Network Working Group D. Royer Internet-Draft IntelliCal LLC Expires: December 26, 2005 June 24, 2005 Basic Internet Calendaring and Scheduling Core Object Specification (iCalendar Basic) draft-royer-ical-basic-03 Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. 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 December 26, 2005. Copyright Notice Copyright (C) The Internet Society (2005). Abstract This is the second release of a iCalendar. After having learned from RFC-2445. This document represents the common objects needed for basic calendaring. The VTODO, VJOURNAL, VTIMEZONE, recurrence rules (RDATE remains), and scheduling and their associated properties have been removed. These removals are expected to appear in new memos at a later time and will be independent extensions of this specification. The new EXTENSIONS property will exist to allow for compatible sets of extensions. Royer Expires December 26, 2005 [Page 1] Internet-Draft iCal-Basic June 2005 A very large part of this memo is text directly from RFC-2445. This memo is intented to be 100% compatible with RFC-2445. By limiting the objects to the ones used by most vendors this version has a better chance for interoperability and standardization. There is a clear need to provide and deploy interoperable calendaring and scheduling services for the Internet. Current group scheduling and Personal Information Management (PIM) products are being extended for use across the Internet, today, in proprietary ways. This memo has been defined to provide the definition of a common format for openly exchanging calendaring and scheduling information across the Internet. This MIME media type provides a standard content type for capturing calendar event entry information. It also can be used to convey free/busy time information. The content type is suitable as a MIME message entity that can be transferred over MIME based email systems, using HTTP or some other Internet transport. In addition, the content type is useful as an object for interactions between desktop applications using the operating system clipboard, drag/drop or file systems capabilities. This memo is based on the earlier work of the vCalendar specification and RFC-2445, RFC-2446, RFC-2447, and CAP [1] (an experimental protocol) for the exchange of personal calendaring and scheduling information. In order to avoid confusion with this referenced work, this memo is to be known as the iCalendar Basic (iCal-Basic) specification. This memo defines the format for specifying iCalendar object methods. An iCalendar object method is a set of usage constraints for the iCalendar object. For example, these methods might define scheduling messages that request an event be scheduled, reply to an event request, send a cancellation notice for an event, modify or replace the definition of an event, provide a counter proposal for an original event request, delegate an event request to another individual, request free or busy time, reply to a free or busy time request, or provide similar scheduling messages. The iCalendar Transport-indendent Interoperability Protocol (iTIP) defined in [3] is one such scheduling protocol. Royer Expires December 26, 2005 [Page 2] Internet-Draft iCal-Basic June 2005 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 6 2. Basic Grammar and Conventions . . . . . . . . . . . . . . . 8 2.1 Formatting Conventions . . . . . . . . . . . . . . . . . . 8 2.2 Related Memos . . . . . . . . . . . . . . . . . . . . . . 9 2.3 International Considerations . . . . . . . . . . . . . . . 9 3. Registration Information . . . . . . . . . . . . . . . . . . 10 3.1 Content Type . . . . . . . . . . . . . . . . . . . . . . . 10 3.2 Parameters . . . . . . . . . . . . . . . . . . . . . . . . 10 3.3 Content Header Fields . . . . . . . . . . . . . . . . . . 11 3.4 Encoding Considerations . . . . . . . . . . . . . . . . . 11 3.5 Security Considerations . . . . . . . . . . . . . . . . . 12 3.6 Interoperability Considerations . . . . . . . . . . . . . 12 3.7 Applications Which Use This Media Type . . . . . . . . . . 12 3.8 Additional Information . . . . . . . . . . . . . . . . . . 13 3.9 Magic Numbers . . . . . . . . . . . . . . . . . . . . . . 13 3.10 File Extensions . . . . . . . . . . . . . . . . . . . . 13 3.11 Contact for Further Information: . . . . . . . . . . . . 13 3.12 Intended Usage . . . . . . . . . . . . . . . . . . . . . 13 4. iCalendar Object Specification . . . . . . . . . . . . . . . 14 4.1 Content Lines . . . . . . . . . . . . . . . . . . . . . . 14 4.1.1 List and Field Separators . . . . . . . . . . . . . . 16 4.1.2 Multiple Values . . . . . . . . . . . . . . . . . . . 17 4.1.3 Binary Content . . . . . . . . . . . . . . . . . . . . 17 4.1.4 Character Set . . . . . . . . . . . . . . . . . . . . 18 4.2 Property Parameters . . . . . . . . . . . . . . . . . . . 18 4.2.1 Alternate Text Representation . . . . . . . . . . . . 19 4.2.2 Common Name . . . . . . . . . . . . . . . . . . . . . 20 4.2.3 Calendar User Type . . . . . . . . . . . . . . . . . . 21 4.2.4 Delegators . . . . . . . . . . . . . . . . . . . . . . 21 4.2.5 Delegatees . . . . . . . . . . . . . . . . . . . . . . 21 4.2.6 Directory Entry Reference . . . . . . . . . . . . . . 22 4.2.7 Inline Encoding . . . . . . . . . . . . . . . . . . . 22 4.2.8 Format Type . . . . . . . . . . . . . . . . . . . . . 23 4.2.9 Free/Busy Time Type . . . . . . . . . . . . . . . . . 23 4.2.10 Language . . . . . . . . . . . . . . . . . . . . . . 24 4.2.11 Group or List Membership . . . . . . . . . . . . . . 25 4.2.12 Participation Status . . . . . . . . . . . . . . . . 25 4.2.13 Recurrence Identifier Range . . . . . . . . . . . . 26 4.2.14 Relationship Type . . . . . . . . . . . . . . . . . 26 4.2.15 Participation Role . . . . . . . . . . . . . . . . . 26 4.2.16 RSVP Expectation . . . . . . . . . . . . . . . . . . 27 4.2.17 Sent By . . . . . . . . . . . . . . . . . . . . . . 27 4.2.18 Value Data Types . . . . . . . . . . . . . . . . . . 27 4.3 Property Value Data Types . . . . . . . . . . . . . . . . 28 4.3.1 Binary . . . . . . . . . . . . . . . . . . . . . . . . 28 4.3.2 Boolean . . . . . . . . . . . . . . . . . . . . . . . 29 Royer Expires December 26, 2005 [Page 3] Internet-Draft iCal-Basic June 2005 4.3.3 Calendar User Address . . . . . . . . . . . . . . . . 30 4.3.4 Date . . . . . . . . . . . . . . . . . . . . . . . . . 30 4.3.5 Date-Time . . . . . . . . . . . . . . . . . . . . . . 31 4.3.6 Duration . . . . . . . . . . . . . . . . . . . . . . . 33 4.3.7 Float . . . . . . . . . . . . . . . . . . . . . . . . 35 4.3.8 Integer . . . . . . . . . . . . . . . . . . . . . . . 35 4.3.9 Period of Time . . . . . . . . . . . . . . . . . . . . 36 4.3.10 Recurrence Rule . . . . . . . . . . . . . . . . . . 37 4.3.11 Text . . . . . . . . . . . . . . . . . . . . . . . . 37 4.3.12 Time . . . . . . . . . . . . . . . . . . . . . . . . 38 4.3.13 URI . . . . . . . . . . . . . . . . . . . . . . . . 40 4.3.14 UTC Offset . . . . . . . . . . . . . . . . . . . . . 41 4.4 iCalendar Object . . . . . . . . . . . . . . . . . . . . . 41 4.5 Property . . . . . . . . . . . . . . . . . . . . . . . . . 41 4.6 Calendar Components . . . . . . . . . . . . . . . . . . . 42 4.6.1 Event Component . . . . . . . . . . . . . . . . . . . 43 4.6.2 To-do Component . . . . . . . . . . . . . . . . . . . 46 4.6.3 Journal Component . . . . . . . . . . . . . . . . . . 46 4.6.4 Free/Busy Component . . . . . . . . . . . . . . . . . 46 4.6.5 Time Zone Component . . . . . . . . . . . . . . . . . 49 4.6.6 Alarm Component . . . . . . . . . . . . . . . . . . . 49 4.7 Calendar Properties . . . . . . . . . . . . . . . . . . . 54 4.7.1 Calendar Scale . . . . . . . . . . . . . . . . . . . . 55 4.7.2 Method . . . . . . . . . . . . . . . . . . . . . . . . 55 4.7.3 Product Identifier . . . . . . . . . . . . . . . . . . 56 4.7.4 Version . . . . . . . . . . . . . . . . . . . . . . . 57 4.8 Component Properties . . . . . . . . . . . . . . . . . . . 58 4.8.1 New Properties . . . . . . . . . . . . . . . . . . . . 58 4.8.2 Descriptive Component Properties . . . . . . . . . . . 59 4.8.3 Date and Time Component Properties . . . . . . . . . . 70 4.8.4 Time Zone Component Properties . . . . . . . . . . . . 75 4.8.5 Time Zone Name . . . . . . . . . . . . . . . . . . . . 75 4.8.6 Time Zone Offset From . . . . . . . . . . . . . . . . 75 4.8.7 Time Zone Offset To . . . . . . . . . . . . . . . . . 75 4.8.8 Time Zone URL . . . . . . . . . . . . . . . . . . . . 75 4.9 Relationship Component Properties . . . . . . . . . . . . 75 4.9.1 Attendee . . . . . . . . . . . . . . . . . . . . . . . 75 4.9.2 Contact . . . . . . . . . . . . . . . . . . . . . . . 78 4.9.3 Organizer . . . . . . . . . . . . . . . . . . . . . . 79 4.9.4 Recurrence ID . . . . . . . . . . . . . . . . . . . . 81 4.9.5 Related To . . . . . . . . . . . . . . . . . . . . . . 81 4.9.6 Uniform Resource Locator . . . . . . . . . . . . . . . 81 4.9.7 Unique Identifier . . . . . . . . . . . . . . . . . . 82 4.10 Recurrence Component Properties . . . . . . . . . . . . 83 4.10.1 Exception Date/Times . . . . . . . . . . . . . . . . 83 4.10.2 Exception Rule . . . . . . . . . . . . . . . . . . . 83 4.10.3 Recurrence Date/Times . . . . . . . . . . . . . . . 83 4.10.4 Recurrence Rule . . . . . . . . . . . . . . . . . . 85 Royer Expires December 26, 2005 [Page 4] Internet-Draft iCal-Basic June 2005 4.11 Alarm Component Properties . . . . . . . . . . . . . . . 85 4.11.1 Action . . . . . . . . . . . . . . . . . . . . . . . 85 4.11.2 Repeat Count . . . . . . . . . . . . . . . . . . . . 86 4.11.3 Trigger . . . . . . . . . . . . . . . . . . . . . . 87 4.12 Change Management Component Properties . . . . . . . . . 89 4.12.1 Date/Time Created . . . . . . . . . . . . . . . . . 89 4.12.2 Date/Time Stamp . . . . . . . . . . . . . . . . . . 89 4.12.3 Last Modified . . . . . . . . . . . . . . . . . . . 90 4.12.4 Sequence Number . . . . . . . . . . . . . . . . . . 91 4.13 Miscellaneous Component Properties . . . . . . . . . . . 92 4.13.1 Non-standard Properties . . . . . . . . . . . . . . 92 4.13.2 Request Status . . . . . . . . . . . . . . . . . . . 93 5. iCalendar Object Examples . . . . . . . . . . . . . . . . . 96 6. Recommended Practices . . . . . . . . . . . . . . . . . . . 99 7. Registration of Content Type Elements . . . . . . . . . . . 101 7.1 Registration of New and Modified iCalendar Object Methods . . . . . . . . . . . . . . . . . . . . . . . . . 101 7.2 Registration of New Properties . . . . . . . . . . . . . . 101 7.2.1 Define the property . . . . . . . . . . . . . . . . . 101 7.2.2 Post the Property definition . . . . . . . . . . . . . 102 7.2.3 Allow a comment period . . . . . . . . . . . . . . . . 102 7.2.4 Submit the property for approval . . . . . . . . . . . 102 7.3 Property Change Control . . . . . . . . . . . . . . . . . 103 8. References (BOILERPLATE) . . . . . . . . . . . . . . . . . . 104 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . 105 10. Authors' and Chairs' Addresses (BOILERPLATE) . . . . . . . . 106 11. Full Copyright Statement (BOILERPLATE) . . . . . . . . . . . 107 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 107 Author's Address . . . . . . . . . . . . . . . . . . . . . . 108 Intellectual Property and Copyright Statements . . . . . . . 109 Royer Expires December 26, 2005 [Page 5] Internet-Draft iCal-Basic June 2005 1. Introduction While implementing iCalendar applications much has been learned. Among those lessions is the need to make a simpler version of iCalendar that includes the common features used by almost all vendors. This memo describes a 'Basic' version of iCalendar that does not include recurrence rules, to-do's, journals, or timezones. These removals may be added in separate memos at a later time. These simplifications are seen as a way for more vendors to produce objects that are compatible with each other and without having to support all of the features possible in RFC-2445. A new property called EXTENSIONS allows for those conforming to this specification to detect any optional features while existing RFC-2445 implementations should already ignore the unknown property. A few properties have been tagged as no longer needed, these are marked as 'deprecated' in the sections that follow (GEO for example). And other properties and components are tagged as not in iCal-Basic, these may be reintroduced in future memos (RRULE for example). The use of calendaring and scheduling has grown considerably in the last decade. Enterprise and inter-enterprise business has become dependent on rapid scheduling of events and actions using this information technology. However, the longer term growth of calendaring and scheduling, is currently limited by the lack of Internet standards for the message content types that are central to these knowledgeware applications. This memo is intended to progress the level of interoperability possible between dissimilar calendaring and scheduling applications. This memo defines a MIME content type for exchanging electronic calendaring and scheduling information. The Internet Calendaring and Scheduling Core Object Specification, or iCalendar, allows for the capture and exchange of information normally stored within a calendaring and scheduling application; such as a Personal Information Manager (PIM) or a Group Scheduling product. The purpose of an iCalendar objects is for exchanging calendar information between applications. iCalendar objects were not designed to be a calendar store file storage format. This specification makes no assumptions or recommendations about how an application stores iCalendar objects it generates or receives for use in its own calendar store. iCalendar objects simply exist to transfer information about a calendar entry from one application to another. When an iCalendar object is stored outside of the applications calendar store, then it should be saved using the ".ics" file extension or transfered in a "text/calendar" MIME object. The MIME transfer of an iCalendar object is described in iTIP and CAP. The email transfer of an iCalendar object is described in iMIP and iTIP. Royer Expires December 26, 2005 [Page 6] Internet-Draft iCal-Basic June 2005 The iCalendar format is suitable as an exchange format between applications or systems. The format is defined in terms of a MIME content type. This will enable the object to be exchanged using several transports, including but not limited to SMTP, HTTP, a file system, desktop interactive protocols such as the use of a memory- based clipboard or drag/drop interactions, point-to-point asynchronous communication, wired-network transport, or some form of unwired transport such as infrared might also be used. The memo also provides for the definition of iCalendar object methods that will map this content type to a set of messages for supporting calendaring and scheduling operations such as requesting, replying to, modifying, and canceling meetings or appointments. The iCalendar object methods can be used to define other calendaring and scheduling operations such a requesting for and replying with free/busy time data. Such a scheduling protocol is defined in the iCalendar Transport-independent Interoperability Protocol (iTIP) defined in [3]. The memo also includes a formal grammar for the content type based on the Internet ABNF defined in [13]. This ABNF is required for the implementation of parsers and to serve as the definitive reference when ambiguities or questions arise in interpreting the descriptive prose definition of the memo. Royer Expires December 26, 2005 [Page 7] Internet-Draft iCal-Basic June 2005 2. Basic Grammar and Conventions The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY" and "OPTIONAL" in this document are to be interoperated as described in [12]. This memo makes use of both a descriptive prose and a more formal notation for defining the calendaring and scheduling format. The notation used in this memo is the ABNF notation of [13]. Readers intending on implementing this format defined in this memo should be familiar with this notation in order to properly interpret the specifications of this memo. All numeric and hexadecimal values used in this memo are given in decimal notation. All names of properties, property parameters, enumerated property values and property parameter values are case-insensitive. However, all other property values are case-sensitive, unless otherwise stated. Note: All indented editorial notes, such as this one, are intended to provide the reader with additional information. The information is not essential to the building of an implementation conformant with this memo. The information is provided to highlight a particular feature or characteristic of the memo. The format for the iCalendar object is based on the syntax of the [15] content type. While the iCalendar object is not a profile of the [15] content type, it does reuse a number of the elements from the [15] specification. 2.1 Formatting Conventions The mechanisms defined in this memo are defined in prose. Many of the terms used to describe these have common usage that is different than the standards usage of this memo. In order to reference within this memo elements of the calendaring and scheduling model, core object (this memo) or interoperability protocol [3] some formatting conventions have been used. 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" within the scheduling protocol defined by [3]. Calendar components defined by this memo are referred to with capitalized, quoted-strings of text. All calendar components start with the letter "V". For example, "VEVENT" refers to the event Royer Expires December 26, 2005 [Page 8] Internet-Draft iCal-Basic June 2005 calendar component. Scheduling methods defined by [3] 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. The properties defined by this memo are referred to with capitalized, quoted-strings of text, followed by the word "property". For example, "ATTENDEE" property refers to the iCalendar property used to convey the calendar address of a calendar user. Property parameters defined by this memo are referred to with lowercase, 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 memo are referred to with capitalized text, either alone or followed by the word "value". For example, the "CANCELED" value can be used with the "STATUS" property. 2.2 Related Memos Implementers will need to be familiar with several other memos that, along with this memo, form a framework for Internet calendaring and scheduling standards. This memo, [ICAL-BASIC], specifies a core specification of objects, data types, properties and property parameters. [3] - specifies an interoperability protocol for scheduling between different implementations; [2] specifies an Internet email binding for [3]. This memo does not attempt to repeat the specification of concepts or definitions from these other memos. Where possible, references are made to the memo that provides for the specification of these concepts or definitions. 2.3 International Considerations In the rest of this document, descriptions of characters are of the form "character name (codepoint)", where "codepoint" is from the US- ASCII character set. The "character name" is the authoritative description; (codepoint) is a reference to that character in US-ASCII or US-ASCII compatible sets (for example the ISO-8859-x family, UTF- 8, ISO-2022-xx, KOI8-R). If a non-US-ASCII compatible character set is used, appropriate code-point from that character set MUST be chosen instead. Use of non-US-ASCII-compatible character sets is NOT recommended. Royer Expires December 26, 2005 [Page 9] Internet-Draft iCal-Basic June 2005 3. Registration Information The Calendaring and Scheduling Core Object Specification is intended for use as a MIME content type. However, the implementation of the memo is in no way limited solely as a MIME content type. 3.1 Content Type The following text is intended to register this memo as the MIME content type "text/calendar". To: ietf-types@uninett.no Subject: Registration of MIME content type text/calendar. MIME media type name: text MIME subtype name: calendar 3.2 Parameters Required parameters: none Optional parameters: charset, method, component and optinfo The "charset" parameter is defined in [10] for other body parts. It is used to identify the default character set used within the body part. The "method" parameter is used to convey the iCalendar object method or transaction semantics for the calendaring and scheduling information. It also is an identifier for the restricted set of properties and values that the iCalendar object consists of. The parameter is to be used as a guide for applications interpreting the information contained within the body part. It SHOULD NOT be used to exclude or require particular pieces of information unless the identified method definition specifically calls for this behavior. Unless specifically forbidden by a particular method definition, a text/calendar content type can contain any set of properties permitted by the Calendaring and Scheduling Core Object Specification. The "method" parameter MUST be the same value as that specified in the "METHOD" component property in the iCalendar object. If one is present, the other MUST also be present. The value for the "method" parameter is defined as follows: method = 1*(ALPHA / DIGIT / "-") Royer Expires December 26, 2005 [Page 10] Internet-Draft iCal-Basic June 2005 ; IANA registered iCalendar object method The "component" parameter conveys the type of iCalendar calendar component within the body part. If the iCalendar object contains more than one calendar component type, then multiple component parameters MUST be specified. The value for the "component" parameter is defined as follows: component = "VFREEBUSY" / x-name / iana-token) The "optinfo" parameter conveys optional information about the iCalendar object within the body part. This parameter can only specify semantics already specified by the iCalendar object and that can be otherwise determined by parsing the body part. In addition, the optional information specified by this parameter MUST be consistent with that information specified by the iCalendar object. For example, it can be used to convey the "Attendee" response status to a meeting request. The parameter value consists of a string value. The parameter can be specified multiple times. This parameter MAY only specify semantics already specified by the iCalendar object and that can be otherwise determined by parsing the body part. The value for the "optinfo" parameter is defined as follows: optinfo = infovalue / qinfovalue infovalue = iana-token / x-name qinfovalue = DQUOTE (infovalue) DQUOTE 3.3 Content Header Fields Optional content header fields: Any header fields defined by [RFC 2045]. 3.4 Encoding Considerations This MIME content type can contain 8bit characters, so the use of quoted-printable or BASE64 MIME content-transfer-encodings might be necessary when iCalendar objects are transferred across protocols restricted to the 7bit repertoire. Note that a text valued property Royer Expires December 26, 2005 [Page 11] Internet-Draft iCal-Basic June 2005 in the content entity can also have content encoding of special characters using a BACKSLASH character (US-ASCII decimal 92) escapement technique. This means that content values can end up encoded twice. 3.5 Security Considerations SPOOFING - - In this memo, the "Organizer" is the only person authorized to make changes to an existing "VEVENT" calendar component and redistribute the updates to the "Attendees". An iCalendar object that maliciously changes or cancels an existing "VEVENT" or "VFREEBUSY" calendar component might be constructed by someone other than the "Organizer" and sent to the "Attendees". In addition in this memo, other than the "Organizer", an "Attendee" of a "VEVENT" calendar component is the only other person 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 can be constructed by someone other than the real "Attendee" and sent to the "Organizer". PROCEDURAL ALARMS - - An iCalendar object can be created that contains a "VEVENT" calendar component with "VALARM" calendar components. The "VALARM" calendar component can be of type PROCEDURE and can have an attachment containing some sort of executable program. Implementations that incorporate these types of alarms are subject to any virus or malicious attack that might occur as a result of executing the attachment. ATTACHMENTS - - An iCalendar object can include references to Uniform Resource Locators that can be programmed resources. Implementers and users of this memo should be aware of the network security implications of accepting and parsing such information. In addition, the security considerations observed by implementations of electronic mail systems should be followed for this memo. 3.6 Interoperability Considerations This MIME content type is intended to define a common format for conveying calendaring and scheduling information between different systems. It is heavily based on the earlier [18] industry specification. 3.7 Applications Which Use This Media Type This content-type is designed for widespread use by Internet calendaring and scheduling applications. In addition, applications in the workflow and document management area might find this content- Royer Expires December 26, 2005 [Page 12] Internet-Draft iCal-Basic June 2005 type applicable. The [3] and [2] Internet protocols directly use this content-type also. Future work on an Internet calendar access protocol will utilize this content-type too. 3.8 Additional Information This memo defines this content-type. 3.9 Magic Numbers None. 3.10 File Extensions The file extension of "ics" is to be used to designate a file containing (an arbitrary set of) calendaring and scheduling information consistent with this MIME content type. This file extension exists to be used by applications and operating systems to uniqely identify iCalendar objects that are placed into a file or sent in email. This specification makes no assumptions or recommendations about how an application stores iCalendar objects it generates or receives for use in its own calendar store. The file extension of "ifb" is to be used to designate a file containing free or busy time information consistent with this MIME content type. Macintosh file type codes: The file type code of "iCal" is to be used in Apple MacIntosh operating system environments to designate a file containing calendaring and scheduling information consistent with this MIME media type. The file type code of "iFBf" is to be used in Apple MacIntosh operating system environments to designate a file containing free or busy time information consistent with this MIME media type. 3.11 Contact for Further Information: Doug Royer 267 Kentlands Blvd., #3041 Gaithersburg, MD 20878 208-612-4639 Doug@Royer.com 3.12 Intended Usage COMMON Royer Expires December 26, 2005 [Page 13] Internet-Draft iCal-Basic June 2005 4. iCalendar Object Specification The following sections define the details of a Calendaring and Scheduling Core Object Specification. This information is intended to be an integral part of the MIME content type registration. In addition, this information can be used independent of such content registration. In particular, this memo has direct applicability for use as a calendaring and scheduling exchange format in file-, memory- or network-based transport mechanisms. 4.1 Content Lines The iCalendar object is organized into individual lines of text, called content lines. Content lines are delimited by a line break, which is a CRLF sequence (US-ASCII decimal 13, followed by US-ASCII decimal 10). Lines of text SHOULD NOT be longer than 75 octets, excluding the line break. Long content lines SHOULD be split into a multiple line representations using a line "folding" technique. That is, a long line can be split between any two characters by inserting a CRLF immediately followed by a single linear white space character (i.e., SPACE, US-ASCII decimal 32 or HTAB, US-ASCII decimal 9). Any sequence of CRLF followed immediately by a single linear white space character is ignored (i.e., removed) when processing the content type. For example the line: DESCRIPTION:This is a long description that exists on a long line. Can be represented as: DESCRIPTION:This is a lo ng description that exists on a long line. The process of moving from this folded multiple line representation to its single line representation is called "unfolding". Unfolding is accomplished by removing the CRLF character and the linear white space character that immediately follows. When parsing a content line, folded lines MUST first be unfolded according to the unfolding procedure described above. When generating a content line, lines longer than 75 octets SHOULD be folded according to the folding procedure described above. The content information associated with an iCalendar object is Royer Expires December 26, 2005 [Page 14] Internet-Draft iCal-Basic June 2005 formatted using a syntax similar to that defined by [15]. That is, the content information consists of CRLF-separated content lines. The following notation defines the lines of content in an iCalendar object: contentline = name *(";" param ) ":" value CRLF ; This ABNF is just a general definition for an initial parsing ; of the content line into its property name, parameter list, ; and value string ; When parsing a content line, folded lines MUST first ; be unfolded according to the unfolding procedure ; described above. When generating a content line, lines ; longer than 75 octets SHOULD be folded according to ; the folding procedure described above. name = x-name / iana-token iana-token = 1*(ALPHA / DIGIT / "-") ; iCalendar identifier registered with IANA x-name = "X-" [vendorid "-"] 1*(ALPHA / DIGIT / "-") ; Reservered for experimental use. Not intended for use in ; released products. vendorid = 3*(ALPHA / DIGIT) ;Vendor identification param = param-name "=" param-value *("," param-value) ; Each property defines the specific ABNF for the parameters ; allowed on the property. Refer to specific properties for ; precise parameter ABNF. param-name = iana-token / x-token param-value = paramtext / quoted-string paramtext = *SAFE-CHAR value = *VALUE-CHAR quoted-string = DQUOTE *QSAFE-CHAR DQUOTE NON-US-ASCII = %x80-F8 ; Use restricted by charset parameter ; on outer MIME object (UTF-8 preferred) Royer Expires December 26, 2005 [Page 15] Internet-Draft iCal-Basic June 2005 QSAFE-CHAR = WSP / %x21 / %x23-7E / NON-US-ASCII ; Any character except CTLs and DQUOTE SAFE-CHAR = WSP / %x21 / %x23-2B / %x2D-39 / %x3C-7E / NON-US-ASCII ; Any character except CTLs, DQUOTE, ";", ":", "," VALUE-CHAR = WSP / %x21-7E / NON-US-ASCII ; Any textual character CR = %x0D ; carriage return LF = %x0A ; line feed CRLF = CR LF ; Internet standard newline CTL = %x00-08 / %x0A-1F / %x7F ; Controls ALPHA = %x41-5A / %x61-7A ; A-Z / a-z DIGIT = %x30-39 ; 0-9 DQUOTE = %x22 ; Quotation Mark WSP = SPACE / HTAB SPACE = %x20 HTAB = %x09 The property value component of a content line has a format that is property specific. Refer to the section describing each property for a definition of this format. All names of properties, property parameters, enumerated property values and property parameter values are case-insensitive. However, all other property values are case-sensitive, unless otherwise stated. 4.1.1 List and Field Separators Some properties and parameters allow a list of values. Values in a Royer Expires December 26, 2005 [Page 16] Internet-Draft iCal-Basic June 2005 list of values MUST be separated by a COMMA character (US-ASCII decimal 44). There is no significance to the order of values in a list. For those parameter values (such as those that specify URI values) that are specified in quoted-strings, the individual quoted- strings are separated by a COMMA character (US-ASCII decimal 44). Some property values are defined in terms of multiple parts. These structured property values MUST have their value parts separated by a SEMICOLON character (US-ASCII decimal 59). Some properties allow a list of parameters. Each property parameter in a list of property parameters MUST be separated by a SEMICOLON character (US-ASCII decimal 59). Property parameters with values containing a COLON, a SEMICOLON or a COMMA character MUST be placed in quoted text. For example, in the following properties a SEMICOLON is used to separate property parameters from each other, and a COMMA is used to separate property values in a value list. ATTENDEE;RSVP=TRUE;ROLE=REQ-PARTICIPANT:MAILTO: jsmith@host.com RDATE;VALUE=DATE:19970304,19970504,19970704,19970904 4.1.2 Multiple Values Some properties defined in the iCalendar object can have multiple values. The general rule for encoding multi-valued items is to simply create a new content line for each value, including the property name. However, it should be noted that some properties support encoding multiple values in a single property by separating the values with a COMMA character (US-ASCII decimal 44). Individual property definitions should be consulted for determining whether a specific property allows multiple values and in which of these two forms. 4.1.3 Binary Content Binary content information in an iCalendar object SHOULD be referenced using a URI within a property value. That is the binary content information SHOULD be placed in an external MIME entity that can be referenced by a URI from within the iCalendar object. In applications where this is not feasible, binary content information can be included within an iCalendar object, but only after first Royer Expires December 26, 2005 [Page 17] Internet-Draft iCal-Basic June 2005 encoding it into text using the "BASE64" encoding method defined in [9]. Inline binary contact SHOULD only be used in applications whose special circumstances demand that an iCalendar object be expressed as a single entity. A property containing inline binary content information MUST specify the "ENCODING" property parameter. Binary content information placed external to the iCalendar object MUST be referenced by a uniform resource identifier (URI). The following example specifies an "ATTACH" property that references an attachment external to the iCalendar object with a URI reference: ATTACH:http://xyz.com/public/quarterly-report.doc The following example specifies an "ATTACH" property with inline binary encoded content information: ATTACH;FMTTYPE=image/basic;ENCODING=BASE64;VALUE=BINARY: MIICajCCAdOgAwIBAgICBEUwDQYJKoZIhvcNAQEEBQAwdzELMAkGA1U EBhMCVVMxLDAqBgNVBAoTI05ldHNjYXBlIENvbW11bmljYXRpb25zIE <...remainder of "BASE64" encoded binary data...> 4.1.4 Character Set There is not a property parameter to declare the character set used in a property value. The default character set for an iCalendar object is UTF-8 as defined in [14]. The "charset" Content-Type parameter can be used in MIME transports to specify any other IANA registered character set. 4.2 Property Parameters A property can have attributes associated with it. These "property parameters" contain meta-information about the property or the property value. Property parameters are provided to specify such information as the location of an alternate text representation for a property value, the language of a text property value, the data type of the property value and other attributes. Property parameter values that contain the COLON (US-ASCII decimal 58), SEMICOLON (US-ASCII decimal 59) or COMMA (US-ASCII decimal 44) character separators MUST be specified as quoted-string text values. Property parameter values MUST NOT contain the DOUBLE-QUOTE (US-ASCII decimal 22) character. The DOUBLE-QUOTE (US-ASCII decimal 22) character is used as a delimiter for parameter values that contain restricted characters or URI text. For example: Royer Expires December 26, 2005 [Page 18] Internet-Draft iCal-Basic June 2005 DESCRIPTION;ALTREP="http://www.wiz.org":The Fall'98 Wild Wizards Conference - - Las Vegas, NV, USA Property parameter values that are not in quoted strings are case insensitive. The general property parameters defined by this memo are defined by the following notation: parameter = altrepparam ; Alternate text representation / cnparam ; Common name / cutypeparam ; Calendar user type / delfromparam ; Delegator / deltoparam ; Delegatee / dirparam ; Directory entry / encodingparam ; Inline encoding / fmttypeparam ; Format type / fbtypeparam ; Free/busy time type / languageparam ; Language for text / memberparam ; Group or list membership / partstatparam ; Participation status / rangeparam ; Recurrence identifier range / trigrelparam ; Alarm trigger relationship / reltypeparam ; Relationship type / roleparam ; Participation role / rsvpparam ; RSVP expectation / sentbyparam ; Sent by / valuetypeparam ; Property value data type / ianaparam ; Some other IANA registered iCalendar parameter. / xparam ; A non-standard, experimental parameter. ianaparam = iana-token "=" param-value *("," param-value) xparam =x-name "=" param-value *("," param-value) 4.2.1 Alternate Text Representation Parameter Name: ALTREP Purpose: To specify an alternate text representation for the property value. Format Definition: The property parameter is defined by the following notation: Royer Expires December 26, 2005 [Page 19] Internet-Draft iCal-Basic June 2005 altrepparam = "ALTREP" "=" DQUOTE uri DQUOTE Description: The parameter specifies a URI that points to an alternate representation for a textual property value. A property specifying this parameter MUST also include a value that reflects the default representation of the text value. The individual URI parameter values MUST each be specified in a quoted-string. Example: DESCRIPTION;ALTREP="CID:":Project XYZ Review Meeting will include the following agenda items: (a) Market Overview, (b) Finances, (c) Project Management The "ALTREP" property parameter value might point to a "text/html" content portion. Content-Type:text/html Content-Id:

Project XYZ Review Meeting will include the following agenda items:

  1. Market Overview
  2. Finances
  3. Project Management

4.2.2 Common Name Parameter Name: CN Purpose: To specify the common name to be associated with the calendar user specified by the property. Format Definition: The property parameter is defined by the following notation: cnparam = "CN" "=" param-value Description: This parameter can be specified on properties with a CAL-ADDRESS value type. The parameter specifies the common name to be associated with the calendar user specified by the property. The parameter value is text. The parameter value can be used for display text to be associated with the calendar address specified by the property. Example: Royer Expires December 26, 2005 [Page 20] Internet-Draft iCal-Basic June 2005 ORGANIZER;CN="John Smith":MAILTO:jsmith@host.com 4.2.3 Calendar User Type Parameter Name: CUTYPE Purpose: To specify the type of calendar user specified by the property. Format Definition: The property parameter is defined by the following notation: cutypeparam = "CUTYPE" "=" ("INDIVIDUAL" ; An individual / "GROUP" ; A group of individuals / "RESOURCE" ; A physical resource / "ROOM" ; A room resource / "UNKNOWN" ; Otherwise not known / x-name ; Experimental type / iana-token) ; Other IANA registered ; type ; Default is INDIVIDUAL Description: This parameter can be specified on properties with a CAL-ADDRESS value type. The parameter identifies the type of calendar user specified by the property. If not specified on a property that allows this parameter, the default is INDIVIDUAL. Example: ATTENDEE;CUTYPE=GROUP:MAILTO:ietf-calsch@imc.org 4.2.4 Delegators Parameter Name: DELEGATED-FROM DELEGATED-FROM is not in iCal-Basic. 4.2.5 Delegatees Parameter Name: DELEGATED-TO DELEGATED-FROM is not in iCal-Basic. Royer Expires December 26, 2005 [Page 21] Internet-Draft iCal-Basic June 2005 4.2.6 Directory Entry Reference Parameter Name: DIR Purpose: To specify reference to a directory entry associated with the calendar user specified by the property. Format Definition: The property parameter is defined by the following notation: dirparam = "DIR" "=" DQUOTE uri DQUOTE Description: This parameter can be specified on properties with a CAL-ADDRESS value type. The parameter specifies a reference to the directory entry associated with the calendar user specified by the property. The parameter value is a URI. The individual URI parameter values MUST each be specified in a quoted-string. Example: ORGANIZER;DIR="ldap://host.com:6666/o=eDABC%20Industries,c=3DUS?? (cn=3DBJim%20Dolittle)":MAILTO:jimdo@host1.com 4.2.7 Inline Encoding Parameter Name: ENCODING Purpose: To specify an alternate inline encoding for the property value. Format Definition: The property parameter is defined by the following notation: encodingparam = "ENCODING" "=" ("8BIT" ; "8bit" text encoding is defined in [RFC.2045] / "BASE64" ; "BASE64" binary encoding format is defined in [RFC.2045] / iana-token ; Some other IANA registered iCalendar encoding type / x-name) ; A non-standard, experimental encoding type Description: The property parameter identifies the inline encoding used in a property value. The default encoding is "8BIT", corresponding to a property value consisting of text. The "BASE64" encoding type corresponds to a property value encoded using the Royer Expires December 26, 2005 [Page 22] Internet-Draft iCal-Basic June 2005 "BASE64" encoding defined in [9]. If the value type parameter is ";VALUE=BINARY", then the inline encoding parameter MUST be specified with the value ";ENCODING=BASE64". Example: ATTACH;FMTYPE=IMAGE/JPEG;ENCODING=BASE64;VALUE=BINARY:MIICajC CAdOgAwIBAgICBEUwDQYJKoZIhvcNAQEEBQAwdzELMAkGA1UEBhMCVVMxLDA qBgNVBAoTI05ldHNjYXBlIENvbW11bmljYXRpb25zIENvcnBvcmF0aW9uMRw <...remainder of "BASE64" encoded binary data...> 4.2.8 Format Type Parameter Name: FMTTYPE Purpose: To specify the content type of a referenced object. Format Definition: The property parameter is defined by the following notation: fmttypeparam = "FMTTYPE" "=" iana-token ; A IANA registered content type / x-name ; A non-standard content type Description: This parameter can be specified on properties that are used to reference an object. The parameter specifies the content type of the referenced object. For example, on the "ATTACH" property, a FTP type URI value does not, by itself, necessarily convey the type of content associated with the resource. The parameter value MUST be the TEXT for either an IANA registered content type or a non-standard content type. Example: ATTACH;FMTTYPE=application/binary:ftp://domain.com/pub/docs/ agenda.doc 4.2.9 Free/Busy Time Type Parameter Name: FBTYPE Purpose: To specify the free or busy time type. Royer Expires December 26, 2005 [Page 23] Internet-Draft iCal-Basic June 2005 Format Definition: The property parameter is defined by the following notation: fbtypeparam = "FBTYPE" "=" ("FREE" / "BUSY" / "BUSY-UNAVAILABLE" / "BUSY-TENTATIVE" / x-name ; Some experimental iCalendar data type. / iana-token) ; Some other IANA registered iCalendar data type. Description: The parameter specifies the free or busy time type. The value FREE indicates that the time interval is free for scheduling. The value BUSY indicates that the time interval is busy because one or more events have been scheduled for that interval. The value BUSY-UNAVAILABLE indicates that the time interval is busy and that the interval can not be scheduled. The value BUSY-TENTATIVE indicates that the time interval is busy because one or more events have been tentatively scheduled for that interval. If not specified on a property that allows this parameter, the default is BUSY. Example: The following is an example of this parameter on a FREEBUSY property. FREEBUSY;FBTYPE=BUSY:19980415T133000Z/19980415T170000Z 4.2.10 Language Parameter Name: LANGUAGE Purpose: To specify the language for text values in a property or property parameter. Format Definition: The property parameter is defined by the following notation: languageparam = "LANGUAGE" "=" language language = 4.3.2 Boolean Value Name: BOOLEAN Purpose: This value type is used to identify properties that contain either a "TRUE" or "FALSE" Boolean value. Formal Definition: The value type is defined by the following notation: boolean = "TRUE" / "FALSE" Description: These values are case insensitive text. No additional content value encoding (i.e., BACKSLASH character encoding) is defined for this value type. Example: The following is an example of a hypothetical property that Royer Expires December 26, 2005 [Page 29] Internet-Draft iCal-Basic June 2005 has a BOOLEAN value type: GIBBERISH:TRUE 4.3.3 Calendar User Address Value Name: CAL-ADDRESS Purpose: This value type is used to identify properties that contain a calendar user address. Formal Definition: The value type is as defined by the following notation: cal-address = uri Description: The value is a URI as defined by [7] or any other IANA registered form for a URI. When used to address an Internet email transport address for a calendar user, the value MUST be a MAILTO URI, as defined by [7]. No additional content value encoding (i.e., BACKSLASH character encoding) is defined for this value type. Example: ATTENDEE:MAILTO:jane_doe@host.com 4.3.4 Date Value Name: DATE Purpose: This value type is used to identify values that contain a calendar date. Formal Definition: The value type is defined by the following notation: date = date-value date-value = date-fullyear date-month date-mday date-fullyear = 4DIGIT date-month = 2DIGIT ;01-12 date-mday = 2DIGIT ;01-28, 01-29, 01-30, 01-31 ;based on month/year Description: If the property permits, multiple "date" values are Royer Expires December 26, 2005 [Page 30] Internet-Draft iCal-Basic June 2005 specified as a COMMA character (US-ASCII decimal 44) separated list of values. The format for the value type is expressed as the [ISO 8601] complete representation, basic format for a calendar date. The textual format specifies a four-digit year, two-digit month, and two- digit day of the month. There are no separator characters between the year, month and day component text. No additional content value encoding (i.e., BACKSLASH character encoding) is defined for this value type. Example: The following represents July 14, 1997: 19970714 4.3.5 Date-Time Value Name: DATE-TIME Purpose: This value type is used to identify values that specify a precise calendar date and time of day. Formal Definition: The value type is defined by the following notation: date-time = date "T" time ;As specified in the date and time ;value definitions Description: If the property permits, multiple "date-time" values are specified as a COMMA character (US-ASCII decimal 44) separated list of values. No additional content value encoding (i.e., BACKSLASH character encoding) is defined for this value type. The "DATE-TIME" data type is used to identify values that contain a precise calendar date and time of day. The format is based on the [4] complete representation, basic format for a calendar date and time of day. The text format is a concatenation of the "date", followed by the LATIN CAPITAL LETTER T character (US-ASCII decimal 84) time designator, followed by the "time" format. The "DATE-TIME" data type expresses time values in three forms: The form of date and time with UTC offset MUST NOT be used. For example, the following is not valid for a date-time value: DTSTART:19980119T230000-0800 ;Invalid time format FORM #1: DATE WITH LOCAL TIME Royer Expires December 26, 2005 [Page 31] Internet-Draft iCal-Basic June 2005 The date with local time form is simply a date-time value that does not contain the UTC designator nor does it reference a time zone. For example, the following represents Janurary 18, 1998, at 11 PM: DTSTART:19980118T230000 Date-time values of this type are said to be "floating" and are not bound to any time zone in particular. They are used to represent the same hour, minute, and second value regardless of which time zone is currently being observed. For example, an event can be defined that indicates that an individual will be busy from 11:00 AM to 1:00 PM every day, no matter which time zone the person is in. In these cases, a local time can be specified. The recipient of an iCalendar object with a property value consisting of a local time, without any relative time zone information, SHOULD interpret the value as being fixed to whatever time zone the ATTENDEE is in at any given moment. This means that two ATTENDEEs, in different time zones, receiving the same event definition as a floating time, may be participating in the event at different actual times. Floating time SHOULD only be used where that is the reasonable behavior. In most cases, a fixed time is desired. To properly communicate a fixed time in a property value, UTC time must be specified. Time zones are not in iCal-Basic and may be added in a future extension. FORM #2: DATE WITH UTC TIME The date with UTC time, or absolute time, is identified by a LATIN CAPITAL LETTER Z suffix character (US-ASCII decimal 90), the UTC designator, appended to the time value. For example, the following represents January 19, 1998, at 0700 UTC: DTSTART:19980119T070000Z FORM #3: DATE WITH LOCAL TIME AND TIME ZONE REFERENCE Are not supported or needed in iCal-Basic implementations. Time zone information is needed only when including recurring rules (the RFC- 2445 RRULE and EXRULE) and they may be added at a later time. Example: The following represents July 14, 1997, at 1:30 PM in New York City in each of the two time formats, using the "DTSTART" property. DTSTART:19970714T133000 ;Local time DTSTART:19970714T173000Z ;UTC time A time value MUST ONLY specify 60 seconds when specifying the Royer Expires December 26, 2005 [Page 32] Internet-Draft iCal-Basic June 2005 periodic "leap second" in the time value. For example: COMPLETED:19970630T235960Z 4.3.6 Duration Value Name: DURATION Purpose: This value type is used to identify properties that contain a duration of time. Formal Definition: The value type is defined by the following notation: dur-value = (["+"] / "-") "P" (dur-date / dur-time / dur-week) dur-date = dur-day [dur-time] dur-time = "T" (dur-of-time) dur-week = 1*DIGIT "W" dur-of-time = 1*DIGIT "H" dur-minute dur-minute = 1*DIGIT "M" dur-second dur-second = 1*DIGIT "S" dur-day = 1*DIGIT "D" Description: If the property permits, multiple "duration" values are specified by a COMMA character (US-ASCII decimal 44) separated list of values. The format is expressed as the [4] basic format for the duration of time. The format can represent durations in terms of weeks, days, hours, minutes, and seconds. No additional content value encoding (i.e., BACKSLASH character encoding) are defined for this value type. One week (1W) is defined to mean seven days (7D). One day (1D) is defined to mean add one to the date part. If is what you really need is 24 hours, use "24H" and not "1D". This matters when one or more instances have their start or end time across a time zone change within one single time zone (Wall clock has 1 hour added to it or subtracted from it when the time zone changes). And the time part is not effected. So "1D" added to a date part when the time zone changes could mean that the appointment is 23 hours long or 25 hours long, depending on how the time zone changes. In all cases, add to the 'date' part and not to the 'time' part for 'dur-day' duration parts. One hour (1H) is defined to mean 60 minutes (60M). Royer Expires December 26, 2005 [Page 33] Internet-Draft iCal-Basic June 2005 One minute (1M) is defined to mean 60 seconds (60S). If an implementation cares about that leap second, then send the time in seconds (Example: Send "61S" or "1M1S" and not "1M"). The 'dur-hour', 'dur-minute', 'dur-minute', and 'dur-day' property value parts do not need to be normalized. Example: One implementation may send "3600S" and another "1H" and they are equivelent. The value part "1D" is not always equivelent to "24H". The order of addition is 'W', 'D', 'H', 'M', then 'S'. In that order. Note that some existing calendaring implementations include the 'dur- time' parts that are zero and others do not. For example one implementation might send a value of "+PT30S" and another implementation might send "+PT0H0M30S". The ABNF above shows that the abbreivated format is deprecated. The new 'dur-of-time' always includes the 'H', 'M', and 'S' parts even when they are zero. This is done so that there is exactly one way to send the time part of a duration. Example: A duration of 15 days, 5 hours and 20 seconds would be: P15DT5H0M20S A duration of 7 weeks would be: P7W Royer Expires December 26, 2005 [Page 34] Internet-Draft iCal-Basic June 2005 Given DTSTART:20050401T235959 DURATATION:+P1DT0H0M1S Add 1D gives: End time of: 20050402T235959 Then add 1S should result in. End time of: 20050403T000000 Given: DTSTART:20050401T235959 DURATION:+P1W Add 1W gives: End time of: 20040408T235959 4.3.7 Float Value Name: FLOAT Deprecated. Was only used with GEO which is deprecated. 4.3.8 Integer Value Name:INTEGER Purpose: This value type is used to identify properties that contain a signed integer value. Formal Definition: The value type is defined by the following notation: integer = (["+"] / "-") 1*DIGIT Description: If the property permits, multiple "integer" values are specified by a COMMA character (US-ASCII decimal 44) separated list of values. The valid range for "integer" is -2147483648 to 2147483647. If the sign is not specified, then the value is assumed to be positive. No additional content value encoding (i.e., BACKSLASH character Royer Expires December 26, 2005 [Page 35] Internet-Draft iCal-Basic June 2005 encoding) is defined for this value type. Example: 1234567890 -1234567890 +1234567890 432109876 4.3.9 Period of Time Value Name: PERIOD Purpose: This value type is used to identify values that contain a precise period of time. Formal Definition: The data type is defined by the following notation: period = period-explicit / period-start period-explicit = date-time "/" date-time ; [ISO.8601] complete representation basic format for a period of ; time consisting of a start and end. The start MUST be before the ; end. period-start = date-time "/" dur-value ; [ISO.8601] complete representation basic format for a period of ; time consisting of a start and positive duration of time. Description: If the property permits, multiple "period" values are specified by a COMMA character (US-ASCII decimal 44) separated list of values. There are two forms of a period of time. First, a period of time is identified by its start and its end. This format is expressed as the [4] complete representation, basic format for "DATE- TIME" start of the period, followed by a SOLIDUS character (US-ASCII decimal 47), followed by the "DATE-TIME" of the end of the period. The start of the period MUST be before the end of the period. Second, a period of time can also be defined by a start and a positive duration of time. The format is expressed as the [4] complete representation, basic format for the "DATE-TIME" start of the period, followed by a SOLIDUS character (US-ASCII decimal 47), followed by the [4] basic format for "DURATION" of the period. Example: The period starting at 18:00:00 UTC, on January 1, 1997 and ending at 07:00:00 UTC on January 2, 1997 would be: Royer Expires December 26, 2005 [Page 36] Internet-Draft iCal-Basic June 2005 19970101T180000Z/19970102T070000Z The period start at 18:00:00 on January 1, 1997 and lasting 5 hours and 30 minutes would be: 19970101T180000Z/PT5H30M No additional content value encoding (i.e., BACKSLASH character encoding) is defined for this value type. 4.3.10 Recurrence Rule Value Name: RECUR Not in iCal-Basic. 4.3.11 Text Value Name: TEXT Purpose This value type is used to identify values that contain human readable text. Formal Definition: The character sets supported by this revision of iCalendar are UTF-8 and US ASCII thereof. The applicability to other character sets is for future work. The value type is defined by the following notation. text = *(TSAFE-CHAR / ":" / DQUOTE / ESCAPED-CHAR) ; Folded according to description above ESCAPED-CHAR = "\\" / "\;" / "\," / "\N" / "\n") ; \\ encodes \, \N or \n encodes newline ; \; encodes ;, \, encodes , TSAFE-CHAR = %x20-21 / %x23-2B / %x2D-39 / %x3C-5B %x5D-7E / NON-US-ASCII ; Any character except CTLs not needed by the current ; character set, DQUOTE, ";", ":", "\", "," Note: Certain other character sets may require modification of the above definitions, but this is beyond the scope of this document. Description: If the property permits, multiple "text" values are specified by a COMMA character (US-ASCII decimal 44) separated list of values. The language in which the text is represented can be controlled by Royer Expires December 26, 2005 [Page 37] Internet-Draft iCal-Basic June 2005 the "LANGUAGE" property parameter. An intentional formatted text line break MUST only be included in a "TEXT" property value by representing the line break with the character sequence of BACKSLASH (US-ASCII decimal 92), followed by a LATIN SMALL LETTER N (US-ASCII decimal 110) or a LATIN CAPITAL LETTER N (US-ASCII decimal 78), that is "\n" or "\N". The "TEXT" property values may also contain special characters that are used to signify delimiters, such as a COMMA character for lists of values or a SEMICOLON character for structured values. In order to support the inclusion of these special characters in "TEXT" property values, they MUST be escaped with a BACKSLASH character. A BACKSLASH character (US-ASCII decimal 92) in a "TEXT" property value MUST be escaped with another BACKSLASH character. A COMMA character in a "TEXT" property value MUST be escaped with a BACKSLASH character (US-ASCII decimal 92). A SEMICOLON character in a "TEXT" property value MUST be escaped with a BACKSLASH character (US-ASCII decimal 92). However, a COLON character in a "TEXT" property value SHALL NOT be escaped with a BACKSLASH character.Example: A multiple line value of: Project XYZ Final Review Conference Room - 3B Come Prepared. would be represented as: Project XYZ Final Review\nConference Room - 3B\nCome Prepared. 4.3.12 Time Value Name: TIME Purpose: This value type is used to identify values that contain a time of day. Formal Definition: The data type is defined by the following notation: time = time-hour time-minute time-second [time-utc] time-hour = 2DIGIT ;00-23 time-minute = 2DIGIT ;00-59 time-second = 2DIGIT ;00-60 ;The "60" value is used to account for "leap" seconds. Royer Expires December 26, 2005 [Page 38] Internet-Draft iCal-Basic June 2005 time-utc = "Z" Description: If the property permits, multiple "time" values are specified by a COMMA character (US-ASCII decimal 44) separated list of values. No additional content value encoding (i.e., BACKSLASH character encoding) is defined for this value type. The "TIME" data type is used to identify values that contain a time of day. The format is based on the [4] complete representation, basic format for a time of day. The text format consists of a two- digit 24-hour of the day (i.e., values 0-23), two- digit minute in the hour (i.e., values 0-59), and two-digit seconds in the minute (i.e., values 0-60). The seconds value of 60 MUST only to be used to account for "leap" seconds. Fractions of a second are not supported by this format. In parallel to the "DATE-TIME" definition above, the "TIME" data type expresses time values in three forms: The form of time with UTC offset MUST NOT be used. For example, the following is NOT VALID for a time value: 230000-0800 ;Invalid time format FORM #1 LOCAL TIME The local time form is simply a time value that does not contain the UTC designator nor does it reference a time zone. For example, 11:00 PM: 230000 Time values of this type are said to be "floating" and are not bound to any time zone in particular. They are used to represent the same hour, minute, and second value regardless of which time zone is currently being observed. For example, an event can be defined that indicates that an individual will be busy from 11:00 AM to 1:00 PM every day, no matter which time zone the person is in. In these cases, a local time can be specified. The recipient of an iCalendar object with a property value consisting of a local time, without any relative time zone information, SHOULD interpret the value as being fixed to whatever time zone the ATTENDEE is in at any given moment. This means that two ATTENDEEs may participate in the same event at different UTC times; floating time SHOULD only be used where that is reasonable behavior. In most cases, a fixed time is desired. To properly communicate a fixed time in a property value, UTC time MUST be specified. Time Royer Expires December 26, 2005 [Page 39] Internet-Draft iCal-Basic June 2005 zones are not in iCal-Basic and may be added in a future extension. FORM #2: UTC TIME UTC time, or absolute time, is identified by a LATIN CAPITAL LETTER Z suffix character (US-ASCII decimal 90), the UTC designator, appended to the time value. For example, the following represents 07:00 AM UTC: 070000Z FORM #3: LOCAL TIME AND TIME ZONE REFERENCE Are not supported or needed in iCal-Basic implementations. Time zone information is needed only when including recurring rules and they may be added at a later time. Example: The following represents 8:30 AM in New York in Winter, five hours behind UTC, in each of the two formats using the "X- TIMEOFDAY" non-standard property: X-TIMEOFDAY:083000 X-TIMEOFDAY:133000Z 4.3.13 URI Value Name: URI Purpose: This value type is used to identify values that contain a uniform resource identifier (URI) type of reference to the property value. Formal Definition: The data type is defined by the following notation: uri = Description: This data type might be used to reference binary information, for values that are large, or otherwise undesirable to include directly in the iCalendar object. The URI value formats in RFC 1738, RFC 2111 and any other IETF registered value format can be specified. Any IANA registered URI format can be used. These include, but are not limited to, those defined in RFC 1738 and RFC 2111. Royer Expires December 26, 2005 [Page 40] Internet-Draft iCal-Basic June 2005 When a property parameter value is a URI value type, the URI MUST be specified as a quoted-string value. No additional content value encoding (i.e., BACKSLASH character encoding) is defined for this value type. Example: The following is a URI for a network file: http://host1.com/my-report.txt 4.3.14 UTC Offset Value Name: UTC-OFFSET Not needed unil recurrence rules are added. 4.4 iCalendar Object The Calendaring and Scheduling Core Object is a collection of calendaring and scheduling information. Typically, this information will consist of a single iCalendar object. However, multiple iCalendar objects can be sequentially grouped together. The first line and last line of the iCalendar object MUST contain a pair of iCalendar object delimiter strings. The syntax for an iCalendar object is as follows: icalobject = 1*("BEGIN" ":" "VCALENDAR" CRLF icalbody "END" ":" "VCALENDAR" CRLF) The following is a simple example of an iCalendar object: BEGIN:VCALENDAR VERSION:2.0 PRODID:-//hacksw/handcal//NONSGML v1.0//EN BEGIN:VEVENT DTSTART:19970714T170000Z DURATION:PT3H30M SUMMARY:Bastille Day Party END:VEVENT END:VCALENDAR 4.5 Property A property is the definition of an individual attribute describing a calendar or a calendar component. A property takes the form defined Royer Expires December 26, 2005 [Page 41] Internet-Draft iCal-Basic June 2005 by the "contentline" notation defined in section 4.1.1. The following is an example of a property: DTSTART:19960415T133000Z This memo imposes no ordering of properties within an iCalendar object. Property names, parameter names and enumerated parameter values are case insensitive. For example, the property name "DUE" is the same as "due" and "Due", DTSTART:19980714T120000 is the same as DtStart: 19980714T120000. 4.6 Calendar Components The body of the iCalendar object consists of a sequence of calendar properties and one or more calendar components. The calendar properties are attributes that apply to the calendar as a whole. The calendar components are collections of properties that express a particular calendar semantic. For example, the calendar component can specify an event entry, free/busy time information, or an alarm. The body of the iCalendar object is defined by the following notation: Royer Expires December 26, 2005 [Page 42] Internet-Draft iCal-Basic June 2005 icalbody = calprops component calprops = 2*( ; 'prodid' and 'version' are both REQUIRED, ; but MUST NOT occur more than once prodid /version / ; 'calscale' and 'method' are optional, ; but MUST NOT occur more than once calscale / method / x-prop ) component = 1*(eventc / freebusyc / / timezonec / iana-comp / x-comp) iana-comp = "BEGIN" ":" iana-token CRLF 1*contentline "END" ":" iana-token CRLF x-comp = "BEGIN" ":" x-name CRLF 1*contentline "END" ":" x-name CRLF An iCalendar object MUST include the "PRODID" and "VERSION" calendar properties. In addition, it MUST include at least one calendar component. Special forms of iCalendar objects are possible to publish just busy time (i.e., only a "VFREEBUSY" calendar component) information. In addition, a complex iCalendar object is possible that is used to capture a complete snapshot of the contents of a calendar (e.g., composite of many different calendar components). More commonly, an iCalendar object will consist of just a single "VEVENT" calendar component. 4.6.1 Event Component Component Name: "VEVENT" Royer Expires December 26, 2005 [Page 43] Internet-Draft iCal-Basic June 2005 Purpose: Provide a grouping of component properties that describe an event. Format Definition: A "VEVENT" calendar component is defined by the following notation: eventc = "BEGIN" ":" "VEVENT" CRLF eventprop *alarmc "END" ":" "VEVENT" CRLF eventprop = *( ; the following are optional, ; but MUST NOT occur more than once class / created / description / dtstart / last-mod / location / organizer / priority / dtstamp / seq / status / summary / transp / uid / url / duration ; the following are optional, ; and MAY occur more than once attach / attendee / categories / comment / contact / rstatus / related / resources / x-prop / rdate ) Description: A "VEVENT" calendar component is a grouping of component properties, and possibly including "VALARM" calendar components, that represents a scheduled amount of time on a calendar. For example, it can be an activity; such as a one-hour long, department meeting from 8:00 AM to 9:00 AM, tomorrow. Generally, an event will take up time on an individual calendar. Hence, the event will appear as an opaque interval in a search for busy time. Alternately, the event can have its Time Transparency set to "TRANSPARENT" in order to prevent blocking of the event in searches for busy time. The "VEVENT" is also the calendar component used to specify an anniversary or daily reminder within a calendar. These events have a DATE value type for the "DTSTART" property instead of the default data type of DATE-TIME. The anniversary type of "VEVENT" can span more than one date (i.e, "DURATION" property value is set to a value that is more than 24 hours). The "DTSTART" property for a "VEVENT" specifies the inclusive start Royer Expires December 26, 2005 [Page 44] Internet-Draft iCal-Basic June 2005 of the event. The "DURATION" property for a "VEVENT" calendar component specifies the non-inclusive end of the event. For cases where a "VEVENT" calendar component specifies a "DTSTART" property with a DATE data type but no "DURATION" property, the events non- inclusive end is the end of the calendar date specified by the "DTSTART" property. For cases where a "VEVENT" calendar component specifies a "DTSTART" property with a DATE-TIME data type but no "DURATION" property, the event ends on the same calendar date and time of day specified by the "DTSTART" property (It consumes no time). The "VEVENT" calendar component cannot be nested within another calendar component. Example: The following is an example of the "VEVENT" calendar component used to represent a meeting that will also be opaque to searches for busy time: BEGIN:VEVENT UID:19970901T130000Z-123401@host.com DTSTAMP:19970901T130000Z DTSTART:19970903T163000Z DURATION:PT3H30M SUMMARY:Annual Employee Review CLASS:PRIVATE CATEGORIES:BUSINESS,HUMAN RESOURCES END:VEVENT The following is an example of the "VEVENT" calendar component used to represent a reminder that will not be opaque, but rather transparent, to searches for busy time: BEGIN:VEVENT UID:19970901T130000Z-123402@host.com DTSTAMP:19970901T1300Z DTSTART:19970401T163000Z DURATION:PT7H30M SUMMARY:Laurel is in sensitivity awareness class. CLASS:PUBLIC CATEGORIES:BUSINESS,HUMAN RESOURCES TRANSP:TRANSPARENT END:VEVENT The following is an example of the "VEVENT" calendar component used to represent an anniversary that will occur once. Since it takes up no time, it will not appear as opaque in a search for busy time; no matter what the value of the "TRANSP" property indicates: Royer Expires December 26, 2005 [Page 45] Internet-Draft iCal-Basic June 2005 BEGIN:VEVENT UID:19970901T130000Z-123403@host.com DTSTAMP:19970901T1300Z DTSTART:19971102 SUMMARY:Our Blissful Anniversary CLASS:CONFIDENTIAL CATEGORIES:ANNIVERSARY,PERSONAL,SPECIAL OCCASION END:VEVENT 4.6.2 To-do Component Component Name: VTODO VTODO is not in iCal-Basic. 4.6.3 Journal Component Component Name: VJOURNAL VJOURNAL is not in iCal-Basic. 4.6.4 Free/Busy Component Component Name: VFREEBUSY Purpose: Provide a grouping of component properties that describe either a request for free/busy time, describe a response to a request for free/busy time or describe a published set of busy time. Formal Definition: A "VFREEBUSY" calendar component is defined by the following notation: Royer Expires December 26, 2005 [Page 46] Internet-Draft iCal-Basic June 2005 freebusyc = "BEGIN" ":" "VFREEBUSY" CRLF fbprop "END" ":" "VFREEBUSY" CRLF fbprop = *( ; the following are optional, ; but MUST NOT occur more than once contact / dtstart / duration / dtstamp / organizer / uid / url / ; the following are optional, ; and MAY occur more than once attendee / comment / freebusy / rstatus / x-prop ) Description: A "VFREEBUSY" calendar component is a grouping of component properties that represents either a request for, a reply to a request for free or busy time information or a published set of busy time information. When used to request free/busy time information, the "ATTENDEE" property specifies the calendar users whose free/busy time is being requested; the "ORGANIZER" property specifies the calendar user who is requesting the free/busy time; the "DTSTART" and "DURATION" properties specify the window of time for which the free/busy time is being requested; the "UID" and "DTSTAMP" properties are specified to assist in proper sequencing of multiple free/busy time requests. When used to reply to a request for free/busy time, the "ATTENDEE" property specifies the calendar user responding to the free/busy time request; the "ORGANIZER" property specifies the calendar user that originally requested the free/busy time; the "FREEBUSY" property specifies the free/busy time information (if it exists); and the "UID" and "DTSTAMP" properties are specified to assist in proper sequencing of multiple free/busy time replies. When used to publish busy time, the "ORGANIZER" property specifies the calendar user associated with the published busy time; the "DTSTART" and "DURATION" properties specify an inclusive time window that surrounds the busy time information; the "FREEBUSY" property specifies the published busy time information; and the "DTSTAMP" property specifies the date/time that iCalendar object was created. Royer Expires December 26, 2005 [Page 47] Internet-Draft iCal-Basic June 2005 The "VFREEBUSY" calendar component cannot be nested within another calendar component. Multiple "VFREEBUSY" calendar components can be specified within an iCalendar object. This permits the grouping of Free/Busy information into logical collections, such as monthly groups of busy time information. The "VFREEBUSY" calendar component is intended for use in iCalendar object methods involving requests for free time, requests for busy time, requests for both free and busy, and the associated replies. Free/Busy information is represented with the "FREEBUSY" property. This property provides a terse representation of time periods. One or more "FREEBUSY" properties can be specified in the "VFREEBUSY" calendar component. When present in a "VFREEBUSY" calendar component, the "DTSTART" and "DURATION" properties SHOULD be specified prior to any "FREEBUSY" properties. In a free time request, these properties can be used in combination with the "DURATION" property to represent a request for a duration of free time within a specified window of time. Example: The following is an example of a "VFREEBUSY" calendar component used to request free or busy time information: BEGIN:VFREEBUSY ORGANIZER:MAILTO:jane_doe@host1.com ATTENDEE:MAILTO:john_public@host2.com DTSTART:19971015T050000Z DURATION:PT24H DTSTAMP:19970901T083000Z END:VFREEBUSY The following is an example of a "VFREEBUSY" calendar component used to reply to the request with busy time information: BEGIN:VFREEBUSY ORGANIZER:MAILTO:jane_doe@host1.com ATTENDEE:MAILTO:john_public@host2.com DTSTAMP:19970901T100000Z FREEBUSY;VALUE=PERIOD:19971015T050000Z/PT8H30M, 19971015T160000Z/PT5H30M,19971015T223000Z/PT6H30M URL:http://host2.com/pub/busy/jpublic-01.ifb COMMENT:This iCalendar file contains busy time information for the next three months. END:VFREEBUSY The following is an example of a "VFREEBUSY" calendar component used to publish busy time information. Royer Expires December 26, 2005 [Page 48] Internet-Draft iCal-Basic June 2005 BEGIN:VFREEBUSY ORGANIZER:jsmith@host.com DTSTART:19980313T141711Z DURATION:PT672H FREEBUSY:19980314T233000Z/19980315T003000Z FREEBUSY:19980316T153000Z/19980316T163000Z FREEBUSY:19980318T030000Z/19980318T040000Z URL:http://www.host.com/calendar/busytime/jsmith.ifb END:VFREEBUSY 4.6.5 Time Zone Component Component Name: VTIMEZONE VTIMEZONE is not in iCal-Basic as it is not needed until recurrence rules are added. Single instances can be specified in GMT. 4.6.6 Alarm Component Component Name: VALARM Purpose: Provide a grouping of component properties that define an alarm. Formal Definition: A "VALARM" calendar component is defined by the following notation: alarmc = "BEGIN" ":" "VALARM" CRLF (audioprop / dispprop / emailprop / procprop) "END" ":" "VALARM" CRLF audioprop = 2*( ; 'action' and 'trigger' are both REQUIRED, ; but MUST NOT occur more than once action / trigger / ; 'duration' and 'repeat' are both optional, ; and MUST NOT occur more than once each, ; but if one occurs, so MUST the other duration / repeat / ; the following is optional, ; but MUST NOT occur more than once Royer Expires December 26, 2005 [Page 49] Internet-Draft iCal-Basic June 2005 attach / ; the following is optional, ; and MAY occur more than once x-prop ) dispprop = 3*( ; the following are all REQUIRED, ; but MUST NOT occur more than once action / description / trigger / ; 'duration' and 'repeat' are both optional, ; and MUST NOT occur more than once each, ; but if one occurs, so MUST the other duration / repeat / ; the following is optional, ; and MAY occur more than once *x-prop ) emailprop = 5*( ; the following are all REQUIRED, ; but MUST NOT occur more than once action / description / trigger / summary ; 'duration' and 'repeat' are both optional, ; and MUST NOT occur more than once each, ; but if one occurs, so MUST the other duration / repeat / ; the following is REQUIRED, ; and MAY occur more than once attendee / ; the following are optional, Royer Expires December 26, 2005 [Page 50] Internet-Draft iCal-Basic June 2005 ; and MAY occur more than once attach / x-prop ) procprop = 3*( ; the following are all REQUIRED, ; but MUST NOT occur more than once action / attach / trigger / ; 'duration' and 'repeat' are both optional, ; and MUST NOT occur more than once each, ; but if one occurs, so MUST the other duration / repeat / ; 'description' is optional, ; and MUST NOT occur more than once description / ; the following is optional, ; and MAY occur more than once x-prop ) Description: A "VALARM" calendar component is a grouping of component properties that is a reminder or alarm for an event. For example, it may be used to define a reminder for a pending event. The "VALARM" calendar component MUST include the "ACTION" and "TRIGGER" properties. The "ACTION" property further constrains the "VALARM" calendar component in the following ways: When the action is "AUDIO", the alarm can also include one and only one "ATTACH" property, which MUST point to a sound resource, which is rendered when the alarm is triggered. When the action is "DISPLAY", the alarm MUST also include a "DESCRIPTION" property, which contains the text to be displayed when the alarm is triggered. When the action is "EMAIL", the alarm MUST include a "DESCRIPTION" property, which contains the text to be used as the message body, a Royer Expires December 26, 2005 [Page 51] Internet-Draft iCal-Basic June 2005 "SUMMARY" property, which contains the text to be used as the message subject, and one or more "ATTENDEE" properties, which contain the email address of attendees to receive the message. It can also include one or more "ATTACH" properties, which are intended to be sent as message attachments. When the alarm is triggered, the email message is sent. When the action is "PROCEDURE", the alarm MUST include one and only one "ATTACH" property, which MUST point to a procedure resource, which is invoked when the alarm is triggered. The "VALARM" calendar component MUST only appear within either a "VEVENT" calendar component. "VALARM" calendar components cannot be nested. Multiple mutually independent "VALARM" calendar components can be specified for a single "VEVENT" calendar component. The "TRIGGER" property specifies when the alarm will be triggered. The "TRIGGER" property specifies a duration prior to the start of an event. The "TRIGGER" edge may be explicitly set to be relative to the "START" or "END" of the event with the "RELATED" parameter of the "TRIGGER" property. The "TRIGGER" property value type can alternatively be set to an absolute calendar date and time of day value. In an alarm set to trigger on the "START" of an event, the "DTSTART" property MUST be present in the associated event. In an alarm in a "VEVENT" calendar component set to trigger on the "END" of the event, the "DTSTART" and "DURATION" properties MUST be present. The alarm can be defined such that it triggers repeatedly. A definition of an alarm with a repeating trigger MUST include both the "DURATION" and "REPEAT" properties. The "DURATION" property specifies the delay period, after which the alarm will repeat. The "REPEAT" property specifies the number of additional repetitions that the alarm will triggered. This repitition count is in addition to the initial triggering of the alarm. Both of these properties MUST be present in order to specify a repeating alarm. If one of these two properties is absent, then the alarm will not repeat beyond the initial trigger. The "ACTION" property is used within the "VALARM" calendar component to specify the type of action invoked when the alarm is triggered. The "VALARM" properties provide enough information for a specific action to be invoked. It is typically the responsibility of a "Calendar User Agent" (CUA) to deliver the alarm in the specified fashion. An "ACTION" property value of AUDIO specifies an alarm that causes a sound to be played to alert the user; DISPLAY specifies an alarm that causes a text message to be displayed to the user; EMAIL Royer Expires December 26, 2005 [Page 52] Internet-Draft iCal-Basic June 2005 specifies an alarm that causes an electronic email message to be delivered to one or more email addresses; and PROCEDURE specifies an alarm that causes a procedure to be executed. The "ACTION" property MUST specify one and only one of these values. In an AUDIO alarm, if the optional "ATTACH" property is included, it MUST specify an audio sound resource. The intention is that the sound will be played as the alarm effect. If an "ATTACH" property is specified that does not refer to a sound resource, or if the specified sound resource cannot be rendered (because its format is unsupported, or because it cannot be retrieved), then the CUA or other entity responsible for playing the sound may choose a fallback action, such as playing a built-in default sound, or playing no sound at all. In a DISPLAY alarm, the intended alarm effect is for the text value of the "DESCRIPTION" property to be displayed to the user. In an EMAIL alarm, the intended alarm effect is for an email message to be composed and delivered to all the addresses specified by the "ATTENDEE" properties in the "VALARM" calendar component. The "DESCRIPTION" property of the "VALARM" calendar component MUST be used as the body text of the message, and the "SUMMARY" property MUST be used as the subject text. Any "ATTACH" properties in the "VALARM" calendar component SHOULD be sent as attachments to the message. In a PROCEDURE alarm, the "ATTACH" property in the "VALARM" calendar component MUST specify a procedure or program that is intended to be invoked as the alarm effect. If the procedure or program is in a format that cannot be rendered, then no procedure alarm will be invoked. If the "DESCRIPTION" property is present, its value specifies the argument string to be passed to the procedure or program. "Calendar User Agents" that receive an iCalendar object with this category of alarm, can disable or allow the "Calendar User" to disable, or otherwise ignore this type of alarm. While a very useful alarm capability, the PROCEDURE type of alarm SHOULD be treated by the "Calendar User Agent" as a potential security risk. Example: The following example is for a "VALARM" calendar component that specifies an audio alarm that will sound at a precise time. BEGIN:VALARM TRIGGER;VALUE=DATE-TIME:19970317T133000Z REPEAT:4 DURATION:PT15M ACTION:AUDIO ATTACH;FMTTYPE=audio/basic:ftp://host.com/pub/sounds/bell-01.aud END:VALARM Royer Expires December 26, 2005 [Page 53] Internet-Draft iCal-Basic June 2005 The following example is for a "VALARM" calendar component that specifies a display alarm that will trigger 30 minutes before the scheduled start of the event of its associated component. BEGIN:VALARM TRIGGER:-PT30M REPEAT:2 DURATION:PT15M ACTION:DISPLAY DESCRIPTION:Breakfast meeting with executive\n team at 8:30 AM EST. END:VALARM The following example is for a "VALARM" calendar component that specifies an email alarm that will trigger 2 days before the scheduled due date/time of its associated component. The email has a subject, body and attachment link. BEGIN:VALARM TRIGGER:-P2D ACTION:EMAIL ATTENDEE:MAILTO:john_doe@host.com SUMMARY:*** REMINDER: SEND AGENDA FOR WEEKLY STAFF MEETING *** DESCRIPTION:A draft agenda needs to be sent out to the attendees to the weekly managers meeting (MGR-LIST). Attached is a pointer the document template for the agenda file. ATTACH;FMTTYPE=application/binary:http://host.com/templates/agen da.doc END:VALARM The following example is for a "VALARM" calendar component that specifies a procedural alarm that will trigger at a precise date/time The alarm will invoke a procedure file. BEGIN:VALARM TRIGGER;VALUE=DATE-TIME:19980101T050000Z ACTION:PROCEDURE REPEAT:23 DURATION:PT1H ATTACH;FMTTYPE=application/binary:ftp://host.com/novo- procs/felizano.exe END:VALARM 4.7 Calendar Properties The Calendar Properties are attributes that apply to the iCalendar object, as a whole. These properties do not appear within a calendar Royer Expires December 26, 2005 [Page 54] Internet-Draft iCal-Basic June 2005 component. They SHOULD be specified after the "BEGIN:VCALENDAR" property and prior to any calendar component. 4.7.1 Calendar Scale Property Name: CALSCALE Purpose: This property defines the calendar scale used for the calendar information specified in the iCalendar object. Value Type: TEXT Property Parameters: Non-standard property parameters can be specified on this property. Conformance: Property can be specified in an iCalendar object. The default value is "GREGORIAN". Description: This memo is based on the Gregorian calendar scale. The Gregorian calendar scale is assumed if this property is not specified in the iCalendar object. It is expected that other calendar scales will be defined in other specifications or by future versions of this memo. Format Definition: The property is defined by the following notation: calscale = "CALSCALE" calparam ":" calvalue CRLF calparam = *(";" xparam) calvalue = "GREGORIAN" / iana-token Example: The following is an example of this property: CALSCALE:GREGORIAN 4.7.2 Method Property Name: METHOD Purpose: This property defines the iCalendar object method associated with the calendar object. Value Type: TEXT Property Parameters: Non-standard property parameters can be specified on this property. Royer Expires December 26, 2005 [Page 55] Internet-Draft iCal-Basic June 2005 Conformance: The property can be specified in an iCalendar object. Description: When used in a MIME message entity, the value of this property MUST be the same as the Content-Type "method" parameter value. This property can only appear once within the iCalendar object. If either the "METHOD" property or the Content-Type "method" parameter is specified, then the other MUST also be specified. No methods are defined by this specification. This is the subject of other specifications, such as the iCalendar Transport-independent Interoperability Protocol (iTIP) defined by [3]. If this property is not present in the iCalendar object, then a scheduling transaction MUST NOT be assumed. In such cases, the iCalendar object is merely being used to transport a snapshot of some calendar information; without the intention of conveying a scheduling semantic. Format Definition: The property is defined by the following notation: method = "METHOD" metparam ":" metvalue CRLF metparam = *(";" xparam) metvalue = iana-token Example: The following is a hypothetical example of this property to convey that the iCalendar object is a request for a meeting: METHOD:REQUEST 4.7.3 Product Identifier Property Name: PRODID Purpose: This property specifies the identifier for the product that created the iCalendar object. Value Type: TEXT Property Parameters: Non-standard property parameters can be specified on this property. Conformance: The property MUST be specified once in an iCalendar object. Royer Expires December 26, 2005 [Page 56] Internet-Draft iCal-Basic June 2005 Description: The vendor of the implementation SHOULD assure that this is a globally unique identifier; using some technique such as an FPI value, as defined in [5]. This property SHOULD not be used to alter the interpretation of an iCalendar object beyond the semantics specified in this memo. For example, it is not to be used to further the understanding of non- standard properties. Format Definition: The property is defined by the following notation: prodid = "PRODID" pidparam ":" pidvalue CRLF pidparam = *(";" xparam) pidvalue = text ;Any text that describes the product and version ;and that is generally assured of being unique. Example: The following is an example of this property. It does not imply that English is the default language. PRODID:-//ABC Corporation//NONSGML My Product//EN 4.7.4 Version Property Name: VERSION Purpose: This property specifies the identifier corresponding to the highest version number or the minimum and maximum range of the iCalendar specification that is required in order to interpret the iCalendar object. Value Type: TEXT Property Parameters: Non-standard property parameters can be specified on this property. Conformance: This property MUST be specified by an iCalendar object, but MUST only be specified once. Description: A value of "2.0" corresponds to this memo. Format Definition: The property is defined by the following notation: Royer Expires December 26, 2005 [Page 57] Internet-Draft iCal-Basic June 2005 version = "VERSION" verparam ":" vervalue CRLF verparam = *(";" xparam) vervalue = "2.0" ;This memo / maxver / (minver ";" maxver) minver = ;Minimum iCalendar version needed to parse the iCalendar object maxver = ;Maximum iCalendar version needed to parse the iCalendar object Example: The following is an example of this property: VERSION:2.0 4.8 Component Properties The following properties can appear within calendar components, as specified by each component property definition. 4.8.1 New Properties 4.8.1.1 IANA Extensions The following properties specify descriptive information about calendar components. Property Name: EXTENSIONS Purpose: The existance of this property notifies the recipient that the sender is conforming to this specification. Value Type: The default value type for this property is multi valued TEXT. Property Parameters: Non-standard property parameters can be specified on this property. Conformance: The property MUST BE specified in "VCALENDAR" calendar components that wish to conform to this specification. The property must exist and may be empty. Description: The property MUST BE specified within "VCALENDAR" calendar components and may be empty. An empty value indicates that Royer Expires December 26, 2005 [Page 58] Internet-Draft iCal-Basic June 2005 the sender conforms to this specification and no other extensions. The value is comma separated list of extensions that are supported by the Organizer. The format for specifying RFC's is to specify the letters 'RFC' in upper case followed by the RFC number without a dash. As in 'RFC1234' and not 'RFC-1234'. Non standard extensions MUST start with "X-" or "x-" as in "x-vendor1-extension1". Support for IETF drafts is discouraged as they expire and are removed making their names reusable and with a possible different meaning at a later time. Format Definition: The property is defined by the following notation: extensions = "EXTENIONS" extparam ":" text *("," text) CRLF extparam = *(";" xparam) Example: The following are examples of this property: EXTENSION: EXTENSION:RFC1234,RFC5678 4.8.2 Descriptive Component Properties The following properties specify descriptive information about calendar components. 4.8.2.1 Attachment Property Name: ATTACH Purpose: The property provides the capability to associate a document object with a calendar component. Value Type: The default value type for this property is URI. The value type can also be set to BINARY to indicate inline binary encoded content information. Property Parameters: Non-standard, inline encoding, format type and value data type property parameters can be specified on this property. Conformance: The property can be specified in a "VEVENT" or "VALARM" calendar components. Royer Expires December 26, 2005 [Page 59] Internet-Draft iCal-Basic June 2005 Description: The property can be specified within "VEVENT" or "VALARM" calendar components. This property can be specified multiple times within an iCalendar object. Format Definition: The property is defined by the following notation: attach = "ATTACH" attparam ":" uri CRLF attach =/ "ATTACH" attparam ";" "ENCODING" "=" "BASE64" ";" "VALUE" "=" "BINARY" ":" binary attparam = *( ; the following is optional, ; but MUST NOT occur more than once (";" fmttypeparam) / ; the following is optional, ; and MAY occur more than once (";" xparam) ) Example: The following are examples of this property: ATTACH:CID:jsmith.part3.960817T083000.xyzMail@host1.com ATTACH;FMTTYPE=application/postscript:ftp://xyzCorp.com/pub/ reports/r-960812.ps 4.8.2.2 Categories Property Name: CATEGORIES Purpose: This property defines the categories for a calendar component. Value Type: TEXT Property Parameters: Non-standard and language property parameters can be specified on this property. Conformance: The property can be specified within "VEVENT" calendar components. Royer Expires December 26, 2005 [Page 60] Internet-Draft iCal-Basic June 2005 Description: This property is used to specify categories or subtypes of the calendar component. The categories are useful in searching for a calendar component of a particular type and category. Within the "VEVENT" calendar components, more than one category can be specified as a list of categories separated by the COMMA character (US-ASCII decimal 44). Format Definition: The property is defined by the following notation: categories = "CATEGORIES" catparam ":" text *("," text) CRLF catparam = *( ; the following is optional, ; but MUST NOT occur more than once (";" languageparam ) / ; the following is optional, ; and MAY occur more than once (";" xparam) ) Example: The following are examples of this property: CATEGORIES:APPOINTMENT,EDUCATION CATEGORIES:MEETING 4.8.2.3 Classification Property Name: CLASS Purpose: This property defines the access classification for a calendar component. Value Type: TEXT Property Parameters: Non-standard property parameters can be specified on this property. Conformance: The property can be specified once in a "VEVENT" calendar components. Royer Expires December 26, 2005 [Page 61] Internet-Draft iCal-Basic June 2005 Description: An access classification is only one component of the general security system within a calendar application. It provides a method of capturing the scope of the access the calendar owner intends for information within an individual calendar entry. The access classification of an individual iCalendar component is useful when measured along with the other security components of a calendar system (e.g., calendar user authentication, authorization, access rights, access role, etc.). Hence, the semantics of the individual access classifications cannot be completely defined by this memo alone. Additionally, due to the "blind" nature of most exchange processes using this memo, these access classifications cannot serve as an enforcement statement for a system receiving an iCalendar object. Rather, they provide a method for capturing the intention of the calendar owner for the access to the calendar component. Format Definition: The property is defined by the following notation: class = "CLASS" classparam ":" classvalue CRLF classparam = *(";" xparam) classvalue = "PUBLIC" / "PRIVATE" / "CONFIDENTIAL" / iana-token / x-name ;Default is PUBLIC Example: The following is an example of this property: CLASS:PUBLIC 4.8.2.4 Comment Property Name: COMMENT Purpose: This property specifies non-processing information intended to provide a comment to the calendar user. Value Type: TEXT Property Parameters: Non-standard, alternate text representation and language property parameters can be specified on this property. Conformance: This property can be specified in "VEVENT" or "VFREEBUSY" calendar components. Description: The property can be specified multiple times. Format Definition: The property is defined by the following notation: Royer Expires December 26, 2005 [Page 62] Internet-Draft iCal-Basic June 2005 comment = "COMMENT" commparam ":" text CRLF commparam = *( ; the following are optional, ; but MUST NOT occur more than once (";" altrepparam) / (";" languageparam) / ; the following is optional, ; and MAY occur more than once (";" xparam) ) Example: The following is an example of this property: COMMENT:The meeting really needs to include both ourselves and the customer. We can't hold this meeting without them. As a matter of fact\, the venue for the meeting ought to be at their site. - - John The data type for this property is TEXT. 4.8.2.5 Description Property Name: DESCRIPTION Purpose: This property provides a more complete description of the calendar component, than that provided by the "SUMMARY" property. Value Type: TEXT Property Parameters: Non-standard, alternate text representation and language property parameters can be specified on this property. Conformance: The property can be specified in the "VEVENT" or "VALARM" calendar components. Description: This property is used in the "VEVENT" to capture lengthy textual decriptions associated with the activity. This property is used in the "VALARM" calendar component to capture the display text for a DISPLAY category of alarm, to capture the body text for an EMAIL category of alarm and to capture the argument string for a PROCEDURE category of alarm. Royer Expires December 26, 2005 [Page 63] Internet-Draft iCal-Basic June 2005 Format Definition: The property is defined by the following notation: description = "DESCRIPTION" descparam ":" text CRLF descparam = *( ; the following are optional, ; but MUST NOT occur more than once (";" altrepparam) / (";" languageparam) / ; the following is optional, ; and MAY occur more than once (";" xparam) ) Example: The following is an example of the property with formatted line breaks in the property value: DESCRIPTION:Meeting to provide technical review for "Phoenix" design.\n Happy Face Conference Room. Phoenix design team MUST attend this meeting.\n RSVP to team leader. The following is an example of the property with folding of long lines: DESCRIPTION:Last draft of the new novel is to be completed for the editor's proof today. 4.8.2.6 Geographic Position Property Name: GEO Deprecated. 4.8.2.7 Location Property Name: LOCATION Purpose: The property defines the intended venue for the activity defined by a calendar component. Value Type: TEXT Property Parameters: Non-standard, alternate text representation and Royer Expires December 26, 2005 [Page 64] Internet-Draft iCal-Basic June 2005 language property parameters can be specified on this property. Conformance: This property can be specified in "VEVENT" calendar component. Description: Specific venues such as conference or meeting rooms may be explicitly specified using this property. An alternate representation may be specified that is a URI that points to directory information with more structured specification of the location. For example, the alternate representation may specify either an LDAP URI pointing to an LDAP server entry or a CID URI pointing to a MIME body part containing a vCard [16] for the location. Format Definition: The property is defined by the following notation: location = "LOCATION locparam ":" text CRLF locparam = *( ; the following are optional, ; but MUST NOT occur more than once (";" altrepparam) / (";" languageparam) / ; the following is optional, ; and MAY occur more than once (";" xparam) ) Example: The following are some examples of this property: LOCATION:Conference Room - F123, Bldg. 002 LOCATION;ALTREP="http://xyzcorp.com/conf-rooms/f123.vcf": Conference Room - F123, Bldg. 002 4.8.2.8 Percent Complete Property Name: PERCENT-COMPLETE PERCENT-COMPLETE is not in iCal-Basic. Royer Expires December 26, 2005 [Page 65] Internet-Draft iCal-Basic June 2005 4.8.2.9 Priority Property Name: PRIORITY Purpose: The property defines the relative priority for a calendar component. Value Type: INTEGER Property Parameters: Non-standard property parameters can be specified on this property. Conformance: The property can be specified in a "VEVENT" calendar component. Description: The priority is specified as an integer in the range zero to nine. A value of zero (US-ASCII decimal 48) specifies an undefined priority. A value of one (US-ASCII decimal 49) is the highest priority. A value of two (US-ASCII decimal 50) is the second highest priority. Subsequent numbers specify a decreasing ordinal priority. A value of nine (US-ASCII decimal 58) is the lowest priority. A CUA with a three-level priority scheme of "HIGH", "MEDIUM" and "LOW" is mapped into this property such that a property value in the range of one (US-ASCII decimal 49) to four (US-ASCII decimal 52) specifies "HIGH" priority. A value of five (US-ASCII decimal 53) is the normal or "MEDIUM" priority. A value in the range of six (US- ASCII decimal 54) to nine (US-ASCII decimal 58) is "LOW" priority. A CUA with a priority schema of "A1", "A2", "A3", "B1", "B2", ..., "C3" is mapped into this property such that a property value of one (US-ASCII decimal 49) specifies "A1", a property value of two (US- ASCII decimal 50) specifies "A2", a property value of three (US-ASCII decimal 51) specifies "A3", and so forth up to a property value of 9 (US-ASCII decimal 58) specifies "C3". Other integer values are reserved for future use. Within a "VEVENT" calendar component, this property specifies a priority for the event. This property may be useful when more than one event is scheduled for a given time period. Format Definition: The property is specified by the following notation: Royer Expires December 26, 2005 [Page 66] Internet-Draft iCal-Basic June 2005 priority = "PRIORITY" prioparam ":" privalue CRLF ;Default is zero prioparam = *(";" xparam) privalue = integer ;Must be in the range [0..9] ; All other values are reserved for future use The following is an example of a property with the highest priority: PRIORITY:1 The following is an example of a property with a next highest priority: PRIORITY:2 Example: The following is an example of a property with no priority. This is equivalent to not specifying the "PRIORITY" property: PRIORITY:0 4.8.2.10 Resources Property Name: RESOURCES Purpose: This property defines the equipment or resources anticipated for an activity specified by a calendar entity.. Value Type: TEXT Property Parameters: Non-standard, alternate text representation and language property parameters can be specified on this property. Conformance: This property can be specified in "VEVENT" calendar component. Description: The property value is an arbitrary text. More than one resource can be specified as a list of resources separated by the COMMA character (US-ASCII decimal 44). Format Definition: The property is defined by the following notation: Royer Expires December 26, 2005 [Page 67] Internet-Draft iCal-Basic June 2005 resources = "RESOURCES" resrcparam ":" text *("," text) CRLF resrcparam = *( ; the following are optional, ; but MUST NOT occur more than once (";" altrepparam) / (";" languageparam) / ; the following is optional, ; and MAY occur more than once (";" xparam) ) Example: The following is an example of this property: RESOURCES:EASEL,PROJECTOR,VCR RESOURCES;LANGUAGE=fr:1 raton-laveur 4.8.2.11 Status Property Name: STATUS Purpose: This property defines the overall status or confirmation for the calendar component. Value Type: TEXT Property Parameters: Non-standard property parameters can be specified on this property. Conformance: This property can be specified in "VEVENT" calendar components. Description: In a group scheduled calendar component, the property is used by the "Organizer" to provide a confirmation of the event to the "Attendees". For example in a "VEVENT" calendar component, the "Organizer" can indicate that a meeting is tentative, confirmed or cancelled. Format Definition: The property is defined by the following notation: Royer Expires December 26, 2005 [Page 68] Internet-Draft iCal-Basic June 2005 ;Status values for a "VEVENT" status = "STATUS" statparam] ":" statvalue CRLF statparam = *(";" xparam) statvalue = "TENTATIVE" ;Indicates event is ;tentative. / "CONFIRMED" ;Indicates event is ;definite. / "CANCELLED" ;Indicates event was ;cancelled. Example: The following is an example of this property for a "VEVENT" calendar component: STATUS:TENTATIVE 4.8.2.12 Summary Property Name: SUMMARY Purpose: This property defines a short summary or subject for the calendar component. Value Type: TEXT Property Parameters: Non-standard, alternate text representation and language property parameters can be specified on this property. Conformance: The property can be specified in "VEVENT" or "VALARM" calendar components. Description: This property is used in the "VEVENT" calendar components to capture a short, one line summary about the activity entry. This property is used in the "VALARM" calendar component to capture the subject of an EMAIL category of alarm. Format Definition: The property is defined by the following notation: Royer Expires December 26, 2005 [Page 69] Internet-Draft iCal-Basic June 2005 summary = "SUMMARY" summparam ":" text CRLF summparam = *( ; the following are optional, ; but MUST NOT occur more than once (";" altrepparam) / (";" languageparam) / ; the following is optional, ; and MAY occur more than once (";" xparam) ) Example: The following is an example of this property: SUMMARY:Department Party 4.8.3 Date and Time Component Properties The following properties specify date and time related information in calendar components. 4.8.3.1 Date/Time Completed Property Name: COMPLETED COMPLETED is not in iCal-Basic. 4.8.3.2 Date/Time End Property Name: DTEND Deprecated, use DURATION. 4.8.3.3 Date/Time Due Property Name: DUE DUE is not in iCal-Basic. 4.8.3.4 Date/Time Start Property Name: DTSTART Royer Expires December 26, 2005 [Page 70] Internet-Draft iCal-Basic June 2005 Purpose: This property specifies when the calendar component begins. Value Type: The default value type is DATE-TIME. The time value MUST be one of the forms defined for the DATE-TIME value type. The value type can be set to a DATE value type. Property Parameters: Non-standard and VALUE data type property parameters can be specified on this property. Conformance: This property can be specified in the "VEVENT", "VFREEBUSY" calendar components. Description: Within the "VEVENT" calendar component, this property defines the start date and time for the event. The property is REQUIRED in "VEVENT" calendar components. Events can have a start date/time but no end date/time. In that case, the event does not take up any time. Within the "VFREEBUSY" calendar component, this property defines the start date and time for the free or busy time information. The time MUST be specified in UTC time. Format Definition: The property is defined by the following notation: dtstart = "DTSTART" dtstparam ":" dtstval CRLF dtstparam = *( ; the following are optional, ; but MUST NOT occur more than once (";" "VALUE" "=" ("DATE-TIME" / "DATE")) / ; the following is optional, ; and MAY occur more than once *(";" xparam) ) dtstval = date-time / date ;Value MUST match value type Example: The following is an example of this property: DTSTART:19980118T073000Z Royer Expires December 26, 2005 [Page 71] Internet-Draft iCal-Basic June 2005 4.8.3.5 Duration Property Name: DURATION Purpose: The property specifies a positive duration of time. Value Type: DURATION Property Parameters: Non-standard property parameters can be specified on this property. Conformance: The property can be specified in "VEVENT", "VFREEBUSY" or "VALARM" calendar components. Description: In a "VEVENT" calendar component the property may be used to specify a duration of the event, instead of an explicit end date/time. In a "VFREEBUSY" calendar component the property may be used to specify the interval of free time being requested. Format Definition: The property is defined by the following notation: duration = "DURATION" durparam ":" dur-value CRLF ;consisting of a positive duration of time. durparam = *(";" xparam) Example: The following is an example of this property that specifies an interval of time of 1 hour and zero minutes and zero seconds: DURATION:PT1H0M0S The following is an example of this property that specifies an interval of time of 15 minutes. DURATION:PT15M 4.8.3.6 Free/Busy Time Property Name: FREEBUSY Purpose: The property defines one or more free or busy time intervals. Value Type: PERIOD. The date and time values MUST be in an UTC time format. Property Parameters: Non-standard or free/busy time type property Royer Expires December 26, 2005 [Page 72] Internet-Draft iCal-Basic June 2005 parameters can be specified on this property. Conformance: The property can be specified in a "VFREEBUSY" calendar component. Property Parameter: "FBTYPE" and non-standard parameters can be specified on this property. Description: These time periods can be specified as either a start and end date-time or a start date-time and duration. The date and time MUST be a UTC time format. "FREEBUSY" properties within the "VFREEBUSY" calendar component SHOULD be sorted in ascending order, based on start time and then end time, with the earliest periods first. The "FREEBUSY" property can specify more than one value, separated by the COMMA character (US-ASCII decimal 44). In such cases, the "FREEBUSY" property values SHOULD all be of the same "FBTYPE" property parameter type (e.g., all values of a particular "FBTYPE" listed together in a single property). Format Definition: The property is defined by the following notation: freebusy = "FREEBUSY" fbparam ":" fbvalue CRLF fbparam = *( ; the following is optional, ; but MUST NOT occur more than once (";" fbtypeparam) / ; the following is optional, ; and MAY occur more than once (";" xparam) ) fbvalue = period *["," period] ;Time value MUST be in the UTC time format. Example: The following are some examples of this property: Royer Expires December 26, 2005 [Page 73] Internet-Draft iCal-Basic June 2005 FREEBUSY;FBTYPE=BUSY-UNAVAILABLE:19970308T160000Z/PT8H30M FREEBUSY;FBTYPE=FREE:19970308T160000Z/PT3H,19970308T200000Z/PT1H FREEBUSY;FBTYPE=FREE:19970308T160000Z/PT3H,19970308T200000Z/PT1H, 19970308T230000Z/19970309T000000Z 4.8.3.7 Time Transparency Property Name: TRANSP Purpose: This property defines whether an event is transparent or not to busy time searches. Value Type: TEXT Property Parameters: Non-standard property parameters can be specified on this property. Conformance: This property can be specified once in a "VEVENT" calendar component. Description: Time Transparency is the characteristic of an event that determines whether it appears to consume time on a calendar. Events that consume actual time for the individual or resource associated with the calendar SHOULD be recorded as OPAQUE, allowing them to be detected by free-busy time searches. Other events, which do not take up the individual's (or resource's) time SHOULD be recorded as TRANSPARENT, making them invisible to free-busy time searches. Format Definition: The property is specified by the following notation: transp = "TRANSP" tranparam ":" transvalue CRLF tranparam = *(";" xparam) transvalue = "OPAQUE" ;Blocks or opaque on busy time searches. / "TRANSPARENT" ;Transparent on busy time searches. ;Default value is OPAQUE Example: The following is an example of this property for an event that is transparent or does not block on free/busy time searches: TRANSP:TRANSPARENT Royer Expires December 26, 2005 [Page 74] Internet-Draft iCal-Basic June 2005 The following is an example of this property for an event that is opaque or blocks on free/busy time searches: TRANSP:OPAQUE 4.8.4 Time Zone Component Properties Property Name: TZID TZID is not in iCal-Basic. 4.8.5 Time Zone Name Property Name: TZNAME TNAME is not in iCal-Basic. 4.8.6 Time Zone Offset From Property Name: TZOFFSETFROM 4.8.7 Time Zone Offset To Property Name: TZOFFSETTO TZOFFSETTO is not in iCal-Basic. 4.8.8 Time Zone URL Property Name: TZURL TZOFFSETTO is not in iCal-Basic. 4.9 Relationship Component Properties The following properties specify relationship information in calendar components. 4.9.1 Attendee Property Name: ATTENDEE Purpose: The property defines an "Attendee" within a calendar component. Value Type: CAL-ADDRESS Royer Expires December 26, 2005 [Page 75] Internet-Draft iCal-Basic June 2005 Property Parameters: Non-standard, language, calendar user type, group or list membership, participation role, participation status, RSVP expectation, delegatee, delegator, sent by, common name or directory entry reference property parameters can be specified on this property. Conformance: This property MUST be specified in an iCalendar object that specifies a group scheduled calendar entity. This property MUST NOT be specified in an iCalendar object when publishing the calendar information (e.g., NOT in an iCalendar object that specifies the publication of a calendar user's busy time, event). This property is not specified in an iCalendar object that defines calendar entities that are not group scheduled entities, but are entities only on a single user's calendar. Description: The property MUST only be specified within calendar components to specify participants, non-participants and the chair of a group scheduled calendar entity. The property is specified within an "EMAIL" category of the "VALARM" calendar component to specify an email address that is to receive the email type of iCalendar alarm. The property parameter CN is for the common or displayable name associated with the calendar address; ROLE, for the intended role that the attendee will have in the calendar component; PARTSTAT, for the status of the attendee's participation; RSVP, for indicating whether the favor of a reply is requested; CUTYPE, to indicate the type of calendar user; MEMBER, to indicate the groups that the attendee belongs to; DELEGATED-TO, to indicate the calendar users that the original request was delegated to; and DELEGATED-FROM, to indicate whom the request was delegated from; SENT-BY, to indicate whom is acting on behalf of the ATTENDEE; and DIR, to indicate the URI that points to the directory information corresponding to the attendee. These property parameters can be specified on an "ATTENDEE" property a "VEVENT" calendar component. They MUST not be specified in an "ATTENDEE" property in a "VFREEBUSY" or "VALARM" calendar component. If the LANGUAGE property parameter is specified, the identified language applies to the CN parameter. A recipient delegated a request MUST inherit the RSVP and ROLE values from the attendee that delegated the request to them. Multiple attendees can be specified by including multiple "ATTENDEE" properties within the calendar component. Format Definition: The property is defined by the following notation: Royer Expires December 26, 2005 [Page 76] Internet-Draft iCal-Basic June 2005 attendee = "ATTENDEE" attparam ":" cal-address CRLF attparam = *( ; the following are optional, ; but MUST NOT occur more than once (";" cutypeparam) / (";"memberparam) / (";" roleparam) / (";" partstatparam) / (";" rsvpparam) / (";" deltoparam) / (";" delfromparam) / (";" sentbyparam) / (";"cnparam) / (";" dirparam) / (";" languageparam) / ; the following is optional, ; and MAY occur more than once (";" xparam) ) The following is an example of this property used for specifying multiple attendees to an event: ORGANIZER:MAILTO:jsmith@host1.com ATTENDEE;ROLE=REQ-PARTICIPANT;PARTSTAT=TENTATIVE;CN=Henry Cabot :MAILTO:hcabot@host2.com ATTENDEE;ROLE=REQ-PARTICIPANT;DELEGATED-FROM="MAILTO:bob@host.com" ;PARTSTAT=ACCEPTED;CN=Jane Doe:MAILTO:jdoe@host1.com The following is an example of this property with a URI to the directory information associated with the attendee: ATTENDEE;CN=John Smith;DIR="ldap://host.com:6666/o=eDABC% 20Industries,c=3DUS??(cn=3DBJim%20Dolittle)":MAILTO:jimdo@ host1.com The following is an example of this property with "delegatee" and "delegator" information for an event: ORGANIZER;CN=John Smith:MAILTO:jsmith@host.com ATTENDEE;ROLE=REQ-PARTICIPANT;PARTSTAT=TENTATIVE;DELEGATED-FROM= "MAILTO:iamboss@host2.com";CN=Henry Cabot:MAILTO:hcabot@ host2.com ATTENDEE;ROLE=NON-PARTICIPANT;PARTSTAT=DELEGATED;DELEGATED-TO= "MAILTO:hcabot@host2.com";CN=The Big Cheese:MAILTO:iamboss @host2.com ATTENDEE;ROLE=REQ-PARTICIPANT;PARTSTAT=ACCEPTED;CN=Jane Doe Royer Expires December 26, 2005 [Page 77] Internet-Draft iCal-Basic June 2005 :MAILTO:jdoe@host1.com Example: The following is an example of this property's use when another calendar user is acting on behalf of the "Attendee": ATTENDEE;SENT-BY=MAILTO:jan_doe@host1.com;CN=John Smith:MAILTO: jsmith@host1.com 4.9.2 Contact Property Name: CONTACT Purpose: The property is used to represent contact information or alternately a reference to contact information associated with the calendar component. Value Type: TEXT Property Parameters: Non-standard, alternate text representation and language property parameters can be specified on this property. Conformance: The property can be specified in a "VEVENT" or "VFREEBUSY" calendar component. Description: The property value consists of textual contact information. An alternative representation for the property value can also be specified that refers to a URI pointing to an alternate form, such as a vCard [16], for the contact information. Format Definition: The property is defined by the following notation: contact = "CONTACT" contparam ":" text CRLF contparam = *( ; the following are optional, ; but MUST NOT occur more than once (";" altrepparam) / (";" languageparam) / ; the following is optional, ; and MAY occur more than once (";" xparam) ) Example: The following is an example of this property referencing Royer Expires December 26, 2005 [Page 78] Internet-Draft iCal-Basic June 2005 textual contact information: CONTACT:Jim Dolittle\, ABC Industries\, +1-919-555-1234 The following is an example of this property with an alternate representation of a LDAP URI to a directory entry containing the contact information: CONTACT;ALTREP="ldap://host.com:6666/o=3DABC%20Industries\, c=3DUS??(cn=3DBJim%20Dolittle)":Jim Dolittle\, ABC Industries\, +1-919-555-1234 The following is an example of this property with an alternate representation of a MIME body part containing the contact information, such as a vCard [16] embedded in a [MIME-DIR] content- type: CONTACT;ALTREP="CID=":Jim Dolittle\, ABC Industries\, +1-919-555-1234 The following is an example of this property referencing a network resource, such as a vCard [16] object containing the contact information: CONTACT;ALTREP="http://host.com/pdi/jdoe.vcf":Jim Dolittle\, ABC Industries\, +1-919-555-1234 4.9.3 Organizer Property Name: ORGANIZER Purpose: The property defines the organizer for a calendar component. Value Type: CAL-ADDRESS Property Parameters: Non-standard, language, common name, directory entry reference, sent by property parameters can be specified on this property. Conformance: This property MUST be specified in an iCalendar object that specifies a group scheduled calendar entity. This property MUST be specified in an iCalendar object that specifies the publication of a calendar user's busy time. This property MUST NOT be specified in an iCalendar object that defines calendar entities that are not group scheduled entities, but are entities only on a single user's calendar. Royer Expires December 26, 2005 [Page 79] Internet-Draft iCal-Basic June 2005 Description: The property is specified within the "VEVENT" calendar components to specify the organizer of a group scheduled calendar entity. The property is specified within the "VFREEBUSY" calendar component to specify the calendar user requesting the free or busy time. When publishing a "VFREEBUSY" calendar component, the property is used to specify the calendar that the published busy time came from. The property has the property parameters CN, for specifying the common or display name associated with the "Organizer", DIR, for specifying a pointer to the directory information associated with the "Organizer", SENT-BY, for specifying another calendar user that is acting on behalf of the "Organizer". The non-standard parameters may also be specified on this property. If the LANGUAGE property parameter is specified, the identified language applies to the CN parameter value. Format Definition: The property is defined by the following notation: organizer = "ORGANIZER" orgparam ":" cal-address CRLF orgparam = *( ; the following are optional, ; but MUST NOT occur more than once (";" cnparam) / (";" dirparam) / (";" sentbyparam) / (";" languageparam) / ; the following is optional, ; and MAY occur more than once (";" xparam) ) Example: The following is an example of this property: ORGANIZER;CN=John Smith:MAILTO:jsmith@host1.com The following is an example of this property with a pointer to the directory information associated with the organizer: ORGANIZER;CN=JohnSmith;DIR="ldap://host.com:6666/o=3DDC%20Associ ates,c=3DUS??(cn=3DJohn%20Smith)":MAILTO:jsmith@host1.com Royer Expires December 26, 2005 [Page 80] Internet-Draft iCal-Basic June 2005 The following is an example of this property used by another calendar user who is acting on behalf of the organizer, with responses intended to be sent back to the organizer, not the other calendar user: ORGANIZER;SENT-BY="MAILTO:jane_doe@host.com": MAILTO:jsmith@host1.com 4.9.4 Recurrence ID Property Name: RECURRENCE-ID 4.9.5 Related To Property Name: RELATED-TO Deprecated. 4.9.6 Uniform Resource Locator Property Name: URL Purpose: This property defines a Uniform Resource Locator (URL) associated with the iCalendar object. Value Type: URI Property Parameters: Non-standard property parameters can be specified on this property. Conformance: This property can be specified once in the "VEVENT" or "VFREEBUSY" calendar components. Description: This property may be used in a calendar component to convey a location where a more dynamic rendition of the calendar information associated with the calendar component can be found. This memo does not attempt to standardize the form of the URI, nor the format of the resource pointed to by the property value. If the URL property and Content-Location MIME header are both specified, they MUST point to the same resource. Format Definition: The property is defined by the following notation: url = "URL" urlparam ":" uri CRLF urlparam = *(";" xparam) Royer Expires December 26, 2005 [Page 81] Internet-Draft iCal-Basic June 2005 Example: The following is an example of this property: URL:http://abc.com/pub/calendars/jsmith/mytime.ics 4.9.7 Unique Identifier Property Name: UID Purpose: This property defines the persistent, globally unique identifier for the calendar component. Value Type: TEXT Property Parameters: Non-standard property parameters can be specified on this property. Conformance: The property MUST be specified in the "VEVENT" or "VFREEBUSY" calendar components. Description: The UID itself MUST be a globally unique identifier. The generator of the identifier MUST guarantee that the identifier is unique. There are several algorithms that can be used to accomplish this. The identifier is RECOMMENDED to be the identical syntax to the [6] addr-spec. A good method to assure uniqueness is to put the domain name or a domain literal IP address of the host on which the identifier was created on the right hand side of the "@", and on the left hand side, put a combination of the current calendar date and time of day (i.e., formatted in as a DATE-TIME value) along with some other currently unique (perhaps sequential) identifier available on the system (for example, a process id number). Using a date/time value on the left hand side and a domain name or domain literal on the right hand side makes it possible to guarantee uniqueness since no two hosts should be using the same domain name or IP address at the same time. Though other algorithms will work, it is RECOMMENDED that the right hand side contain some domain identifier (either of the host itself or otherwise) such that the generator of the message identifier can guarantee the uniqueness of the left hand side within the scope of that domain. This is the method for correlating scheduling messages with the referenced "VEVENT" calendar component. This property is an important method for group scheduling applications to match requests with later replies, modifications or deletion requests. Calendaring and scheduling applications MUST generate this property in "VEVENT" calendar components to assure Royer Expires December 26, 2005 [Page 82] Internet-Draft iCal-Basic June 2005 interoperability with other group scheduling applications. This identifier is created by the calendar system that generates an iCalendar object. Implementations MUST be able to receive and persist values of at least 255 characters for this property. Format Definition: The property is defined by the following notation: uid = "UID" uidparam ":" text CRLF uidparam = *(";" xparam) Example: The following is an example of this property: UID:19960401T080045Z-4000F192713-0052@host1.com 4.10 Recurrence Component Properties In iCal-Basic there are no recurrence rules. To add instances, just re-issue the component. When all of the instances can not be described in a single "VEVENT" calendar component, then use the "METHOD" property with a value of "ADD" to signify that you are adding ZZone or more instances to an existing UID. 4.10.1 Exception Date/Times Property Name: EXDATE EXDATE is not in iCal-Basic 4.10.2 Exception Rule Property Name: EXRULE EXRULE is not in iCal-Basic 4.10.3 Recurrence Date/Times Property Name: RDATE Purpose: This property defines the list of additional date/times for a recurrence set. Value Type: The default value type for this property is DATE-TIME. The value type can be set to DATE or PERIOD. Royer Expires December 26, 2005 [Page 83] Internet-Draft iCal-Basic June 2005 Property Parameters: Non-standard, value data type and time zone identifier property parameters can be specified on this property. Conformance: The property can be specified in "VEVENT" calendar component. Description: This property can appear to define an aggregate set of repeating occurrences. The recurrence dates, if specified, are used in computing the recurrence set. The recurrence set is the complete set of recurrence instances for a calendar component. The recurrence set is generated by considering the initial "DTSTART" property along with the "RDATE" properties contained within the iCalendar object. The "DTSTART" property defines the first instance in the recurrence set. Where duplicate instances are generated by the "RDATE" properties, only one recurrence is considered. Duplicate instances are ignored. The value MUST BE in UTC or have no time zone identifier (localtime). Format Definition: The property is defined by the following notation: rdate = "RDATE" rdtparam ":" rdtval *("," rdtval) CRLF rdtparam = *( ; ; the following are optional, ; but MUST NOT occur more than once (";" "VALUE" "=" ("DATE-TIME" / "PERIOD")) ; Note that a value type of 'DATE' and 'DATE-TIME' is ; deprecated in order to avoid older end time calculations ; that were not done the same by all implementations. ; ; The following is optional, ; and MAY occur more than once ; (";" xparam) ) ; rdtval = period ; MUST BE IN UTC or local time ;Value MUST match value type If it is the Organizers intention to end an appointment at a specific date and time, use the value type of 'period-explicit' (See Section 4.3.9). Royer Expires December 26, 2005 [Page 84] Internet-Draft iCal-Basic June 2005 If it is the Organizer intention to end an appointment after a specific duration of time has elapsed, use the 'period-start' value type (See Section 4.3.9). Example: The following are examples of this property: RDATE;VALUE=PERIOD:19960403T020000Z/19960403T040000Z, 19960404T010000Z/PT3H 4.10.4 Recurrence Rule Property Name: RRULE RRULE is not in iCal-Basic 4.11 Alarm Component Properties The following properties specify alarm information in calendar components. 4.11.1 Action Property Name: ACTION Purpose: This property defines the action to be invoked when an alarm is triggered. Value Type: TEXT Property Parameters: Non-standard property parameters can be specified on this property. Conformance: This property MUST be specified once in a "VALARM" calendar component. Description: Each "VALARM" calendar component has a particular type of action associated with it. This property specifies the type of action Format Definition: The property is defined by the following notation: Royer Expires December 26, 2005 [Page 85] Internet-Draft iCal-Basic June 2005 action = "ACTION" actionparam ":" actionvalue CRLF actionparam = *(";" xparam) actionvalue = "AUDIO" / "DISPLAY" / "EMAIL" / "PROCEDURE" / iana-token / x-name Example: The following are examples of this property in a "VALARM" calendar component: ACTION:AUDIO ACTION:DISPLAY ACTION:PROCEDURE 4.11.2 Repeat Count Property Name: REPEAT Purpose: This property defines the number of time the alarm should be repeated, after the initial trigger. Value Type: INTEGER Property Parameters: Non-standard property parameters can be specified on this property. Conformance: This property can be specified in a "VALARM" calendar component. Description: If the alarm triggers more than once, then this property MUST be specified along with the "DURATION" property. Format Definition: The property is defined by the following notation: repeatcnt = "REPEAT" repparam ":" integer CRLF ;Default is "0", zero. repparam = *(";" xparam) Example: The following is an example of this property for an alarm that repeats 4 additional times with a 5 minute delay after the initial triggering of the alarm: REPEAT:4 DURATION:PT5M Royer Expires December 26, 2005 [Page 86] Internet-Draft iCal-Basic June 2005 4.11.3 Trigger Property Name: TRIGGER Purpose: This property specifies when an alarm will trigger. Value Type: The default value type is DURATION. The value type can be set to a DATE-TIME value type, in which case the value MUST specify a UTC formatted DATE-TIME value. Property Parameters: Non-standard, value data type, or trigger relationship property parameters can be specified on this property. The trigger relationship property parameter MUST only be specified when the value type is DURATION. Conformance: This property MUST be specified in the "VALARM" calendar component. Description: Within the "VALARM" calendar component, this property defines when the alarm will trigger. The default value type is DURATION, specifying a relative time for the trigger of the alarm. The default duration is relative to the start of an event that the alarm is associated with. The duration can be explicitly set to trigger from either the end or the start of the associated event with the "RELATED" parameter. A value of START will set the alarm to trigger off the start of the associated event. A value of END will set the alarm to trigger off the end of the associated event. Either a positive or negative duration may be specified for the "TRIGGER" property. An alarm with a positive duration is triggered after the associated start or end of the event. An alarm with a negative duration is triggered before the associated start or end of the event. The "RELATED" property parameter is not valid if the value type of the property is set to DATE-TIME (i.e., for an absolute date and time alarm trigger). If a value type of DATE-TIME is specified, then the property value MUST be specified in the UTC time format. If the trigger is set relative to START, then the "DTSTART" property MUST be present in the associated "VEVENT" calendar component. If an alarm is specified for an event with the trigger set relative to the END, then the "DSTART" and "DURATION' properties MUST be present in the associated "VEVENT" calendar component. Alarms specified in an event which is defined in terms of a DATE value type will be triggered relative to 00:00:00 UTC on the Royer Expires December 26, 2005 [Page 87] Internet-Draft iCal-Basic June 2005 specified date. For example, if "DTSTART:19980205Z, then the duration trigger will be relative to19980205T000000Z. Format Definition: The property is defined by the following notation: trigger = "TRIGGER" (trigrel / trigabs) trigrel = *( ; the following are optional, ; but MUST NOT occur more than once (";" "VALUE" "=" "DURATION") / (";" trigrelparam) / ; the following is optional, ; and MAY occur more than once (";" xparam) ) ":" dur-value trigabs = 1*( ; the following is REQUIRED, ; but MUST NOT occur more than once (";" "VALUE" "=" "DATE-TIME") / ; the following is optional, ; and MAY occur more than once (";" xparam) ) ":" date-time Example: A trigger set 15 minutes prior to the start of the event. TRIGGER:-P15M A trigger set 5 minutes after the end of the event. TRIGGER;RELATED=END:P5M A trigger set to an absolute date/time. TRIGGER;VALUE=DATE-TIME:19980101T050000Z Royer Expires December 26, 2005 [Page 88] Internet-Draft iCal-Basic June 2005 4.12 Change Management Component Properties The following properties specify change management information in calendar components. 4.12.1 Date/Time Created Property Name: CREATED Purpose: This property specifies the date and time that the calendar information was created by the calendar user agent in the calendar store. Note: This is analogous to the creation date and time for a file in the file system. Value Type: DATE-TIME Property Parameters: Non-standard property parameters can be specified on this property. Conformance: The property can be specified once in "VEVENT" calendar components. Description: The date and time is a UTC value. Format Definition: The property is defined by the following notation: created = "CREATED" creaparam ":" date-time CRLF creaparam = *(";" xparam) Example: The following is an example of this property: CREATED:19960329T133000Z 4.12.2 Date/Time Stamp Property Name: DTSTAMP Purpose: The property indicates the date/time that the instance of the iCalendar object was created. Value Type: DATE-TIME Property Parameters: Non-standard property parameters can be specified on this property. Royer Expires December 26, 2005 [Page 89] Internet-Draft iCal-Basic June 2005 Conformance: This property MUST be included in the "VEVENT" or "VFREEBUSY" calendar components. Description: The value MUST be specified in the UTC time format. This property is also useful to protocols such as [2] that have inherent latency issues with the delivery of content. This property will assist in the proper sequencing of messages containing iCalendar objects. This property is different than the "CREATED" and "LAST-MODIFIED" properties. These two properties are used to specify when the particular calendar data in the calendar store was created and last modified. This is different than when the iCalendar object representation of the calendar service information was created or last modified. Format Definition: The property is defined by the following notation: dtstamp = "DTSTAMP" stmparam ":" date-time CRLF stmparam = *(";" xparam) Example: DTSTAMP:19971210T080000Z 4.12.3 Last Modified Property Name: LAST-MODIFIED Purpose: The property specifies the date and time that the information associated with the calendar component was last revised in the calendar store. Note: This is analogous to the modification date and time for a file in the file system. Value Type: DATE-TIME Property Parameters: Non-standard property parameters can be specified on this property. Conformance: This property can be specified in the "VEVENT" calendar components. Description: The property value MUST be specified in the UTC time Royer Expires December 26, 2005 [Page 90] Internet-Draft iCal-Basic June 2005 format. Format Definition: The property is defined by the following notation: last-mod = "LAST-MODIFIED" lstparam ":" date-time CRLF lstparam = *(";" xparam) Example: The following is are examples of this property: LAST-MODIFIED:19960817T133000Z 4.12.4 Sequence Number Property Name: SEQUENCE Purpose: This property defines the revision sequence number of the calendar component within a sequence of revisions. Value Type: integer Property Parameters: Non-standard property parameters can be specified on this property. Conformance: The property can be specified in "VEVENT" calendar component. Description: When a calendar component is created, its sequence number is zero (US-ASCII decimal 48). It is monotonically incremented by the "Organizer's" CUA each time the "Organizer" makes a revision to the calendar component. Any change to a component requires the "SEQUENCE" property value to be incremented. The "Organizer" includes this property in an iCalendar object that it sends to an "Attendee" to specify the current version of the calendar component. The "Attendee" includes this property in an iCalendar object that it sends to the "Organizer" to specify the version of the calendar component that the "Attendee" is referring to. A change to the sequence number is not the mechanism that an "Organizer" uses to request a response from the "Attendees". The "RSVP" parameter on the "ATTENDEE" property is used by the "Organizer" to indicate that a response from the "Attendees" is requested. Royer Expires December 26, 2005 [Page 91] Internet-Draft iCal-Basic June 2005 Format Definition: This property is defined by the following notation: seq = "SEQUENCE" seqparam ":" integer CRLF ; Default is "0" seqparam = *(";" xparam) Example: The following is an example of this property for a calendar component that was just created by the "Organizer". SEQUENCE:0 The following is an example of this property for a calendar component that has been revised two different times by the "Organizer". SEQUENCE:2 4.13 Miscellaneous Component Properties The following properties specify information about a number of miscellaneous features of calendar components. 4.13.1 Non-standard Properties Property Name: Any property name with a "X-" prefix Purpose: This class of property provides a framework for defining non-standard properties. Value Type: TEXT Property Parameters: Non-standard and language property parameters can be specified on this property. Conformance: This property can be specified in any calendar component. Description: The MIME Calendaring and Scheduling Content Type provides a "standard mechanism for doing non-standard things". This extension support is provided for implementers to "push the envelope" on the existing version of the memo. Extension properties are specified by property and/or property parameter names that have the prefix text of "X-" (the two character sequence: LATIN CAPITAL LETTER X character followed by the HYPEN-MINUS character). It is recommended that vendors concatenate onto this sentinel another short prefix text to identify the vendor. This will facilitate readability Royer Expires December 26, 2005 [Page 92] Internet-Draft iCal-Basic June 2005 of the extensions and minimize possible collision of names between different vendors. User agents that support this content type are expected to be able to parse the extension properties and property parameters but can ignore them. At present, there is no registration authority for names of extension properties and property parameters. The data type for this property is TEXT. Optionally, the data type can be any of the other valid data types. Format Definition: The property is defined by the following notation: x-prop = x-name *(";" xparam) [";" languageparam] ":" text CRLF ; Lines longer than 75 octets should be folded Example: The following might be the ABC vendor's extension for an audio-clip form of subject property: X-ABC-MMSUBJ;X-ABC-MMSUBJTYPE=wave:http://load.noise.org/mysubj.wav 4.13.2 Request Status Property Name: REQUEST-STATUS Purpose: This property defines the status code returned for a scheduling request. Value Type: TEXT Property Parameters: Non-standard and language property parameters can be specified on this property. Conformance: The property can be specified in "VEVENT" or "VFREEBUSY" calendar component. Description: This property is used to return status code information related to the processing of an associated iCalendar object. The data type for this property is TEXT. The value consists of a short return status component, a longer return status description component, and optionally a status-specific data component. The components of the value are separated by the SEMICOLON character (US-ASCII decimal 59). The short return status is a PERIOD character (US-ASCII decimal 46) separated 3-tuple of integers. For example, "3.1.1". The successive levels of integers provide for a successive level of status code Royer Expires December 26, 2005 [Page 93] Internet-Draft iCal-Basic June 2005 granularity. The following are initial classes for the return status code. Individual iCalendar object methods will define specific return status codes for these classes. In addition, other classes for the return status code may be defined using the registration process defined later in this memo. |==============+===============================================| | Short Return | Longer Return Status Description | | Status Code | | |==============+===============================================| | 1.xx | Preliminary success. This class of status | | | of status code indicates that the request has | | | request has been initially processed but that | | | completion is pending. | |==============+===============================================| | 2.xx | Successful. This class of status code | | | indicates that the request was completed | | | successfuly. However, the exact status code | | | can indicate that a fallback has been taken. | |==============+===============================================| | 3.xx | Client Error. This class of status code | | | indicates that the request was not successful.| | | The error is the result of either a syntax or | | | a semantic error in the client formatted | | | request. Request should not be retried until | | | the condition in the request is corrected. | |==============+===============================================| | 4.xx | Scheduling Error. This class of status code | | | indicates that the request was not successful.| | | Some sort of error occurred within the | | | calendaring and scheduling service, not | | | directly related to the request itself. | |==============+===============================================| Format Definition: The property is defined by the following notation: Royer Expires December 26, 2005 [Page 94] Internet-Draft iCal-Basic June 2005 rstatus = "REQUEST-STATUS" rstatparam ":" statcode ";" statdesc [";" extdata] rstatparam = *( ; the following is optional, ; but MUST NOT occur more than once (";" languageparm) / ; the following is optional, ; and MAY occur more than once (";" xparam) ) statcode = 1*DIGIT *("." 1*DIGIT) ;Hierarchical, numeric return status code statdesc = text ;Textual status description extdata = text ;Textual exception data. For example, the offending property ;name and value or complete property line. Example: The following are some possible examples of this property. The COMMA and SEMICOLON separator characters in the property value are BACKSLASH character escaped because they appear in a text value. The 2.8 status would be returned by iCal-Basic only implementations as recurring ruules do not exist. REQUEST-STATUS:2.0;Success REQUEST-STATUS:3.1;Invalid property value;DTSTART:96-Apr-01 REQUEST-STATUS:2.8; Success\, repeating event ignored. Scheduled as a single event.;RRULE:FREQ=WEEKLY\;INTERVAL=2 REQUEST-STATUS:4.1;Event conflict. Date/time is busy. REQUEST-STATUS:3.7;Invalid calendar user;ATTENDEE: MAILTO:jsmith@host.com Royer Expires December 26, 2005 [Page 95] Internet-Draft iCal-Basic June 2005 5. iCalendar Object Examples The following examples are provided as an informational source of illustrative iCalendar objects consistent with this content type. The following example specifies a three-day conference that begins at 8:00 AM EDT, September 18, 1996 and end at 6:00 PM EDT, September 20, 1996. BEGIN:VCALENDAR PRODID:-//xyz Corp//NONSGML PDA Calendar Verson 1.0//EN VERSION:2.0 BEGIN:VEVENT DTSTAMP:19960704T120000Z UID:uid1@host.com ORGANIZER:MAILTO:jsmith@host.com DTSTART:19960918T143000Z DURATION:PT34H STATUS:CONFIRMED CATEGORIES:CONFERENCE SUMMARY:Networld+Interop Conference DESCRIPTION:Networld+Interop Conference and Exhibit\nAtlanta World Congress Center\n Atlanta, Georgia END:VEVENT END:VCALENDAR The following example specifies a group scheduled meeting that begin at 8:30 AM UTC on March 12, 1998 and end at 9:30 AM UTC on March 12, 1998. The "Organizer" has scheduled the meeting with one or more calendar users in a group. BEGIN:VCALENDAR PRODID:-//RDU Software//NONSGML HandCal//EN VERSION:2.0 BEGIN:VEVENT DTSTAMP:19980309T231000Z UID:guid-1.host1.com ORGANIZER;ROLE=CHAIR:MAILTO:mrbig@host.com ATTENDEE;RSVP=TRUE;ROLE=REQ-PARTICIPANT;CUTYPE=GROUP: MAILTO:employee-A@host.com DESCRIPTION:Project XYZ Review Meeting CATEGORIES:MEETING CLASS:PUBLIC CREATED:19980309T130000Z SUMMARY:XYZ Project Review DTSTART:19980312T083000Z DURATION:PT1H LOCATION:1CP Conference Room 4350 END:VEVENT END:VCALENDAR The following is an example of an iCalendar object passed in a MIME Royer Expires December 26, 2005 [Page 96] Internet-Draft iCal-Basic June 2005 message with a single body part consisting of a "text/calendar" Content Type. TO:jsmith@host1.com FROM:jdoe@host1.com MIME-VERSION:1.0 MESSAGE-ID: CONTENT-TYPE:text/calendar BEGIN:VCALENDAR METHOD:xyz VERSION:2.0 PRODID:-//ABC Corporation//NONSGML My Product//EN BEGIN:VEVENT DTSTAMP:19970324T1200Z SEQUENCE:0 UID:uid3@host1.com ORGANIZER:MAILTO:jdoe@host1.com ATTENDEE;RSVP=TRUE:MAILTO:jsmith@host1.com DTSTART:19970324T123000Z DURATION:PT8H30M CATEGORIES:MEETING,PROJECT CLASS:PUBLIC SUMMARY:Calendaring Interoperability Planning Meeting DESCRIPTION:Discuss how we can test c&s interoperability\n using iCalendar and other IETF standards. LOCATION:LDB Lobby ATTACH;FMTTYPE=application/postscript:ftp://xyzCorp.com/pub/ conf/bkgrnd.ps END:VEVENT END:VCALENDAR The following is an example of published busy time information. The iCalendar object might be placed in the network resource www.host.com/calendar/busytime/jsmith.ifb. Royer Expires December 26, 2005 [Page 97] Internet-Draft iCal-Basic June 2005 BEGIN:VCALENDAR VERSION:2.0 PRODID:-//RDU Software//NONSGML HandCal//EN BEGIN:VFREEBUSY ORGANIZER:MAILTO:jsmith@host.com DTSTART:19980313T141711Z DURATION:PT24H FREEBUSY:19980314T233000Z/19980315T003000Z FREEBUSY:19980316T153000Z/19980316T163000Z FREEBUSY:19980318T030000Z/19980318T040000Z URL:http://www.host.com/calendar/busytime/jsmith.ifb END:VFREEBUSY E^^&0  =QBVEQ ID" properties values are the same then the one with the larger "SEQUENCE" value is the newest. If the "UID" and "SEQUENCE" property values are the same then the one with the newer "DTSTAMP" property value is the newest. If all three are the same, then the objects are considered to be of the same age. Royer Expires December 26, 2005 [Page 100] Internet-Draft iCal-Basic June 2005 7. Registration of Content Type Elements This section provides the process for registration of MIME Calendaring and Scheduling Content Type iCalendar object methods and new or modified properties. 7.1 Registration of New and Modified iCalendar Object Methods New MIME Calendaring and Scheduling Content Type iCalendar object methods are registered by the publication of an IETF Request for Comments (RFC). Changes to an iCalendar object method are registered by the publication of a revision of the RFC defining the method. 7.2 Registration of New Properties This section defines procedures by which new properties or enumerated property values for the MIME Calendaring and Scheduling Content Type can be registered with the IANA. Non-IANA properties can be used by bilateral agreement, provided the associated properties names follow the "X-" convention. The procedures defined here are designed to allow public comment and review of new properties, while posing only a small impediment to the definition of new properties. Registration of a new property is accomplished by the following steps. 7.2.1 Define the property A property is defined by completing the following template. To: ietf-calendar@imc.org Subject: Registration of text/calendar MIME property XXX Property name: Property purpose: Property value type(s): Property parameter (s): Conformance: Description: Royer Expires December 26, 2005 [Page 101] Internet-Draft iCal-Basic June 2005 Format definition: Examples: The meaning of each field in the template is as follows. Property name: The name of the property, as it will appear in the body of an text/calendar MIME Content-Type "property: value" line to the left of the colon ":". Property purpose: The purpose of the property (e.g., to indicate a delegate for the event, etc.). Give a short but clear description. Property value type (s): Any of the valid value types for the property value needs to be specified. The default value type also needID" properties values are the same then the one with the larger "SEQUENCE" value is the newest. If the "UID" and "SEQUENCE" property values are the same then the one with the newer "DTSTAMP" property value is the newest. If all three are the same, then the objects are considered to be of the same age. Royer Expires December 26, 2005 [Page 100] Internet-Draft iCal-Basic June 2005 7. Registration of Content Type Elements This section provides the process for registration of MIME Calendaring and Scheduling Content Type iCalendar object methods and new or modified properties. 7.1 Registration of New and Modified iCalendar Object Methods New MIME Calendaring and Scheduling Content Type iCalendar object methods are registered by the publication of an IETF Request for Comments (RFC). Changes to an iCalendar object method are registered by the publication of a revision of the RFC defining the method. 7.2 Registration of New Properties This section defines procedures by which new properties or enumerated property values for the MIME Calendaring and Scheduling Content Type can be registered with the IANA. Non-IANA properties can be used by bilateral agreement, provided the associated properties names follow the "X-" convention. The procedures defined here are designed to allow public comment and review of new properties, while posing only a small impediment to the definition of new properties. Registration of a new property is accomplished by the following steps. 7.2.1 Define the property A property is defined by completing the following template. To: ietf-calendar@imc.org Subject: Registration of text/calendar MIME property XXX Property name: Property purpose: Property value type(s): Property parameter (s): Conformance: Description: Royer Expires December 26, 2005 [Page 101] Internet-Draft iCal-Basic June 2005 Format definition: Examples: The meaning of each field in the template is as follows. Property name: The name of the property, as it will appear in the body of an text/calendar MIME Content-Type "property: value" line to the left of the colon ":". Property purpose: The purpose of the property (e.g., to indicate a delegate for the event, etc.). Give a short but clear description. Property value type (s): Any of the valid value types for the property value needs to be specified. The default value type also needs to be specified. If a new value type is specified, it needs to be declared in this section. Property parameter (s): Any of the valid property parameters for the property needs to be specified. Conformance: The calendar components that the property can appear in needs to be specified. Description: Any special notes about the property, how it is to be used, etc. Format definition: The ABNF for the property definition needs to be specified. Examples: One or more examples of instances of the property needs to be specified. 7.2.2 Post the Property definition The property description MUST be posted to the new property discussion list, ietf-calendar@imc.org. 7.2.3 Allow a comment period Discussion on the new property MUST be allowed to take place on the list for a minimum of two weeks. Consensus MUST be reached on the property before proceeding to the next step. 7.2.4 Submit the property for approval Once the two-week comment period has elapsed, and the proposer is convinced consensus has been reached on the property, the Royer Expires December 26, 2005 [Page 102] Internet-Draft iCal-Basic June 2005 registration application should be submitted to the Method Reviewer for approval. The Method Reviewer is appointed to the Application Area Directors and can either accept or reject the property registration. An accepted registration should be passed on by the Method Reviewer to the IANA for inclusion in the official IANA method registry. The registration can be rejected for any of the following reasons. 1) Insufficient comment period; 2) Consensus not reached; 3) Technical deficiencies raised on the list or elsewhere have not been addressed. The Method Reviewer's decision to reject a property can be appealed by the proposer to the IESG, or the objections raised can be addressed by the proposer and the property resubmitted. 7.3 Property Change Control Existing properties can be changed using the same process by which they were registered. 1. Define the change 2. Post the change 3. Allow a comment period 4. Submit the property for approval Note that the original author or any other interested party can propose a change to an existing property, but that such changes should only be proposed when there are serious omissions or errors in the published memo. The Method Reviewer can object to a change if it is not backward compatible, but is not required to do so. Property definitions can never be deleted from the IANA registry, but properties which are no longer believed to be useful can be declared OBSOLETE by a change to their "intended use" field. Royer Expires December 26, 2005 [Page 103] Internet-Draft iCal-Basic June 2005 8. References (BOILERPLATE) This RFC contained boilerplate in this section which has been moved to the RFC2223-compliant unnumbered section "References." Royer Expires December 26, 2005 [Page 104] Internet-Draft iCal-Basic June 2005 9. Acknowledgments A hearty thanks to the IETF Calendaring and Scheduling Working Group and also the following individuals who have participated in the drafting, review and discussion of this memo: TODO Royer Expires December 26, 2005 [Page 105] Internet-Draft iCal-Basic June 2005 10. Authors' and Chairs' Addresses (BOILERPLATE) This RFC contained boilerplate in this section which has been moved to the RFC2223-compliant unnumbered section "Author's Address." Royer Expires December 26, 2005 [Page 106] Internet-Draft iCal-Basic June 2005 11. Full Copyright Statement (BOILERPLATE) This RFC contained boilerplate in this section which has been moved to the RFC2223-compliant unnumbered section "Full Copyright Statement." 12. References [1] Royer, D., "Calendar Access Protocol (CAP)", XXXXX 2005. [2] Dawson, F., Mansour, S., and S. Silverberg, "iCalendar Message- based Interoperability Protocol (IMIP)", November 1998. [3] Silverberg, S., Mansour, S., Dawson, F., and R. Hopson, "iCalendar Transport-Independent Interoperability Protocol (iTIP) : Scheduling Events, Busy Time, To-dos and Journal Entries", November 1998. [4] "ISO 8601, Data elements and interchange formats-Information interchange--Representation of dates and times International Organization for Standardization", June 1988. [5] "ISO/IEC 9070, Information Technology_SGML Support Facilities-- Registration Procedures for Public Text Owner Identifiers Second Edition, International Organization for Standardization", April 1991. [6] Crocker, D., "Standard for the Format of ARPA Internet Text Messages", August 1982. [7] Berners-Lee, T., Masinter, L., and M. McCahill, "Uniform Resource Locators (URL", December 1994. [8] Alvestrand, H., "Tags for the Identification of Languages", March 1995. [9] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) - Part One: Format of Internet Message Bodies", November 1996. [10] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) - Part Two: Media Types", November 1996. [11] Freed, N., Klensin, J., and J. Postel, "Multipurpose Internet Mail Extensions (MIME) - Part Four: Registration Procedures", January 1997. [12] Bradner, S., "Key words for use in RFCs to Indicate Requirement Royer Expires December 26, 2005 [Page 107] Internet-Draft iCal-Basic June 2005 Levels", March 1997. [13] Crocker, D. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", November 1997. [14] Yergeau, F., "UTF-8, a transformation format of ISO 10646", January 1998. [15] Howes, T., Smith, M., and F. Dawson, "A MIME Content-Type for Directory Information", September 1998. [16] Dawson, F. and T. Howes, "vCard MIME Directory Profile", September 1998. [17] Olson, A., "Time zone code and data, ftp://elsie.nci.nih.gov/pub/, updated periodically", . [18] "Internet Mail Consortium, vCalendar - The Electronic Calendaring and Scheduling Exchange Format http://www.imc.org/pdi/vcal-10.txt", September 1996, . Author's Address Doug Royer IntelliCal LLC 267 Kentlands Blvd., #3041 Gaithersburg, MD 20878 USA Phone: +1-208-612-4638 Email: Doug@IntelliCal.net URI: http://Royer.com Royer Expires December 26, 2005 [Page 108] Internet-Draft iCal-Basic June 2005 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. Disclaimer of Validity This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Copyright Statement Copyright (C) The Internet Society (2005). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Royer Expires December 26, 2005 [Page 109]