= Calendaring Support =

imip-agent aims to provide broad support for the following standards:

 * [[https://tools.ietf.org/html/rfc5545|iCalendar]]
 * [[https://tools.ietf.org/html/rfc5546|iTIP]]
 * [[https://tools.ietf.org/html/rfc6047|iMIP]]

The following sections indicate notable deviations or deficiencies in the support
for these standards.

== iCalendar ==

The general iCalendar format should be mostly supported, but the interpretation
of calendar objects in imip-agent is currently limited to events and free/busy
data, and the software does not seek to understand the other object types
described in the specification.

The `VTIMEZONE` component is not interpreted. Instead, `TZID` properties are
expected to provide [[https://en.wikipedia.org/wiki/Tz_database|tz database]]
(tzinfo, zoneinfo, Olson database) identifiers that indicate the time zone or
"regime" applying to the indicated datetimes.

The `VALARM` component is not interpreted since imip-agent does not seek to
implement reminders or notifications, although it is conceivable that a mechanism
could be implemented to achieve this over e-mail.

Week numbers (`BYWEEKNO`) are not yet supported in recurring datetimes.

Only the essential scheduling properties are interpreted by imip-agent. Thus,
support for attachments, categories, and so on is not provided in the
[[../CalendarManager|management interface]]. Such support may eventually be
added, and existing calendar clients may, of course, use such features without
any restrictions imposed by imip-agent.

== iTIP ==

Only event and free/busy object types are supported in scheduling.

`VTIMEZONE` and `VALARM` are not interpreted.

Delegation
([[http://tools.ietf.org/html/rfc5546#section-2.1.2|RFC 5546 section 2.1.2]])
is not yet supported.

Multiple recurrence updates using the `THISANDFUTURE` attribute on the
`RECURRENCE-ID` property
([[http://tools.ietf.org/html/rfc5546#section-4.4.5|RFC 5546 section 4.4.5]])
is not yet supported.

The `REQUEST-STATUS` property is not yet supported. (See
[[http://tools.ietf.org/html/rfc5546#section-7.3|RFC 5546 section 7.3]].)

Support is provided in the [[../Configuration|configuration]] of imip-agent
for interpreting `REQUEST` messages that should really be `COUNTER` messages,
generated by some mail programs. See the `IMIP_COUNTER_AS_REQUEST` setting in
`config.txt`.

== iMIP ==

Since attachments are not supported by the
[[../CalendarManager|management interface]], imip-agent does not generate or
interpret the various methods of referencing attachments in exchanged objects.
(See [[https://tools.ietf.org/html/rfc6047#section-4.3|RFC 6047 section 4.3]].)
