
NOT have "Attendees". Its expected usage is for encapsulating an
arbitrary "VTODO" calendar component as an iCalendar object. The
"Organizer" MAY subsequently update (with another "PUBLISH" method),
add instances to (with an "ADD" method), or cancel (with a "CANCEL"
method) a previously published "VTODO" calendar component.
This method type is an iCalendar object that conforms to the
following property constraints:
Component/Property Presence
------------------- ----------------------------------------------
METHOD 1 MUST be "PUBLISH"
VTODO 1+
DTSTAMP 1
DTSTART 1
ORGANIZER 1
PRIORITY 1
SEQUENCE 0 or 1 MUST be present if value is greater than
0, MAY be present if 0
SUMMARY 1 Can be null.
UID 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 Can be null
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 an instance 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+
STATUS 0 or 1 MAY be one of COMPLETED/NEEDS ACTION/IN-
PROCESS/CANCELLED
URL 0 or 1
X-PROPERTY 0+
ATTENDEE 0
REQUEST-STATUS 0
VTIMEZONE 0+ MUST be present if any date/time refers to
a timezone
VALARM 0+
X-COMPONENT 0+
VFREEBUSY 0
VEVENT 0
VJOURNAL 0
3.4.2 REQUEST
The "REQUEST" method in a "VTODO" calendar component provides the
following scheduling functions:
. Assign a to-do to one or more "Calendar Users";
. Reschedule an existing to-do;
. Update the details of an existing to-do, without rescheduling
it;
. Update the completion status of "Attendees" of an existing
to-do, without rescheduling it;
. Reconfirm an existing to-do, without rescheduling it;
. Delegate/reassign an existing to-do to another "Calendar User".
The assigned "Calendar Users" are identified in the "VTODO" calendar
component by individual "ATTENDEE;ROLE=REQ-PARTICIPANT" property
value sequences.
The originator of a "REQUEST" is the "Organizer" of the to-do. The
recipient of a "REQUEST" is the "Calendar User" assigned the to-do.
The "Attendee" uses the "REPLY" method to convey their acceptance and
completion status to the "Organizer" of the "REQUEST".
The "UID", "SEQUENCE", and "DTSTAMP" properties are used to
distinguish the various uses of the "REQUEST" method. If the "UID"
property value in the "REQUEST" is not found on the recipient's
calendar, then the "REQUEST" is for a new to-do. If the "UID"
property value is found on the recipient's calendar, then the
"REQUEST" is a rescheduling, an update, or a reconfirm of the "VTODO"
calendar object.
If the "Organizer" of the "REQUEST" method is not authorized to make
a to-do request on the "Attendee's" calendar system, then an
exception is returned in the "REQUEST-STATUS" property of a
subsequent "REPLY" method, but no scheduling action is performed.
For the "REQUEST" method, multiple "VTODO" components in a single
iCalendar object are only permitted when for components with the same
"UID" property. That is, a series of recurring events may have
instance-specific information. In this case, multiple "VTODO"
components are needed to express the entire series.
This method type is an iCalendar object that conforms to the
following property constraints:
Component/Property Presence
------------------- ----------------------------------------------
METHOD 1 MUST be "REQUEST"
VTODO 1+ All components must have the same UID
ATTENDEE 1+
DTSTAMP 1
DTSTART 1
ORGANIZER 1
PRIORITY 1
SEQUENCE 0 or 1 MUST be present if value is greater than
0, MAY be present if 0
SUMMARY 1 Can be null.
UID 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 Can be null
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 present if referring to an instance 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+
STATUS 0 or 1 MAY be one of COMPLETED/NEEDS ACTION/IN-
PROCESS
URL 0 or 1
X-PROPERTY 0+
REQUEST-STATUS 0
VALARM 0+
VTIMEZONE 0+ MUST be present if any date/time refers
to a timezone
X-COMPONENT 0+
VEVENT 0
VFREEBUSY 0
VJOURNAL 0
3.4.2.1 REQUEST for Rescheduling a VTODO
The "REQUEST" method may be used to reschedule a "VTODO" calendar
component.
Rescheduling a "VTODO" calendar component involves a change to the
existing "VTODO" calendar component in terms of its start or due time
or recurrence intervals and possibly the description. If the
recipient CUA of a "REQUEST" method finds that the "UID" property
value already exists on the calendar, but that the "SEQUENCE"
property value in the "REQUEST" is greater than the value for the
existing VTODO, then the "REQUEST" method describes a rescheduling of
the "VTODO" calendar component.
3.4.2.2 REQUEST for Update or Reconfirmation of a VTODO
The "REQUEST" method may be used to update or reconfirm a "VTODO"
calendar component. Reconfirmation is merely an update of "Attendee"
completion status or overall "VTODO" calendar component status.
An update to an existing "VTODO" calendar component does not involve
changes to the start or due time or recurrence intervals, nor
generally to the description for the "VTODO" calendar component. If
the recipient CUA of a "REQUEST" method finds that the "UID" property
value already exists on the calendar and that the "SEQUENCE" property
value in the "REQUEST" is the same as the value for the existing
event, then the "REQUEST" method describes an update of the "VTODO"
calendar component details, but not a rescheduling of the "VTODO"
calendar component.
The update "REQUEST" is the appropriate response to a "REFRESH"
method sent from an "Attendee" to the "Organizer" of a "VTODO"
calendar component.
Unsolicited "REQUEST" methods MAY be sent by the "Organizer" of a
"VTODO" calendar component. The unsolicited "REQUEST" methods are
used to update the details of the "VTODO" (without rescheduling it or
updating the completion status of "Attendees") or the "VTODO"
calendar component itself (i.e., reconfirm the "VTODO").
3.4.2.3 REQUEST for Delegating a VTODO
The "REQUEST" method is also used to delegate or reassign ownership
of a "VTODO" calendar component to another "Calendar User". For
example, it may be used to delegate an "Attendee's" role (i.e.
"chair", or "participant") for a "VTODO" calendar component. The
"REQUEST" method is sent by one of the "Attendees" of an existing
"VTODO" calendar component to some other individual. An "Attendee" of
a "VTODO" calendar component MUST NOT delegate to the "Organizer" of
the event.
For the purposes of this description, the "Attendee" delegating the
"VTODO" calendar component is referred to as the "Delegator". The
"Attendee" receiving the delegation request is referred to as the
"Delegate".
The "Delegator" of a "VTODO" calendar component MUST forward the
existing "REQUEST" method for a "VTODO" calendar component to the
"Delegate". The "VTODO" calendar component description MUST include
the "Delegator's" up-to-date "VTODO" calendar component definition.
The "REQUEST" method MUST also include an "ATTENDEE" property with
the calendar address of the "Delegate". The "Delegator" MUST also
send a "REPLY" method back to the "Organizer" with the "Delegator's"
"Attendee" property "partstat" parameter value set to "DELEGATED". In
addition, the "delegated-to" parameter MUST be included with the
calendar address of the "Delegate". A response to the delegation
"REQUEST" is sent from the "Delegate" to the "Organizer" and
optionally, to the "Delegator". The "REPLY" method from the
"Delegate" SHOULD include the "ATTENDEE" property with their calendar
address and the "delegated-from" parameter with the value of the
"Delegator's" calendar address.
The delegation "REQUEST" method MUST assign a value for the "RSVP"
property parameter associated with the "Delegator's" "Attendee"
property to that of the "Delegate's" "ATTENDEE" property. For example
if the "Delegator's" "ATTENDEE" property specifies "RSVP=TRUE", then
the "Delegate's" "ATTENDEE" property MUST specify "RSVP=TRUE".
3.4.2.4 REQUEST Forwarded To An Uninvited Calendar User
An "Attendee" assigned a "VTODO" calendar component may send the
"VTODO" calendar component to another new CU, not previously
associated with the "VTODO" calendar component. The current
"Attendee" assigned the "VTODO" calendar component does this by
forwarding the original "REQUEST" method to the new CU. The new CU
can send a "REPLY" to the "Organizer" of the "VTODO" calendar
component. The reply contains an "ATTENDEE" property for the new CU.
The "Organizer" ultimately decides whether or not the new CU becomes
part of the to-do and is not obligated to do anything with a "REPLY"
from a new (uninvited) CU. If the "Organizer" does not want the new
CU to be part of the to-do, the new "ATTENDEE" property is not added
to the "VTODO" calendar component. The "Organizer" MAY send the CU a
"CANCEL" message to indicate that they will not be added to the to-
do. If the "Organizer" decides to add the new CU, the new "ATTENDEE"
property is added to the "VTODO" calendar component. Furthermore, the
"Organizer" is free to change any "ATTENDEE" property parameter from
the values supplied by the new CU to something the "Organizer"
considers appropriate.
3.4.2.5 REQUEST Updated Attendee Status
An "Organizer" of a "VTODO" may request an updated status from one or
more "Attendees". The "Organizer" sends a "REQUEST" method to the
"Attendee" with the "ATTENDEE;RSVP=TRUE" property sequence. The
"SEQUENCE" property for the "VTODO" is not changed from its previous
value. A recipient determines that the only change in the "REQUEST"
is that their "RSVP" property parameter indicates a request for an
updated status. The recipient SHOULD respond with a "REPLY" method
indicating their current status with respect to the "REQUEST".
3.4.3 REPLY
The "REPLY" method in a "VTODO" calendar component is used to respond
(e.g., accept or decline) to a request or to reply to a delegation
request. It is also used by an "Attendee" to update their completion
status. When used to provide a delegation response, the "Delegator"
MUST include the calendar address of the "Delegate" in the
"delegated-to" parameter of the "Delegator's" "ATTENDEE" property.
The "Delegate" MUST include the calendar address of the "Delegator"
on the "delegated-from" parameter of the "Delegate's" "ATTENDEE"
property.
The "REPLY" method MAY also be used to respond to an unsuccessful
"VTODO" calendar component "REQUEST" method. Depending on the
"REQUEST-STATUS" value, no scheduling action may have been performed.
The "Organizer" of a "VTODO" calendar component MAY receive a "REPLY"
method from a "Calendar User" not in the original "REQUEST". For
example, a "REPLY" method MAY be received from a "Delegate" of a
"VTODO" calendar component. In addition, the "REPLY" method MAY be
received from an unknown "Calendar User", having been forwarded the
"REQUEST" by an original "Attendee" of the "VTODO" calendar
component. This uninvited "Attendee" MAY be accepted, or the
"Organizer" MAY cancel the "VTODO" calendar component for the
uninvited "Attendee" by sending them a "CANCEL" method.
This method type is an iCalendar object that conforms to the
following property constraints:
Component/Property Presence
------------------- ---------------------------------------------
METHOD 1 MUST be "REPLY"
VTODO 1+ All component MUST have the same UID
ATTENDEE 1+
DTSTAMP 1
ORGANIZER 1
REQUEST-STATUS 1+
UID 1 MUST must be the address of the replying
attendee
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
PRIORITY 0 or 1
RDATE 0+
RELATED-TO 0+
RESOURCES 0 or 1 This property may contain a list of values
RRULE 0+
RECURRENCE-ID 0 or 1 MUST only if referring to an instance of a
Recurring calendar component. Otherwise it
MUST NOT be present
SEQUENCE 0 or 1 MUST be the sequence number of
the original REQUEST if greater than 0.
MAY be present if 0.
STATUS 0 or 1
SUMMARY 0 or 1 Can be null
URL 0 or 1
X-PROPERTY 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
3.4.4 ADD
The "ADD" method in a "VTODO" calendar component is used to add one
or more instances to an existing to-do.
If the "UID" property value in the "ADD" is not found on the
recipient's calendar, then the recipient SHOULD send a "REFRESH" to
the "Organizer" in order to be updated with the latest version of the
"VTODO". If an "Attendee" implementation does not support the "ADD"
method it should respond with a "REQUEST-STATUS" value of 5.3 and ask
for a "REFRESH".
The "SEQUENCE" property value is incremented as the sequence of to-
dos has changed.
This method type is an iCalendar object that conforms to the
following property constraints:
Component/Property Presence
------------------- ----------------------------------------------
METHOD 1 MUST be "ADD"
VTODO 1
DTSTAMP 1
ORGANIZER 1
PRIORITY 1
SEQUENCE 1 MUST be greater than 0
SUMMARY 1 Can be null.
UID 1 MUST match that of the original to-do
ATTACH 0+
ATTENDEE 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 Can be null
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+
RELATED-TO 0+
RESOURCES 0 or 1 This property may contain a list of
values
RRULE 0+
STATUS 0 or 1 MAY be one of COMPLETED/NEEDS ACTION/IN-
PROCESS
URL 0 or 1
X-PROPERTY 0+
RECURRENCE-ID 0
REQUEST-STATUS 0
VALARM 0+
VTIMEZONE 0+ MUST be present if any date/time refers
to a timezone
X-COMPONENT 0+
VEVENT 0
VJOURNAL 0
VFREEBUSY 0
3.4.5 CANCEL
The "CANCEL" method in a "VTODO" calendar component is used to send a
cancellation notice of an existing "VTODO" calendar request to the
"Attendees". The message is sent by the "Organizer" of a "VTODO"
calendar component to the "Attendees" of the "VTODO" calendar
component. For a recurring "VTODO" calendar component, either the
whole "VTODO" calendar component or instances of a "VTODO" calendar
component may be cancelled. To cancel the complete range of a
recurring "VTODO" calendar component, the "UID" property value for
the "VTODO" calendar component MUST be specified and a "RECURRENCE-
ID" MUST NOT be specified in the "CANCEL" method. In order to cancel
an individual instance of a recurring "VTODO" calendar component, the
"RECURRENCE-ID" property value for the "VTODO" calendar component
MUST be specified in the "CANCEL" method.
There are two options for canceling a sequence of instances of a
recurring "VTODO" calendar component:
(a) the "RECURRENCE-ID" property for an instance in the sequence MUST
be specified with the "RANGE" property parameter value of
THISANDPRIOR (or THISANDFUTURE) to indicate cancellation of the
specified "VTODO" calendar component and all instances before (or
after); or
(b) individual recurrence instances may be cancelled by specifying
multiple "RECURRENCE-ID" properties corresponding to the
instances to be cancelled.
When a "VTODO" is cancelled, the "SEQUENCE" property value MUST be
incremented.
This method type is an iCalendar object that conforms to the
following property constraints:
Component/Property Presence
------------------- ---------------------------------------------
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
3.4.6 REFRESH
The "REFRESH" method in a "VTODO" calendar component is used by
"Attendees" of an existing "VTODO" calendar component to request an
updated description from the "Organizer" of the "VTODO" calendar
component. The "Organizer" of the "VTODO" calendar component MAY use
this method to request an updated status from the "Attendees". The
"REFRESH" method MUST specify the "UID" property corresponding to the
"VTODO" calendar component needing update.
A refresh of a recurrence instance of a "VTODO" calendar component
may be requested by specifying the "RECURRENCE-ID" property
corresponding to the associated "VTODO" calendar component. The
"Organizer" responds with the latest description and rendition of the
"VTODO" calendar component. In most cases this will be a REQUEST
unless the "VTODO" has been cancelled, in which case the ORGANIZER
MUST send a "CANCEL". This method is intended to facilitate machine
processing of requests for updates to a "VTODO" calendar component.
This method type is an iCalendar object that conforms to the
following property constraints:
Component/Property Presence
------------------- ---------------------------------------------
METHOD 1 MUST be "REFRESH"
VTODO 1
ATTENDEE 1
DTSTAMP 1
UID 1 MUST echo original UID
RECURRENCE-ID 0 or 1 MUST only if referring to an instance of a
Recurring calendar component. Otherwise it
MUST NOT be present
X-PROPERTY 0+
ATTACH 0
CATEGORIES 0
CLASS 0
COMMENT 0
CONTACT 0
CREATED 0
DESCRIPTION 0
DTSTART 0
DUE 0
DURATION 0
EXDATE 0
EXRULE 0
GEO 0
LAST-MODIFIED 0
LOCATION 0
ORGANIZER 0
PERCENT-COMPLETE 0
PRIORITY 0
RDATE 0
RELATED-TO 0
REQUEST-STATUS 0
RESOURCES 0
RRULE 0
SEQUENCE 0
STATUS 0
URL 0
X-COMPONENT 0+
VALARM 0
VEVENT 0
VFREEBUSY 0
VTIMEZONE 0
3.4.7 COUNTER
The "COUNTER" method in a "VTODO" calendar component is used by an
"Attendee" of an existing "VTODO" calendar component to submit to the
"Organizer" a counter proposal for the "VTODO" calendar component.
The "Attendee" sends the message to the "Organizer" of the "VTODO"
calendar component.
The counter proposal is an iCalendar object consisting of a "VTODO"
calendar component describing the complete description of the
alternate "VTODO" calendar component.
The "Organizer" rejects the counter proposal by sending the
"Attendee" a "DECLINECOUNTER" method. The "Organizer" accepts the
counter proposal by sending all of the "Attendees" of the "VTODO"
calendar component a "REQUEST" method rescheduling the "VTODO"
calendar component. In the latter case, the "Organizer" SHOULD reset
the individual "RSVP" property parameter values to TRUE on each
"ATTENDEE" property; in order to force a response by the "Attendees".
This method type is an iCalendar object that conforms to the
following property constraints:
Component/Property Presence
------------------- ----------------------------------------------
METHOD 1 MUST be "COUNTER"
VTODO 1
ATTENDEE 1+
DTSTAMP 1
ORGANIZER 1
PRIORITY 1
SUMMARY 1 Can be null
UID 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 Can be null
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 3.5if referring to an instance of a
recurring calendar component. Otherwise it
MUST NOT be present.
RELATED-TO 0+
REQUEST-STATUS 0+
RESOURCES 0 or 1 This property MAY contain a list of values
RRULE 0 or 1
SEQUENCE 0 or 1 MUST echo the original SEQUENCE number.
MUST be present if non-zero. MAY be present
if zero.
STATUS 0 or 1 MAY be one of COMPLETED/NEEDS ACTION/IN-
PROCESS/CANCELLED
URL 0 or 1
X-PROPERTY 0+
VALARM 0+
VTIMEZONE 0 or 1 MUST be present if any date/time refers to
a timezone
X-COMPONENT 0+
VEVENT 0
VFREEBUSY 0
3.4.8 DECLINECOUNTER
The "DECLINECOUNTER" method in a "VTODO" calendar component is used
by an "Organizer" of "VTODO" calendar component to reject a counter
proposal offered by one of the "Attendees". The "Organizer" sends the
message to the "Attendee" that sent the "COUNTER" method to the
"Organizer".
This method type is an iCalendar object that conforms to the
following property constraints:
Component/Property Presence
------------------- ---------------------------------------------
METHOD 1 MUST be "DECLINECOUNTER"
VTODO 1
ATTENDEE 1+ MUST for all attendees
DTSTAMP 1
ORGANIZER 1
SEQUENCE 1 MUST echo the original SEQUENCE number
UID 1 MUST echo original UID
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
PRIORITY 0 or 1
RDATE 0+
RECURRENCE-ID 0 or 1 MUST only if referring to an instance of a
recurring calendar component. Otherwise
it MUST NOT be present.
RELATED-TO 0+
REQUEST-STATUS 0+
RESOURCES 0 or 1 This property MAY contain a list of values
RRULE 0+
STATUS 0 or 1 MAY be one of COMPLETED/NEEDS ACTION/IN-
PROCESS
URL 0 or 1
X-PROPERTY 0+
VTIMEZONE 0+ MUST be present if any date/time refers to
a timezone
X-COMPONENT 0+
VALARM 0
VEVENT 0
VFREEBUSY 0
3.5 Methods For VJOURNAL Components
This section defines the property set for the methods that are
applicable to the "VJOURNAL" calendar component.
The following summarizes the methods that are defined for the
"VJOURNAL" calendar component.
+================+==================================================+
| Method | Description |
|================+==================================================|
| PUBLISH | Post a journal entry. Used primarily as a method |
| | of advertising the existence of a journal entry. |
| | |
| ADD | Add one or more instances to an existing journal |
| | entry. |
| | |
| CANCEL | Cancel one or more instances of an existing |
| | journal entry. |
+================+==================================================+
3.5.1 PUBLISH
The "PUBLISH" method in a "VJOURNAL" calendar component has no
associated response. It is simply a posting of an iCalendar object
that may be added to a calendar. It MUST have an "Organizer". It MUST
NOT have "Attendees". The expected usage is for encapsulating an
arbitrary journal entry as an iCalendar object. The "Organizer" MAY
subsequently update (with another "PUBLISH" method) or cancel (with a
"CANCEL" method) a previously published journal entry.
This method type is an iCalendar object that conforms to the
following property constraints:
Component/Property Presence
------------------- ----------------------------------------------
METHOD 1 MUST be "PUBLISH"
VJOURNAL 1+
DESCRIPTION 1 Can be null.
DTSTAMP 1
DTSTART 1
ORGANIZER 1
UID 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
EXDATE 0+
EXRULE 0+
LAST-MODIFIED 0 or 1
RDATE 0+
RECURRENCE-ID 0 or 1 MUST only if referring to an instance of a
recurring calendar component. Otherwise
it MUST NOT be present.
RELATED-TO 0+
RRULE 0+
SEQUENCE 0 or 1 MUST echo the original SEQUENCE number.
MUST be present if non-zero. MAY be
present if zero.
STATUS 0 or 1 MAY be one of DRAFT/FINAL/CANCELLED
SUMMARY 0 or 1 Can be null
URL 0 or 1
X-PROPERTY 0+
ATTENDEE 0
VALARM 0+
VTIMEZONE 0+ MUST be present if any date/time refers to
a timezone
X-COMPONENT 0+
VEVENT 0
VFREEBUSY 0
VTODO 0
3.5.2 ADD
The "ADD" method in a "VJOURNAL" calendar component is used to add
one or more instances to an existing "VJOURNAL" entry. There is no
response to the "Organizer".
If the "UID" property value in the "ADD" is not found on the
recipient's calendar, then the recipient MAY treat the "ADD" as a
"PUBLISH".
This method type is an iCalendar object that conforms to the
following property constraints:
Component/Property Presence
------------------- ----------------------------------------------
METHOD 1 MUST be "ADD"
VJOURNAL 1
DESCRIPTION 1 Can be null.
DTSTAMP 1
DTSTART 1
ORGANIZER 1
SEQUENCE 1 MUST be greater than 0
UID 1 MUST match that of the original journal
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
EXDATE 0+
EXRULE 0+
LAST-MODIFIED 0 or 1
RDATE 0+
RELATED-TO 0+
RRULE 0+
STATUS 0 or 1 MAY be one of DRAFT/FINAL/CANCELLED
SUMMARY 0 or 1 Can be null
URL 0 or 1
X-PROPERTY 0+
ATTENDEE 0
RECURRENCE-ID 0
VALARM 0+
VTIMEZONE 0 or 1 MUST be present if any date/time refers to
a timezone
X-COMPONENT 0+
VEVENT 0
VFREEBUSY 0
VTODO 0
3.5.3 CANCEL
The "CANCEL" method in a "VJOURNAL" calendar component is used to
send a cancellation notice of an existing journal entry. The message
is sent by the "Organizer" of a journal entry. For a recurring
journal entry, either the whole journal entry or instances of a
journal entry may be cancelled. To cancel the complete range of a
recurring journal entry, the "UID" property value for the journal
entry MUST be specified and a "RECURRENCE-ID" property MUST NOT be
specified in the "CANCEL" method. In order to cancel an individual
instance of the journal entry, the "RECURRENCE-ID" property value for
the journal entry MUST be specified in the "CANCEL" method.
There are two options for canceling a sequence of instances of a
recurring "VJOURNAL" calendar component:
(a) the "RECURRENCE-ID" property for an instance in the sequence MUST
be specified with the "RANGE" property parameter value of
THISANDPRIOR (or THISANDFUTURE) to indicate cancellation of the
specified "VTODO" calendar component and all instances before (or
after); or
(b) individual recurrence instances may be cancelled by specifying
multiple "RECURRENCE-ID" properties corresponding to the
instances to be cancelled.
When a "VJOURNAL" is cancelled, the "SEQUENCE" property value MUST be
incremented.
This method type is an iCalendar object that conforms to the
following property constraints:
Component/Property Presence
------------------- ---------------------------------------------
METHOD 1 MUST be "CANCEL"
VJOURNAL 1+ All MUST have the same UID
DTSTAMP 1
ORGANIZER 1
SEQUENCE 1
UID 1 MUST be the UID of the original REQUEST
ATTACH 0+
ATTENDEE 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
EXDATE 0+
EXRULE 0+
LAST-MODIFIED 0 or 1
RDATE 0+
RECURRENCE-ID 0 or 1 only if referring to an instance of a
recurring calendar component. Otherwise
it MUST NOT be present.
RELATED-TO 0+
RRULE 0+
STATUS 0 or 1 MAY be present, must be "CANCELLED" if
present
SUMMARY 0 or 1
URL 0 or 1
X-PROPERTY 0+
REQUEST-STATUS 0
VTIMEZONE 0+ MUST be present if any date/time refers to
a timezone
X-COMPONENT 0+
VALARM 0
VEVENT 0
VFREEBUSY 0
VTODO 0
3.6 Status Replies
The "REQUEST-STATUS" property may include the following values:
|==============+============================+=========================|
| Short Return | Longer Return Status | Offending Data |
| Status Code | Description | |
|==============+============================+=========================|
| 2.0 | Success. | None. |
|==============+============================+=========================|
| 2.1 | Success but fallback taken | Property name and value |
| | on one or more property | MAY be specified. |
| | values. | |
|==============+============================+=========================|
| 2.2 | Success, invalid property | Property name MAY be |
| | ignored. | specified. |
|==============+============================+=========================|
| 2.3 | Success, invalid property | Property parameter name |
| | parameter ignored. | and value MAY be |
| | | specified. |
|==============+============================+=========================|
| 2.4 | Success, unknown non- | Non-standard property |
| | standard property ignored. | name MAY be specified. |
|==============+============================+=========================|
| 2.5 | Success, unknown non | Property and non- |
| | standard property value | standard value MAY be |
| | ignored. | specified. |
|==============+============================+=========================|
| 2.6 | Success, invalid calendar | Calendar component |
| | component ignored. | sentinel (e.g., BEGIN: |
| | | ALARM) MAY be |
| | | specified. |
|==============+============================+=========================|
| 2.7 | Success, request forwarded | Original and forwarded |
| | to Calendar User. | caluser addresses MAY |
| | | be specified. |
|==============+============================+=========================|
| 2.8 | Success, repeating event | RRULE or RDATE property |
| | ignored. Scheduled as a | name and value MAY be |
| | single component. | specified. |
|==============+============================+=========================|
| 2.9 | Success, truncated end date| DTEND property value |
| | time to date boundary. | MAY be specified. |
|==============+============================+=========================|
| 2.10 | Success, repeating VTODO | RRULE or RDATE property |
| | ignored. Scheduled as a | name and value MAY be |
| | single VTODO. | specified. |
|==============+============================+=========================|
| 2.11 | Success, unbounded RRULE | RRULE property name and |
| | clipped at some finite | value MAY be specified. |