2.2.122 [RFC5546] Section 3.2.7 COUNTER

V0275:

The specification states that a counter proposal is an iCalendar object consisting of a VEVENT calendar component describing the complete description of the alternate event.

Microsoft Office Outlook 2007, Microsoft Outlook 2010, Microsoft Outlook 2013, Microsoft Outlook 2016, Microsoft Outlook 2019

Outlook only exports counter proposals to the start and/or end time of a meeting. On import, Outlook renders all of the properties in the VEVENT of a COUNTER-type iCalendar object to the user. However, if the organizer accepts the counter proposal, only the start and/or end time of the meeting is updated.

C0033:

The specification lists a VALARM component in the table of allowed components and properties in a COUNTER-type iCalendar object. The indentation of the VALARM component is the same as the VEVENT component.

Office Outlook 2007, Outlook 2010, Outlook 2013, Outlook 2016, Outlook 2019

It is assumed that the author intended to indent the VALARM component to visually indicate that it is a sub-component of the VEVENT.

C0034:

The table in [RFC5546] contains a value of "1" for the SEQUENCE property in the VEVENT component of a CANCEL-type iCalendar object. However, this is contradicted by the comment in the table: "MUST be present if value greater than 0, MAY be present if 0."

Office Outlook 2007, Outlook 2010, Outlook 2013, Outlook 2016, Outlook 2019

Outlook conforms to the comment in the table. It is assumed that the value of "1" was intended to be "0 or 1".

V0276:

The specification specifies the allowed number of instances of components and properties in a COUNTER-type iCalendar object in the following table.

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 echo the original SEQUENCE number. MUST be present if non-zero. MAY be present if zero.
•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+
•CLASS	0 or 1
•COMMENT	0+
•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+
•GEO	0 or 1
•LAST-MODIFIED	0 or 1
•LOCATION	0 or 1
•PRIORITY	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+
•RESOURCES	0+	This property may contain a list of values.
•REQUEST-STATUS	0+
•RRULE	0 or 1
•STATUS	0 or 1	Value must be one of CONFIRMED/TENTATIVE/CANCELLED.
•TRANSP	0 or 1
•URL	0 or 1
•IANA-PROPERTY	0+
•X-PROPERTY	0+
•VALARM	0
VTIMEZONE	0+	MUST be present if any date/time refers to a timezone.
IANA-COMPONENT	0+
X-COMPONENT	0+
VTODO	0
VJOURNAL	0
VFREEBUSY	0

Office Outlook 2007, Outlook 2010, Outlook 2013, Outlook 2016, Outlook 2019

The following table specifies the number of instances Outlook exports for these components and properties in a COUNTER-type iCalendar object.

Component/property	Number of instances exported	Notes
METHOD	1	Is set to "COUNTER".
VEVENT	1
•ATTENDEE	1	Set to the address of the sender. Outlook does not support counter-proposal of new attendees.
•DTSTAMP	1
•DTSTART	1
•ORGANIZER	0	See section 2.1.19.
•SEQUENCE	0-1
•UID	1	Set to the same value as the UID in the original REQUEST.
•COMMENT	0-1
•ATTACH	0+
•CATEGORIES	0-1	Can be a list.
•CLASS	0-1
•CONTACT	0-1
•CREATED	0-1
•DESCRIPTION	0-1
•DTEND	1
•DURATION	0
•EXDATE	0-1
•EXRULE	0
•GEO	0
•LAST-MODIFIED	0-1
•LOCATION	0-1
•PRIORITY	0-1
•RDATE	0-2
•RECURRENCE-ID	0-1
•RELATED-TO	0
•RESOURCES	0-1	Can be a list.
•REQUEST-STATUS	0
•RRULE	0-1
•STATUS	0
•SUMMARY	0-1	Can be an empty string.
•TRANSP	0-1
•URL	0
•IANA-PROPERTY	0
•X-PROPERTY	0
VTIMEZONE	0-1	A VTIMEZONE is exported for each unique TZID parameter in the iCalendar object.
IANA-COMPONENT	0
X-COMPONENT	0
•VALARM	0-1
VFREEBUSY	0
VJOURNAL	0
VTODO	0

The following table specifies the number of instances Outlook imports for these components and properties in a COUNTER-type iCalendar object. If more instances are found, they are ignored. If fewer instances are found, the outer component is considered invalid and ignored.

Component/Property	Number of instances imported	Notes
METHOD	1	MUST be set to "COUNTER".
VEVENT	1
•ATTENDEE	1+	Exactly one ATTENDEE property MUST have the PARTSTAT parameter set, or the import fails. All other attendees are ignored.
•DTSTAMP	0-1
•DTSTART	0-1
•ORGANIZER	0-1	ORGANIZER is only used to render the message.
•SEQUENCE	0-1
•UID	1
•COMMENT	0-1	If multiple COMMENT properties are present, only the last one is imported.
•ATTACH	0+
•CATEGORIES	0+	Can import a list.
•CLASS	0-1
•CONTACT	0+
•CREATED	0
•DESCRIPTION	0-1
•DTEND	0-1	If both DTEND and DURATION are specified, DTEND is used.
•DURATION	0-1	If both DTEND and DURATION are specified, DTEND is used.
•EXDATE	0+
•EXRULE	0
•GEO	0
•LAST-MODIFIED	0
•LOCATION	0-1
•PRIORITY	0-1
•RDATE	0+
•RECURRENCE-ID	0-1
•RELATED-TO	0
•RESOURCES	0+	Can import a list.
•REQUEST-STATUS	0
•RRULE	0-1
•STATUS	0-1	STATUS is only used to render the message.
•SUMMARY	0-1	Can be an empty string.
•TRANSP	0-1
•URL	0
•IANA-PROPERTY	0
•X-PROPERTY	0+
VTIMEZONE	0+	If TZID references an undeclared VTIMEZONE, a default time zone is used.
IANA-COMPONENT	0
X-COMPONENT	0
•VALARM	0-1
VFREEBUSY	0
VJOURNAL	0
VTODO	0