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Network Working Group D. Royer Internet-Draft IntelliCal LLC Expires: July17,29, 2005 January16,28, 2005 Basic Internet Calendaring and Scheduling Core Object Specification (iCalendar Basic)draft-royer-ical-basic-01draft-royer-ical-basic-02 Status of this Memo This document is an Internet-Draft and is subject to all provisions of section 3 of RFC 3667. 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 become aware will be disclosed, in accordance with RFC 3668. 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 July17,29, 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, recurrencerules,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 forcompatible sets of extensions.Royer Expires July17,29, 2005 [Page 1] Internet-DraftiCalendariCal-Basic January 2005 compatible sets of extensions. 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 July17,29, 2005 [Page 2] Internet-DraftiCalendariCal-Basic January 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 . . . . . . . . . . . . . . 21 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 July17,29, 2005 [Page 3] Internet-DraftiCalendariCal-Basic January 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 . . . . . . . . . . . . . . . . . . . . . . . . 33 4.3.8 Integer . . . . . . . . . . . . . . . . . . . . . . .3433 4.3.9 Period of Time . . . . . . . . . . . . . . . . . . . . 34 4.3.10 Recurrence Rule . . . . . . . . . . . . . . . . . . 35 4.3.11 Text . . . . . . . . . . . . . . . . . . . . . . . . 35 4.3.12 Time . . . . . . . . . . . . . . . . . . . . . . . . 37 4.3.13 URI . . . . . . . . . . . . . . . . . . . . . . . . 39 4.3.14 UTC Offset . . . . . . . . . . . . . . . . . . . . . 39 4.4 iCalendar Object . . . . . . . . . . . . . . . . . . . . . 39 4.5 Property . . . . . . . . . . . . . . . . . . . . . . . . . 40 4.6 Calendar Components . . . . . . . . . . . . . . . . . . . 40 4.6.1 Event Component . . . . . . . . . . . . . . . . . . . 41 4.6.2 To-do Component . . . . . . . . . . . . . . . . . . . 44 4.6.3 Journal Component . . . . . . . . . . . . . . . . . . 44 4.6.4 Free/Busy Component . . . . . . . . . . . . . . . . . 44 4.6.5 Time Zone Component . . . . . . . . . . . . . . . . . 47 4.6.6 Alarm Component . . . . . . . . . . . . . . . . . . . 47 4.7 Calendar Properties . . . . . . . . . . . . . . . . . . . 52 4.7.1 Calendar Scale . . . . . . . . . . . . . . . . . . . .5253 4.7.2 Method . . . . . . . . . . . . . . . . . . . . . . . . 53 4.7.3 Product Identifier . . . . . . . . . . . . . . . . . .5354 4.7.4 Version . . . . . . . . . . . . . . . . . . . . . . .5455 4.8 Component Properties . . . . . . . . . . . . . . . . . . .5556 4.8.1 New Properties . . . . . . . . . . . . . . . . . . . .5556 4.8.2 Descriptive Component Properties . . . . . . . . . . .5657 4.8.3 Date and Time Component Properties . . . . . . . . . .6768 4.8.4 Time Zone Component Properties . . . . . . . . . . . .7273 4.8.5 Time Zone Name . . . . . . . . . . . . . . . . . . . .7273 4.8.6 Time Zone Offset From . . . . . . . . . . . . . . . .7273 4.8.7 Time Zone Offset To . . . . . . . . . . . . . . . . .7273 4.8.8 Time Zone URL . . . . . . . . . . . . . . . . . . . .7273 4.9 Relationship Component Properties . . . . . . . . . . . .7273 4.9.1 Attendee . . . . . . . . . . . . . . . . . . . . . . .7273 4.9.2 Contact . . . . . . . . . . . . . . . . . . . . . . .7576 4.9.3 Organizer . . . . . . . . . . . . . . . . . . . . . .7677 4.9.4 Recurrence ID . . . . . . . . . . . . . . . . . . . .7879 4.9.5 Related To . . . . . . . . . . . . . . . . . . . . . .7879 4.9.6 Uniform Resource Locator . . . . . . . . . . . . . . .7879 4.9.7 Unique Identifier . . . . . . . . . . . . . . . . . .7980 4.10 Recurrence Component Properties . . . . . . . . . . . .8081 4.10.1 Exception Date/Times . . . . . . . . . . . . . . . .8081 4.10.2 Exception Rule . . . . . . . . . . . . . . . . . . .8081 4.10.3 Recurrence Date/Times . . . . . . . . . . . . . . .8081 4.10.4 Recurrence Rule . . . . . . . . . . . . . . . . . .8183 Royer Expires July17,29, 2005 [Page 4] Internet-DraftiCalendariCal-Basic January 2005 4.11 Alarm Component Properties . . . . . . . . . . . . . . .8183 4.11.1 Action . . . . . . . . . . . . . . . . . . . . . . .8183 4.11.2 Repeat Count . . . . . . . . . . . . . . . . . . . .8284 4.11.3 Trigger . . . . . . . . . . . . . . . . . . . . . .8285 4.12 Change Management Component Properties . . . . . . . . .8487 4.12.1 Date/Time Created . . . . . . . . . . . . . . . . .8487 4.12.2 Date/Time Stamp . . . . . . . . . . . . . . . . . .8487 4.12.3 Last Modified . . . . . . . . . . . . . . . . . . .8588 4.12.4 Sequence Number . . . . . . . . . . . . . . . . . .8689 4.13 Miscellaneous Component Properties . . . . . . . . . . .8790 4.13.1 Non-standard Properties . . . . . . . . . . . . . .8790 4.13.2 Request Status . . . . . . . . . . . . . . . . . . .8891 5. iCalendar Object Examples . . . . . . . . . . . . . . . . .9294 6. Recommended Practices . . . . . . . . . . . . . . . . . . .9597 7. Registration of Content Type Elements . . . . . . . . . . .9698 7.1 Registration of New and Modified iCalendar Object Methods . . . . . . . . . . . . . . . . . . . . . . . . .9698 7.2 Registration of New Properties . . . . . . . . . . . . . .9698 7.2.1 Define the property . . . . . . . . . . . . . . . . .9698 7.2.2 Post the Property definition . . . . . . . . . . . . .9799 7.2.3 Allow a comment period . . . . . . . . . . . . . . . .9799 7.2.4 Submit the property for approval . . . . . . . . . . .9799 7.3 Property Change Control . . . . . . . . . . . . . . . . .98100 8. References (BOILERPLATE) . . . . . . . . . . . . . . . . . .99101 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . .100102 10. Authors' and Chairs' Addresses (BOILERPLATE) . . . . . . . .101103 11. Full Copyright Statement (BOILERPLATE) . . . . . . . . . . .102104 12. References . . . . . . . . . . . . . . . . . . . . . . . . .102104 Author's Address . . . . . . . . . . . . . . . . . . . . . .103105 Intellectual Property and Copyright Statements . . . . . . .104106 Royer Expires July17,29, 2005 [Page 5] Internet-DraftiCalendariCal-Basic January 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 July17,29, 2005 [Page 6] Internet-DraftiCalendariCal-Basic January 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 July17,29, 2005 [Page 7] Internet-DraftiCalendariCal-Basic January 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 calendar component. Scheduling methods defined by [3] are referred Royer Expires July17,29, 2005 [Page 8] Internet-DraftiCalendariCal-Basic January 2005 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 July17,29, 2005 [Page 9] Internet-DraftiCalendariCal-Basic January 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 / "-") ; 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 Royer Expires July17,29, 2005 [Page 10] Internet-DraftiCalendariCal-Basic January 2005 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 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. Royer Expires July17,29, 2005 [Page 11] Internet-DraftiCalendariCal-Basic January 2005 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- 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. Royer Expires July17,29, 2005 [Page 12] Internet-DraftiCalendariCal-Basic January 2005 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 July17,29, 2005 [Page 13] Internet-DraftiCalendariCal-Basic January 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 formatted using a syntax similar to that defined by [15]. That is, Royer Expires July17,29, 2005 [Page 14] Internet-DraftiCalendariCal-Basic January 2005 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) QSAFE-CHAR = WSP / %x21 / %x23-7E / NON-US-ASCII Royer Expires July17,29, 2005 [Page 15] Internet-DraftiCalendariCal-Basic January 2005 ; 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 list of values MUST be separated by a COMMA character (US-ASCII Royer Expires July17,29, 2005 [Page 16] Internet-DraftiCalendariCal-Basic January 2005 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 encoding it into text using the "BASE64" encoding method defined in Royer Expires July17,29, 2005 [Page 17] Internet-DraftiCalendariCal-Basic January 2005 [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: DESCRIPTION;ALTREP="http://www.wiz.org":The Fall'98 Wild Wizards Royer Expires July17,29, 2005 [Page 18] Internet-DraftiCalendariCal-Basic January 2005 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: altrepparam = "ALTREP" "=" DQUOTE uri DQUOTE Royer Expires July17,29, 2005 [Page 19] Internet-DraftiCalendariCal-Basic January 2005 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:<part3.msg.970415T083000@host.com>":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:<part3.msg.970415T083000@host.com> <html><body> <p><b>Project XYZ Review Meeting</b> will include the following agenda items:<ol><li>Market Overview</li><li>Finances</li><li>Project Management</li></ol></p> </body></html> 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: ORGANIZER;CN="John Smith":MAILTO:jsmith@host.com Royer Expires July17,29, 2005 [Page 20] Internet-DraftiCalendariCal-Basic January 2005 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. 4.2.6 Directory Entry Reference Parameter Name: DIR Purpose: To specify reference to a directory entry associated with Royer Expires July17,29, 2005 [Page 21] Internet-DraftiCalendariCal-Basic January 2005 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 "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". Royer Expires July17,29, 2005 [Page 22] Internet-DraftiCalendariCal-Basic January 2005 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. Format Definition: The property parameter is defined by the following notation: Royer Expires July17,29, 2005 [Page 23] Internet-DraftiCalendariCal-Basic January 2005 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 = <Text identifying a language, as defined in [RFC.1766] Description: This parameter can be specified on properties with a text value type. The parameter identifies the language of the text in the property or property parameter value. The value of the "language" property parameter is that defined in [8]. For transport in a MIME entity, the Content-Language header field can be used to set the default language for the entire body part. Otherwise, no default language is assumed. Example: Royer Expires July17,29, 2005 [Page 24] Internet-DraftiCalendariCal-Basic January 2005 SUMMARY;LANGUAGE=us-EN:Company Holiday Party LOCATION;LANGUAGE=en:Germany LOCATION;LANGUAGE=no:Tyskland The following example makes use of the Quoted-Printable encoding in order to represent non-ASCII characters. LOCATION;LANGUAGE=da:K=F8benhavn LOCATION;LANGUAGE=en:Copenhagen 4.2.11 Group or List Membership Parameter Name: MEMBER Purpose: To specify the group or list membership of the calendar user specified by the property. Format Definition: The property parameter is defined by the following notation: memberparam = "MEMBER" "=" DQUOTE cal-address DQUOTE *("," DQUOTE cal-address DQUOTE) Description: This parameter can be specified on properties with a CAL-ADDRESS value type. The parameter identifies the groups or list membership for the calendar user specified by the property. The parameter value either a single calendar address in a quoted-string or a COMMA character (US-ASCII decimal 44) list of calendar addresses, each in a quoted-string. The individual calendar address parameter values MUST each be specified in a quoted-string. Example: ATTENDEE;MEMBER="MAILTO:ietf-calsch@imc.org":MAILTO:jsmith@host.com ATTENDEE;MEMBER="MAILTO:projectA@host.com","MAILTO:projectB@host. com":MAILTO:janedoe@host.com 4.2.12 Participation Status Parameter Name: PARTSTAT Purpose: To specify the participation status for the calendar user specified by the property. Royer Expires July17,29, 2005 [Page 25] Internet-DraftiCalendariCal-Basic January 2005 Format Definition: The property parameter is defined by the following notation: ; These are the participation statuses for a "VEVENT". Default is ; NEEDS-ACTION partstatparam = "PARTSTAT" "=" ("NEEDS-ACTION" ; Event needs action / "ACCEPTED" ; Event accepted / "DECLINED" ; Event declined / "TENTATIVE" ; Event tentatively ; accepted / "DELEGATED" ; Event delegated / x-name ; Experimental status / iana-token) ; Other IANA registered ; status Description: This parameter can be specified on properties with a CAL-ADDRESS value type. The parameter identifies the participation status for the calendar user specified by the property value. The parameter values differ depending on whether they are associated with a group scheduled "VEVENT". The values MUST match one of the values allowed for the given calendar component. If not specified on a property that allows this parameter, the default value is NEEDS-ACTION. Example: ATTENDEE;PARTSTAT=DECLINED:MAILTO:jsmith@host.com 4.2.13 Recurrence Identifier Range Not in iCal-Basic. 4.2.14 Relationship Type Parameter Name: RELTYPE Deprecated along with the RELATED-TO property. 4.2.15 Participation Role Parameter Name: ROLE Purpose: To specify the participation role for the calendar user specified by the property. Royer Expires July17,29, 2005 [Page 26] Internet-DraftiCalendariCal-Basic January 2005 Format Definition: The property parameter is defined by the following notation: roleparam = "ROLE" "=" ("CHAIR" ; Indicates chair of the ; calendar entity / "REQ-PARTICIPANT" ; Indicates a participant whose ; participation is required / "OPT-PARTICIPANT" ; Indicates a participant whose ; participation is optional / "NON-PARTICIPANT" ; Indicates a participant who is ; copied for information ; purposes only / x-name ; Experimental role / iana-token) ; Other IANA role ; Default is REQ-PARTICIPANT Description: This parameter can be specified on properties with a CAL-ADDRESS value type. The parameter specifies the participation role for the calendar user specified by the property in the group schedule calendar component. If not specified on a property that allows this parameter, the default value is REQ-PARTICIPANT. Example: ATTENDEE;ROLE=CHAIR:MAILTO:mrbig@host.com 4.2.16 RSVP Expectation Parameter Name: RSVP RSVP is not in iCal-Basic. 4.2.17 Sent By Parameter Name: SENT-BY SENT-BY is not in iCal-Basic. 4.2.18 Value Data Types Parameter Name: VALUE Purpose: To explicitly specify the data type format for a property value. Format Definition: The "VALUE" property parameter is defined by the Royer Expires July17,29, 2005 [Page 27] Internet-DraftiCalendariCal-Basic January 2005 following notation: valuetypeparam = "VALUE" "=" valuetype valuetype = ("BINARY" / "BOOLEAN" / "CAL-ADDRESS" / "DATE" / "DATE-TIME" / "DURATION" / "INTEGER" / "PERIOD" / "TEXT" / "TIME" / "URI" /"UTC-OFFSET" /x-name ; Some experimental iCalendar data type. / iana-token) ; Some other IANA registered iCalendar data type. Description: The parameter specifies the data type and format of the property value. The property values MUST be of a single value type. For example, a "RDATE" property cannot have a combination of DATE- TIME and TIME value types. If the property's value is the default value type, then this parameter need not be specified. However, if the property's default value type is overridden by some other allowable value type, then this parameter MUST be specified. 4.3 Property Value Data Types The properties in an iCalendar object are strongly typed. The definition of each property restricts the value to be one of the value data types, or simply value types, defined in this section. The value type for a property will either be specified implicitly as the default value type or will be explicitly specified with the "VALUE" parameter. If the value type of a property is one of the alternate valid types, then it MUST be explicitly specified with the "VALUE" parameter. 4.3.1 Binary Value Name: BINARY Purpose: This value type is used to identify properties that contain a character encoding of inline binary data. For example, an inlineRoyer Expires July 17, 2005 [Page 28] Internet-Draft iCalendar January 2005attachment of an object code might be included in an iCalendar Royer Expires July 29, 2005 [Page 28] Internet-Draft iCal-Basic January 2005 object. Formal Definition: The value type is defined by the following notation: binary = *(4b-char) [b-end] ; A "BASE64" encoded character string, as defined by [RFC.2045]. b-end = (2b-char "==") / (3b-char "=") b-char = ALPHA / DIGIT / "+" / "/" Description: Property values with this value type MUST also include the inline encoding parameter sequence of ";ENCODING=BASE64". That is, all inline binary data MUST first be character encoded using the "BASE64" encoding method defined in [9]. No additional content value encoding (i.e., BACKSLASH character encoding) is defined for this value type. Example: The following is an abridged example of a "BASE64" encoded binary value data. ATTACH;VALUE=BINARY;ENCODING=BASE64:MIICajCCAdOgAwIBAgICBEUwDQY JKoZIhvcNAQEEBQAwdzELMAkGA1UEBhMCVVMxLDAqBgNVBAoTI05ldHNjYXBlI ENvbW11bmljYXRpb25zIENvcnBvcmF0aW9uMRwwGgYDVQQLExNJbmZv <...remainder of "BASE64" encoded binary data...> 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 has a BOOLEAN value type: GIBBERISH:TRUE Royer Expires July17,29, 2005 [Page 29] Internet-DraftiCalendariCal-Basic January 2005GIBBERISH:TRUE4.3.3 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 specified as a COMMA character (US-ASCII decimal 44) separated list of values. The format for the value type is expressed as the [ISORoyer Expires July 17, 2005 [Page 30] Internet-Draft iCalendar January 20058601] 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 Royer Expires July 29, 2005 [Page 30] Internet-Draft iCal-Basic January 2005 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 The date with local time form is simply a date-time value that doesRoyer Expires July 17, 2005 [Page 31] Internet-Draft iCalendar January 2005not contain the UTC designator nor does it reference a time zone. For example, the following represents Janurary 18, 1998, at 11 PM: Royer Expires July 29, 2005 [Page 31] Internet-Draft iCal-Basic January 2005 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 recurringinstancesrules (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 periodic "leap second" in the time value. For example: COMPLETED:19970630T235960Z Royer Expires July17,29, 2005 [Page 32] Internet-DraftiCalendariCal-Basic January 2005COMPLETED:19970630T235960Z4.3.6 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-hour / dur-minute / dur-second) dur-week = 1*DIGIT "W" dur-hour = 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. Example: A duration of 15 days, 5 hours and 20 seconds would be: P15DT5H0M20S A duration of 7 weeks would be: P7W 4.3.7 Float Value Name: FLOAT Deprecated. Was only used with GEO which is deprecated. 4.3.8 Integer Value Name:INTEGER Royer Expires July17,29, 2005 [Page 33] Internet-DraftiCalendariCal-Basic January 20054.3.8 Integer Value Name:INTEGERPurpose: 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 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 ofRoyer Expires July 17, 2005 [Page 34] Internet-Draft iCalendar January 2005; 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 Royer Expires July 29, 2005 [Page 34] Internet-Draft iCal-Basic January 2005 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: 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. Royer Expires July17,29, 2005 [Page 35] Internet-DraftiCalendariCal-Basic January 2005 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 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: Royer Expires July17,29, 2005 [Page 36] Internet-DraftiCalendariCal-Basic January 2005 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. 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 Royer Expires July17,29, 2005 [Page 37] Internet-DraftiCalendariCal-Basic January 2005 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 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 recurringinstancesrules 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 Royer Expires July17,29, 2005 [Page 38] Internet-DraftiCalendariCal-Basic January 2005 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 = <As defined by any IETF RFC> 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. 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 Royer Expires July17,29, 2005 [Page 39] Internet-DraftiCalendariCal-Basic January 2005 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 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 July17,29, 2005 [Page 40] Internet-DraftiCalendariCal-Basic January 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 July17,29, 2005 [Page 41] Internet-DraftiCalendariCal-Basic January 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 July17,29, 2005 [Page 42] Internet-DraftiCalendariCal-Basic January 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 July17,29, 2005 [Page 43] Internet-DraftiCalendariCal-Basic January 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 July17,29, 2005 [Page 44] Internet-DraftiCalendariCal-Basic January 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 July17,29, 2005 [Page 45] Internet-DraftiCalendariCal-Basic January 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 July17,29, 2005 [Page 46] Internet-DraftiCalendariCal-Basic January 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 / ;the following is'duration' and 'repeat' are both optional, ;butand MUST NOT occur more than onceattacheach, ; but if one occurs, so MUST the other duration / repeat / ; the following is optional, ;and MAYbut MUST NOT occur more than oncex-propRoyer Expires July17,29, 2005 [Page 47] Internet-DraftiCalendariCal-Basic January 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 July 29, 2005 [Page 48] Internet-Draft iCal-Basic January 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 /Royer Expires July 17, 2005 [Page 48] Internet-Draft iCalendar January 2005; 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 July 29, 2005 [Page 49] Internet-Draft iCal-Basic January 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.Royer Expires July 17, 2005 [Page 49] Internet-Draft iCalendar January 2005In 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"ACTION" property is used withinalarm can be defined such that it triggers repeatedly. A definition of an alarm with a repeating trigger MUST include both the"VALARM" calendar component to specify"DURATION" and "REPEAT" properties. The "DURATION" property specifies thetype of action invoked whendelay period, after which the alarmis triggered.will repeat. The"VALARM" properties provide enough information for a specific action to be invoked. It is typically"REPEAT" property specifies theresponsibilitynumber ofa "Calendar User Agent" (CUA) to deliveradditional repetitions that the alarm will triggered. This repitition count is in addition to thespecified fashion.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 July 29, 2005 [Page 50] Internet-Draft iCal-Basic January 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 veryRoyer Expires July 17, 2005 [Page 50] Internet-Draft iCalendar January 2005useful 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 July 29, 2005 [Page 51] Internet-Draft iCal-Basic January 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.Royer Expires July 17, 2005 [Page 51] Internet-Draft iCalendar January 2005BEGIN: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 July 29, 2005 [Page 52] Internet-Draft iCal-Basic January 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:GREGORIANRoyer Expires July 17, 2005 [Page 52] Internet-Draft iCalendar January 20054.7.2 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 July 29, 2005 [Page 53] Internet-Draft iCal-Basic January 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: PRODIDRoyer Expires July 17, 2005 [Page 53] Internet-Draft iCalendar January 2005Purpose: 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 July 29, 2005 [Page 54] Internet-Draft iCal-Basic January 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 SHOUL