Network Working Group C. Daboo, Ed. Internet-Draft Apple Inc. Obsoletes: 2446 (if approved) October 4, 2009 Updates: 5545 (if approved) Intended status: Standards Track Expires: April 7, 2010 iCalendar Transport-Independent Interoperability Protocol (iTIP) draft-ietf-calsify-2446bis-10 Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November 10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to allow modifications of such material outside the IETF Standards Process. Without obtaining an adequate license from the person(s) controlling the copyright in such materials, this document may not be modified outside the IETF Standards Process, and derivative works of it may not be created outside the IETF Standards Process, except to format it for publication as an RFC or to translate it into languages other than English. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on April 7, 2010. Copyright Notice Copyright (c) 2009 IETF Trust and the persons identified as the document authors. All rights reserved. Daboo Expires April 7, 2010 [Page 1]
Internet-Draft iTIP October 2009 This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents in effect on the date of publication of this document (http://trustee.ietf.org/license-info). Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Abstract This document specifies a protocol using the iCalendar object specification to provide scheduling interoperability between different calendaring systems. This is done without reference to a specific transport protocol so as to allow multiple methods of communication between systems. Subsequent documents will define profiles of this protocol using specific interoperable methods of communications between systems. iTIP complements the iCalendar object specification by adding semantics for group scheduling methods commonly available in current calendaring systems. These scheduling methods permit two or more calendaring systems to perform transactions such as publish, schedule, reschedule, respond to scheduling requests, negotiation of changes or cancel. Daboo Expires April 7, 2010 [Page 2]
Internet-Draft iTIP October 2009 Table of Contents 1. Introduction and Overview . . . . . . . . . . . . . . . . . . 6 1.1. Formatting Conventions . . . . . . . . . . . . . . . . . 6 1.2. Related Documents . . . . . . . . . . . . . . . . . . . . 7 1.3. Roles . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.4. Methods . . . . . . . . . . . . . . . . . . . . . . . . . 8 2. Interoperability Models . . . . . . . . . . . . . . . . . . . 9 2.1. Application Protocol . . . . . . . . . . . . . . . . . . 10 2.1.1. Scheduling State . . . . . . . . . . . . . . . . . . 10 2.1.2. Delegation . . . . . . . . . . . . . . . . . . . . . 11 2.1.3. Acting on Behalf of other Calendar Users . . . . . . 11 2.1.4. Component Revisions . . . . . . . . . . . . . . . . . 11 2.1.5. Message Sequencing . . . . . . . . . . . . . . . . . 13 3. Application Protocol Elements . . . . . . . . . . . . . . . . 14 3.1. Common Component Restriction Tables . . . . . . . . . . . 15 3.1.1. VCALENDAR . . . . . . . . . . . . . . . . . . . . . . 15 3.1.2. VTIMEZONE . . . . . . . . . . . . . . . . . . . . . . 15 3.1.3. VALARM . . . . . . . . . . . . . . . . . . . . . . . 16 3.2. Methods for VEVENT Calendar Components . . . . . . . . . 17 3.2.1. PUBLISH . . . . . . . . . . . . . . . . . . . . . . . 18 3.2.2. REQUEST . . . . . . . . . . . . . . . . . . . . . . . 20 3.2.3. REPLY . . . . . . . . . . . . . . . . . . . . . . . . 24 3.2.4. ADD . . . . . . . . . . . . . . . . . . . . . . . . . 27 3.2.5. CANCEL . . . . . . . . . . . . . . . . . . . . . . . 28 3.2.6. REFRESH . . . . . . . . . . . . . . . . . . . . . . . 31 3.2.7. COUNTER . . . . . . . . . . . . . . . . . . . . . . . 32 3.2.8. DECLINECOUNTER . . . . . . . . . . . . . . . . . . . 34 3.3. Methods For VFREEBUSY Components . . . . . . . . . . . . 36 3.3.1. PUBLISH . . . . . . . . . . . . . . . . . . . . . . . 36 3.3.2. REQUEST . . . . . . . . . . . . . . . . . . . . . . . 38 3.3.3. REPLY . . . . . . . . . . . . . . . . . . . . . . . . 40 3.4. Methods For VTODO Components . . . . . . . . . . . . . . 41 3.4.1. PUBLISH . . . . . . . . . . . . . . . . . . . . . . . 42 3.4.2. REQUEST . . . . . . . . . . . . . . . . . . . . . . . 44 3.4.3. REPLY . . . . . . . . . . . . . . . . . . . . . . . . 49 3.4.4. ADD . . . . . . . . . . . . . . . . . . . . . . . . . 51 3.4.5. CANCEL . . . . . . . . . . . . . . . . . . . . . . . 53 3.4.6. REFRESH . . . . . . . . . . . . . . . . . . . . . . . 55 3.4.7. COUNTER . . . . . . . . . . . . . . . . . . . . . . . 57 3.4.8. DECLINECOUNTER . . . . . . . . . . . . . . . . . . . 58 3.5. Methods For VJOURNAL Components . . . . . . . . . . . . . 60 3.5.1. PUBLISH . . . . . . . . . . . . . . . . . . . . . . . 60 3.5.2. ADD . . . . . . . . . . . . . . . . . . . . . . . . . 63 3.5.3. CANCEL . . . . . . . . . . . . . . . . . . . . . . . 65 3.6. Status Replies . . . . . . . . . . . . . . . . . . . . . 67 3.7. Implementation Considerations . . . . . . . . . . . . . . 74 3.7.1. Working With Recurrence Instances . . . . . . . . . . 74 Daboo Expires April 7, 2010 [Page 3]
Internet-Draft iTIP October 2009 3.7.2. Attendee Property Considerations . . . . . . . . . . 75 3.7.3. Extension Tokens . . . . . . . . . . . . . . . . . . 75 4. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 76 4.1. Published Event Examples . . . . . . . . . . . . . . . . 76 4.1.1. A Minimal Published Event . . . . . . . . . . . . . . 76 4.1.2. Changing A Published Event . . . . . . . . . . . . . 77 4.1.3. Canceling A Published Event . . . . . . . . . . . . . 77 4.1.4. A Rich Published Event . . . . . . . . . . . . . . . 78 4.1.5. Anniversaries or Events attached to entire days . . . 79 4.2. Group Event Examples . . . . . . . . . . . . . . . . . . 80 4.2.1. A Group Event Request . . . . . . . . . . . . . . . . 81 4.2.2. Reply To A Group Event Request . . . . . . . . . . . 81 4.2.3. Update An Event . . . . . . . . . . . . . . . . . . . 82 4.2.4. Countering an Event Proposal . . . . . . . . . . . . 83 4.2.5. Delegating an Event . . . . . . . . . . . . . . . . . 85 4.2.6. Delegate Accepts the Meeting . . . . . . . . . . . . 87 4.2.7. Delegate Declines the Meeting . . . . . . . . . . . . 88 4.2.8. Forwarding an Event Request . . . . . . . . . . . . . 89 4.2.9. Cancel A Group Event . . . . . . . . . . . . . . . . 89 4.2.10. Removing Attendees . . . . . . . . . . . . . . . . . 91 4.2.11. Replacing the Organizer . . . . . . . . . . . . . . . 92 4.3. Busy Time Examples . . . . . . . . . . . . . . . . . . . 93 4.3.1. Publish Busy Time . . . . . . . . . . . . . . . . . . 93 4.3.2. Request Busy Time . . . . . . . . . . . . . . . . . . 94 4.3.3. Reply To A Busy Time Request . . . . . . . . . . . . 95 4.4. Recurring Event and Time Zone Examples . . . . . . . . . 95 4.4.1. A Recurring Event Spanning Time Zones . . . . . . . . 95 4.4.2. Modify A Recurring Instance . . . . . . . . . . . . . 97 4.4.3. Cancel an Instance . . . . . . . . . . . . . . . . . 99 4.4.4. Cancel Recurring Event . . . . . . . . . . . . . . . 100 4.4.5. Change All Future Instances . . . . . . . . . . . . . 100 4.4.6. Add A New Instance To A Recurring Event . . . . . . . 101 4.4.7. Add A New Series of Instances To A Recurring Event . 102 4.4.8. Refreshing A Recurring Event . . . . . . . . . . . . 104 4.4.9. Counter An Instance Of A Recurring Event . . . . . . 106 4.4.10. Error Reply To A Request . . . . . . . . . . . . . . 107 4.5. Group To-do Examples . . . . . . . . . . . . . . . . . . 109 4.5.1. A VTODO Request . . . . . . . . . . . . . . . . . . . 110 4.5.2. A VTODO Reply . . . . . . . . . . . . . . . . . . . . 110 4.5.3. A VTODO Request for Updated Status . . . . . . . . . 111 4.5.4. A Reply: Percent-Complete . . . . . . . . . . . . . . 111 4.5.5. A Reply: Completed . . . . . . . . . . . . . . . . . 112 4.5.6. An Updated VTODO Request . . . . . . . . . . . . . . 112 4.5.7. Recurring VTODOs . . . . . . . . . . . . . . . . . . 113 4.6. Journal Examples . . . . . . . . . . . . . . . . . . . . 114 4.7. Other Examples . . . . . . . . . . . . . . . . . . . . . 114 4.7.1. Event Refresh . . . . . . . . . . . . . . . . . . . . 114 4.7.2. Bad RECURRENCE-ID . . . . . . . . . . . . . . . . . . 115 Daboo Expires April 7, 2010 [Page 4]
Internet-Draft iTIP October 2009 5. Application Protocol Fallbacks . . . . . . . . . . . . . . . 118 5.1. Partial Implementation . . . . . . . . . . . . . . . . . 118 5.1.1. Event-Related Fallbacks . . . . . . . . . . . . . . . 118 5.1.2. Free/Busy-Related Fallbacks . . . . . . . . . . . . . 120 5.1.3. To-Do-Related Fallbacks . . . . . . . . . . . . . . . 121 5.1.4. Journal-Related Fallbacks . . . . . . . . . . . . . . 123 5.2. Latency Issues . . . . . . . . . . . . . . . . . . . . . 124 5.2.1. Cancellation of an Unknown Calendar Component. . . . 124 5.2.2. Unexpected Reply from an Unknown Delegate . . . . . . 125 5.3. Sequence Number . . . . . . . . . . . . . . . . . . . . . 125 6. Security Considerations . . . . . . . . . . . . . . . . . . . 125 6.1. Security Threats . . . . . . . . . . . . . . . . . . . . 125 6.1.1. Spoofing the "Organizer" . . . . . . . . . . . . . . 125 6.1.2. Spoofing the "Attendee" . . . . . . . . . . . . . . . 125 6.1.3. Unauthorized Replacement of the Organizer . . . . . . 126 6.1.4. Eavesdropping and Data Integrity . . . . . . . . . . 126 6.1.5. Flooding a Calendar . . . . . . . . . . . . . . . . . 126 6.1.6. Unauthorized REFRESH Requests . . . . . . . . . . . . 126 6.2. Recommendations . . . . . . . . . . . . . . . . . . . . . 126 6.2.1. Securing iTIP transactions . . . . . . . . . . . . . 126 6.2.2. Implementation Controls . . . . . . . . . . . . . . . 127 6.2.3. Access Controls and Filtering . . . . . . . . . . . . 127 6.3. Privacy Issues . . . . . . . . . . . . . . . . . . . . . 127 7. IANA Consideration . . . . . . . . . . . . . . . . . . . . . 128 7.1. Registration Template for REQUEST-STATUS Values . . . . . 128 7.2. Additions to iCalendar METHOD Registry . . . . . . . . . 128 7.3. REQUEST-STATUS Value Registry . . . . . . . . . . . . . . 129 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 130 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 131 9.1. Normative References . . . . . . . . . . . . . . . . . . 131 9.2. Informative References . . . . . . . . . . . . . . . . . 131 Appendix A. Differences from RFC 2446 . . . . . . . . . . . . . 131 A.1. Changed Restrictions . . . . . . . . . . . . . . . . . . 131 A.2. Deprecated features . . . . . . . . . . . . . . . . . . . 132 Appendix B. Change History (to be removed prior to publication as an RFC) . . . . . . . . . . . . . . . 132 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 135 Daboo Expires April 7, 2010 [Page 5]
Internet-Draft iTIP October 2009 1. Introduction and Overview This document specifies how calendaring systems use iCalendar [RFC5545] objects to interoperate with other calendaring systems. In particular, it specifies how to schedule events, to-dos, or daily journal entries. It further specifies how to search for available busy time information. It does so in a general way without specifying how communication between different systems actually takes place. Subsequent documents specify transport bindings between systems that use this protocol. This protocol is based on messages sent from an originator to one or more recipients. For certain types of messages, a recipient may reply, in order to update their status and may also return transaction/request status information. The protocol supports the ability for the message originator to modify or cancel the original message. The protocol also supports the ability for recipients to suggest changes to the originator of a message. The elements of the protocol also define the user roles for its transactions. This specification obsoletes RFC 2446 - a list of important changes is provided in Appendix A. 1.1. Formatting Conventions The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. Calendaring and scheduling roles are referred to in quoted-strings of text with the first character of each word in upper case. For example, "Organizer" refers to a role of a "Calendar User" (CU) within the scheduling protocol. Calendar components defined by [RFC5545] are referred to with capitalized, quoted-strings of text. All calendar components start with the letter "V". For example, "VEVENT" refers to the event calendar component, "VTODO" refers to the to-do calendar component and "VJOURNAL" refers to the daily journal calendar component. Scheduling methods are referred to with capitalized, quoted-strings of text. For example, "REQUEST" refers to the method for requesting a scheduling calendar component be created or modified, "REPLY" refers to the method a recipient of a request uses to update their status with the "Organizer" of the calendar component. Properties defined by [RFC5545] are referred to with capitalized, quoted-strings of text, followed by the word "property". For Daboo Expires April 7, 2010 [Page 6]
Internet-Draft iTIP October 2009 example, "ATTENDEE" property refers to the iCalendar property used to convey the calendar address of a "Calendar User". Property parameters defined by this specification are referred to with capitalized, quoted-strings of text, followed by the word "parameter". For example, "VALUE" parameter refers to the iCalendar property parameter used to override the default data type for a property value. Enumerated values defined by this specification are referred to with capitalized text, either alone or followed by the word "value". In tables, the quoted-string text is specified without quotes in order to minimize the table length. 1.2. Related Documents Implementers will need to be familiar with several other specifications that, along with this one, describe the Internet calendaring and scheduling standards. The related documents are: [RFC5545] - specifies the objects, data types, properties and property parameters used in the protocols, along with the methods for representing and encoding them. [I-D.ietf-calsify-rfc2447bis] specifies an Internet email binding for iTIP. This specification does not attempt to repeat the concepts or definitions from these other specifications. Where possible, explicit references are made to the other specifications. 1.3. Roles Exchanges of iCalendar objects for the purposes of group calendaring and scheduling occur between "Calendar Users" (CUs). CUs take on several roles in iTIP: +-----------+-------------------------------------------------------+ | Role | Description | +-----------+-------------------------------------------------------+ | Organizer | The CU who initiates an exchange takes on the role of | | | "Organizer". For example, the CU who proposes a | | | group meeting is the "Organizer". | | | | Daboo Expires April 7, 2010 [Page 7]
Internet-Draft iTIP October 2009 | Attendee | CUs who are included in the scheduling message as | | | possible recipients of that scheduling message. For | | | example, the CUs asked to participate in a group | | | meeting by the "Organizer" take on the role of | | | "Attendee". | | | | | Other CU | A CU that is not explicitly included in a scheduling | | | message, i.e., not the "Organizer" or an "Attendee". | +-----------+-------------------------------------------------------+ Note that "ROLE" is also a descriptive parameter to the iCalendar "ATTENDEE" property. Its use is to convey descriptive context about an "Attendee" such as "chair", "required participant" or "non- required participant" and has nothing to do with the calendaring workflow. 1.4. Methods The iTIP methods are listed below and their usage and semantics are defined in section 3 of this document. +----------------+--------------------------------------------------+ | Method | Description | +----------------+--------------------------------------------------+ | PUBLISH | Used to publish an iCalendar object to one or | | | more Calendar Users. There is no interactivity | | | between the publisher and any other calendar | | | user. An example might include a baseball team | | | publishing its schedule to the public. | | | | | REQUEST | Used to schedule an iCalendar object with other | | | Calendar Users. Requests are interactive in | | | that they require the receiver to respond using | | | the reply methods. Meeting requests, busy time | | | requests and the assignment of tasks to other | | | Calendar Users are all examples. Requests are | | | also used by the "Organizer" to update the | | | status of an iCalendar object. | | | | | REPLY | A reply is used in response to a request to | | | convey "Attendee" status to the "Organizer". | | | Replies are commonly used to respond to meeting | | | and task requests. | | | | | ADD | Add one or more new instances to an existing | | | recurring iCalendar object. | | | | Daboo Expires April 7, 2010 [Page 8]
Internet-Draft iTIP October 2009 | CANCEL | Cancel one or more instances of an existing | | | iCalendar object. | | | | | REFRESH | The Refresh method is used by an "Attendee" to | | | request the latest version of an iCalendar | | | object. | | | | | COUNTER | The Counter method is used by an "Attendee" to | | | negotiate a change in an iCalendar object. | | | Examples include the request to change a | | | proposed event time or change the due date for a | | | task. | | | | | DECLINECOUNTER | Used by the "Organizer" to decline the proposed | | | counter-proposal. | +----------------+--------------------------------------------------+ Group scheduling in iTIP is accomplished using the set of "request" and "response" methods described above. The following table shows the methods broken down by who can send them. +------------+------------------------------------------------------+ | Originator | Methods | +------------+------------------------------------------------------+ | Organizer | PUBLISH, REQUEST, ADD, CANCEL, DECLINECOUNTER | | | | | Attendee | REPLY, REFRESH, COUNTER, REQUEST (only when | | | delegating) | +------------+------------------------------------------------------+ Note that for some calendar component types, the allowable methods are a subset of the above set. In addition, apart from "VTIMEZONE" iCalendar components, only one component type is allowed in a single iTIP message. 2. Interoperability Models There are two distinct protocols relevant to interoperability: an "Application Protocol" and a "Transport Protocol". The Application Protocol defines the content of the iCalendar objects sent between sender and receiver to accomplish the scheduling transactions listed above. The Transport Protocol defines how the iCalendar objects are sent between the sender and receiver. This document focuses on the Application Protocol. Binding documents such as [I-D.ietf-calsify-rfc2447bis] focus on the Transport Protocol. The connection between Sender and Receiver in the diagram below Daboo Expires April 7, 2010 [Page 9]
Internet-Draft iTIP October 2009 refers to the Application Protocol. The iCalendar objects passed from the Sender to the Receiver are presented in Section 3, Application Protocol Elements. +----------+ +----------+ | | iTIP | | | Sender |<-------------->| Receiver | | | | | +----------+ +----------+ There are several variations of this diagram in which the Sender and Receiver take on various roles of a "Calendar User Agent" (CUA) or a "Calendar Service" (CS). The architecture of iTIP is depicted in the diagram below. An application written to this specification may work with bindings for the store-and-forward transport, the real time transport, or both. Also note that iTIP could be bound to other transports. +--------------------------------------------------------+ | iTIP Protocol | +--------------------------------------------------------+ | Transport | + - - - - - + - - - - - - + - - - - - + | Real-time | Store-and-Forward | Others | +-----------------+--------------------+-----------------+ 2.1. Application Protocol In the iTIP model, an iCalendar object is created and managed by an "Organizer". The "Organizer" interacts with other CUs by sending one or more of the iTIP messages listed above. "Attendees" use the "REPLY" method to communicate their status. "Attendees" do not make direct changes to the master iCalendar object. They can, however, use the "COUNTER" method to suggest changes to the "Organizer". In any case, the "Organizer" has complete control over the master iCalendar object. 2.1.1. Scheduling State There are two distinct states relevant to iCalendar objects used in scheduling: the overall state of the iCalendar object and the state associated with an "Attendee" in that iCalendar object. Daboo Expires April 7, 2010 [Page 10]
Internet-Draft iTIP October 2009 The state of an iCalendar object is defined by the "STATUS" property and is controlled by the "Organizer." There is no default value for the "STATUS" property. The "Organizer" sets the "STATUS" property to the appropriate value for each iCalendar object. The state of a particular "Attendee" relative to a iCalendar object used for scheduling is defined by the "PARTSTAT" parameter in the "ATTENDEE" property for each "Attendee". When an "Organizer" issues the initial iCalendar object, "Attendee" status is typically unknown. The "Organizer" specifies this by setting the "PARTSTAT" parameter to "NEEDS-ACTION". Each "Attendee" modifies their "ATTENDEE" property "PARTSTAT" parameter to an appropriate value as part of a "REPLY" message sent back to the "Organizer". 2.1.2. Delegation Delegation is defined as the process by which an "Attendee" grants another CU (or several CUs) the right to attend on their behalf. The "Organizer" is made aware of this change because the delegating "Attendee" informs the "Organizer". These steps are detailed in the REQUEST method section. 2.1.3. Acting on Behalf of other Calendar Users In many organizations one user will act on behalf of another to organize and/or respond to meeting requests. iTIP provides two mechanisms that support these activities. First, the "Organizer" is treated as a special entity, separate from "Attendees". All responses from "Attendees" flow to the "Organizer", making it easy to separate a calendar user organizing a meeting from calendar users attending the meeting. Additionally, iCalendar provides descriptive roles for each "Attendee". For instance, a role of "chair" may be ascribed to one or more "Attendees". The "chair" and the "Organizer" may or may not be the same calendar user. This maps well to scenarios where an assistant may manage meeting logistics for another individual who chairs a meeting. Second, a "SENT-BY" parameter may be specified in either the "Organizer" or "Attendee" properties. When specified, the "SENT-BY" parameter indicates that the responding CU acted on behalf of the specified "Attendee" or "Organizer". 2.1.4. Component Revisions The "SEQUENCE" property is used by the "Organizer" to indicate revisions to the calendar component. When the "Organizer" makes changes to one of the following properties, the sequence number MUST Daboo Expires April 7, 2010 [Page 11]
Internet-Draft iTIP October 2009 be incremented: o "DTSTART" o "DTEND" o "DURATION" o "DUE" o "RRULE" o "RDATE" o "EXDATE" o "STATUS" In addition, changes made by the "Organizer" to other properties MAY also require the sequence number to be incremented. The "Organizer" CUA MUST increment the sequence number whenever it makes changes to properties in the calendar component that the "Organizer" deems will jeopardize the validity of the participation status of the "Attendees". For example, changing the location of a meeting from one location to another distant location could effectively impact the participation status of the "Attendees". Depending on the "METHOD", the "SEQUENCE" property MUST follow these rules in the context of iTIP: o For the "PUBLISH" and "REQUEST" methods, the "SEQUENCE" property value is incremented according to the rules stated above. o The "SEQUENCE" property value MUST be incremented each time the "Organizer" uses the "ADD" or "CANCEL" methods. o The "SEQUENCE" property value MUST NOT be incremented when using "REPLY", "REFRESH", "COUNTER", "DECLINECOUNTER", or when sending a delegation "REQUEST". In some circumstances the "Organizer" may not have received responses to the final revision sent out. In this situation, the "Organizer" may wish to send an update "REQUEST", and set "RSVP=TRUE" for all "Attendees", so that current responses can be collected. The value of the "SEQUENCE" property contained in a response from an "Attendee" may not always match the "Organizer's" revision. Implementations may choose to have the CUA indicate to the CU that the response is to an iCalendar object that has been revised and allow the CU to decide whether or not to accept the response. Whilst a change in sequence number is indicative of a significant change to a previously scheduled item, "Attendee" CUAs SHOULD NOT rely solely on a change in sequence number as a means of detecting a significant change. Instead CUAs SHOULD compare the old and new Daboo Expires April 7, 2010 [Page 12]
Internet-Draft iTIP October 2009 versions of the calendar components and determine the exact nature of the changes and make decisions, possibly based on calendar user preferences, as to whether the user needs to be explicitly informed of the change. 2.1.5. Message Sequencing CUAs that handle the iTIP application protocol must often correlate a component in a calendar store with a component received in the iTIP message. For example, an event may be updated with a later revision of the same event. To accomplish this, a CUA must correlate the version of the event already in its calendar store with the version sent in the iTIP message. In addition to this correlation, there are several factors that can cause iTIP messages to arrive in an unexpected order. That is, an "Organizer" could receive a reply to an earlier revision of a component AFTER receiving a reply to a later revision. To maximize interoperability and to handle messages that arrive in an unexpected order, use the following rules: 1. The primary key for referencing a particular iCalendar component is the "UID" property value. To reference an instance of a recurring component, the primary key is composed of the "UID" and the "RECURRENCE-ID" properties. 2. The secondary key for referencing a component is the "SEQUENCE" property value. For components where the "UID" and "RECURRENCE-ID" property values are the same, the component with the highest numeric value for the "SEQUENCE" property obsoletes all other revisions of the component with lower values. 3. "Attendees" send "REPLY" messages to the "Organizer". For replies where the "UID" and "RECURRENCE-ID" property values are the same, the value of the "SEQUENCE" property indicates the revision of the component to which the "Attendee" is replying. The reply with the highest numeric value for the "SEQUENCE" property obsoletes all other replies with lower values. 4. In situations where the "UID", "RECURRENCE-ID", and "SEQUENCE" property values match, the "DTSTAMP" property is used as the tie- breaker. The component with the latest "DTSTAMP" overrides all others. Similarly, for "Attendee" responses where the "UID", "RECURRENCE-ID", and "SEQUENCE" property values match, the response with the latest "DTSTAMP" overrides all others. Hence, CUAs will need to persist the following component properties in order to correctly process iTIP messages: "UID", "RECURRENCE-ID", Daboo Expires April 7, 2010 [Page 13]
Internet-Draft iTIP October 2009 "SEQUENCE", and "DTSTAMP". Furthermore, for each "ATTENDEE" property of a component, "Organizer" CUAs will need to persist the "SEQUENCE" and "DTSTAMP" property values associated with the "Attendee's" last response, so that any earlier responses from an "Attendee" that are received out of order (e.g., due to a delay in the transport) can be correctly discarded. 3. Application Protocol Elements iTIP messages are "text/calendar" MIME entities that contain calendaring and scheduling information. The particular type of iCalendar message is referred to as the "method type". Each method type is identified by a "METHOD" property specified as part of the "text/calendar" content type. The table below shows various combinations of calendar components and the method types that this specification supports. +----------------+--------+-------+----------+-----------+ | | VEVENT | VTODO | VJOURNAL | VFREEBUSY | +----------------+--------+-------+----------+-----------+ | PUBLISH | Yes | Yes | Yes | Yes | | REQUEST | Yes | Yes | No | Yes | | REFRESH | Yes | Yes | No | No | | CANCEL | Yes | Yes | Yes | No | | ADD | Yes | Yes | Yes | No | | REPLY | Yes | Yes | No | Yes | | COUNTER | Yes | Yes | No | No | | DECLINECOUNTER | Yes | Yes | No | No | +----------------+--------+-------+----------+-----------+ Each method type is defined in terms of its associated components and properties. Some components and properties are required, some are optional and others are excluded. The restrictions are expressed in this document using a simple "restriction table". The first column indicates the name of a component or property. Properties of the iCalendar object are not indented. Properties of a component are indented. The second column (the "Presence" column) indicates whether a component or property should be present or not, and if present how many times it can occur. The third column contains comments for further clarification. The presence column uses the following values to assert whether a property is required, is optional and the number of times it may appear in the iCalendar object. Daboo Expires April 7, 2010 [Page 14]
Internet-Draft iTIP October 2009 +----------------+--------------------------------------------------+ | Presence Value | Description | +----------------+--------------------------------------------------+ | 1 | One instance MUST be present | | 1+ | At least one instance MUST be present | | 0 | Instances of this property MUST NOT be present | | 0+ | Multiple instances MAY be present | | 0 or 1 | Up to 1 instance of this property MAY be present | +----------------+--------------------------------------------------+ The tables also call out "IANA-PROPERTY", "X-PROPERTY", "IANA- COMPONENT" and "X-COMPONENT" to show where registered and vendor- specific property and component extensions can appear. The tables do not lay out the restrictions of property parameters. Those restrictions are defined in [RFC5545]. 3.1. Common Component Restriction Tables 3.1.1. VCALENDAR The restriction table below applies to properties of the iCalendar object. That is, the properties at the outermost scope. +-----------------------------------------------------+ | Constraints for properties in a VCALENDAR Component | +-----------------------------------------------------+ +--------------------+----------+---------------------+ | Component/Property | Presence | Comment | +--------------------+----------+---------------------+ | CALSCALE | 0 or 1 | | | PRODID | 1 | | | VERSION | 1 | Value MUST be "2.0" | | IANA-PROPERTY | 0+ | | | X-PROPERTY | 0+ | | +--------------------+----------+---------------------+ 3.1.2. VTIMEZONE "VTIMEZONE" components may be referred to by other components via a "TZID" parameter on a "DATETIME" value type. The property restrictions in the table below apply to any "VTIMEZONE" component in an iTIP message. +--------------------------------------+ | Constraints for VTIMEZONE Components | +--------------------------------------+ Daboo Expires April 7, 2010 [Page 15]
Internet-Draft iTIP October 2009 +--------------------+----------+-----------------------------------+ | Component/Property | Presence | Comment | +--------------------+----------+-----------------------------------+ | VTIMEZONE | 0+ | MUST be present if any date/time | | | | refers to timezone | | DAYLIGHT | 0+ | MUST be one or more of either | | | | STANDARD or DAYLIGHT | | COMMENT | 0+ | | | DTSTART | 1 | MUST be local time format | | RDATE | 0+ | | | RRULE | 0 or 1 | | | TZNAME | 0+ | | | TZOFFSETFROM | 1 | | | TZOFFSETTO | 1 | | | IANA-PROPERTY | 0+ | | | X-PROPERTY | 0+ | | | LAST-MODIFIED | 0 or 1 | | | STANDARD | 0+ | MUST be one or more of either | | | | STANDARD or DAYLIGHT | | COMMENT | 0+ | | | DTSTART | 1 | MUST be local time format | | RDATE | 0+ | if present RRULE MUST NOT be | | | | present | | RRULE | 0 or 1 | if present RDATE MUST NOT be | | | | present | | TZNAME | 0+ | | | TZOFFSETFROM | 1 | | | TZOFFSETTO | 1 | | | IANA-PROPERTY | 0+ | | | X-PROPERTY | 0+ | | | TZID | 1 | | | TZURL | 0 or 1 | | | IANA-PROPERTY | 0+ | | | X-PROPERTY | 0+ | | +--------------------+----------+-----------------------------------+ 3.1.3. VALARM The property restrictions in the table below apply to any "VALARM" component in an iTIP message. +-----------------------------------+ | Constraints for VALARM Components | +-----------------------------------+ Daboo Expires April 7, 2010 [Page 16]
Internet-Draft iTIP October 2009 +--------------------+----------+-----------------------------------+ | Component/Property | Presence | Comment | +--------------------+----------+-----------------------------------+ | VALARM | 0+ | | | ACTION | 1 | | | ATTACH | 0+ | | | ATTENDEE | 0+ | | | DESCRIPTION | 0 or 1 | | | DURATION | 0 or 1 | if present REPEAT MUST be present | | REPEAT | 0 or 1 | if present DURATION MUST be | | | | present | | SUMMARY | 0 or 1 | | | TRIGGER | 1 | | | IANA-PROPERTY | 0+ | | | X-PROPERTY | 0+ | | +--------------------+----------+-----------------------------------+ 3.2. Methods for VEVENT Calendar Components This section defines the property set restrictions for the method types that are applicable to the "VEVENT" calendar component. Each method is defined using a table that clarifies the property constraints that define the particular method. The following summarizes the methods that are defined for the "VEVENT" calendar component. +----------------+--------------------------------------------------+ | Method | Description | +----------------+--------------------------------------------------+ | PUBLISH | Post notification of an event. Used primarily | | | as a method of advertising the existence of an | | | event. | | | | | REQUEST | Make a request for an event. This is an | | | explicit invitation to one or more "Attendees". | | | Event requests are also used to update or change | | | an existing event. Clients that cannot handle | | | REQUEST MAY degrade the event to view it as an | | | PUBLISH. | | | | | REPLY | Reply to an event request. Clients may set | | | their status ("PARTSTAT") to ACCEPTED, DECLINED, | | | TENTATIVE, or DELEGATED. | | | | | ADD | Add one or more instances to an existing event. | | | | Daboo Expires April 7, 2010 [Page 17]
Internet-Draft iTIP October 2009 | CANCEL | Cancel one or more instances of an existing | | | event. | | | | | REFRESH | A request is sent to an "Organizer" by an | | | "Attendee" asking for the latest version of an | | | event to be resent to the requester. | | | | | COUNTER | Counter a REQUEST with an alternative proposal, | | | Sent by an "Attendee" to the "Organizer". | | | | | DECLINECOUNTER | Decline a counter proposal. Sent to an | | | "Attendee" by the "Organizer". | +----------------+--------------------------------------------------+ 3.2.1. PUBLISH The "PUBLISH" method in a "VEVENT" calendar component is an unsolicited posting of an iCalendar object. Any CU may add published components to their calendar. The "Organizer" MUST be present in a published iCalendar component. "Attendees" MUST NOT be present. Its expected usage is for encapsulating an arbitrary event 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 "VEVENT" calendar component. This method type is an iCalendar object that conforms to the following property constraints: +----------------------------------------------+ | Constraints for a METHOD:PUBLISH of a VEVENT | +----------------------------------------------+ +--------------------+----------+-----------------------------------+ | Component/Property | Presence | Comment | +--------------------+----------+-----------------------------------+ | METHOD | 1 | MUST equal "PUBLISH" | | | | | | VEVENT | 1+ | | | DTSTAMP | 1 | | | DTSTART | 1 | | | ORGANIZER | 1 | | | SUMMARY | 1 | Can be null. | | UID | 1 | | | RECURRENCE-ID | 0 or 1 | Only if referring to an instance | | | | of a recurring calendar | | | | component. Otherwise it MUST NOT | | | | be present. | Daboo Expires April 7, 2010 [Page 18]
Internet-Draft iTIP October 2009 | SEQUENCE | 0 or 1 | MUST be present if value is | | | | greater than 0, MAY be present if | | | | 0 | | ATTACH | 0+ | | | CATEGORIES | 0+ | | | CLASS | 0 or 1 | | | COMMENT | 0+ | | | CONTACT | 0 or 1 | | | CREATED | 0 or 1 | | | DESCRIPTION | 0 or 1 | Can be null | | 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+ | | | RELATED-TO | 0+ | | | RESOURCES | 0+ | | | RRULE | 0 or 1 | | | STATUS | 0 or 1 | MAY be one of | | | | TENTATIVE/CONFIRMED/CANCELLED | | TRANSP | 0 or 1 | | | URL | 0 or 1 | | | IANA-PROPERTY | 0+ | | | X-PROPERTY | 0+ | | | ATTENDEE | 0 | | | REQUEST-STATUS | 0 | | | | | | | VALARM | 0+ | | | | | | | VFREEBUSY | 0 | | | | | | | VJOURNAL | 0 | | | | | | | VTODO | 0 | | | | | | | VTIMEZONE | 0+ | MUST be present if any date/time | | | | refers to a timezone | | | | | | IANA-COMPONENT | 0+ | | | X-COMPONENT | 0+ | | +--------------------+----------+-----------------------------------+ Daboo Expires April 7, 2010 [Page 19]
Internet-Draft iTIP October 2009 3.2.2. REQUEST The "REQUEST" method in a "VEVENT" component provides the following scheduling functions: o Invite "Attendees" to an event o Reschedule an existing event o Response to a REFRESH request o Update the details of an existing event, without rescheduling it o Update the status of "Attendees" of an existing event, without rescheduling it o Reconfirm an existing event, without rescheduling it o Forward a "VEVENT" to another uninvited CU o For an existing "VEVENT" calendar component, delegate the role of "Attendee" to another CU o For an existing "VEVENT" calendar component, changing the role of "Organizer" to another CU The "Organizer" originates the "REQUEST". The recipients of the "REQUEST" method are the CUs invited to the event, the "Attendees". "Attendees" use the "REPLY" method to convey attendance status to the "Organizer". The "UID" and "SEQUENCE" 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 "VEVENT" calendar component. If the "UID" property value is found on the recipient's calendar, then the "REQUEST" is for a rescheduling, an update, or a reconfirm of the "VEVENT" calendar component. For the "REQUEST" method, multiple "VEVENT" 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 "VEVENT" components are needed to express the entire series. This method type is an iCalendar object that conforms to the following property constraints: +----------------------------------------------+ | Constraints for a METHOD:REQUEST of a VEVENT | +----------------------------------------------+ +--------------------+----------+-----------------------------------+ | Component/Property | Presence | Comment | +--------------------+----------+-----------------------------------+ | METHOD | 1 | MUST be "REQUEST" | Daboo Expires April 7, 2010 [Page 20]
Internet-Draft iTIP October 2009 | | | | | VEVENT | 1+ | All components MUST have the same | | | | UID | | ATTENDEE | 1+ | | | DTSTAMP | 1 | | | DTSTART | 1 | | | ORGANIZER | 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+ | | | CLASS | 0 or 1 | | | COMMENT | 0+ | | | CONTACT | 0+ | | | CREATED | 0 or 1 | | | DESCRIPTION | 0 or 1 | Can be null | | 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+ | | | REQUEST-STATUS | 0 | | | RESOURCES | 0+ | | | RRULE | 0 or 1 | | | STATUS | 0 or 1 | MAY be one of TENTATIVE/CONFIRMED | | 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 | | | | | Daboo Expires April 7, 2010 [Page 21]
Internet-Draft iTIP October 2009 | IANA-COMPONENT | 0+ | | | X-COMPONENT | 0+ | | | | | | | VFREEBUSY | 0 | | | | | | | VJOURNAL | 0 | | | | | | | VTODO | 0 | | +--------------------+----------+-----------------------------------+ 3.2.2.1. Rescheduling an Event The "REQUEST" method may be used to reschedule an event. A rescheduled event involves a change to the existing event in terms of its time or recurrence intervals and possibly the location or description. If the recipient CUA of a "REQUEST" method finds that the "UID" property value already exists on the calendar, but that the "SEQUENCE" (or "DTSTAMP") property value in the "REQUEST" method is greater than the value for the existing event, then the "REQUEST" method describes a rescheduling of the event. 3.2.2.2. Updating or Reconfirmation of an Event The "REQUEST" method may be used to update or reconfirm an event. An update to an existing event does not involve changes to the time or recurrence intervals, and might not involve a change to the location or description for the event. 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 event details, but no rescheduling of the event. The update "REQUEST" method is the appropriate response to a "REFRESH" method sent from an "Attendee" to the "Organizer" of an event. The "Organizer" of an event may also send unsolicited "REQUEST" methods. The unsolicited "REQUEST" methods may be used to update the details of the event without rescheduling it, to update the "PARTSTAT" parameter of "Attendees", or to reconfirm the event. 3.2.2.3. Delegating an Event to another CU Some calendar and scheduling systems allow "Attendees" to delegate their presence at an event to another calendar user. iTIP supports this concept using the following workflow. Any "Attendee" may delegate their right to participate in a calendar VEVENT to another Daboo Expires April 7, 2010 [Page 22]
Internet-Draft iTIP October 2009 CU. The implication is that the delegate participates in lieu of the original "Attendee"; NOT in addition to the "Attendee". The delegator MUST notify the "Organizer" of this action using the steps outlined below. Implementations may support or restrict delegation as they see fit. For instance, some implementations may restrict a delegate from delegating a "REQUEST" to another CU. The "Delegator" of an event forwards the existing "REQUEST" to the "Delegate". The "REQUEST" method MUST include an "ATTENDEE" property with the calendar address of the "Delegate". The "Delegator" MUST also send a "REPLY" method 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". Also, a new "ATTENDEE" property for the "Delegate" MUST be included and must specify the calendar user address set in the "DELEGATED-TO" parameter, as above. In response to the request, the "Delegate" MUST send a "REPLY" method to the "Organizer" and optionally, to the "Delegator". The "REPLY" method SHOULD include the "ATTENDEE" property with the "DELEGATED- FROM" parameter value of the "Delegator's" calendar address. The "Delegator" may continue to receive updates to the event even though they will not be attending. This is accomplished by the "Delegator" setting their "role" attribute to "NON-PARTICIPANT" in the "REPLY" to the "Organizer" 3.2.2.4. Changing the Organizer The situation may arise where the "Organizer" of a VEVENT is no longer able to perform the "Organizer" role and abdicates without passing on the "Organizer" role to someone else. When this occurs the "Attendees" of the VEVENT may use out-of-band mechanisms to communicate the situation and agree upon a new "Organizer". The new "Organizer" should then send out a new "REQUEST" with a modified version of the VEVENT in which the "SEQUENCE" number has been incremented and the "ORGANIZER" property has been changed to the new "Organizer". 3.2.2.5. Sending on Behalf of the Organizer There are a number of scenarios that support the need for a calendar user to act on behalf of the "Organizer" without explicit role changing. This might be the case if the CU designated as "Organizer" was sick or unable to perform duties associated with that function. In these cases iTIP supports the notion of one CU acting on behalf of another. Using the "SENT-BY" parameter, a calendar user could send an updated "VEVENT" REQUEST. In the case where one CU sends on Daboo Expires April 7, 2010 [Page 23]
Internet-Draft iTIP October 2009 behalf of another CU, the "Attendee" responses are still directed back towards the CU designated as "Organizer". 3.2.2.6. Forwarding to An Uninvited CU An "Attendee" invited to a "VEVENT" calendar component may send the "VEVENT" calendar component to another new CU, not previously associated with the "VEVENT" calendar component. The current "Attendee" invited to the "VEVENT" 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 "VEVENT" 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 event 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 event, the new "ATTENDEE" property is not added to the "VEVENT" calendar component. The "Organizer" MAY send the CU a "CANCEL" message to indicate that they will not be added to the event. If the "Organizer" decides to add the new CU, the new "ATTENDEE" property is added to the "VEVENT" 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. The "Organizer" SHOULD send the new CU a "REQUEST" message to inform them that they have been added. When forwarding a "REQUEST" to another CU, the forwarding "Attendee" MUST NOT make changes to the original message. 3.2.2.7. Updating Attendee Status The "Organizer" of an event may also request updated status from one or more "Attendees. The "Organizer" sends a "REQUEST" method to the "Attendee" and sets the "ATTENDEE;RSVP=TRUE" property parameter. The "SEQUENCE" property for the event is not changed from its previous value. A recipient will determine that the only change in the "REQUEST" is that their "RSVP" property parameter indicates a request for updated status. The recipient SHOULD respond with a "REPLY" method indicating their current status with respect to the "REQUEST". 3.2.3. REPLY The "REPLY" method in a "VEVENT" calendar component is used to respond (e.g., accept or decline) to a "REQUEST" or to reply to a delegation "REQUEST". When used to provide a delegation response, the "Delegator" SHOULD include the calendar address of the "Delegate" on the "DELEGATED-TO" property parameter of the "Delegator's" Daboo Expires April 7, 2010 [Page 24]
Internet-Draft iTIP October 2009 "ATTENDEE" property. The "Delegate" SHOULD include the calendar address of the "Delegator" on the "DELEGATED-FROM" property parameter of the "Delegate's" "ATTENDEE" property. The "REPLY" method is also used when processing of a "REQUEST" fails. Depending on the value of the "REQUEST-STATUS" property no scheduling action may have been performed. The "Organizer" of an event may receive the "REPLY" method from a CU not in the original "REQUEST". For example, a "REPLY" may be received from a "Delegate" to an event. In addition, the "REPLY" method may be received from an unknown CU (a "Party Crasher"). This uninvited "Attendee" may be accepted, or the "Organizer" may cancel the event for the uninvited "Attendee" by sending a "CANCEL" method to the uninvited "Attendee". An "Attendee" MAY include a message to the "Organizer" using the "COMMENT" property. For example, if the user indicates tentative acceptance and wants to let the "Organizer" know why, the reason can be expressed in the "COMMENT" property value. The "Organizer" may also receive a "REPLY" from one CU on behalf of another. Like the scenario enumerated above for the "Organizer", "Attendees" may have another CU respond on their behalf. This is done using the "SENT-BY" parameter. The optional properties listed in the table below (those listed as "0+" or "0 or 1") MUST NOT be changed from those of the original request. If property changes are desired the COUNTER message must be used. This method type is an iCalendar object that conforms to the following property constraints: +--------------------------------------------+ | Constraints for a METHOD:REPLY of a VEVENT | +--------------------------------------------+ +--------------------+----------+-----------------------------------+ | Component/Property | Presence | Comment | +--------------------+----------+-----------------------------------+ | METHOD | 1 | MUST be "REPLY" | | | | | | VEVENT | 1+ | All components MUST have the same | | | | UID | | ATTENDEE | 1 | MUST be the address of the | | | | Attendee replying. | | DTSTAMP | 1 | | Daboo Expires April 7, 2010 [Page 25]
Internet-Draft iTIP October 2009 | ORGANIZER | 1 | | | RECURRENCE-ID | 0 or 1 | Only if referring to an instance | | | | of a recurring calendar | | | | component. Otherwise it MUST NOT | | | | be present. | | UID | 1 | MUST be the UID of the original | | | | REQUEST | | SEQUENCE | 0 or 1 | MUST if non-zero, MUST be the | | | | sequence number of the original | | | | REQUEST. MAY be present if 0. | | ATTACH | 0+ | | | 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 | | DTSTART | 0 or 1 | | | 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+ | | | RELATED-TO | 0+ | | | RESOURCES | 0+ | | | REQUEST-STATUS | 0+ | | | RRULE | 0 or 1 | | | STATUS | 0 or 1 | | | SUMMARY | 0 or 1 | | | TRANSP | 0 or 1 | | | URL | 0 or 1 | | | IANA-PROPERTY | 0+ | | | X-PROPERTY | 0+ | | | | | | | VALARM | 0 | | | | | | | VTIMEZONE | 0 or 1 | MUST be present if any date/time | | | | refers to a timezone | | | | | | IANA-COMPONENT | 0+ | | | X-COMPONENT | 0+ | | | | | | | VFREEBUSY | 0 | | Daboo Expires April 7, 2010 [Page 26]
Internet-Draft iTIP October 2009 | | | | | VJOURNAL | 0 | | | | | | | VTODO | 0 | | +--------------------+----------+-----------------------------------+ 3.2.4. ADD The "ADD" method allows the "Organizer" to add one or more new instances to an existing "VEVENT" using a single iTIP message without having to send the entire "VEVENT" with all the existing instance data, as it would have to do if the "REQUEST" method were used. The "UID" must be that of the existing event. 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 "VEVENT". If an "Attendee" implementation does not support the "ADD" method it should respond with a "REQUEST-STATUS" value of 3.14 and ask for a "REFRESH". When handling an "ADD" message, the "Attendee" treats each component in the "ADD" message as if it were referenced via an "RDATE"in the main component. This method type is an iCalendar object that conforms to the following property constraints: +------------------------------------------+ | Constraints for a METHOD:ADD of a VEVENT | +------------------------------------------+ +--------------------+----------+-----------------------------------+ | Component/Property | Presence | Comment | +--------------------+----------+-----------------------------------+ | METHOD | 1 | MUST be "ADD" | | | | | | VEVENT | 1 | | | DTSTAMP | 1 | | | DTSTART | 1 | | | ORGANIZER | 1 | | | SEQUENCE | 1 | MUST be greater than 0 | | SUMMARY | 1 | Can be null | | UID | 1 | MUST match that of the original | | | | event | | ATTACH | 0+ | | | ATTENDEE | 0+ | | | CATEGORIES | 0+ | | | CLASS | 0 or 1 | | Daboo Expires April 7, 2010 [Page 27]
Internet-Draft iTIP October 2009 | COMMENT | 0+ | | | CONTACT | 0+ | | | CREATED | 0 or 1 | | | DESCRIPTION | 0 or 1 | Can be null | | DTEND | 0 or 1 | if present DURATION MUST NOT be | | | | present | | DURATION | 0 or 1 | if present DTEND MUST NOT be | | | | present | | GEO | 0 or 1 | | | LAST-MODIFIED | 0 or 1 | | | LOCATION | 0 or 1 | | | PRIORITY | 0 or 1 | | | RELATED-TO | 0+ | | | RESOURCES | 0+ | | | STATUS | 0 or 1 | MAY be one of TENTATIVE/CONFIRMED | | TRANSP | 0 or 1 | | | URL | 0 or 1 | | | IANA-PROPERTY | 0+ | | | X-PROPERTY | 0+ | | | EXDATE | 0 | | | RECURRENCE-ID | 0 | | | REQUEST-STATUS | 0 | | | RDATE | 0 | | | RRULE | 0 | | | | | | | VALARM | 0+ | | | | | | | VTIMEZONE | 0+ | MUST be present if any date/time | | | | refers to a timezone | | | | | | IANA-COMPONENT | 0+ | | | X-COMPONENT | 0+ | | | | | | | VFREEBUSY | 0 | | | | | | | VTODO | 0 | | | | | | | VJOURNAL | 0 | | +--------------------+----------+-----------------------------------+ 3.2.5. CANCEL The "CANCEL" method in a "VEVENT" calendar component is used to send a cancellation notice of an existing event request to the affected "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 Daboo Expires April 7, 2010 [Page 28]
Internet-Draft iTIP October 2009 "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 "THISANDFUTURE" to indicate cancellation of the specified "VEVENT" calendar component and all instances after; or b. individual recurrence instances may be cancelled by specifying multiple "VEVENT" components each with a "RECURRENCE-ID" property corresponding to one of the instances to be cancelled. The "Organizer" MUST send a "CANCEL" message to each "Attendee" affected by the cancellation. This can be done using a single "CANCEL" message for all "Attendees", or multiple messages with different subsets of the affected "Attendees" in each. When a "VEVENT" is cancelled, the "SEQUENCE" property value MUST be incremented as described in Section 2.1.4. This method type is an iCalendar object that conforms to the following property constraints: +---------------------------------------------+ | Constraints for a METHOD:CANCEL of a VEVENT | +---------------------------------------------+ +--------------------+----------+-----------------------------------+ | Component/Property | Presence | Comment | +--------------------+----------+-----------------------------------+ | METHOD | 1 | MUST be "CANCEL" | | | | | | VEVENT | 1+ | All must have the same UID | | ATTENDEE | 0+ | MUST include some or all | | | | "Attendees" being removed from | | | | the event. MUST include some or | | | | 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+ | | Daboo Expires April 7, 2010 [Page 29]
Internet-Draft iTIP October 2009 | ATTACH | 0+ | | | CATEGORIES | 0+ | | | 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+ | | | 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+ | | | RRULE | 0 or 1 | | | STATUS | 0 or 1 | MUST be set to CANCELLED to | | | | cancel the entire event. If | | | | uninviting specific "Attendees" | | | | then MUST NOT be included. | | SUMMARY | 0 or 1 | | | TRANSP | 0 or 1 | | | URL | 0 or 1 | | | IANA-PROPERTY | 0+ | | | X-PROPERTY | 0+ | | | REQUEST-STATUS | 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 | | | | | | Daboo Expires April 7, 2010 [Page 30]
Internet-Draft iTIP October 2009 | VFREEBUSY | 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: +----------------------------------------------+ | Constraints for a METHOD:REFRESH of a VEVENT | +----------------------------------------------+ +--------------------+----------+-----------------------------------+ | Component/Property | Presence | Comment | +--------------------+----------+-----------------------------------+ | METHOD | 1 | MUST be "REFRESH" | | | | | | VEVENT | 1 | | | ATTENDEE | 1 | MUST be the address of requester | | DTSTAMP | 1 | | | ORGANIZER | 1 | | | UID | 1 | MUST be the UID associated with | | | | original REQUEST | | COMMENT | 0+ | | | RECURRENCE-ID | 0 or 1 | Only if referring to an instance | | | | of a recurring calendar | | | | component. Otherwise it MUST NOT | | | | be present. | | IANA-PROPERTY | 0+ | | | X-PROPERTY | 0+ | | | ATTACH | 0 | | | CATEGORIES | 0 | | | CLASS | 0 | | | CONTACT | 0 | | | CREATED | 0 | | | DESCRIPTION | 0 | | | DTEND | 0 | | | DTSTART | 0 | | | DURATION | 0 | | | EXDATE | 0 | | Daboo Expires April 7, 2010 [Page 31]
Internet-Draft iTIP October 2009 | 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 | | | | | | | VALARM | 0 | | | | | | | VTIMEZONE | 0+ | | | | | | | IANA-COMPONENT | 0+ | | | X-COMPONENT | 0+ | | | | | | | VTODO | 0 | | | | | | | VJOURNAL | 0 | | | | | | | VFREEBUSY | 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. 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 "DECLINECOUNTER" method. The "Organizer" accepts the counter proposal by rescheduling the event as described in section 3.2.2.1 Rescheduling an Event. The "Organizers" CUA SHOULD send a "REQUEST" message to all "Attendees" affected by any change triggered by an accepted "COUNTER". This method type is an iCalendar object that conforms to the Daboo Expires April 7, 2010 [Page 32]
Internet-Draft iTIP October 2009 following property constraints: +----------------------------------------------+ | Constraints for a METHOD:COUNTER of a VEVENT | +----------------------------------------------+ +--------------------+----------+-----------------------------------+ | Component/Property | Presence | Comment | +--------------------+----------+-----------------------------------+ | 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+ | | | REQUEST-STATUS | 0+ | | Daboo Expires April 7, 2010 [Page 33]
Internet-Draft iTIP October 2009 | RESOURCES | 0+ | | | RRULE | 0 or 1 | | | STATUS | 0 or 1 | Value must be one of | | | | CONFIRMED/TENATIVE/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 | | +--------------------+----------+-----------------------------------+ 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: +-----------------------------------------------------+ | Constraints for a METHOD:DECLINECOUNTER of a VEVENT | +-----------------------------------------------------+ +--------------------+----------+-----------------------------------+ | Component/Property | Presence | Comment | +--------------------+----------+-----------------------------------+ | METHOD | 1 | MUST be "DECLINECOUNTER" | | | | | | VEVENT | 1+ | All components MUST have the same | | | | UID | | ATTENDEE | 1+ | MUST for all attendees | | DTSTAMP | 1 | | Daboo Expires April 7, 2010 [Page 34]
Internet-Draft iTIP October 2009 | ORGANIZER | 1 | | | SEQUENCE | 1 | MUST echo the original SEQUENCE | | | | number | | UID | 1 | MUST echo original UID | | ATTACH | 0+ | | | CATEGORIES | 0+ | | | CLASS | 0 or 1 | | | COMMENT | 0+ | | | CONTACT | 0+ | | | CREATED | 0 or 1 | | | DESCRIPTION | 0 or 1 | Can be null | | DTSTART | 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+ | | | REQUEST-STATUS | 0+ | | | RESOURCES | 0+ | | | RRULE | 0 or 1 | | | STATUS | 0 or 1 | MAY be one of TENTATIVE/CONFIRMED | | SUMMARY | 0 or 1 | Can be null | | TRANSP | 0 or 1 | | | URL | 0 or 1 | | | IANA-PROPERTY | 0+ | | | X-PROPERTY | 0+ | | | | | | | | | | | VTIMEZONE | 0+ | MUST be present if any date/time | | | | refers to a timezone | | | | | | IANA-COMPONENT | 0+ | | | X-COMPONENT | 0+ | | | | | | | VALARM | 0 | | | VFREEBUSY | 0 | | | | | | | VJOURNAL | 0 | | Daboo Expires April 7, 2010 [Page 35]
Internet-Draft iTIP October 2009 | | | | | VTODO | 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 "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. Busy time periods can also span a day boundary. 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 way to send Daboo Expires April 7, 2010 [Page 36]
Internet-Draft iTIP October 2009 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 "ORGANIZER" property MUST be specified in the busy time information. The value is the CU address of the originator of the 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 "ORGANIZER", "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. This method type is an iCalendar object that conforms to the following property constraints: +-------------------------------------------------+ | Constraints for a METHOD:PUBLISH of a VFREEBUSY | +-------------------------------------------------+ Daboo Expires April 7, 2010 [Page 37]
Internet-Draft iTIP October 2009 +--------------------+----------+-----------------------------------+ | Component/Property | Presence | Comment | +--------------------+----------+-----------------------------------+ | 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 | 0+ | MUST be BUSYTIME. Multiple | | | | instances are allowed. Multiple | | | | instances SHOULD be sorted in | | | | ascending order | | ORGANIZER | 1 | MUST contain the address of | | | | originator of busy time data. | | UID | 1 | | | COMMENT | 0+ | | | CONTACT | 0 or 1 | | | IANA-PROPERTY | 0+ | | | X-PROPERTY | 0+ | | | URL | 0 or 1 | Specifies busy time URL | | ATTENDEE | 0 | | | DURATION | 0 | | | REQUEST-STATUS | 0 | | | | | | | VALARM | 0 | | | | | | | IANA-COMPONENT | 0+ | | | X-COMPONENT | 0+ | | | | | | | VEVENT | 0 | | | | | | | VTODO | 0 | | | | | | | VJOURNAL | 0 | | | | | | | VTIMEZONE | 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 Daboo Expires April 7, 2010 [Page 38]
Internet-Draft iTIP October 2009 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: +-------------------------------------------------+ | Constraints for a METHOD:REQUEST of a VFREEBUSY | +-------------------------------------------------+ +--------------------+----------+-----------------------------------+ | Component/Property | Presence | Comment | +--------------------+----------+-----------------------------------+ | METHOD | 1 | MUST be "REQUEST" | | | | | | VFREEBUSY | 1 | | | ATTENDEE | 1+ | contains the calendar user | | | | addresses of the calendar users | | | | whose freebusy is being requested | | 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+ | | | CONTACT | 0 or 1 | | | IANA-PROPERTY | 0+ | | | X-PROPERTY | 0+ | | | FREEBUSY | 0 | | | DURATION | 0 | | | REQUEST-STATUS | 0 | | | URL | 0 | | | | | | | VALARM | 0 | | | | | | | IANA-COMPONENT | 0+ | | | X-COMPONENT | 0+ | | | | | | | VEVENT | 0 | | | | | | | VTODO | 0 | | | | | | | VJOURNAL | 0 | | Daboo Expires April 7, 2010 [Page 39]
Internet-Draft iTIP October 2009 | | | | | 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: +-----------------------------------------------+ | Constraints for a METHOD:REPLY of a VFREEBUSY | +-----------------------------------------------+ Daboo Expires April 7, 2010 [Page 40]
Internet-Draft iTIP October 2009 +--------------------+----------+-----------------------------------+ | Component/Property | Presence | Comment | +--------------------+----------+-----------------------------------+ | METHOD | 1 | MUST be "REPLY" | | | | | | VFREEBUSY | 1 | | | ATTENDEE | 1 | MUST be the address of the | | | | Attendee replying. | | DTSTAMP | 1 | | | DTEND | 1 | DateTime values must be in UTC | | DTSTART | 1 | DateTime values must be in UTC | | FREEBUSY | 0+ | MUST be BUSYTIME. Multiple | | | | instances are allowed. Multiple | | | | instances SHOULD be sorted in | | | | ascending order | | ORGANIZER | 1 | MUST be the request originator's | | | | address | | UID | 1 | MUST be the UID of the original | | | | REQUEST | | COMMENT | 0+ | | | CONTACT | 0 or 1 | | | REQUEST-STATUS | 0+ | | | URL | 0 or 1 | specifies busy time URL | | IANA-PROPERTY | 0+ | | | X-PROPERTY | 0+ | | | DURATION | 0 | | | SEQUENCE | 0 | | | | | | | VALARM | 0 | | | | | | | IANA-COMPONENT | 0+ | | | X-COMPONENT | 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. Daboo Expires April 7, 2010 [Page 41]
Internet-Draft iTIP October 2009 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: Daboo Expires April 7, 2010 [Page 42]
Internet-Draft iTIP October 2009 +---------------------------------------------+ | Constraints for a METHOD:PUBLISH of a VTODO | +---------------------------------------------+ +--------------------+----------+-----------------------------------+ | Component/Property | Presence | Comment | +--------------------+----------+-----------------------------------+ | 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+ | | | CLASS | 0 or 1 | | | COMMENT | 0+ | | | COMPLETED | 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+ | | | 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 | Only if referring to an instance | | | | of a recurring calendar | | | | component. Otherwise it MUST NOT | | | | be present. | | RELATED-TO | 0+ | | | RESOURCES | 0+ | | | RRULE | 0 or 1 | | | STATUS | 0 or 1 | MAY be one of | | | | COMPLETED/NEEDS-ACTION/ | | | | IN-PROCESS/CANCELLED | | URL | 0 or 1 | | Daboo Expires April 7, 2010 [Page 43]
Internet-Draft iTIP October 2009 | IANA-PROPERTY | 0+ | | | X-PROPERTY | 0+ | | | ATTENDEE | 0 | | | REQUEST-STATUS | 0 | | | | | | | VALARM | 0+ | | | | | | | VTIMEZONE | 0+ | MUST be present if any date/time | | | | refers to a timezone | | | | | | IANA-COMPONENT | 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: o Assign a to-do to one or more "Calendar Users" o Reschedule an existing to-do o Update the details of an existing to-do, without rescheduling it o Update the completion status of "Attendees" of an existing to-do, without rescheduling it o Reconfirm an existing to-do, without rescheduling it o 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. Typically the originator of a "REQUEST" is the "Organizer" of the to-do, and 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 Daboo Expires April 7, 2010 [Page 44]
Internet-Draft iTIP October 2009 "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: +---------------------------------------------+ | Constraints for a METHOD:REQUEST of a VTODO | +---------------------------------------------+ +--------------------+----------+-----------------------------------+ | Component/Property | Presence | Comment | +--------------------+----------+-----------------------------------+ | 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+ | | | CLASS | 0 or 1 | | | COMMENT | 0+ | | | COMPLETED | 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 | Daboo Expires April 7, 2010 [Page 45]
Internet-Draft iTIP October 2009 | DURATION | 0 or 1 | If present DUE MUST NOT be | | | | present | | EXDATE | 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 | Only if referring to an instance | | | | of a recurring calendar | | | | component. Otherwise it MUST NOT | | | | be present. | | RELATED-TO | 0+ | | | RESOURCES | 0+ | | | RRULE | 0 or 1 | | | STATUS | 0 or 1 | MAY be one of | | | | COMPLETED/NEEDS-ACTION/ | | | | IN-PROCESS | | URL | 0 or 1 | | | IANA-PROPERTY | 0+ | | | X-PROPERTY | 0+ | | | REQUEST-STATUS | 0 | | | | | | | VALARM | 0+ | | | | | | | VTIMEZONE | 0+ | MUST be present if any date/time | | | | refers to a timezone | | | | | | IANA-COMPONENT | 0+ | | | 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" Daboo Expires April 7, 2010 [Page 46]
Internet-Draft iTIP October 2009 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. 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. Daboo Expires April 7, 2010 [Page 47]
Internet-Draft iTIP October 2009 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. The "Organizer" SHOULD send the new attendee a "REQUEST" message to inform them that they have been added. When forwarding a "REQUEST" to another CU, the forwarding "Attendee" MUST NOT make changes to the original message. Daboo Expires April 7, 2010 [Page 48]
Internet-Draft iTIP October 2009 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: +-------------------------------------------+ | Constraints for a METHOD:REPLY of a VTODO | +-------------------------------------------+ +--------------------+----------+-----------------------------------+ | Component/Property | Presence | Comment | +--------------------+----------+-----------------------------------+ | METHOD | 1 | MUST be "REPLY" | Daboo Expires April 7, 2010 [Page 49]
Internet-Draft iTIP October 2009 | | | | | VTODO | 1+ | All component MUST have the same | | | | UID | | ATTENDEE | 1 | MUST be the address of the | | | | Attendee replying. | | DTSTAMP | 1 | | | ORGANIZER | 1 | | | REQUEST-STATUS | 0+ | | | UID | 1 | MUST be the UID of the original | | | | REQUEST | | ATTACH | 0+ | | | CATEGORIES | 0+ | | | CLASS | 0 or 1 | | | COMMENT | 0+ | | | COMPLETED | 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+ | | | 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+ | | | RRULE | 0 or 1 | | | RECURRENCE-ID | 0 or 1 | 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 | | | IANA-PROPERTY | 0+ | | | X-PROPERTY | 0+ | | | | | | | VALARM | 0 | | | | | | Daboo Expires April 7, 2010 [Page 50]
Internet-Draft iTIP October 2009 | VTIMEZONE | 0 or 1 | MUST be present if any date/time | | | | refers to a timezone | | | | | | IANA-COMPONENT | 0+ | | | X-COMPONENT | 0+ | | | | | | | VEVENT | 0 | | | | | | | VFREEBUSY | 0 | | +--------------------+----------+-----------------------------------+ 3.4.4. ADD The "ADD" method allows the "Organizer" to add one or more new instances to an existing "VTODO" using a single iTIP message without having to send the entire "VTODO" with all the existing instance data, as it would have to do if the "REQUEST" method were used. The "UID" must be that of the 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 3.14 and ask for a "REFRESH". When handling an "ADD" message, the "Attendee" treats each component in the "ADD" message as if it were referenced via an "RDATE"in the main component. 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: +-----------------------------------------+ | Constraints for a METHOD:ADD of a VTODO | +-----------------------------------------+ +--------------------+----------+-----------------------------------+ | Component/Property | Presence | Comment | +--------------------+----------+-----------------------------------+ | METHOD | 1 | MUST be "ADD" | | | | | | VTODO | 1 | | | DTSTAMP | 1 | | | ORGANIZER | 1 | | | PRIORITY | 1 | | Daboo Expires April 7, 2010 [Page 51]
Internet-Draft iTIP October 2009 | 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+ | | | CLASS | 0 or 1 | | | COMMENT | 0+ | | | COMPLETED | 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 | | GEO | 0 or 1 | | | LAST-MODIFIED | 0 or 1 | | | LOCATION | 0 or 1 | | | PERCENT-COMPLETE | 0 or 1 | | | RELATED-TO | 0+ | | | RESOURCES | 0+ | | | STATUS | 0 or 1 | MAY be one of | | | | COMPLETED/NEEDS-ACTION/ | | | | IN-PROCESS | | URL | 0 or 1 | | | IANA-PROPERTY | 0+ | | | X-PROPERTY | 0+ | | | EXDATE | 0 | | | RECURRENCE-ID | 0 | | | REQUEST-STATUS | 0 | | | RDATE | 0 | | | RRULE | 0 | | | | | | | VALARM | 0+ | | | | | | | VTIMEZONE | 0+ | MUST be present if any date/time | | | | refers to a timezone | | | | | | IANA-COMPONENT | 0+ | | | X-COMPONENT | 0+ | | | | | | | VEVENT | 0 | | | | | | | VJOURNAL | 0 | | | | | | Daboo Expires April 7, 2010 [Page 52]
Internet-Draft iTIP October 2009 | 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 affected "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 "THISANDFUTURE" to indicate cancellation of the specified "VTODO" calendar component and all instances after b. individual recurrence instances may be cancelled by specifying multiple "VTODO" components with a "RECURRENCE-ID" property corresponding to one of the instances to be cancelled The "Organizer" MUST send a "CANCEL" message to each "Attendee" affected by the cancellation. This can be done using a single "CANCEL" message for all "Attendees", or multiple messages with different subsets of the affected "Attendees" in each. When a "VTODO" is cancelled, the "SEQUENCE" property value MUST be incremented as described in Section 2.1.4. This method type is an iCalendar object that conforms to the following property constraints: +--------------------------------------------+ | Constraints for a METHOD:CANCEL of a VTODO | +--------------------------------------------+ Daboo Expires April 7, 2010 [Page 53]
Internet-Draft iTIP October 2009 +--------------------+----------+-----------------------------------+ | Component/Property | Presence | Comment | +--------------------+----------+-----------------------------------+ | METHOD | 1 | MUST be "CANCEL" | | | | | | VTODO | 1+ | | | ATTENDEE | 0+ | MUST include some or all | | | | "Attendees" being removed from | | | | the to-do. MUST include some or | | | | all "Attendees" if the entire | | | | to-do is cancelled. | | UID | 1 | MUST echo original UID | | DTSTAMP | 1 | | | ORGANIZER | 1 | | | SEQUENCE | 1 | | | ATTACH | 0+ | | | CATEGORIES | 0+ | | | CLASS | 0 or 1 | | | COMMENT | 0+ | | | COMPLETED | 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+ | | | 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 | Only if referring to an instance | | | | of a recurring calendar | | | | component. Otherwise it MUST NOT | | | | be present. | | RELATED-TO | 0+ | | | RESOURCES | 0+ | | | RRULE | 0 or 1 | | | PRIORITY | 0 or 1 | | | STATUS | 0 or 1 | MUST be set to CANCELLED to | | | | cancel the entire VTODO. If | | | | removing specific "Attendees" | | | | then MUST NOT be included. | | URL | 0 or 1 | | | IANA-PROPERTY | 0+ | | Daboo Expires April 7, 2010 [Page 54]
Internet-Draft iTIP October 2009 | X-PROPERTY | 0+ | | | REQUEST-STATUS | 0 | | | | | | | VALARM | 0 | | | | | | | VTIMEZONE | 0 or 1 | MUST be present if any date/time | | | | refers to a timezone | | | | | | IANA-COMPONENT | 0+ | | | X-COMPONENT | 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: +---------------------------------------------+ | Constraints for a METHOD:REFRESH of a VTODO | +---------------------------------------------+ +--------------------+----------+-----------------------------------+ | Component/Property | Presence | Comment | +--------------------+----------+-----------------------------------+ | METHOD | 1 | MUST be "REFRESH" | | | | | | VTODO | 1 | | Daboo Expires April 7, 2010 [Page 55]
Internet-Draft iTIP October 2009 | ATTENDEE | 1 | | | DTSTAMP | 1 | | | UID | 1 | MUST echo original UID | | RECURRENCE-ID | 0 or 1 | Only if referring to an instance | | | | of a recurring calendar | | | | component. Otherwise it MUST NOT | | | | be present. | | IANA-PROPERTY | 0+ | | | X-PROPERTY | 0+ | | | ATTACH | 0 | | | CATEGORIES | 0 | | | CLASS | 0 | | | COMMENT | 0 | | | COMPLETED | 0 | | | CONTACT | 0 | | | CREATED | 0 | | | DESCRIPTION | 0 | | | DTSTART | 0 | | | DUE | 0 | | | DURATION | 0 | | | EXDATE | 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 | | | | | | | VALARM | 0 | | | | | | | VTIMEZONE | 0+ | | | | | | | IANA-COMPONENT | 0+ | | | X-COMPONENT | 0+ | | | | | | | VEVENT | 0 | | | | | | | VFREEBUSY | 0 | | +--------------------+----------+-----------------------------------+ Daboo Expires April 7, 2010 [Page 56]
Internet-Draft iTIP October 2009 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 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 rescheduling the to-do as described in section 3.4.2.1 Rescheduling a To-Do. The "Organizers" CUA SHOULD send a "REQUEST" message to all "Attendees" affected by any change triggered by an accepted "COUNTER". This method type is an iCalendar object that conforms to the following property constraints: +---------------------------------------------+ | Constraints for a METHOD:COUNTER of a VTODO | +---------------------------------------------+ +--------------------+----------+-----------------------------------+ | Component/Property | Presence | Comment | +--------------------+----------+-----------------------------------+ | 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+ | | | CLASS | 0 or 1 | | | COMMENT | 0+ | | | COMPLETED | 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 | Daboo Expires April 7, 2010 [Page 57]
Internet-Draft iTIP October 2009 | DURATION | 0 or 1 | If present DUE MUST NOT be | | | | present | | EXDATE | 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 | 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+ | | | 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 | | | IANA-PROPERTY | 0+ | | | X-PROPERTY | 0+ | | | | | | | VALARM | 0+ | | | | | | | VTIMEZONE | 0 or 1 | MUST be present if any date/time | | | | refers to a timezone | | | | | | IANA-COMPONENT | 0+ | | | 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". Daboo Expires April 7, 2010 [Page 58]
Internet-Draft iTIP October 2009 This method type is an iCalendar object that conforms to the following property constraints: +----------------------------------------------------+ | Constraints for a METHOD:DECLINECOUNTER of a VTODO | +----------------------------------------------------+ +--------------------+----------+-----------------------------------+ | Component/Property | Presence | Comment | +--------------------+----------+-----------------------------------+ | 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+ | | | CLASS | 0 or 1 | | | COMMENT | 0+ | | | COMPLETED | 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+ | | | 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 | 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+ | | | RRULE | 0 or 1 | | Daboo Expires April 7, 2010 [Page 59]
Internet-Draft iTIP October 2009 | STATUS | 0 or 1 | MAY be one of | | | | COMPLETED/NEEDS-ACTION/ | | | | IN-PROCESS | | 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+ | | | | | | | 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 Daboo Expires April 7, 2010 [Page 60]
Internet-Draft iTIP October 2009 (with a "CANCEL" method) a previously published journal entry. This method type is an iCalendar object that conforms to the following property constraints: +------------------------------------------------+ | Constraints for a METHOD:PUBLISH of a VJOURNAL | +------------------------------------------------+ Daboo Expires April 7, 2010 [Page 61]
Internet-Draft iTIP October 2009 +--------------------+----------+-----------------------------------+ | Component/Property | Presence | Comment | +--------------------+----------+-----------------------------------+ | METHOD | 1 | MUST be "PUBLISH" | | | | | | VJOURNAL | 1+ | | | DESCRIPTION | 1 | Can be null. | | DTSTAMP | 1 | | | DTSTART | 1 | | | ORGANIZER | 1 | | | UID | 1 | | | ATTACH | 0+ | | | CATEGORIES | 0+ | | | CLASS | 0 or 1 | | | COMMENT | 0+ | | | CONTACT | 0+ | | | CREATED | 0 or 1 | | | EXDATE | 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 or 1 | | | SEQUENCE | 0 or 1 | 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 | | | IANA-PROPERTY | 0+ | | | X-PROPERTY | 0+ | | | ATTENDEE | 0 | | | REQUEST-STATUS | 0 | | | | | | | VALARM | 0+ | | | | | | | VTIMEZONE | 0+ | MUST be present if any date/time | | | | refers to a timezone | | | | | | IANA-COMPONENT | 0+ | | | X-COMPONENT | 0+ | | | | | | | VEVENT | 0 | | | | | | | VFREEBUSY | 0 | | Daboo Expires April 7, 2010 [Page 62]
Internet-Draft iTIP October 2009 | | | | | VTODO | 0 | | +--------------------+----------+-----------------------------------+ 3.5.2. ADD The "ADD" method allows the "Organizer" to add one or more new instances to an existing "VJOURNAL" using a single iTIP message without having to send the entire "VJOURNAL" with all the existing instance data, as it would have to do if the "REQUEST" method were used. The "UID" must be that of the existing journal entry. 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". When handling an "ADD" message, the "Attendee" treats each component in the "ADD" message as if it were referenced via an "RDATE"in the main component. There is no response to the "Organizer". This method type is an iCalendar object that conforms to the following property constraints: +--------------------------------------------+ | Constraints for a METHOD:ADD of a VJOURNAL | +--------------------------------------------+ Daboo Expires April 7, 2010 [Page 63]
Internet-Draft iTIP October 2009 +--------------------+----------+-----------------------------------+ | Component/Property | Presence | Comment | +--------------------+----------+-----------------------------------+ | 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+ | | | CLASS | 0 or 1 | | | COMMENT | 0+ | | | CONTACT | 0+ | | | CREATED | 0 or 1 | | | LAST-MODIFIED | 0 or 1 | | | RELATED-TO | 0+ | | | STATUS | 0 or 1 | MAY be one of | | | | DRAFT/FINAL/CANCELLED | | SUMMARY | 0 or 1 | Can be null | | URL | 0 or 1 | | | IANA-PROPERTY | 0+ | | | X-PROPERTY | 0+ | | | ATTENDEE | 0 | | | EXDATE | 0 | | | RECURRENCE-ID | 0 | | | REQUEST-STATUS | 0 | | | RDATE | 0 | | | RRULE | 0 | | | | | | | VALARM | 0+ | | | | | | | VTIMEZONE | 0 or 1 | MUST be present if any date/time | | | | refers to a timezone | | | | | | IANA-COMPONENT | 0+ | | | X-COMPONENT | 0+ | | | | | | | VEVENT | 0 | | | | | | | VFREEBUSY | 0 | | | | | | | VTODO | 0 | | +--------------------+----------+-----------------------------------+ Daboo Expires April 7, 2010 [Page 64]
Internet-Draft iTIP October 2009 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 "THISANDFUTURE" to indicate cancellation of the specified "VTODO" calendar component and all instances after b. individual recurrence instances may be cancelled by specifying multiple "VJOURNAL" components with a "RECURRENCE-ID" property corresponding to one of the instances to be cancelled When a "VJOURNAL" is cancelled, the "SEQUENCE" property value MUST be incremented as described in Section 2.1.4. This method type is an iCalendar object that conforms to the following property constraints: +-----------------------------------------------+ | Constraints for a METHOD:CANCEL of a VJOURNAL | +-----------------------------------------------+ Daboo Expires April 7, 2010 [Page 65]
Internet-Draft iTIP October 2009 +--------------------+----------+-----------------------------------+ | Component/Property | Presence | Comment | +--------------------+----------+-----------------------------------+ | 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+ | | | CLASS | 0 or 1 | | | COMMENT | 0+ | | | CONTACT | 0+ | | | CREATED | 0 or 1 | | | DESCRIPTION | 0 or 1 | | | DTSTART | 0 or 1 | | | EXDATE | 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 or 1 | | | STATUS | 0 or 1 | MAY be present, must be | | | | "CANCELLED" if present | | SUMMARY | 0 or 1 | | | URL | 0 or 1 | | | IANA-PROPERTY | 0+ | | | X-PROPERTY | 0+ | | | REQUEST-STATUS | 0 | | | | | | | VALARM | 0 | | | | | | | VTIMEZONE | 0+ | MUST be present if any date/time | | | | refers to a timezone | | | | | | IANA-COMPONENT | 0+ | | | X-COMPONENT | 0+ | | | | | | | VEVENT | 0 | | | | | | | VFREEBUSY | 0 | | Daboo Expires April 7, 2010 [Page 66]
Internet-Draft iTIP October 2009 | | | | | VTODO | 0 | | +--------------------+----------+-----------------------------------+ 3.6. Status Replies The "REQUEST-STATUS" property is used to convey status information about a REPLY, COUNTER or DECLINECOUNTER iTIP message. The codes listed in the table below SHOULD be used. If the "REQUEST-STATUS" property is not present in one of these iTIP messages, then a status code of "2.0" (success) MUST be assumed. This specification adds a new IANA registry for REQUEST-STATUS values, as defined in Section 7, which includes a new registration template for defining the specific components of the REQUEST-STATUS value. Additional codes MAY be used provided the process described in Section 8.2.1 of [RFC5545] is used to register them. This specification allows for multiple "REQUEST-STATUS" properties to be returned in iCalendar components in the appropriate iTIP messages. When multiple "REQUEST-STATUS" properties are present, the following restrictions apply: 1. Within any one component, the "top-level" numeric value of the "short return status code" MUST be the same for all REQUEST- STATUS properties. i.e. there cannot be a mixture of e.g., 2.xx and 5.xx codes within a single component. 2. Across all components in the iTIP message, the following applies: A. If any one component would have a 5.xx code, then all components MUST have a code in that range or "REQUEST-STATUS" MUST NOT be present in the other components if a 5.xx code is not appropriate for those components. B. Otherwise, if any one component would have a 3.xx code, then all components MUST have a code in that range or "REQUEST- STATUS" MUST NOT be present in the other components if a 3.xx code is not appropriate for those components. C. 2.xx and 4.xx codes can be used in different components provided that each component follows the restriction in (1) above. The following "REQUEST-STATUS" codes are defined (any "Offending Data" MAY be specified in the "REQUEST-STATUS" value as the extdata field): 3.6.1. Status Code 2.0 Daboo Expires April 7, 2010 [Page 67]
Internet-Draft iTIP October 2009 Status Code: 2.0 Status Description: Success. Status Exception Data: None. Description: iTIP operation succeeded. 3.6.2. Status Code 2.1 Status Code: 2.1 Status Description: Success but fallback taken on one or more property values. Status Exception Data: Property name and value MAY be specified. Description: iTIP operation succeeded with fallback on one or more property values. 3.6.3. Status Code 2.2 Status Code: 2.2 Status Description: Success, invalid property ignored. Status Exception Data: Property name MAY be specified. Description: iTIP operation succeeded but a property was ignored. 3.6.4. Status Code 2.3 Status Code: 2.3 Status Description: Success, invalid property parameter ignored. Status Exception Data: Property parameter name and value MAY be specified. Description: iTIP operation succeeded but a property parameter was ignored because it was invalid. 3.6.5. Status Code 2.4 Status Code: 2.4 Status Description: Success, unknown non-standard property ignored. Status Exception Data: Non-standard property name MAY be specified. Description: iTIP operation succeeded but a property parameter was ignored because it was unknown. 3.6.6. Status Code 2.5 Status Code: 2.5 Status Description: Success, unknown non-standard property value ignored. Status Exception Data: Property and non-standard value MAY be specified. Daboo Expires April 7, 2010 [Page 68]
Internet-Draft iTIP October 2009 Description: iTIP operation succeeded but a property was ignored because its value was unknown. 3.6.7. Status Code 2.6 Status Code: 2.6 Status Description: Success, invalid calendar component ignored. Status Exception Data: Calendar component sentinel (e.g., BEGIN: ALARM) MAY be specified. Description: iTIP operation succeeded but a component was ignored because it was invalid. 3.6.8. Status Code 2.7 Status Code: 2.7 Status Description: Success, request forwarded to Calendar User. Status Exception Data: Original and forwarded calendar user addresses MAY be specified. Description: iTIP operation succeeded, and the request was forwarded to another calendar user. 3.6.9. Status Code 2.8 Status Code: 2.8 Status Description: Success, repeating event ignored. Scheduled as a single component. Status Exception Data: RRULE or RDATE property name and value MAY be specified. Description: iTIP operation succeeded, but a repeating event was truncated to a single instance. 3.6.10. Status Code 2.9 Status Code: 2.9 Status Description: Success, truncated end date time to date boundary. Status Exception Data: DTEND property value MAY be specified. Description: iTIP operation succeeded, but the end time was truncated to a date boundary. 3.6.11. Status Code 2.10 Status Code: 2.10 Status Description: Success, repeating VTODO ignored. Scheduled as a single VTODO. Daboo Expires April 7, 2010 [Page 69]
Internet-Draft iTIP October 2009 Status Exception Data: RRULE or RDATE property name and value MAY be specified. Description: iTIP operation succeeded, but a repeating todo was truncated to a single instance. 3.6.12. Status Code 2.11 Status Code: 2.11 Status Description: Success, unbounded RRULE clipped at some finite number of instances. Status Exception Data: RRULE property name and value MAY be specified. Number of instances MAY also be specified. Description: iTIP operation succeeded, but an unbounded repeating object was clipped to a finite number of instances. 3.6.13. Status Code 3.0 Status Code: 3.0 Status Description: Invalid property name. Status Exception Data: Property name MAY be specified. Description: iTIP operation failed because of an invalid property name. 3.6.14. Status Code 3.1 Status Code: 3.1 Status Description: Invalid property value. Status Exception Data: Property name and value MAY be specified. Description: iTIP operation failed because of an invalid property value. 3.6.15. Status Code 3.2 Status Code: 3.2 Status Description: Invalid property parameter. Status Exception Data: Property parameter name and value MAY be specified. Description: iTIP operation failed because of an invalid property parameter. 3.6.16. Status Code 3.3 Status Code: 3.3 Status Description: Invalid property parameter value. Daboo Expires April 7, 2010 [Page 70]
Internet-Draft iTIP October 2009 Status Exception Data: Property parameter name and value MAY be specified. Description: iTIP operation failed because of an invalid property parameter value. 3.6.17. Status Code 3.4 Status Code: 3.4 Status Description: Invalid calendar component sequence. Status Exception Data: Calendar component sentinel MAY be specified (e.g., BEGIN:VTIMEZONE). Description: iTIP operation failed because of an invalid component. 3.6.18. Status Code 3.5 Status Code: 3.5 Status Description: Invalid date or time. Status Exception Data: Date/time value(s) MAY be specified. Description: iTIP operation failed because of an invalid date or time property. 3.6.19. Status Code 3.6 Status Code: 3.6 Status Description: Invalid rule. Status Exception Data: Rule value MAY be specified. Description: iTIP operation failed because of an invalid rule property. 3.6.20. Status Code 3.7 Status Code: 3.7 Status Description: Invalid Calendar User. Status Exception Data: Attendee property value MAY be specified. Description: iTIP operation failed because of an invalid Attendee property. 3.6.21. Status Code 3.8 Status Code: 3.8 Status Description: No authority. Status Exception Data: METHOD and Attendee property values MAY be specified. Description: iTIP operation failed because an Attendee does not have suitable privileges for the operation. Daboo Expires April 7, 2010 [Page 71]
Internet-Draft iTIP October 2009 3.6.22. Status Code 3.9 Status Code: 3.9 Status Description: Unsupported version. Status Exception Data: VERSION property name and value MAY be specified. Description: iTIP operation failed because the calendar data version is not supported. 3.6.23. Status Code 3.10 Status Code: 3.10 Status Description: Request entity too large. Status Exception Data: Request entity too large. Description: iTIP operation failed because the calendar data was too large. 3.6.24. Status Code 3.11 Status Code: 3.11 Status Description: Required component or property missing. Status Exception Data: Component or property name MAY be specified. Description: iTIP operation failed because the calendar data did not contain a required property or component. 3.6.25. Status Code 3.12 Status Code: 3.12 Status Description: Unknown component or property found. Status Exception Data: Component or property name MAY be specified. Description: iTIP operation failed because the calendar data contained an unknown property or component. 3.6.26. Status Code 3.13 Status Code: 3.13 Status Description: Unsupported component or property found. Status Exception Data: Component or property name MAY be specified. Description: iTIP operation failed because the calendar data contained an unsupported property or component. 3.6.27. Status Code 3.14 Status Code: 3.14 Daboo Expires April 7, 2010 [Page 72]
Internet-Draft iTIP October 2009 Status Description: Unsupported capability. Status Exception Data: METHOD or action MAY be specified. Description: iTIP operation failed because the operation is not supported. 3.6.28. Status Code 4.0 Status Code: 4.0 Status Description: Event conflict. Date/time is busy. Status Exception Data: DTSTART and DTEND property name and values MAY be specified. Description: iTIP operation failed because the event overlaps the date and time of another event. 3.6.29. Status Code 5.0 Status Code: 5.0 Status Description: Request not supported. Status Exception Data: METHOD property value MAY be specified. Description: iTIP operation failed because the operation is not supported. 3.6.30. Status Code 5.1 Status Code: 5.1 Status Description: Service unavailable. Status Exception Data: ATTENDEE property value MAY be specified. Description: iTIP operation failed because scheduling is not active. 3.6.31. Status Code 5.2 Status Code: 5.2 Status Description: Invalid calendar service. Status Exception Data: ATTENDEE property value MAY be specified. Description: iTIP operation failed because there is no scheduling capability. 3.6.32. Status Code 5.3 Status Code: 5.3 Status Description: No scheduling support for user. Status Exception Data: ATTENDEE property value MAY be specified. Description: iTIP operation failed because scheduling is not enabled for an Attendee. Daboo Expires April 7, 2010 [Page 73]
Internet-Draft iTIP October 2009 3.7. Implementation Considerations 3.7.1. Working With Recurrence Instances iCalendar includes a recurrence grammar to represent recurring events. The benefit of such a grammar is the ability to represent a number of events in a single object. However, while this simplifies creation of a recurring event, meeting instances still need to be referenced. For instance, an "Attendee" may decline the third instance of a recurring Friday event. Similarly, the "Organizer" may change the time or location to a single instance of the recurring event. Since implementations may elect to store recurring events as either a single event object or a collection of discrete, related event objects, the protocol is designed so that each recurring instance may be both referenced and versioned. Hence, implementations that choose to maintain per-instance properties (such as "ATTENDEE" property "PARTSTAT" parameter) may do so. However, the protocol does not require per-instance recognition unless the instance itself must be renegotiated. The scenarios for recurrence instance referencing are listed below. For purposes of simplification a change to an event refers to a "trigger property." That is, a property that has a substantive effect on the meeting itself such as start time, location, due date (for "VTODO" calendar component components) and possibly description. "Organizer" initiated actions: o "Organizer" deletes or changes a single instance of a recurring event o "Organizer" makes changes that affect all future instances o "Organizer" makes changes that affect all previous instances o "Organizer" deletes or modifies a previously changed instance "Attendee" initiated actions: o "Attendee" changes status for a particular recurrence instance o "Attendee" sends event-Counter for a particular recurrence instance An instance of a recurring event is assigned a unique identification, "RECURRENCE-ID" property, when that instance is renegotiated. Negotiation may be necessary when a substantive change to the event or to-do has been made (such as changing the start time, end time, due date or location). The "Organizer" can identify a specific recurrence instance using the "RECURRENCE-ID" property. The property Daboo Expires April 7, 2010 [Page 74]
Internet-Draft iTIP October 2009 value is equal to the date/time of the instance. If the "Organizer" wishes to change the "DTSTART", the original unmodified "DTSTART" value of the instance is used as the value "RECURRENCE-ID" property and the new "DTSTART" and "DTEND" values reflect the change. 3.7.2. Attendee Property Considerations The "ORGANIZER" property is required on published events, to-dos, and journal entries for two reasons. First, only the "Organizer" is allowed to update and redistribute an event or to-do component. It follows that the "ORGANIZER" property MUST be present in the event, to-do, or journal entry component so that the CUA has a basis for authorizing an update. Second, it is prudent to provide a point of contact for anyone who receives a published component in case of problems. Email addresses that correspond to groups of calendar users could be specified as a mailto: URI [RFC2368] calendar user address. Sending email to such an address results in email being sent to multiple recipients. Such an address may be used as the value of an "ATTENDEE" property. Thus, it is possible that the recipient of a "REQUEST" does not appear explicitly in the list. It is recommended that the general approach to finding a "Calendar User" in an attendee list be as follows: 1. Search for the "Calendar User" in the attendee list where "CUTYPE=INDIVIDUAL" 2. Failing (1) look for attendees where "CUTYPE=GROUP" or 'CUTYPE=UNKNOWN". The CUA then determines if the "Calendar User" is a member of one of these groups. If so, the "REPLY" method sent to the "Organizer" MUST contain a new "ATTENDEE" property in which: 3. * the "TYPE" property parameter is set to INDIVIDUAL * the "MEMBER" property parameter is set to the name of the group 4. Failing (2) the CUA MAY ignore or accept the request as the "Calendar User" wishes. 3.7.3. Extension Tokens To make iCalendar objects extensible, new component, property or property parameters can be used. Two types of extension exist: IANA registered tokens and X- vendor-specific tokens. A client SHOULD save IANA tokens and MAY use them in replies. A client MAY save X- Tokens and MAY use them in replies. When delegating or forwarding messages to other CUs, a client SHOULD include IANA and X- tokens. Daboo Expires April 7, 2010 [Page 75]
Internet-Draft iTIP October 2009 4. Examples 4.1. Published Event Examples In the calendaring and scheduling context, publication refers to the one way transfer of event information. Consumers of published events simply incorporate the event into a calendar. No reply is expected. Individual "A" publishes an event. Individual "B" reads the event and incorporates it into their calendar. Events are published in several ways including: embedding the event as an object in a web page, e-mailing the event to a distribution list, or posting the event to a newsgroup. The table below illustrates the sequence of events between the publisher and the consumers of a published event. +-----------------+-----------------------+-------------------------+ | Action | Organizer | Receiver | +-----------------+-----------------------+-------------------------+ | Publish an | "A" sends or posts a | "B" reads a published | | event | PUBLISH message | event | | | | | | Publish an | "A" sends or posts a | "B" reads the updated | | updated event | PUBLISH message | event | | | | | | Cancel a | "A" sends or posts a | "B" reads the canceled | | published event | CANCEL message | event publication | +-----------------+-----------------------+-------------------------+ 4.1.1. A Minimal Published Event The iCalendar object below describes a single event that begins on July 1, 1997 at 20:00 UTC. This event contains the minimum set of properties for a "PUBLISH" for a "VEVENT" calendar component. BEGIN:VCALENDAR METHOD:PUBLISH PRODID:-//Example/ExampleCalendarClient//EN VERSION:2.0 BEGIN:VEVENT ORGANIZER:mailto:a@example.com DTSTART:19970701T200000Z DTSTAMP:19970611T190000Z SUMMARY:ST. PAUL SAINTS -VS- DULUTH-SUPERIOR DUKES UID:0981234-1234234-23@example.com END:VEVENT END:VCALENDAR Daboo Expires April 7, 2010 [Page 76]
Internet-Draft iTIP October 2009 4.1.2. Changing A Published Event The iCalendar object below describes an update to the event described in 4.1.1, the time has been changed, an end time has been added, and the sequence number has been adjusted. BEGIN:VCALENDAR METHOD:PUBLISH VERSION:2.0 PRODID:-//Example/ExampleCalendarClient//EN BEGIN:VEVENT ORGANIZER:mailto:a@example.com DTSTAMP:19970612T190000Z DTSTART:19970701T210000Z DTEND:19970701T230000Z SEQUENCE:1 UID:0981234-1234234-23@example.com SUMMARY:ST. PAUL SAINTS -VS- DULUTH-SUPERIOR DUKES END:VEVENT END:VCALENDAR The "UID" property is used by the client to identify the event. The "SEQUENCE" property indicates that this is a change to the event. The event with a matching UID and sequence number 0 is superseded by this event. The "SEQUENCE" property provides a reliable way to distinguish different versions of the same event. Each time an event is published, its sequence number is incremented. If a client receives an event with a sequence number 5 and finds it has the same event with sequence number 2, the event SHOULD be updated. However, if the client received an event with sequence number 2 and finds it already has sequence number 5 of the same event, the event MUST NOT be updated. 4.1.3. Canceling A Published Event The iCalendar object below cancels the event described in 4.1.1. This cancels the event with "SEQUENCE" property of 0, 1, and 2. Daboo Expires April 7, 2010 [Page 77]
Internet-Draft iTIP October 2009 BEGIN:VCALENDAR METHOD:CANCEL VERSION:2.0 PRODID:-//Example/ExampleCalendarClient//EN BEGIN:VEVENT ORGANIZER:mailto:a@example.com COMMENT:DUKES forfeit the game SEQUENCE:2 UID:0981234-1234234-23@example.com DTSTAMP:19970613T190000Z END:VEVENT END:VCALENDAR 4.1.4. A Rich Published Event This example describes the same event as in 4.1.1, but in much greater detail. BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:PUBLISH SCALE:GREGORIAN VERSION:2.0 BEGIN:VTIMEZONE TZID:America-Chicago TZURL:http://example.com/tz/America-Chicago BEGIN:STANDARD DTSTART:19671029T020000 RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10 TZOFFSETFROM:-0500 TZOFFSETTO:-0600 TZNAME:CST END:STANDARD BEGIN:DAYLIGHT DTSTART:19870405T020000 RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4 TZOFFSETFROM:-0600 TZOFFSETTO:-0500 TZNAME:CDT END:DAYLIGHT END:VTIMEZONE BEGIN:VEVENT ORGANIZER:mailto:a@example.com ATTACH:http://www.example.com/ CATEGORIES:SPORTS EVENT,ENTERTAINMENT CLASS:PRIVATE Daboo Expires April 7, 2010 [Page 78]
Internet-Draft iTIP October 2009 DESCRIPTION:MIDWAY STADIUM\n Big time game. MUST see.\n Expected duration:2 hours\n DTEND;TZID=America-Chicago:19970701T180000 DTSTART;TZID=America-Chicago:19970702T160000 DTSTAMP:19970614T190000Z STATUS:CONFIRMED LOCATION;VALUE=URI:http://stadium.example.com/ PRIORITY:2 RESOURCES:SCOREBOARD SEQUENCE:3 SUMMARY:ST. PAUL SAINTS -VS- DULUTH-SUPERIOR DUKES UID:0981234-1234234-23@example.com RELATED-TO:0981234-1234234-14@example.com BEGIN:VALARM TRIGGER:-PT2H ACTION:DISPLAY DESCRIPTION:You should be leaving for the game now. END:VALARM BEGIN:VALARM TRIGGER:-PT30M ACTION:AUDIO END:VALARM END:VEVENT END:VCALENDAR The "RELATED-TO" field contains the "UID" property of a related calendar event. The "SEQUENCE" property 3 indicates that this event supersedes versions 0, 1, and 2. 4.1.5. Anniversaries or Events attached to entire days This example demonstrates the use of the "VALUE" parameter to tie a "VEVENT" to day rather than a specific time. BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:PUBLISH VERSION:2.0 BEGIN:VEVENT ORGANIZER:mailto:a@example.com DTSTAMP:19970614T190000Z UID:0981234-1234234-23@example.com DTSTART;VALUE=DATE:19970714 RRULE:FREQ=YEARLY;INTERVAL=1 SUMMARY: Bastille Day Daboo Expires April 7, 2010 [Page 79]
Internet-Draft iTIP October 2009 END:VEVENT END:VCALENDAR 4.2. Group Event Examples Group events are distinguished from published events in that they have "Attendees" and that there is interaction between the "Attendees" and the "Organizer" with respect to the event. Individual "A" requests a meeting between individuals "A", "B", "C" and "D". Individual "B" confirms attendance to the meeting. Individual "C" declines attendance. Individual "D" tentatively confirms attendance. The following table illustrates the the message flow between these individuals. A, the CU scheduling the meeting, is referenced as the "Organizer". +--------------+-----------------------+----------------------------+ | Action | "Organizer" | Attendee | +--------------+-----------------------+----------------------------+ | Initiate a | "A" sends a REQUEST | | | meeting | message to "B", "C", | | | request | and "D" | | | | | | | Accept the | | "B" sends a REPLY message | | meeting | | to "A" with its ATTENDEE | | request | | "PARTSTAT" parameter set | | | | to "ACCEPTED" | | | | | | Decline the | | "C" sends a REPLY message | | meeting | | to "A" with its ATTENDEE | | request | | "PARTSTAT" parameter set | | | | to "DECLINED" | | | | | | Tentatively | | "D" sends a REPLY message | | accept the | | to "A" with its ATTENDEE | | meeting | | "PARTSTAT" parameter set | | request | | to "TENTATIVE" | | | | | | Confirm | "A" sends a REQUEST | | | meeting | message to "B" and | | | status with | "D" with updated | | | attendees | information. | | +--------------+-----------------------+----------------------------+ Daboo Expires April 7, 2010 [Page 80]
Internet-Draft iTIP October 2009 4.2.1. A Group Event Request A sample meeting request is sent from "A" to "B", "C", and "D". "E" is also sent a copy of the request but is not expected to attend and need not reply. "E" illustrates how CUAs might implement an "FYI" type feature. Note the use of the "ROLE" parameter. The default value for the "ROLE" parameter is "REQ-PARTICIPANT" and it need not be enumerated. In this case we are using the value "NON-PARTICIPANT" to indicate "E" is a non-attending CU. The parameter is not needed on other "Attendees" since "PARTICIPANT" is the default value. BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REQUEST VERSION:2.0 BEGIN:VEVENT ORGANIZER:mailto:a@example.com ATTENDEE;ROLE=CHAIR;PARTSTAT=ACCEPTED;CN=A:mailto:a@example.com ATTENDEE;RSVP=TRUE;CUTYPE=INDIVIDUAL;CN=B:mailto:b@example.com ATTENDEE;RSVP=TRUE;CUTYPE=INDIVIDUAL;CN=C:mailto:c@example.com ATTENDEE;RSVP=TRUE;CUTYPE=INDIVIDUAL;CN=Hal:mailto:d@example.com ATTENDEE;RSVP=FALSE;CUTYPE=ROOM:conf_big@example.com ATTENDEE;ROLE=NON-PARTICIPANT;RSVP=FALSE:mailto:e@example.com DTSTAMP:19970611T190000Z DTSTART:19970701T200000Z DTEND:19970701T2100000Z SUMMARY:Conference UID:calsrv.example.com-873970198738777@example.com SEQUENCE:0 STATUS:CONFIRMED END:VEVENT END:VCALENDAR 4.2.2. Reply To A Group Event Request Attendee "B" accepts the meeting. Daboo Expires April 7, 2010 [Page 81]
Internet-Draft iTIP October 2009 BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REPLY VERSION:2.0 BEGIN:VEVENT ATTENDEE;PARTSTAT=ACCEPTED:mailto:b@example.com ORGANIZER:mailto:a@example.com UID:calsrv.example.com-873970198738777@example.com SEQUENCE:0 REQUEST-STATUS:2.0;Success DTSTAMP:19970612T190000Z END:VEVENT END:VCALENDAR "B" could have declined the meeting or indicated tentative acceptance by setting the "ATTENDEE" "PARTSTAT" parameter to "DECLINED" or "TENTATIVE", respectively. Also, "REQUEST-STATUS" is not required in successful transactions. 4.2.3. Update An Event The event is moved to a different time. The combination of the "UID" property (unchanged) and the "SEQUENCE" (bumped to 1) properties indicate the update. BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REQUEST VERSION:2.0 BEGIN:VEVENT ORGANIZER:mailto:a@example.com ATTENDEE;ROLE=CHAIR;PARTSTAT=ACCEPTED:mailto:a@example.com ATTENDEE;RSVP=TRUE;CUTYPE=INDIVIDUAL:mailto:b@example.com ATTENDEE;RSVP=TRUE;CUTYPE=INDIVIDUAL:mailto:c@example.com ATTENDEE;RSVP=TRUE;CUTYPE=INDIVIDUAL;CN=Hal:mailto:d@example.com ATTENDEE;ROLE=NON-PARTICIPANT;RSVP=FALSE; CUTYPE=ROOM:mailto:conf@example.com ATTENDEE;ROLE=NON-PARTICIPANT;RSVP=FALSE:mailto:e@example.com DTSTART:19970701T180000Z DTEND:19970701T190000Z SUMMARY:Phone Conference UID:calsrv.example.com-873970198738777@example.com SEQUENCE:1 DTSTAMP:19970613T190000Z STATUS:CONFIRMED END:VEVENT Daboo Expires April 7, 2010 [Page 82]
Internet-Draft iTIP October 2009 END:VCALENDAR 4.2.4. Countering an Event Proposal "A" sends a "REQUEST" to "B" and "C". "B" makes a counter-proposal to "A" to change the time and location. "A" sends the following "REQUEST": BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REQUEST VERSION:2.0 BEGIN:VEVENT ORGANIZER:mailto:a@example.com ATTENDEE;ROLE=CHAIR;PARTSTAT=ACCEPTED:mailto:a@example.com ATTENDEE;RSVP=TRUE;CUTYPE=INDIVIDUAL:mailto:b@example.com ATTENDEE;RSVP=TRUE;CUTYPE=INDIVIDUAL:mailto:c@example.com DTSTART:19970701T190000Z DTEND:19970701T200000Z SUMMARY:Discuss the Merits of the election results LOCATION:Green Conference Room UID:calsrv.example.com-873970198738777a@example.com SEQUENCE:0 DTSTAMP:19970611T190000Z STATUS:CONFIRMED END:VEVENT END:VCALENDAR "B" sends "COUNTER" to "A", requesting changes to time and place. "B" uses the "COMMENT" property to communicate a rationale for the change. Note that the "SEQUENCE" property is NOT incremented on a "COUNTER". Daboo Expires April 7, 2010 [Page 83]
Internet-Draft iTIP October 2009 BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:COUNTER VERSION:2.0 BEGIN:VEVENT ORGANIZER:mailto:a@example.com ATTENDEE;ROLE=CHAIR;PARTSTAT=ACCEPTED:mailto:a@example.com ATTENDEE;RSVP=TRUE;CUTYPE=INDIVIDUAL:mailto:b@example.com ATTENDEE;RSVP=TRUE;CUTYPE=INDIVIDUAL:mailto:c@example.com DTSTART:19970701T160000Z DTEND:19970701T170000Z DTSTAMP:19970612T190000Z SUMMARY:Discuss the Merits of the election results LOCATION:Blue Conference Room COMMENT:This time works much better and I think the big conference room is too big UID:calsrv.example.com-873970198738777a@example.com SEQUENCE:0 END:VEVENT END:VCALENDAR "A" accepts the changes from "B". To accept a counter-proposal, the "Organizer" sends a new event "REQUEST" with an incremented sequence number. BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REQUEST VERSION:2.0 BEGIN:VEVENT ORGANIZER:mailto:a@example.com ATTENDEE;ROLE=CHAIR;PARTSTAT=ACCEPTED:mailto:a@example.com ATTENDEE;RSVP=TRUE;CUTYPE=INDIVIDUAL:mailto:b@example.com ATTENDEE;RSVP=TRUE;CUTYPE=INDIVIDUAL:mailto:c@example.com DTSTAMP:19970613T190000Z DTSTART:19970701T160000Z DTEND:19970701T170000Z SUMMARY:Discuss the Merits of the election results - changed to meet B's schedule LOCATION:Blue Conference Room UID:calsrv.example.com-873970198738777@example.com SEQUENCE:1 STATUS:CONFIRMED END:VEVENT END:VCALENDAR Daboo Expires April 7, 2010 [Page 84]
Internet-Draft iTIP October 2009 Instead, "A" rejects "B's" counter proposal BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:DECLINECOUNTER VERSION:2.0 BEGIN:VEVENT ORGANIZER:mailto:a@example.com ATTENDEE;RSVP=TRUE;CUTYPE=INDIVIDUAL:mailto:b@example.com COMMENT:Sorry, I cannot change this meeting time UID:calsrv.example.com-873970198738777@example.com SEQUENCE:0 DTSTAMP:19970614T190000Z END:VEVENT END:VCALENDAR 4.2.5. Delegating an Event When delegating an event request to another "Calendar User", the "Delegator" must both update the "Organizer" with a "REPLY" and send a request to the "Delegate". There is currently no protocol limitation to delegation depth. It is possible for the original delegate to delegate the meeting to someone else, and so on. When a request is delegated from one CUA to another there are a number of responsibilities required of the "Delegator". The "Delegator" MUST: o Send a "REPLY" to the "Organizer" with the following updates: A. The "Delegator's" "ATTENDEE" property "PARTSTAT" parameter set to "DELEGATED" and the "DELEGATED-TO" parameter is set to the address of the "Delegate" B. Add an additional "ATTENDEE" property for the "Delegate" with the "DELEGATED-FROM" property parameter set to the "Delegator" C. Indicate whether they want to continue to receive updates when the "Organizer" sends out updated versions of the event. Setting the "RSVP" property parameter to "TRUE" will cause the updates to be sent, setting it to "FALSE" causes no further updates to be sent. Note that in either case, if the "Delegate" declines the invitation the "Delegator" will be notified. o The "Delegator" MUST also send a copy of the original "REQUEST" method to the "Delegate", with changes (A) and (B) as detailed above applied. If the "Delegate" declines the meeting, the "Organizer" MUST send an update "REQUEST" to the "Delegator" so that the "Delegator" may elect to delegate the "REQUEST" to another CUA. Daboo Expires April 7, 2010 [Page 85]
Internet-Draft iTIP October 2009 +-----------------+----------------+--------------------------------+ | Action | "Organizer" | Attendee | +-----------------+----------------+--------------------------------+ | Initiate a | "A" sends a | | | meeting request | REQUEST | | | | message to "B" | | | | and "C" | | | | | | | Delegate: "C" | | "C" sends a REPLY to "A" with | | delegates to | | the ATTENDEE "PARTSTAT" | | "E" | | parameter set to "DELEGATED" | | | | and with a new "ATTENDEE" | | | | property for "E". "E's" | | | | ATTENDEE "DELEGATED-FROM" | | | | parameter is set to "C". | | | | "C's" ATTENDEE "DELEGATED-TO" | | | | parameter is set to "E". "C" | | | | sends REQUEST message to "E" | | | | with the original meeting | | | | request information. The | | | | "PARTSTAT" property parameter | | | | for "C" is set to "DELEGATED" | | | | and the "DELEGATED-TO" | | | | parameter is set to the | | | | address of "E". An "ATTENDEE" | | | | property is added for "E" and | | | | the "DELEGATED-FROM" parameter | | | | is set to the address of "C". | | | | | | Confirm meeting | | "E" sends REPLY message to "A" | | attendance | | and optionally "C" with its | | | | "PARTSTAT" property parameter | | | | set to "ACCEPTED" | | | | | | Optional: | "A" sends | | | Redistribute | REQUEST | | | meeting to | message to | | | attendees | "B", "C" and | | | | "E". | | +-----------------+----------------+--------------------------------+ "C" responds to the "Organizer". Daboo Expires April 7, 2010 [Page 86]
Internet-Draft iTIP October 2009 BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REPLY VERSION:2.0 BEGIN:VEVENT ORGANIZER:mailto:a@example.com ATTENDEE;PARTSTAT=DELEGATED;DELEGATED- TO="mailto:e@example.com":mailto:c@example.com UID:calsrv.example.com-873970198738777@example.com SEQUENCE:0 REQUEST-STATUS:2.0;Success DTSTAMP:19970611T190000Z END:VEVENT END:VCALENDAR Attendee "C" delegates presence at the meeting to "E". BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REQUEST VERSION:2.0 BEGIN:VEVENT ORGANIZER:mailto:a@example.com ATTENDEE;PARTSTAT=DELEGATED;DELEGATED- TO="mailto:e@example.com":mailto:c@example.com ATTENDEE;RSVP=TRUE; DELEGATED-FROM="mailto:c@example.com":mailto:e@example.com DTSTART:19970701T180000Z DTEND:19970701T200000Z SUMMARY:Phone Conference UID:calsrv.example.com-873970198738777@example.com SEQUENCE:0 STATUS:CONFIRMED DTSTAMP:19970611T190000Z END:VEVENT END:VCALENDAR 4.2.6. Delegate Accepts the Meeting To accept a delegated meeting, the delegate, "E", sends the following message to "A" and "C": Daboo Expires April 7, 2010 [Page 87]
Internet-Draft iTIP October 2009 BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REPLY VERSION:2.0 BEGIN:VEVENT ORGANIZER:mailto:a@example.com ATTENDEE;PARTSTAT=ACCEPTED;DELEGATED- FROM="mailto:c@example.com":mailto:e@example.com ATTENDEE;PARTSTAT=DELEGATED; DELEGATED-TO="mailto:e@example.com":mailto:c@example.com UID:calsrv.example.com-873970198738777@example.com SEQUENCE:0 REQUEST-STATUS:2.0;Success DTSTAMP:19970614T190000Z END:VEVENT END:VCALENDAR 4.2.7. Delegate Declines the Meeting In this example the "Delegate" declines the meeting request and sets the "ATTENDEE" property "PARTSTAT" parameter to "DECLINED". The "Organizer" SHOULD resend the "REQUEST" to "C" with the "PARTSTAT" parameter of the "Delegate" set to "DECLINED". This lets the "Delegator" know that the "Delegate" has declined and provides an opportunity to the "Delegator" to either accept the request or delegate it to another CU. Response from "E" to "A" and "C". Note the use of the "COMMENT" property "E" uses to indicate why the delegation was declined. BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REPLY VERSION:2.0 BEGIN:VEVENT ORGANIZER:mailto:a@example.com ATTENDEE;PARTSTAT=DELEGATED; DELEGATED-TO="mailto:e@example.com":mailto:c@example.com ATTENDEE;PARTSTAT=DECLINED; DELEGATED-FROM="mailto:c@example.com":mailto:e@example.com COMMENT:Sorry, I will be out of town at that time. UID:calsrv.example.com-873970198738777@example.com SEQUENCE:0 REQUEST-STATUS:2.0;Success DTSTAMP:19970614T190000Z END:VEVENT Daboo Expires April 7, 2010 [Page 88]
Internet-Draft iTIP October 2009 END:VCALENDAR "A" resends the "REQUEST" method to "C". "A" may also wish to express the fact that the item was delegated in the "COMMENT" property. BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REQUEST VERSION:2.0 BEGIN:VEVENT ORGANIZER:mailto:a@example.com ATTENDEE;PARTSTAT=DECLINED; DELEGATED-FROM="mailto:c@example.com":mailto:e@example.com ATTENDEE;RSVP=TRUE:mailto:c@example.com UID:calsrv.example.com-873970198738777@example.com SEQUENCE:0 SUMMARY:Phone Conference DTSTART:19970701T180000Z DTEND:19970701T200000Z DTSTAMP:19970614T200000Z COMMENT:DELEGATE (ATTENDEE mailto:e@example.com) DECLINED YOUR INVITATION END:VEVENT END:VCALENDAR 4.2.8. Forwarding an Event Request The protocol does not prevent an "Attendee" from "forwarding" an "VEVENT" calendar component to other "Calendar Users". Forwarding differs from delegation in that the forwarded "Calendar User" (often referred to as a "Party Crasher") does not replace the forwarding "Calendar User". Implementations are not required to add the "Party Crasher" to the "Attendee" list and hence there is no guarantee that a "Party Crasher" will receive additional updates to the event. The forwarding "Calendar User" SHOULD NOT add the "Party Crasher" to the attendee list. The "Organizer" MAY add the forwarded "Calendar User" to the attendee list. 4.2.9. Cancel A Group Event Individual "A" requests a meeting between individuals "A", "B", "C", and "D". Individual "B" declines attendance to the meeting. Individual "A" decides to cancel the meeting. The following table illustrates the sequence of messages that would be exchanged between Daboo Expires April 7, 2010 [Page 89]
Internet-Draft iTIP October 2009 these individuals. Messages related to a previously canceled event ("SEQUENCE" property value is less than the "SEQUENCE" property value of the "CANCEL" message) MUST be ignored. +-------------+--------------------+--------------------------------+ | Action | "Organizer" | "Attendee" | +-------------+--------------------+--------------------------------+ | Initiate a | "A" sends a | | | meeting | REQUEST message to | | | request | "B", "C", and "D" | | | | | | | Decline the | | "B" sends a "REPLY" message to | | meeting | | "A" with its "PARTSTAT" | | request | | parameter set to "DECLINED". | | | | | | Cancel the | "A" sends a CANCEL | | | meeting | message to "B", | | | | "C" and "D" | | +-------------+--------------------+--------------------------------+ The example shows how "A" cancels the event. BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:CANCEL VERSION:2.0 BEGIN:VEVENT ORGANIZER:mailto:a@example.com ATTENDEE;CUTYPE=INDIVIDUAL;mailto:a@example.com ATTENDEE;CUTYPE=INDIVIDUAL:mailto:b@example.com ATTENDEE;CUTYPE=INDIVIDUAL:mailto:c@example.com ATTENDEE;CUTYPE=INDIVIDUAL:mailto:d@example.com COMMENT:Mr. B cannot attend. It's raining. Lets cancel. UID:calsrv.example.com-873970198738777@example.com SEQUENCE:1 STATUS:CANCELLED DTSTAMP:19970613T190000Z END:VEVENT END:VCALENDAR Daboo Expires April 7, 2010 [Page 90]
Internet-Draft iTIP October 2009 4.2.10. Removing Attendees "A" wants to remove "B" from a meeting. This is done by sending a "CANCEL" to "B" and removing "B" from the attendee list in the master copy of the event. +-------------------+----------------------------------+------------+ | Action | "Organizer" | "Attendee" | +-------------------+----------------------------------+------------+ | Remove "B" as an | "A" sends a CANCEL message to | | | "Attendee" | "B" | | | | | | | Update the master | "A" optionally sends the updated | | | copy of the event | event to the remaining | | | | "Attendees" | | +-------------------+----------------------------------+------------+ The original meeting includes "A", "B", "C", and "D". The example below shows the "CANCEL" that "A" sends to "B". Note that in the example below the "STATUS" property is omitted. This is used when the meeting itself is cancelled and not when the intent is to remove an "Attendee" from the event. BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:CANCEL VERSION:2.0 BEGIN:VEVENT ORGANIZER:mailto:a@example.com ATTENDEE:mailto:b@example.com COMMENT:You're off the hook for this meeting UID:calsrv.example.com-873970198738777@example.com DTSTAMP:19970613T193000Z SEQUENCE:1 END:VEVENT END:VCALENDAR The updated master copy of the event is shown below. The "Organizer" MAY resend the updated event to the remaining "Attendees". Note that "B" has been removed. Daboo Expires April 7, 2010 [Page 91]
Internet-Draft iTIP October 2009 BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REQUEST VERSION:2.0 BEGIN:VEVENT ORGANIZER:mailto:a@example.com ATTENDEE;ROLE=CHAIR;PARTSTAT=ACCEPTED:mailto:a@example.com ATTENDEE;CUTYPE=INDIVIDUAL:mailto:c@example.com ATTENDEE;CUTYPE=INDIVIDUAL:mailto:d@example.com ATTENDEE;CUTYPE=ROOM:mailto:cr_big@example.com ATTENDEE;ROLE=NON-PARTICIPANT; RSVP=FALSE:mailto:e@example.com DTSTAMP:19970611T190000Z DTSTART:19970701T200000Z DTEND:19970701T203000Z SUMMARY:Phone Conference UID:calsrv.example.com-873970198738777@example.com SEQUENCE:2 STATUS:CONFIRMED END:VEVENT END:VCALENDAR 4.2.11. Replacing the Organizer The scenario for this example begins with "A" as the "Organizer" for a recurring meeting with "B", "C", and "D". "A" receives a new job offer in another country and drops out of touch. "A" left no forwarding address or way to be reached. Using out-of-band communication, the other "Attendees" eventually learn what has happened and reach an agreement that "B" should become the new "Organizer" for the meeting. To do this, "B" sends out a new version of the event and the other "Attendees" agree to accept "B" as the new "Organizer". "B" also removes "A" from the event. When the "Organizer" is replaced, the "SEQUENCE" property value MUST be incremented. This is the message "B" sends to "C" and "D" Daboo Expires April 7, 2010 [Page 92]
Internet-Draft iTIP October 2009 BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REQUEST VERSION:2.0 BEGIN:VEVENT ORGANIZER:mailto:b@example.com ATTENDEE;ROLE=CHAIR;STATUS=ACCEPTED:mailto:b@example.com ATTENDEE;CUTYPE=INDIVIDUAL:mailto:c@example.com ATTENDEE;CUTYPE=INDIVIDUAL:mailto:d@example.com DTSTAMP:19970611T190000Z DTSTART:19970701T200000Z DTEND:19970701T203000Z RRULE:FREQ=WEEKLY SUMMARY:Phone Conference UID:123456@example.com SEQUENCE:1 STATUS:CONFIRMED END:VEVENT END:VCALENDAR 4.3. Busy Time Examples Busy time objects can be used in several ways. First, a CU may request busy time from another CU for a specific range of time. That request can be answered with a busy time Reply. Additionally, a CU may simply publish their busy time for a given interval and point other CUs to the published location. The following examples outline both scenarios. 4.3.1. Publish Busy Time Individual "A" publishes busy time for one week. Daboo Expires April 7, 2010 [Page 93]
Internet-Draft iTIP October 2009 BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN VERSION:2.0 METHOD:PUBLISH BEGIN:VFREEBUSY DTSTAMP:19980101T124100Z ORGANIZER:mailto:a@example.com DTSTART:19980101T124200Z DTEND:19980108T124200Z FREEBUSY:19980101T180000Z/19980101T190000Z FREEBUSY:19980103T020000Z/19980103T050000Z FREEBUSY:19980107T020000Z/19980107T050000Z FREEBUSY:19980113T000000Z/19980113T010000Z FREEBUSY:19980115T190000Z/19980115T200000Z FREEBUSY:19980115T220000Z/19980115T230000Z FREEBUSY:19980116T013000Z/19980116T043000Z END:VFREEBUSY END:VCALENDAR 4.3.2. Request Busy Time Individual "A" requests busy time from individuals "B", "C". Individual "B" and "C" replies with busy time data to individual "A". The following table illustrates the sequence of messages that would be exchanged between these individuals. +----------------------+--------------------+-----------------------+ | Action | "Organizer" | Attendee | +----------------------+--------------------+-----------------------+ | Initiate a busy time | "A" sends | | | request | "REQUEST" message | | | | to "B" and "C" | | | | | | | Reply to the "BUSY" | | "B" sends a "REPLY" | | request with "BUSY" | | message to "A" with | | time data | | busy time data | +----------------------+--------------------+-----------------------+ "A" sends a "BUSY-REQUEST" to "B" and "C" for busy time Daboo Expires April 7, 2010 [Page 94]
Internet-Draft iTIP October 2009 BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REQUEST VERSION:2.0 BEGIN:VFREEBUSY ORGANIZER:mailto:a@example.com ATTENDEE;ROLE=CHAIR:mailto:a@example.com ATTENDEE:mailto:b@example.com ATTENDEE:mailto:c@example.com DTSTAMP:19970613T190000Z DTSTART:19970701T080000Z DTEND:19970701T200000 UID:calsrv.example.com-873970198738777@example.com END:VFREEBUSY END:VCALENDAR 4.3.3. Reply To A Busy Time Request "B" sends a "REPLY" method type of a "VFREEBUSY" calendar component to "A" BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REPLY VERSION:2.0 BEGIN:VFREEBUSY ORGANIZER:mailto:a@example.com ATTENDEE:mailto:b@example.com DTSTART:19970701T080000Z DTEND:19970701T200000Z UID:calsrv.example.com-873970198738777@example.com FREEBUSY:19970701T090000Z/PT1H,19970701T140000Z/PT30M DTSTAMP:19970613T190030Z END:VFREEBUSY END:VCALENDAR "B" is busy from 09:00 to 10:00 and from 14:00 to 14:30. 4.4. Recurring Event and Time Zone Examples 4.4.1. A Recurring Event Spanning Time Zones This event describes a weekly phone conference. The "Attendees" are each in a different time zone. Daboo Expires April 7, 2010 [Page 95]
Internet-Draft iTIP October 2009 BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REQUEST VERSION:2.0 BEGIN:VTIMEZONE TZID:America-SanJose TZURL:http://example.com/tz/America-SanJose BEGIN:STANDARD DTSTART:19671029T020000 RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10 TZOFFSETFROM:-0700 TZOFFSETTO:-0800 TZNAME:PST END:STANDARD BEGIN:DAYLIGHT DTSTART:19870405T020000 RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4 TZOFFSETFROM:-0800 TZOFFSETTO:-0700 TZNAME:PDT END:DAYLIGHT END:VTIMEZONE BEGIN:VEVENT ORGANIZER:mailto:a@example.com ATTENDEE;ROLE=CHAIR;PARTSTAT=ACCEPTED; CUTYPE=INDIVIDUAL:a@example.com ATTENDEE;RSVP=TRUE;CUTYPE=INDIVIDUAL:b@example.fr ATTENDEE;RSVP=TRUE;CUTYPE=INDIVIDUAL:c@example.jp DTSTAMP:19970613T190030Z DTSTART;TZID=America-SanJose:19970701T140000 DTEND;TZID=America-SanJose:19970701T150000 RRULE:FREQ=WEEKLY;COUNT=20;WKST=SU;BYDAY=TU RDATE;TZID=America-SanJose:19970910T140000 EXDATE;TZID=America-SanJose:19970909T140000 EXDATE;TZID=America-SanJose:19971028T140000 SUMMARY:Weekly Phone Conference UID:calsrv.example.com-873970198738777@example.com SEQUENCE:0 STATUS:CONFIRMED END:VEVENT END:VCALENDAR The first component of this iCalendar object is the time zone component. The "DTSTART" date coincides with the first instance of the RRULE property. The recurring meeting is defined in a particular time zone, Daboo Expires April 7, 2010 [Page 96]
Internet-Draft iTIP October 2009 presumably that of the originator. The client for each "Attendee" has the responsibility of determining the recurrence time in the "Attendee's" time zone. The repeating event starts on Tuesday, July 1, 1997 at 2:00pm PDT (UTC-7). "Attendee" B@example.fr is in France where the local time on this date is 9 hours ahead of PDT or 23:00 CEST (UTC+2). "Attendee" C@example.jp is in Japan where local time is 16 hours ahead of PDT or Wednesday, July 2 at 06:00 JST (UTC+9). The event repeats weekly on Tuesdays (in PST/PDT). The "RRULE" property results in 20 instances. The last instance falls on Tuesday, November 11, 1997 2:00pm PST. The "RDATE" property adds another instance: WED, 10-SEP-1997 2:00 PM PDT. There are also two exception dates to the recurrence rule. The first one is: o TUE, 09-SEP-1997 14:00 PDT (UTC-7) o TUE, 09-SEP-1997 23:00 CEST (UTC+2) o WED, 10-SEP-1997 06:00 JST (UTC+9) and the second is: o TUE, 28-OCT-1997 14:00 PST (UTC-8) o TUE, 28-OCT-1997 23:00 CET (UTC+1) o WED, 29-OCT-1997 07:00 JST (UTC+9) 4.4.2. Modify A Recurring Instance In this example the "Organizer" issues a recurring meeting. Later the "Organizer" changes an instance of the event by changing the "DTSTART" property. Note the use of "RECURRENCE-ID" property and "SEQUENCE" property in the second request. Original Request: Daboo Expires April 7, 2010 [Page 97]
Internet-Draft iTIP October 2009 BEGIN:VCALENDAR METHOD:REQUEST PRODID:-//Example/ExampleCalendarClient//EN VERSION:2.0 BEGIN:VEVENT UID:guid-1@example.com SEQUENCE:0 RRULE:FREQ=MONTHLY;BYMONTHDAY=1;UNTIL=19980901T210000Z ORGANIZER:mailto:a@example.com ATTENDEE;ROLE=CHAIR;PARTSTAT=ACCEPTED:mailto:a@example.com ATTENDEE:mailto:b@example.com ATTENDEE:mailto:c@example.com ATTENDEE:mailto:d@example.com DESCRIPTION:IETF-C&S Conference Call CLASS:PUBLIC SUMMARY:IETF Calendaring Working Group Meeting DTSTART:19970601T210000Z DTEND:19970601T220000Z LOCATION:Conference Call DTSTAMP:19970526T083000Z STATUS:CONFIRMED END:VEVENT END:VCALENDAR The event request below is to change the time of a specific instance. This changes the July 1st instance to July 3rd. Daboo Expires April 7, 2010 [Page 98]
Internet-Draft iTIP October 2009 BEGIN:VCALENDAR METHOD:REQUEST PRODID:-//Example/ExampleCalendarClient//EN VERSION:2.0 BEGIN:VEVENT UID:guid-1@example.com RECURRENCE-ID:19970701T210000Z 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 ATTENDEE:mailto:d@example.com DESCRIPTION:IETF-C&S Conference Call CLASS:PUBLIC SUMMARY:IETF Calendaring Working Group Meeting DTSTART:19970703T210000Z DTEND:19970703T220000Z LOCATION:Conference Call DTSTAMP:19970626T093000Z STATUS:CONFIRMED END:VEVENT END:VCALENDAR 4.4.3. Cancel an Instance In this example the "Organizer" of a recurring event deletes the August 1st instance. BEGIN:VCALENDAR METHOD:CANCEL PRODID:-//Example/ExampleCalendarClient//EN VERSION:2.0 BEGIN:VEVENT UID:guid-1@example.com ORGANIZER:mailto:a@example.com ATTENDEE;ROLE=CHAIR;PARTSTAT=ACCEPTED:mailto:a@example.com ATTENDEE:mailto:b@example.com ATTENDEE:mailto:c@example.com ATTENDEE:mailto:d@example.com RECURRENCE-ID:19970801T210000Z SEQUENCE:2 STATUS:CANCELLED DTSTAMP:19970721T093000Z END:VEVENT END:VCALENDAR Daboo Expires April 7, 2010 [Page 99]
Internet-Draft iTIP October 2009 4.4.4. Cancel Recurring Event In this example the "Organizer" wishes to cancel the entire recurring event and any exceptions. BEGIN:VCALENDAR METHOD:CANCEL PRODID:-//Example/ExampleCalendarClient//EN VERSION:2.0 BEGIN:VEVENT UID:guid-1@example.com ORGANIZER:mailto:a@example.com ATTENDEE;ROLE=CHAIR;PARTSTAT=ACCEPTED:mailto:a@example.com ATTENDEE:mailto:b@example.com ATTENDEE:mailto:c@example.com ATTENDEE:mailto:d@example.com DTSTAMP:19970721T103000Z STATUS:CANCELLED SEQUENCE:3 END:VEVENT END:VCALENDAR 4.4.5. Change All Future Instances This example changes the meeting location from a conference call to Seattle starting September 1 and extends to all future instances. Daboo Expires April 7, 2010 [Page 100]
Internet-Draft iTIP October 2009 BEGIN:VCALENDAR METHOD:REQUEST PRODID:-//Example/ExampleCalendarClient//EN VERSION:2.0 BEGIN:VEVENT UID:guid-1@example.com RECURRENCE-ID;THISANDFUTURE:19970901T210000Z SEQUENCE:3 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 ATTENDEE;RSVP=TRUE:mailto:d@example.com DESCRIPTION:IETF-C&S Discussion CLASS:PUBLIC SUMMARY:IETF Calendaring Working Group Meeting DTSTART:19970901T210000Z DTEND:19970901T220000Z LOCATION:Building 32, Microsoft, Seattle, WA DTSTAMP:19970526T083000Z STATUS:CONFIRMED END:VEVENT END:VCALENDAR 4.4.6. Add A New Instance To A Recurring Event This example adds a one-time additional instance to the recurring event. "Organizer" adds a second July meeting on the 15th. Daboo Expires April 7, 2010 [Page 101]
Internet-Draft iTIP October 2009 BEGIN:VCALENDAR METHOD:ADD PRODID:-//Example/ExampleCalendarClient//EN VERSION:2.0 BEGIN:VEVENT UID:123456789@example.com SEQUENCE:4 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 ATTENDEE;RSVP=TRUE:mailto:d@example.com DESCRIPTION:IETF-C&S Conference Call CLASS:PUBLIC SUMMARY:IETF Calendaring Working Group Meeting DTSTART:19970715T210000Z DTEND:19970715T220000Z LOCATION:Conference Call DTSTAMP:19970629T093000Z STATUS:CONFIRMED END:VEVENT END:VCALENDAR 4.4.7. Add A New Series of Instances To A Recurring Event The scenario for this example involves an ongoing meeting, originally set up to occur every Tuesday. The "Organizer" later decides that the meetings need to be on Tuesdays and Thursdays. The original event: Daboo Expires April 7, 2010 [Page 102]
Internet-Draft iTIP October 2009 BEGIN:VCALENDAR METHOD:REQUEST PRODID:-//Example/ExampleCalendarClient//EN VERSION:2.0 BEGIN:VEVENT UID:123456789@example.com SEQUENCE:0 RRULE:WKST=SU;BYDAY=TU;FREQ=WEEKLY ORGANIZER:mailto:a@example.com ATTENDEE;ROLE=CHAIR;PARTSTAT=ACCEPTED:mailto:a@example.com ATTENDEE;RSVP=TRUE:mailto:b@example.com SUMMARY:Review Accounts DTSTART:19980303T210000Z DTEND:19980303T220000Z LOCATION:The White Room DTSTAMP:19980301T093000Z STATUS:CONFIRMED END:VEVENT END:VCALENDAR The entire event can be rescheduled using a "REQUEST". This is done by using the "UID" of the event to reschedule and including the modified "RRULE". Note, that since this is an entire rescheduling of the event, any instance-specific information will be lost, unless explicitly included with the update "REQUEST". BEGIN:VCALENDAR METHOD:REQUEST PRODID:-//Example/ExampleCalendarClient//EN VERSION:2.0 BEGIN:VEVENT UID:123456789@example.com SEQUENCE:7 RRULE:WKST=SU;BYDAY=TU,TH;FREQ=WEEKLY ORGANIZER:mailto:a@example.com ATTENDEE;ROLE=CHAIR;PARTSTAT=ACCEPTED:mailto:a@example.com ATTENDEE;RSVP=TRUE:mailto:b@example.com SUMMARY:Review Accounts DTSTART:19980303T210000Z DTEND:19980303T220000Z DTSTAMP:19980303T193000Z LOCATION:The White Room STATUS:CONFIRMED END:VEVENT END:VCALENDAR Daboo Expires April 7, 2010 [Page 103]
Internet-Draft iTIP October 2009 4.4.8. Refreshing A Recurring Event The next series of examples illustrate how an "Organizer" would respond to a "REFRESH" submitted by an "Attendee" after a series of instance-specific modifications. To convey all instance-specific changes, the "Organizer" must provide the latest event description and the relevant instances. The first three examples show the history including the initial "VEVENT" request and subsequent instance changes and finally the "REFRESH". Original Request: BEGIN:VCALENDAR METHOD:REQUEST PRODID:-//Example/ExampleCalendarClient//EN VERSION:2.0 BEGIN:VEVENT UID:123456789@example.com SEQUENCE:0 RDATE:19980304T180000Z RDATE:19980311T180000Z RDATE:19980318T180000Z ORGANIZER:mailto:a@example.com ATTENDEE;ROLE=CHAIR;PARTSTAT=ACCEPTED:mailto:a@example.com ATTENDEE;RSVP=TRUE:mailto:b@example.com SUMMARY:Review Accounts DTSTART:19980304T180000Z DTEND:19980304T200000Z DTSTAMP:19980303T193000Z LOCATION:Conference Room A STATUS:CONFIRMED END:VEVENT END:VCALENDAR Organizer changes 2nd instance Location and Time: Daboo Expires April 7, 2010 [Page 104]
Internet-Draft iTIP October 2009 BEGIN:VCALENDAR METHOD:REQUEST PRODID:-//Example/ExampleCalendarClient//EN VERSION:2.0 BEGIN:VEVENT UID:123456789@example.com SEQUENCE:1 RECURRENCE-ID:19980311T180000Z ORGANIZER:mailto:a@example.com ATTENDEE;ROLE=CHAIR;PARTSTAT=ACCEPTED:mailto:a@example.com ATTENDEE;RSVP=TRUE:mailto:b@example.com SUMMARY:Review Accounts DTSTART:19980311T160000Z DTEND:19980311T180000Z DTSTAMP:19980306T193000Z LOCATION:The Small conference room STATUS:CONFIRMED END:VEVENT END:VCALENDAR Organizer adds a 4th instance of the meeting using the "ADD" method BEGIN:VCALENDAR METHOD:ADD PRODID:-//Example/ExampleCalendarClient//EN VERSION:2.0 BEGIN:VEVENT UID:123456789@example.com SEQUENCE:2 ORGANIZER:mailto:a@example.com ATTENDEE;ROLE=CHAIR;PARTSTAT=ACCEPTED:mailto:a@example.com ATTENDEE;RSVP=TRUE:mailto:b@example.com SUMMARY:Review Accounts DTSTART:19980315T180000Z DTEND:19980315T200000Z DTSTAMP:19980307T193000Z LOCATION:Conference Room A STATUS:CONFIRMED END:VEVENT END:VCALENDAR If "B" requests a "REFRESH", "A" responds with the following to capture all instance-specific data. In this case both the initial request and an additional "VEVENT" that specifies the instance- specific data are included. Because these are both of the same type Daboo Expires April 7, 2010 [Page 105]
Internet-Draft iTIP October 2009 (they are both "VEVENTS"), they can be conveyed in the same iCalendar object. BEGIN:VCALENDAR METHOD:REQUEST PRODID:-//Example/ExampleCalendarClient//EN VERSION:2.0 BEGIN:VEVENT UID:123456789@example.com SEQUENCE:2 RDATE:19980304T180000Z RDATE:19980311T160000Z RDATE:19980315T180000Z ORGANIZER:mailto:a@example.com ATTENDEE;ROLE=CHAIR;PARTSTAT=ACCEPTED:mailto:a@example.com ATTENDEE;RSVP=TRUE:mailto:b@example.com SUMMARY:Review Accounts DTSTART:19980304T180000Z DTEND:19980304T200000Z DTSTAMP:19980303T193000Z LOCATION:Conference Room A STATUS:CONFIRMED END:VEVENT BEGIN:VEVENT SEQUENCE:2 RECURRENCE-ID:19980311T160000Z ATTENDEE;ROLE=CHAIR;PARTSTAT=ACCEPTED:mailto:a@example.com ATTENDEE;RSVP=TRUE:mailto:b@example.com SUMMARY:Review Accounts DTSTART:19980311T160000Z DTEND:19980304T180000Z DTSTAMP:19980306T193000Z LOCATION:The Small conference room STATUS:CONFIRMED END:VEVENT END:VCALENDAR 4.4.9. Counter An Instance Of A Recurring Event In this example one of the "Attendees" counters the "DTSTART" property of the proposed second July meeting. Daboo Expires April 7, 2010 [Page 106]
Internet-Draft iTIP October 2009 BEGIN:VCALENDAR METHOD:COUNTER PRODID:-//Example/ExampleCalendarClient//EN VERSION:2.0 BEGIN:VEVENT UID:guid-1@example.com RECURRENCE-ID:19970715T210000Z SEQUENCE:4 ORGANIZER:mailto:a@example.com ATTENDEE;ROLE=CHAIR;RSVP=TRUE:mailto:a@example.com ATTENDEE;RSVP=TRUE:mailto:b@example.com ATTENDEE;RSVP=TRUE:mailto:c@example.com ATTENDEE;RSVP=TRUE:mailto:d@example.com DESCRIPTION:IETF-C&S Conference Call CLASS:PUBLIC SUMMARY:IETF Calendaring Working Group Meeting DTSTART:19970715T220000Z DTEND:19970715T230000Z LOCATION:Conference Call COMMENT:May we bump this by an hour? I have a conflict DTSTAMP:19970629T094000Z END:VEVENT END:VCALENDAR 4.4.10. Error Reply To A Request The following example illustrates a scenario where a meeting is proposed containing an unsupported property and a bad property. Original Request Daboo Expires April 7, 2010 [Page 107]
Internet-Draft iTIP October 2009 BEGIN:VCALENDAR METHOD:REQUEST PRODID:-//Example/ExampleCalendarClient//EN VERSION:2.0 BEGIN:VEVENT UID:guid-1@example.com SEQUENCE:0 RRULE:FREQ=MONTHLY;BYMONTHDAY=1 ORGANIZER:mailto:a@example.com ATTENDEE;ROLE=CHAIR:mailto:a@example.com ATTENDEE;RSVP=TRUE:mailto:b@example.com ATTENDEE;RSVP=TRUE:mailto:c@example.com ATTENDEE;RSVP=TRUE:mailto:d@example.com DESCRIPTION:IETF-C&S Conference Call CLASS:PUBLIC SUMMARY:IETF Calendaring Working Group Meeting DTSTART:19970601T210000Z DTEND:19970601T220000Z DTSTAMP:19970602T094000Z LOCATION:Conference Call STATUS:CONFIRMED FOO:BAR END:VEVENT END:VCALENDAR Response from "B" to indicate that RRULE is not supported and an unrecognized property was encountered BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REPLY VERSION:2.0 BEGIN:VEVENT ORGANIZER:mailto:a@example.com ATTENDEE:mailto:b@example.com REQUEST-STATUS:3.0;Invalid Property Name;FOO UID:guid-1@example.com SEQUENCE:0 DTSTAMP:19970603T094000Z END:VEVENT END:VCALENDAR Daboo Expires April 7, 2010 [Page 108]
Internet-Draft iTIP October 2009 4.5. Group To-do Examples Individual "A" creates a group task in which individuals "A", "B", "C" and "D" will participate. Individual "B" confirms acceptance of the task. Individual "C" declines the task. Individual "D" tentatively accepts the task. The following table illustrates the sequence of messages that would be exchanged between these individuals. Individual "A" then issues a "REQUEST" method to obtain the status of the to-do from each participant. The response indicates the individual "Attendee's" completion status. The table below illustrates the message flow. +--------------+------------------------+---------------------------+ | Action | "Organizer" | Attendee | +--------------+------------------------+---------------------------+ | Initiate a | "A" sends a REQUEST | | | to-do | message to "B", "C", | | | request | and "D" | | | | | | | Accept the | | "B" sends a "REPLY" | | to-do | | message to "A" with its | | request | | "PARTSTAT" parameter set | | | | to "ACCEPTED". | | | | | | Decline the | | "C" sends a REPLY message | | to-do | | to "A" with its | | request | | "PARTSTAT" parameter set | | | | to "DECLINED". | | | | | | Tentatively | | "D" sends a REPLY message | | accept the | | to "A" with its | | to-do | | "PARTSTAT" parameter set | | request | | to "TENTATIVE". | | | | | | Check | "A" sends a REQUEST | | | attendee | message to "B" and "D" | | | completion | with current | | | status | information. | | | | | | | Attendee | | "B" sends a "REPLY" | | indicates | | message indicating | | percent | | percent complete | | complete | | | | | | | | Attendee | | "D" sends a "REPLY" | | indicates | | message indicating | | completion | | completion | +--------------+------------------------+---------------------------+ Daboo Expires April 7, 2010 [Page 109]
Internet-Draft iTIP October 2009 4.5.1. A VTODO Request A sample "REQUEST" for a "VTODO" calendar component that "A" sends to "B", "C", and "D". BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REQUEST VERSION:2.0 BEGIN:VTODO ORGANIZER:mailto:a@example.com ATTENDEE;ROLE=CHAIR:mailto:a@example.com ATTENDEE;RSVP=TRUE:mailto:b@example.com ATTENDEE;RSVP=TRUE:mailto:c@example.com ATTENDEE;RSVP=TRUE:mailto:d@example.com DTSTART:19970701T170000Z DUE:19970722T170000Z PRIORITY:1 SUMMARY:Create the requirements document UID:calsrv.example.com-873970198738777-00@example.com SEQUENCE:0 DTSTAMP:19970717T200000Z STATUS:NEEDS-ACTION END:VTODO END:VCALENDAR 4.5.2. A VTODO Reply "B" accepts the to-do. BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REPLY VERSION:2.0 BEGIN:VTODO ORGANIZER:mailto:a@example.com ATTENDEE;PARTSTAT=ACCEPTED:mailto:b@example.com UID:calsrv.example.com-873970198738777-00@example.com COMMENT:I'll send you my input by e-mail SEQUENCE:0 DTSTAMP:19970717T203000Z REQUEST-STATUS:2.0;Success END:VTODO END:VCALENDAR Daboo Expires April 7, 2010 [Page 110]
Internet-Draft iTIP October 2009 "B" could have declined the TODO or indicated tentative acceptance by setting the "PARTSTAT" property parameter sequence to "DECLINED" or "TENTATIVE", respectively. 4.5.3. A VTODO Request for Updated Status "A" requests status from all "Attendees". BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REQUEST VERSION:2.0 BEGIN:VTODO ORGANIZER:mailto:a@example.com ATTENDEE;ROLE=CHAIR:mailto:a@example.com ATTENDEE;RSVP=TRUE;CUTYPE=INDIVIDUAL:mailto:b@example.com ATTENDEE;RSVP=TRUE;CUTYPE=INDIVIDUAL:mailto:d@example.com UID:calsrv.example.com-873970198738777-00@example.com SUMMARY:Create the requirements document PRIORITY:1 SEQUENCE:0 STATUS:IN-PROCESS DTSTART:19970701T170000Z DTSTAMP:19970717T230000Z END:VTODO END:VCALENDAR 4.5.4. A Reply: Percent-Complete A reply indicating the task being worked on and that "B" is 75% complete with "B's" part of the assignment. BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REPLY VERSION:2.0 BEGIN:VTODO ORGANIZER:mailto:a@example.com ATTENDEE;PARTSTAT=IN-PROCESS:mailto:b@example.com PERCENT-COMPLETE:75 UID:calsrv.example.com-873970198738777-00@example.com DTSTAMP:19970717T233000Z SEQUENCE:0 END:VTODO END:VCALENDAR Daboo Expires April 7, 2010 [Page 111]
Internet-Draft iTIP October 2009 4.5.5. A Reply: Completed A reply indicating that "D" completed "D's" part of the assignment. BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REPLY VERSION:2.0 BEGIN:VTODO ORGANIZER:mailto:a@example.com ATTENDEE;PARTSTAT=COMPLETED:mailto:d@example.com UID:calsrv.example.com-873970198738777-00@example.com DTSTAMP:19970717T233000Z SEQUENCE:0 END:VTODO END:VCALENDAR 4.5.6. An Updated VTODO Request Organizer "A" resends the "VTODO" calendar component. "A" sets the overall completion for the to-do at 40%. BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REQUEST VERSION:2.0 BEGIN:VTODO ORGANIZER:mailto:a@example.com ATTENDEE;ROLE=CHAIR;PARTSTAT=ACCEPTED:mailto:a@example.com ATTENDEE;PARTSTAT=ACCEPTED;CUTYPE=INDIVIDUAL:mailto:b@example.com ATTENDEE;PARTSTAT=COMPLETED;CUTYPE=INDIVIDUAL:mailto:d@example.com DTSTART:19970701T170000Z DUE:19970722T170000Z PRIORITY:1 SUMMARY:Create the requirements document UID:calsrv.example.com-873970198738777-00@example.com SEQUENCE:1 DTSTAMP:19970718T100000Z STATUS:IN-PROCESS PERCENT-COMPLETE:40 END:VTODO END:VCALENDAR Daboo Expires April 7, 2010 [Page 112]
Internet-Draft iTIP October 2009 4.5.7. Recurring VTODOs The following examples relate to recurring "VTODO" calendar components. 4.5.7.1. Request for a Recurring VTODO In this example "A" sends a recurring "VTODO" calendar component to "B" and "D". BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REQUEST VERSION:2.0 BEGIN:VTODO ORGANIZER:mailto:a@example.com ATTENDEE;ROLE=CHAIR:mailto:a@example.com ATTENDEE;RSVP=TRUE;CUTYPE=INDIVIDUAL:mailto:b@example.com ATTENDEE;RSVP=TRUE;CUTYPE=INDIVIDUAL:mailto:d@example.com RRULE:FREQ=MONTHLY;COUNT=10;BYDAY=1FR DTSTART:19980101T100000Z DUE:19980103T100000Z SUMMARY:Send Status Reports to Area Managers UID:calsrv.example.com-873970198738777-00@example.com SEQUENCE:0 DTSTAMP:19970717T200000Z STATUS:NEEDS-ACTION PRIORITY:1 END:VTODO END:VCALENDAR 4.5.7.2. Replying to an instance of a recurring VTODO In this example "B" updates "A" on a single instance of the "VTODO" calendar component. Daboo Expires April 7, 2010 [Page 113]
Internet-Draft iTIP October 2009 BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REPLY VERSION:2.0 BEGIN:VTODO ATTENDEE;PARTSTAT=IN-PROCESS:mailto:b@example.com PERCENT-COMPLETE:75 UID:calsrv.example.com-873970198738777-00@example.com DTSTAMP:19970717T233000Z RECURRENCE-ID:19980101T170000Z SEQUENCE:1 END:VTODO END:VCALENDAR 4.6. Journal Examples The iCalendar object below describes a single journal entry for October 2, 1997. The "RELATED-TO" property references the phone conference event for which minutes were taken. BEGIN:VCALENDAR METHOD:PUBLISH PRODID:-//Example/ExampleCalendarClient//EN VERSION:2.0 BEGIN:VJOURNAL DTSTART:19971002T200000Z DTSTAMP:19970717T233100Z ORGANIZER:mailto:a@example.com SUMMARY:Phone conference minutes DESCRIPTION:The editors meeting was held on October 1, 1997. Details are in the attached document. UID:0981234-1234234-2410@example.com RELATED-TO:0981234-1234234-2402-35@example.com ATTACH:ftp://ftp.example.com/pub/ed/minutes100197.txt END:VJOURNAL END:VCALENDAR 4.7. Other Examples 4.7.1. Event Refresh Refresh the event with "UID" property value of "guid-1-12345@example.com": Daboo Expires April 7, 2010 [Page 114]
Internet-Draft iTIP October 2009 BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REFRESH VERSION:2.0 BEGIN:VEVENT ORGANIZER:mailto:a@example.com ATTENDEE;ROLE=CHAIR;PARTSTAT=ACCEPTED:mailto:a@example.com ATTENDEE:mailto:b@example.com ATTENDEE:mailto:c@example.com ATTENDEE:mailto:d@example.com UID:guid-1-12345@example.com DTSTAMP:19970603T094000 END:VEVENT END:VCALENDAR 4.7.2. Bad RECURRENCE-ID Component instances are identified by the combination of "UID", "RECURRENCE-ID", and "SEQUENCE". When an "Organizer" sends an iTIP message to an "Attendee", there are three cases in which an instance cannot be found. They are: 1. The component with the referenced "UID" and "RECURRENCE-ID" has been found but the "SEQUENCE" number in the calendar store does not match that of the iTIP message. 2. The component with the referenced "UID" has been found, the "SEQUENCE" numbers match, but the "RECURRENCE-ID" cannot be found. 3. The "UID" and "SEQUENCE" numbers are found but the CUA does not support recurrences. In case (1), two things can happen. If the "SEQUENCE" number of the "Attendee's" instance is larger than that in the "Organizer's" message then the "Attendee" is receiving an out-of-sequence message and MUST ignore it. If the "SEQUENCE" number of the "Attendee's" instance is smaller, then the "Organizer" is sending out a newer version of the component and the "Attendee's" version needs to be updated. Since one or more updates have been missed, the "Attendee" SHOULD send a "REFRESH" message to the "Organizer" to get an updated version of the event. In case (2), something has gone wrong. Both the "Organizer" and the "Attendee" should have the same instances, but the "Attendee" does not have the referenced instance. In this case the "Attendee" SHOULD send a "REFRESH" to the "Organizer" to get an updated version of the event. Daboo Expires April 7, 2010 [Page 115]
Internet-Draft iTIP October 2009 In case (3), the limitations of the "Attendee's" CUA makes it impossible to match an instance other than the single instance scheduled. In this case, the "Attendee" need not send a "REFRESH" to the "Organizer". The example below shows a sequence in which an "Attendee" sends a "REFRESH" to the "Organizer". +-------------------------+--------------------+--------------------+ | Action | "Organizer" | Attendee | +-------------------------+--------------------+--------------------+ | Update an instance | "A" sends | | | request | "REQUEST" message | | | | to "B" | | | | | | | Attendee requests | | "B" sends a | | refresh because | | "REFRESH" message | | "RECURRENCE-ID" was not | | to "A" | | found | | | | | | | | Refresh the entire | "A" sends the | | | event | latest copy of the | | | | event to "B" | | | | | | | Attendee handles the | | "B" updates to the | | request and updates the | | latest copy of the | | instance | | meeting. | +-------------------------+--------------------+--------------------+ Request from "A": Daboo Expires April 7, 2010 [Page 116]
Internet-Draft iTIP October 2009 BEGIN:VCALENDAR METHOD:REQUEST PRODID:-//Example/ExampleCalendarClient//EN VERSION:2.0 BEGIN:VEVENT UID:example-12345@example.com SEQUENCE:3 RRULE:FREQ=WEEKLY RDATE;VALUE=PERIOD:19970819T210000Z/199700819T220000Z ORGANIZER:mailto:a@example.com ATTENDEE;ROLE=CHAIR;PARTSTAT=ACCEPTED:mailto:a@example.com ATTENDEE:mailto:b@example.com DESCRIPTION:IETF-C&S Conference Call SUMMARY:IETF Calendaring Working Group Meeting DTSTART:19970801T210000Z DTEND:19970801T220000Z RECURRENCE-ID:19970809T210000Z DTSTAMP:19970726T083000 STATUS:CONFIRMED END:VEVENT END:VCALENDAR "B" has the event with "UID" property "example-12345@example.com" but "B's" "SEQUENCE" property value is "1" and the event does not have an instance at the specified recurrence time. This means that "B" has missed at least one update and needs a new copy of the event. "B" requests the latest copy of the event with the following refresh message: BEGIN:VCALENDAR PRODID:-//Example/ExampleCalendarClient//EN METHOD:REFRESH VERSION:2.0 BEGIN:VEVENT ORGANIZER:mailto:a@example.com ATTENDEE:mailto:b@example.com UID:example-12345@example.com DTSTAMP:19970603T094000 END:VEVENT END:VCALENDAR Daboo Expires April 7, 2010 [Page 117]
Internet-Draft iTIP October 2009 5. Application Protocol Fallbacks 5.1. Partial Implementation Applications that support this specification are not required to support the entire protocol. The following describes how methods and properties SHOULD "fallback" in applications that do not support the complete protocol. If a method or property is not addressed in this section, it may be ignored. 5.1.1. Event-Related Fallbacks +----------------+--------------------------------------------------+ | Method | Fallback | +----------------+--------------------------------------------------+ | PUBLISH | Required | | REQUEST | PUBLISH | | REPLY | Required | | ADD | Required if recurrences supported, otherwise | | | reply with a REQUEST-STATUS "2.8;Success, | | | repeating event ignored. Scheduled as a single | | | component." and schedule as a single component. | | CANCEL | Required | | REFRESH | Required | | COUNTER | Reply with "Not Supported" | | DECLINECOUNTER | Required if COUNTER is implemented for VEVENTs, | | | otherwise reply with "Not Supported" | +----------------+--------------------------------------------------+ +-----------------+-------------------------------------------------+ | iCalendar | Fallback | | Property | | +-----------------+-------------------------------------------------+ | CALSCALE | Ignore - assume GREGORIAN | | PRODID | Ignore | | METHOD | Required as described in the Method list above | | VERSION | Ignore | +-----------------+-------------------------------------------------+ +-----------------+-------------------------------------------------+ | Event-Related | Fallback | | Components | | +-----------------+-------------------------------------------------+ | VALARM | Reply with "Not Supported" | | VTIMEZONE | Required if any DateTime value refers to a time | | | zone. | +-----------------+-------------------------------------------------+ Daboo Expires April 7, 2010 [Page 118]
Internet-Draft iTIP October 2009 +-----------------+-------------------------------------------------+ | Component | Fallback | | Property | | +-----------------+-------------------------------------------------+ | ATTACH | Ignore | | ATTENDEE | Required if METHOD is REQUEST, otherwise ignore | | CATEGORIES | Ignore | | CLASS | Ignore | | COMMENT | Ignore | | COMPLETED | Ignore | | CONTACT | Ignore | | CREATED | Ignore | | DESCRIPTION | Ignore | | DURATION | Required | | DTSTAMP | Required | | DTSTART | Required | | DTEND | Required | | EXDATE | Ignore | | GEO | Ignore | | LAST-MODIFIED | Ignore | | LOCATION | Required | | ORGANIZER | Required if METHOD is REQUEST, otherwise ignore | | PRIORITY | Ignore | | RELATED-TO | Ignore | | RDATE | Ignore | | RRULE | Ignore - assume the first instance occurs on | | | the DTSTART property. If implemented, | | | VTIMEZONE MUST also be implemented. | | RECURRENCE-ID | Required if RRULE is implemented, otherwise | | | Ignore | | REQUEST-STATUS | Required | | RESOURCES | Ignore | | SEQUENCE | Required | | STATUS | Ignore | | SUMMARY | Ignore | | TRANSP | Required if FREEBUSY is implemented, otherwise | | | Ignore | | URL | Ignore | | UID | Required | | X- | Ignore | +-----------------+-------------------------------------------------+ Daboo Expires April 7, 2010 [Page 119]
Internet-Draft iTIP October 2009 5.1.2. Free/Busy-Related Fallbacks +---------+---------------------------------------------------------+ | Method | Fallback | +---------+---------------------------------------------------------+ | PUBLISH | Required if freebusy lookups are supported, otherwise | | | reply with a REQUEST-STATUS "3.14;Unsupported | | | capability" | | REQUEST | Required if freebusy lookups are supported, otherwise | | | reply with a REQUEST-STATUS "3.14;Unsupported | | | capability" | | REPLY | Required if freebusy lookups are supported, otherwise | | | reply with a REQUEST-STATUS "3.14;Unsupported | | | capability" | +---------+---------------------------------------------------------+ +-----------------+-------------------------------------------------+ | iCalendar | Fallback | | Property | | +-----------------+-------------------------------------------------+ | CALSCALE | Ignore - assume GREGORIAN. | | PRODID | Ignore | | METHOD | Required as described in the Method list above. | | VERSION | Ignore | +-----------------+-------------------------------------------------+ +-----------------+-------------------------------------------------+ | Component | Fallback | | Property | | +-----------------+-------------------------------------------------+ | ATTENDEE | Required if METHOD is REQUEST, otherwise ignore | | COMMENT | Ignore | | CONTACT | Ignore | | DTEND | Required | | DTSTAMP | Required | | DTSTART | Required | | DURATION | Ignore | | FREEBUSY | Required | | ORGANIZER | Required if METHOD is REQUEST, otherwise ignore | | REQUEST-STATUS | Ignore | | UID | Required | | URL | Ignore | | X- | Ignore | +-----------------+-------------------------------------------------+ Daboo Expires April 7, 2010 [Page 120]
Internet-Draft iTIP October 2009 5.1.3. To-Do-Related Fallbacks +----------------+--------------------------------------------------+ | Method | Fallback | +----------------+--------------------------------------------------+ | PUBLISH | Required | | REQUEST | PUBLISH | | REPLY | Required | | ADD | Required if recurrences supported, otherwise | | | reply with a REQUEST-STATUS "2.8;Success, | | | repeating event ignored. Scheduled as a single | | | component." and schedule as a single component. | | CANCEL | Required | | REFRESH | Required | | COUNTER | Reply with "Not Supported" | | DECLINECOUNTER | Required if COUNTER for VTODOs is implemented, | | | otherwise reply with "Not Supported" | +----------------+--------------------------------------------------+ +-----------------+-------------------------------------------------+ | iCalendar | Fallback | | Property | | +-----------------+-------------------------------------------------+ | CALSCALE | Ignore - assume GREGORIAN. | | PRODID | Ignore | | METHOD | Required as described in the Method list above. | | VERSION | Ignore | +-----------------+-------------------------------------------------+ +-----------------+-------------------------------------------------+ | To-Do-Related | Fallback | | Components | | +-----------------+-------------------------------------------------+ | VALARM | Reply with "Not Supported" | | VTIMEZONE | Required if any DateTime value refers to a time | | | zone. | +-----------------+-------------------------------------------------+ Daboo Expires April 7, 2010 [Page 121]
Internet-Draft iTIP October 2009 +------------------+------------------------------------------------+ | Component | Fallback | | Property | | +------------------+------------------------------------------------+ | ATTACH | Ignore | | ATTENDEE | Required if METHOD is REQUEST, otherwise | | | ignore | | CATEGORIES | Ignore | | CLASS | Ignore | | COMMENT | Ignore | | COMPLETED | Required | | CONTACT | Ignore | | CREATED | Ignore | | DESCRIPTION | Required if METHOD is REQUEST, otherwise | | | ignore | | DUE | Required | | DURATION | Required | | DTSTAMP | Required | | DTSTART | Required | | EXDATE | Ignore - reply with "Not Supported" | | LAST-MODIFIED | Ignore | | LOCATION | Ignore | | ORGANIZER | Required if METHOD is REQUEST, otherwise | | | ignore | | PERCENT-COMPLETE | Ignore | | PRIORITY | Required | | RECURRENCE-ID | Required if RRULE is implemented, otherwise | | | Ignore | | RELATED-TO | Ignore | | REQUEST-STATUS | Ignore | | RDATE | Ignore | | RRULE | Ignore - assume the first instance occurs on | | | the DTSTART property. If implemented, | | | VTIMEZONE MUST also be implemented. | | RESOURCES | Ignore | | SEQUENCE | Required | | STATUS | Required | | SUMMARY | Ignore | | URL | Ignore | | UID | Required | | X- | Ignore | +------------------+------------------------------------------------+ Daboo Expires April 7, 2010 [Page 122]
Internet-Draft iTIP October 2009 5.1.4. Journal-Related Fallbacks +---------+---------------------------------------------------------+ | Method | Fallback | +---------+---------------------------------------------------------+ | PUBLISH | Implementations MAY ignore the METHOD type. The | | | REQUEST-STATUS "3.14;Unsupported capability" MUST be | | | returned. | | ADD | Implementations MAY ignore the METHOD type. The | | | REQUEST-STATUS "3.14;Unsupported capability" MUST be | | | returned. | | CANCEL | Implementations MAY ignore the METHOD type. The | | | REQUEST-STATUS "3.14;Unsupported capability" MUST be | | | returned. | +---------+---------------------------------------------------------+ +-----------------+-------------------------------------------------+ | iCalendar | Fallback | | Property | | +-----------------+-------------------------------------------------+ | CALSCALE | Ignore - assume GREGORIAN. | | PRODID | Ignore | | METHOD | Required as described in the Method list above. | | VERSION | Ignore | +-----------------+-------------------------------------------------+ +-----------------+-------------------------------------------------+ | Journal-Related | Fallback | | Components | | +-----------------+-------------------------------------------------+ | VTIMEZONE | Required if any DateTime value refers to a time | | | zone | +-----------------+-------------------------------------------------+ Daboo Expires April 7, 2010 [Page 123]
Internet-Draft iTIP October 2009 +-----------------+-------------------------------------------------+ | Component | Fallback | | Property | | +-----------------+-------------------------------------------------+ | ATTACH | Ignore | | ATTENDEE | Ignore | | CATEGORIES | Ignore | | CLASS | Ignore | | COMMENT | Ignore | | CONTACT | Ignore | | CREATED | Ignore | | DESCRIPTION | Ignore | | DTSTAMP | Required | | DTSTART | Required | | EXDATE | Ignore | | LAST-MODIFIED | Ignore | | ORGANIZER | Ignore | | RECURRENCE-ID | Required if RRULE is implemented, otherwise | | | Ignore | | RELATED-TO | Ignore | | RDATE | Ignore. | | RRULE | Ignore - assume the first instance occurs on | | | the DTSTART property. If implemented, | | | VTIMEZONE MUST also be implemented. | | SEQUENCE | Required | | STATUS | Ignore | | SUMMARY | Required | | URL | Ignore | | UID | Required | | X- | Ignore | +-----------------+-------------------------------------------------+ 5.2. Latency Issues With a store-and-forward transport, it is possible for events to arrive out of sequence. That is, a "CANCEL" method may be received prior to receiving the associated "REQUEST" for the calendar component. This section discusses a few of these scenarios. 5.2.1. Cancellation of an Unknown Calendar Component. When a "CANCEL" method is received before the original "REQUEST" method the calendar will be unable to correlate the "UID" property of the cancellation with an existing calendar component. It is suggested that messages that can not be correlated that also contain non-zero sequence numbers be held and not discarded. Implementations MAY age them out if no other messages arrive with the same "UID" property value and a lower sequence number. Daboo Expires April 7, 2010 [Page 124]
Internet-Draft iTIP October 2009 5.2.2. Unexpected Reply from an Unknown Delegate When an "Attendee" delegates an item to another CU they MUST send a "REPLY" method to the "Organizer" using the "ATTENDEE" properties to indicate that the request was delegated and to whom. Hence, it is possible for an "Organizer" to receive an "REPLY" from a CU not listed as one of the original "Attendees". The resolution is left to the implementation but it is expected that the calendaring software will either accept the reply or hold it until the related "REPLY" method is received from the "Delegator". If the version of the "REPLY" method is out of date the "Organizer" SHOULD treat the message as a "REFRESH" message and update the delegate with the correct version provided that delegation to that delegate is acceptable. 5.3. Sequence Number Under some conditions, a CUA may receive requests and replies with the same "SEQUENCE" property value. The "DTSTAMP" property is utilized as a tie-breaker when two items with the same "SEQUENCE" property value are evaluated. 6. Security Considerations iTIP is an abstract transport protocol which will be bound to a real- time transport, a store-and-forward transport, and perhaps other transports. The transport protocol will be responsible for providing facilities for authentication and encryption using standard Internet mechanisms that are mutually understood between the sender and receiver. 6.1. Security Threats 6.1.1. Spoofing the "Organizer" In iTIP, the "Organizer" (or someone working on the "Organizer's" behalf) is the only person authorized to make changes to an existing "VEVENT", "VTODO", "VJOURNAL" calendar component and republish it or redistribute updates to the "Attendees". An iCalendar object that maliciously changes or cancels an existing "VEVENT", "VTODO" or "VJOURNAL" calendar component may be constructed by someone other than the "Organizer" and republished or sent to the "Attendees". 6.1.2. Spoofing the "Attendee" In iTIP, an "Attendee" of a "VEVENT" or "VTODO" calendar component (or someone working on the "Attendee's" behalf) is the only person Daboo Expires April 7, 2010 [Page 125]
Internet-Draft iTIP October 2009 authorized to update any parameter associated with their "ATTENDEE" property and send it to the "Organizer". An iCalendar object that maliciously changes the "ATTENDEE" parameters may be constructed by someone other than the real "Attendee" and sent to the "Organizer". 6.1.3. Unauthorized Replacement of the Organizer There will be circumstances when "Attendees" of an event or to-do decide, using out-of-band mechanisms, that the "Organizer" must be replaced. When the new "Organizer" sends out the updated "VEVENT" or "VTODO" the "Attendee's" CUA will detect that the "Organizer" has been changed, but it has no way of knowing whether or not the change was mutually agreed upon. 6.1.4. Eavesdropping and Data Integrity The iCalendar object is constructed with human-readable clear text. Any information contained in an iCalendar object may be read and/or changed by unauthorized persons while the object is in transit. 6.1.5. Flooding a Calendar Implementations could provide a means to automatically incorporate "REQUEST" methods into a calendar. This presents the opportunity for a calendar to be flooded with requests, which effectively block all the calendar's free time. 6.1.6. Unauthorized REFRESH Requests It is possible for an "Organizer" to receive a "REFRESH" request from someone who is not an "Attendee" of an event or to-do. Only "Attendee's" of an event or to-do are authorized to receive replies to "REFRESH" requests. Replying to such requests to anyone who is not an "Attendee" may be a security problem. 6.2. Recommendations For an application where the information is sensitive or critical and the network is subject to a high probability of attack, iTIP transactions SHOULD be encrypted and authenticated. This helps mitigate the threats of spoofing, eavesdropping and malicious changes in transit. 6.2.1. Securing iTIP transactions iTIP transport bindings MUST provide a mechanism to enable authentication of the sender's identity, and privacy and integrity of the data being transmitted. This allows the receiver of a signed Daboo Expires April 7, 2010 [Page 126]
Internet-Draft iTIP October 2009 iCalendar object to verify the identity of the sender. This sender may then be correlated to an "ATTENDEE" property in the iCalendar object. If the correlation is made and the sender is authorized to make the requested change or update then the operation may proceed. It also allows the message to be encrypted to prevent unauthorized reading of the message contents in transit. iTIP transport binding documents describe this process in detail. 6.2.2. Implementation Controls The threat of unauthorized replacement of the "Organizer" SHOULD be mitigated by a calendar system that uses this protocol by providing controls or alerts that make "Calendar Users" aware of such "Organizer" changes and allowing them to decide whether or not the request should be honored. The threat of flooding a calendar SHOULD be mitigated by a calendar system that uses this protocol by providing controls that may be used to limit the acceptable sources for iTIP transactions, and perhaps the size of messages and volume of traffic, by source. The threat of unauthorized "REFRESH" requests SHOULD be mitigated by a calendar system that uses this protocol by providing controls or alerts that allow "Calendar User" to decide whether or not the request should be honored. An implementation MAY decide to maintain, for audit or historical purposes, "Calendar Users" who were part of an attendee list and who were subsequently uninvited. Similar controls or alerts should be provided when a "REFRESH" request is received from these "Calendar Users" as well. 6.2.3. Access Controls and Filtering In many environments there could be restrictions on who is allowed to scheduled with whom, and who allowed delegates are for particular calendar users. iTIP transport bindings SHOULD provide mechanisms for implementing access controls or filtering to ensure iTIP transactions only take place between authorized calendar users. That would include preventing one calendar user from scheduling with another, or a calendar user delegating to another. 6.3. Privacy Issues The "Organizer" might want to keep "Attendees" from knowing which other "Attendees" are participating in an event or to-do. The "Organizer" has the choice of sending single iTIP messages with a full list of "Attendees" or sending iTIP messages to each "Attendee" Daboo Expires April 7, 2010 [Page 127]
Internet-Draft iTIP October 2009 with only that "Attendee" listed. 7. IANA Consideration 7.1. Registration Template for REQUEST-STATUS Values This specification updates [RFC5545] by adding a "REQUEST-STATUS" value registry to the iCalendar Elements registry. A "REQUEST-STATUS" value is defined by completing the following template. Status Code: Hierarchical, numeric return status code, following the rules defined in Section 3.8.8.3 of [RFC5545]. Status Description: Textual status description. A short but clear description of the error. Status Exception Data: Textual exception data. A short but clear description of what might appear in this field. Description: Describe the underlying cause for this status code value. 7.2. Additions to iCalendar METHOD Registry This documents defines the following values for the iCalendar "METHOD" property using the values template from Section 8.2.6 of [RFC5545]. These should be added to the Methods Registry defined in Section 8.3.12 of [RFC5545]: 7.2.1. METHOD:PUBLISH Value: PUBLISH Purpose: Standard iTIP "METHOD" value. Conformance: Only used with the "METHOD" property. Examples: See this RFC. 7.2.2. METHOD:REQUEST Value: REQUEST Purpose: Standard iTIP "METHOD" value. Conformance: Only used with the "METHOD" property. Examples: See this RFC. 7.2.3. METHOD:REPLY Daboo Expires April 7, 2010 [Page 128]
Internet-Draft iTIP October 2009 Value: REPLY Purpose: Standard iTIP "METHOD" value. Conformance: Only used with the "METHOD" property. Examples: See this RFC. 7.2.4. METHOD:ADD Value: ADD Purpose: Standard iTIP "METHOD" value. Conformance: Only used with the "METHOD" property. Examples: See this RFC. 7.2.5. METHOD:CANCEL Value: CANCEL Purpose: Standard iTIP "METHOD" value. Conformance: Only used with the "METHOD" property. Examples: See this RFC. 7.2.6. METHOD:REFRESH Value: REFRESH Purpose: Standard iTIP "METHOD" value. Conformance: Only used with the "METHOD" property. Examples: See this RFC. 7.2.7. METHOD:COUNTER Value: COUNTER Purpose: Standard iTIP "METHOD" value. Conformance: Only used with the "METHOD" property. Examples: See this RFC. 7.2.8. METHOD:DECLINECOUNTER Value: DECLINECOUNTER Purpose: Standard iTIP "METHOD" value. Conformance: Only used with the "METHOD" property. Examples: See this RFC. 7.3. REQUEST-STATUS Value Registry The following table is to be used to initialize the "REQUEST-STATUS" value registry. Daboo Expires April 7, 2010 [Page 129]
Internet-Draft iTIP October 2009 +-------------+---------+-------------------------+ | Status Code | Status | Reference | +-------------+---------+-------------------------+ | 2.0 | Current | RFCXXXX, Section 3.6.1 | | 2.1 | Current | RFCXXXX, Section 3.6.2 | | 2.2 | Current | RFCXXXX, Section 3.6.3 | | 2.3 | Current | RFCXXXX, Section 3.6.4 | | 2.4 | Current | RFCXXXX, Section 3.6.5 | | 2.5 | Current | RFCXXXX, Section 3.6.6 | | 2.6 | Current | RFCXXXX, Section 3.6.7 | | 2.7 | Current | RFCXXXX, Section 3.6.8 | | 2.8 | Current | RFCXXXX, Section 3.6.9 | | 2.9 | Current | RFCXXXX, Section 3.6.10 | | 2.10 | Current | RFCXXXX, Section 3.6.11 | | 2.11 | Current | RFCXXXX, Section 3.6.12 | | 3.0 | Current | RFCXXXX, Section 3.6.13 | | 3.1 | Current | RFCXXXX, Section 3.6.14 | | 3.2 | Current | RFCXXXX, Section 3.6.15 | | 3.3 | Current | RFCXXXX, Section 3.6.16 | | 3.4 | Current | RFCXXXX, Section 3.6.17 | | 3.5 | Current | RFCXXXX, Section 3.6.18 | | 3.6 | Current | RFCXXXX, Section 3.6.19 | | 3.7 | Current | RFCXXXX, Section 3.6.20 | | 3.8 | Current | RFCXXXX, Section 3.6.21 | | 3.9 | Current | RFCXXXX, Section 3.6.22 | | 3.10 | Current | RFCXXXX, Section 3.6.23 | | 3.11 | Current | RFCXXXX, Section 3.6.24 | | 3.12 | Current | RFCXXXX, Section 3.6.25 | | 3.13 | Current | RFCXXXX, Section 3.6.26 | | 3.14 | Current | RFCXXXX, Section 3.6.27 | | 4.0 | Current | RFCXXXX, Section 3.6.28 | | 5.0 | Current | RFCXXXX, Section 3.6.29 | | 5.1 | Current | RFCXXXX, Section 3.6.30 | | 5.2 | Current | RFCXXXX, Section 3.6.31 | | 5.3 | Current | RFCXXXX, Section 3.6.32 | +-------------+---------+-------------------------+ 8. Acknowledgments This is an update to the original iTIP document authored by S. Silverberg, S. Mansour, F. Dawson and R. Hopson. This revision is the product of the Calsify IETF Working Group, and several participants have made important contributions to this specification, including: Oliver Block, Bernard Desruisseaux, Mike Douglass, Tim Hare, Ciny Joy, Bruce Kahn, Reinhold Kainhofer, Eliot Lear, Jonathan Lennox, Andy Mabbett, Aki Niemi, John W. Noerenberg Daboo Expires April 7, 2010 [Page 130]
Internet-Draft iTIP October 2009 II, Robert Ransdell, Caleb Richardson. 9. References 9.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2368] Hoffman, P., Masinter, L., and J. Zawinski, "The mailto URL scheme", RFC 2368, July 1998. [RFC5545] Desruisseaux, B., "Internet Calendaring and Scheduling Core Object Specification (iCalendar)", RFC 5545, September 2009. 9.2. Informative References [I-D.ietf-calsify-rfc2447bis] Melnikov, A., "iCalendar Message-Based Interoperability Protocol (iMIP)", draft-ietf-calsify-rfc2447bis-06 (work in progress), September 2009. Appendix A. Differences from RFC 2446 A.1. Changed Restrictions This specification now defines an allowed combination of "REQUEST- STATUS" codes when multiple iCalendar components are included in an iTIP message. This specification now restricts "RECURRENCE-ID" to only a single occurrence in any one iCalendar component in an iTIP message as required by [RFC5545]. Changed "RECURRENCE-ID" entry in component restriction table to "0 or 1" from "0+" to fall in line with [RFC5545]. Changed "FREEBUSY" entry in "VFREEBUSY" "PUBLISH" and "REPLY" restriction table to "0+" from "1+" to fall in line with [RFC5545]. Changed "FREEBUSY" description in "VFREEBUSY" "REPLY" restriction table to indicate that different "FBTYPE" ranges MUST NOT overlap. Changed "TZNAME" entry in "VTIMEZONE" restriction table to "0+" from "0 or 1" to fall in line with [RFC5545]. Daboo Expires April 7, 2010 [Page 131]
Internet-Draft iTIP October 2009 Changed "COMMENT" entry in component restriction tables to "0+" from "0 or 1" to fall in line with [RFC5545]. Added "ATTENDEE" entry in "VALARM" restriction table to match email alarm type in [RFC5545]. Changed "CATEGORIES" entry in component restriction tables to "0+" from "0 or 1" to fall in line with [RFC5545]. Changed "RESOURCES" entry in component restriction tables to "0+" from "0 or 1" to fall in line with [RFC5545]. Changed "CONTACT" entry in "VFREEBUSY" restriction table to "0 or 1" from "0+" to fall in line with [RFC5545]. Changed "UID" entry in "VFREEBUSY" "PUBLISH" restriction table to "1" from "0" to fall in line with [RFC5545]. Added "COMPLETED" entry in "VTODO" restriction tables to fall in line with [RFC5545]. Added "REQUEST-STATUS" entry in "VJOURNAL" restriction tables to fall in line with [RFC5545]. A.2. Deprecated features The "EXRULE" property was removed in [RFC5545] and references to that have been removed in this document too. The "PROCEDURE" value for the "ACTION" property was removed in [RFC5545] and references to that have been removed in this document too. The "THISANDPRIOR" option for the "RANGE" parameter was removed in [RFC5545] and references to that have been removed in this document too. Appendix B. Change History (to be removed prior to publication as an RFC) Changes in -10: a. Gen-ART: changed section title "Eavesdropping" to "Eavesdropping and Data Integrity". b. SecDir: changed "encrypted" to "encrypted and authenticated" in 6.2. Daboo Expires April 7, 2010 [Page 132]
Internet-Draft iTIP October 2009 c. SecDir: removed S/MIME reference and changed text to just talk about "generic" authentication and encryption. d. SecDir: added access controls and filtering section. e. IESG: fixed "THISANDFUTURE" -> "THISANDPRIOR" in A.2. f. IESG: 2447bis is now an informative reference. g. IESG: Changed text about email groups to reference mailto URI. h. IESG: tweaked fallback text for free/busy methods. i. IESG: fallback for DURATION in events and to-dos now required. j. IESG: removed last sentence in 6.2.1. k. IESG: added reference to values template section in 2445bis in IANA section. l. IESG: clarified that 2.0 is the default REQUEST-STATUS if the property is not present. m. IANA: added registry for REQUEST-STATUS codes. n. Updated to RFC 5545 reference! o. Fixed minor typos. Changes in -09: a. Updated to RFC5322 reference. b. Fixed more issues from Reinhold Kainhofer review being tracked on the WG wiki. Changes in -08: a. AD review: Changed "calendar entry" to "iCalendar object". b. AD review: Added extra captions above restriction tables for more clarity. c. AD review: Added missing step of uninvited CU replying to Organizer in description of event forwarding. d. AD review: Clarified text about "unsuccessful" REQUEST processing. e. AD review: VFREEBUSY text about allowing multiple components moved into description of PUBLISH method. f. AD review: VTODO description changed to reflect fact that originator is not always the Organizer. g. AD review: Changed VTODO ADD description to use proper 3.14 code instead of 5.3. h. AD review: Changed short description on 5.0 status code. i. AD review: Added IANA-PROPERTY/COMPONENT items to restrictions tables and changed 3.7.3 to better reflect requirements on handling extensions. j. AD review: Fixed example in 4.2.4. k. AD review: Clarified who is responsible for updating the delegator in 4.2.5. l. AD review: Fixed PARTSTAT in example in 4.2.6. m. AD review: Added reference to IANA methods registry in 2445bis in IANA section. Daboo Expires April 7, 2010 [Page 133]
Internet-Draft iTIP October 2009 n. Removed section on calculating recurring due dates as that is covered in 2445bis. o. Fixed lots of issues from Reinhold Kainhofer review being tracked on the WG wiki. p. Fixed DECLINE-COUNTER -> DECLINECOUNTER. Changes in -07: a. IANA considerations now registers METHOD values. b. Added Appendix with key 2446 changes and text to the introduction pointing to that. Changes in -06: a. Added text to SEQUENCE number description about detecting a significant change. b. Added text to REQUEST-STATUS section describing the allowed combinations of codes. c. Added text to REQUEST-STATUS section to require new codes to be defined in a standard or experimental RFC. d. Removed THISANDFUTURE. e. Cleaned up some examples. Changes in -05: a. Changed "memo" to "specification". b. Removed EXRULE as it is no longer in 2445bis. c. Removed section on PROCEDURE alarms since those are no longer in 2445bis. d. Changed TYPE= to CUTYPE=. e. Fixed formatting of examples. f. Use lowercase mailto everywhere. Changes in -04: a. Added empty IANA Considerations section - to be done. b. Formatting fixes. c. Changed VEVENT, VTODO, VJOURNAL cancel descriptions that incorrectly implied RECURRENCE-ID could appear multiple times in a single component. d. [Issue91] FREEBUSY properties changed to '0+' from '1+' in VFREEBUSY PUBLISH and REPLY tables. e. [Issue89] Description for VEVENT ADD method simplified for clarity. f. Fixed some iCalendar property/parameter/value capitalization issues. g. MAY NOT -> MUST NOT in VFREEBUSY FREEBUSY response type. Changes in -03: a. Added empty IANA Considerations section - to be done. Changes in -02: Daboo Expires April 7, 2010 [Page 134]
Internet-Draft iTIP October 2009 a. Tweaked abstract wording. b. Fixed some improper references. c. Removed bogus TZOFFSET entry from VTIMEZONE restriction table. d. Changed TZNAME entry in VTIMEZONE restriction table to "0+" from "0 or 1" to fall in line with 2445. e. Changed COMMENT entry in component restriction tables to "0+" from "0 or 1" to fall in line with 2445. f. Added ATTENDEE entry in VALARM restriction table to match email alarm type in 2445. g. Changed CATEGORIES entry in component restriction tables to "0+" from "0 or 1" to fall in line with 2445. h. Changed RESOURCES entry in component restriction tables to "0+" from "0 or 1" to fall in line with 2445. i. Changed CONTACT entry in VFREEBUSY restriction table to "0 or 1" from "0+" to fall in line with 2445. j. Made UID required in VFREEBUSY publish. k. Added COMPLETED entry in VTODO restriction tables to fall in line with 2445. l. Added REQUEST-STATUS entry in VJOURNAL restriction tables to fall in line with 2445. Changes in -01: a. Updated to 2445bis and 2447bis references. Changes in -00 (from RFC2446): a. Updated to latest i-d boilerplate text. b. Rewrote abstract and introduction. c. Reformatted Formatting Conventions section. d. Split iTIP Roles and Transactions into two sections e. iTIP roles uses a table to describe different roles f. Converted tables into xml2rfc format. Author's Address Cyrus Daboo (editor) Apple Inc. 1 Infinite Loop Cupertino, CA 95014 USA Email: cyrus@daboo.name URI: http://www.apple.com/ Daboo Expires April 7, 2010 [Page 135]
