Network Working Group                               Frank Dawson, Lotus
Internet Draft                               Derik Stenerson, Microsoft
<draft-ietf-calsch-ical-00.txt>                        February 3,
<ietf-calsch-ical-01.txt>                                March 26, 1997
Expires August September 1997

     Internet Calendaring and Scheduling Core Object Specification
                              (iCalendar)

Status of this Memo

   This document is an Internet-Draft. 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. Internet-Drafts may be updated, replaced, or made obsolete by
   other documents at any time. It is not appropriate to use Internet-
   Drafts as reference material or to cite them other than as a "working
   draft" or "work in progress".

   To learn the current status of any Internet-Draft, please check the
   1id-abstracts.txt listing contained in the Internet-Drafts Shadow
   Directories on ds.internic.net (US East Coast), nic.nordu.net
   (Europe), ftp.isi.edu (US West Coast), or munnari.oz.au (Pacific
   Rim).

   Distribution of this document is unlimited.

Abstract

   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
   document has been defined to provide the a definition of a common
   format for openly exchanging calendaring and scheduling information
   across the Internet.

   This memo is formatted as a registration for a MIME media type per
   [RFC1521].
   [RFC 2048]. However, the format in this memo is equally applicable
   for use outside of a MIME message content type.

        [Editor NOTE: This form will be changed to reflect the new MIME
        memos in the next draft.]

   The proposed media type value is "TEXT/CALENDAR". This string would
   label a media type containing calendaring and scheduling information
   encoded as text characters formatted in a manner outlined below.

   This MIME media type provides a standard content type for capturing
   calendar event and to-do 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

Dawson/Stenerson                   1                Expires August 1997
   or using HTTP. 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.

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   This document is based on the earlier work of the vCalendar
   specification for the exchange of personal calendaring and scheduling
   information. In order to avoid confusion with this referenced work,
   this document is to be known as the iCalendar specification.

   This document also includes the format for defining content type
   profiles. A content type profile is a document that defines a set of
   usage constraints for the iCalendar Object. For example, a profile
   might be defined to specify how the iCalendar Object can be used to
   provide for a set of interpersonal scheduling messages. Such a
   profile 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 for
   a to-do calendar component.

   Table of Contents

1. Introduction........................................................4
 1.1 Definitions ......................................................5
  1.1.1
2. Basic Grammar and Conventions.......................................5
3. Definitions.........................................................5
 3.1 Alarm ............................................................6
 3.2 Busy Time ........................................................6
 3.3 Calendar Component ...............................................6
 3.4 Calendar Date ....................................................6
 3.5 Calendar Object ..................................................6
 3.6 Calendar Properties ..............................................6
 3.7 Calendar Scale ................................................5
  1.1.2 ...................................................6
 3.8 Component Properties .............................................6
 3.9 Coordinate Universal Time (UTC) ...............................5
  1.1.3 ..................................7
 3.10 Daylight Saving Time (DST) ....................................5
  1.1.4 ......................................7
 3.11 Event ...........................................................7
 3.12 Free Time .......................................................7
 3.13 Gregorian Calendar ............................................5
  1.1.5 ..............................................7
 3.14 Journal .........................................................7
 3.15 Local Time ....................................................5
  1.1.6 ......................................................7
 3.16 Period ..........................................................8
 3.17 Recurrence Rule .................................................8
 3.18 Reminder ........................................................8
 3.19 Repeating Event or To-do ........................................8
 3.20 Standard Time .................................................6
  1.1.7 ...................................................8
 3.21 Time Zone .....................................................6
2. .......................................................8
 3.22 To-do ...........................................................9
4. TEXT/CALENDAR Registration Information..............................6
3. Intended Use........................................................7
 3.1 Published specification ..........................................8
  3.1.1 Existing Message Header Fields ................................8
    3.1.1.1 Content-Type Header Field .................................8
     3.1.1.1.1 CHARSET Header Field Parameter .........................8
    3.1.1.2 Content-ID Header Field ...................................9
    3.1.1.3 Content-Language ..........................................9
    3.1.1.4 Message-ID Header Field ...................................9
    3.1.1.5 Transfer-Encoding Header Field ............................9
  3.1.2 Additional Content Type Parameter .............................9
    3.1.2.1 Profile ...................................................9
  3.1.3 Content Information..............................9
5. iCalendar Object Specification.....................................11
 5.1 Syntax Considerations ................................10
    3.1.3.1 Property .................................................10
    3.1.3.2 Delimiters ...............................................11
    3.1.3.3 Property Value Transfer Encoding .........................12
    3.1.3.4 Property Value ...........................................11
  5.1.1 Content Lines ................................................12
  5.1.2 List and Field Separators ....................................13
  5.1.3 Grouping .....................................................14
  5.1.4 Multiple Values ..............................................14
  5.1.5 Character Set .............................12
    3.1.3.5 Property Value ................................................15
  5.1.6 Language ..................................13
    3.1.3.6 Property Value Data Type .................................13
    3.1.3.7 Date and Time ............................................16
    3.1.3.8 Time Duration ............................................18 .....................................................15

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    3.1.3.9 Value Location ...........................................19
    3.1.3.10
  5.1.7 Content Encoding .............................................15
  5.1.8 Binary Property Values ..................................19
    3.1.3.11 Content ...............................................15
  5.1.9 Recurrence Rule Grammar .................................19
  3.1.4 Body Delimiter Properties ....................................20
    3.1.4.1 Calendar Set ...............................................15
  5.1.10 Data Types ..................................................16
    5.1.10.1 URL .....................................................16
    5.1.10.2 Text ....................................................16
    5.1.10.3 Date ....................................................16
    5.1.10.4 Time ....................................................17
    5.1.10.5 Date-Time ...............................................18
    5.1.10.6 Duration ................................................18
    5.1.10.7 Period of Time ..........................................19
    5.1.10.8 Boolean .................................................19
    5.1.10.9 Integer .................................................20
    5.1.10.10 Float ..................................................20
    5.1.10.11 RFC 822 Address ........................................20
    5.1.10.12 UTC Offset .............................................21
 5.2 iCalendar Object ..........................................20
    3.1.4.2 ................................................21
 5.3 Property ........................................................22
 5.4 Calendar Components .............................................22
  5.4.1 Event Component ..........................................20
    3.1.4.3 ..............................................22
  5.4.2 To-do Component ..........................................21
  3.1.5 ..............................................23
  5.4.3 Journal Component ............................................24
  5.4.4 Free/Busy Component ..........................................24
  5.4.5 Alarm Component ..............................................25
  5.4.6 Timezone Component ...........................................26
  5.4.7 Calendar Object Properties ...................................21
    3.1.5.1 Calendar Content Profile .................................21
    3.1.5.2 ..........................................28
    5.4.7.1 Calendar Scale ...........................................24
    3.1.5.3 Daylight Savings Rule ....................................24
    3.1.5.4 ...........................................28
    5.4.7.2 Geographic Position ......................................25
    3.1.5.5 ......................................29
    5.4.7.3 Product Identifier .......................................25
    3.1.5.6 Time Zone ................................................26
    3.1.5.7 .......................................29
    5.4.7.4 Profile ..................................................30
    5.4.7.5 Profile Version ..................................................26
  3.1.6 Event and To-do ..........................................30
    5.4.7.6 Source ...................................................31
    5.4.7.7 Source Name ..............................................31
    5.4.7.8 Version ..................................................31
 5.5 Component Properties .........................26
    3.1.6.1 ............................................32
    5.5.1.1 Attachment ...............................................26
    3.1.6.2 ...............................................32
    5.5.1.2 Attendee .................................................27
    3.1.6.3 Audio Reminder ...........................................32
    3.1.6.4 .................................................32
    5.5.1.3 Categories ...............................................33
    3.1.6.5 ...............................................34
    5.5.1.4 Classification ...........................................34
    3.1.6.6 ...........................................35
    5.5.1.5 Date/Time Created ........................................35
    3.1.6.7
    5.5.1.6 Date/Time Completed ......................................35
    3.1.6.8 ......................................36
    5.5.1.7 Daylight .................................................36
    5.5.1.8 Description ..............................................36
    3.1.6.9 Display Reminder .........................................36
    3.1.6.10
    5.5.1.9 Due Date/Time ...........................................37
    3.1.6.11 ............................................37
    5.5.1.10 Duration ................................................37
    3.1.6.12
    5.5.1.11 Start Date/Time .........................................38
    5.5.1.12 End Date/Time ...........................................37
    3.1.6.13 ...........................................38
    5.5.1.13 Exception Date/Times ....................................38
    3.1.6.14 ....................................39
    5.5.1.14 Exception Rule ..........................................38
    3.1.6.15 ..........................................39
    5.5.1.15 Free/Busy Time ..........................................40
    5.5.1.16 Last Modified ...........................................38
    3.1.6.16 ...........................................41
    5.5.1.17 Location ................................................39
    3.1.6.17 Mail Reminder ...........................................39
    3.1.6.18 Number Recurrences ......................................40
    3.1.6.19 ................................................41
    5.5.1.18 Priority ................................................40
    3.1.6.20 Procedure Reminder ......................................40
    3.1.6.21 ................................................42
    5.5.1.19 Related To ..............................................41
    3.1.6.22 ..............................................42

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    5.5.1.20 Recurrence Date/Times ...................................41
    3.1.6.23 ...................................43
    5.5.1.21 Recurrence Rule .........................................42
    3.1.6.24 .........................................44
    5.5.1.22 Resources ...............................................42
    3.1.6.25 ...............................................49
    5.5.1.23 Response Sequence Number ................................43
    3.1.6.26 ................................50
    5.5.1.24 Sequence Number .........................................44
    3.1.6.27 Start Date/Time .........................................44
    3.1.6.28 .........................................50
    5.5.1.25 Status ..................................................44
    3.1.6.29 ..................................................51
    5.5.1.26 Summary .................................................46
    3.1.6.30 .................................................51
    5.5.1.27 Time Transparency .......................................46
    3.1.6.31 .......................................52
    5.5.1.28 Time Zone Name ..........................................52
    5.5.1.29 Time Zone Offset ........................................53
    5.5.1.30 Time Zone Transition Time ...............................53
    5.5.1.31 Uniform Resource Locator ................................46
    3.1.6.32 ................................53
    5.5.1.32 Unique Identifier .......................................46
    3.1.6.33 .......................................54
    5.5.1.33 Non-standard Properties .................................47
 3.2 Formal .................................54
 5.6 Complete Format Definition ...............................................47
 3.3 Basic Recurrence Rule Grammar ...................................53
  3.3.1 Daily Rule ...................................................53
  3.3.2 Weekly Rule ..................................................54
  3.3.3 Monthly Rule .................................................54

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  3.3.4 Yearly Rule ..................................................55
  3.3.5 Grammar ......................................................56
  3.3.6 Grammar Glossary .............................................57
  3.3.7 Policies .....................................................58
4. ......................................55
6. Registration of Content Type Profiles..............................59
 4.1 Profiles..............................65
 6.1 Define the profile ..............................................59
 4.2 ..............................................65
 6.2 Post the profile definition .....................................60
 4.3 .....................................66
 6.3 Allow a comment period ..........................................60
 4.4 ..........................................66
 6.4 Submit the profile for approval .................................60
 4.5 .................................66
 6.5 Profile Change Control ..........................................60
 4.6 ..........................................66
 6.6 Registration of New Content Type Properties .....................61
  4.6.1 ..................................67
  6.6.1 Define the property ..........................................61
  4.6.2 ..........................................67
  6.6.2 Post the Property definition .................................62
  4.6.3 .................................68
  6.6.3 Allow a comment period .......................................62
  4.6.4 .......................................68
  6.6.4 Submit the property for approval .............................62
 4.7 Content Type .............................68
 6.7 Property Change Control ............................62
5. .........................................68
7. File extension.....................................................63
6. extension.....................................................69
8. Macintosh File Type Code...........................................63
7. Bibliography.......................................................63
8. Acknowledgments....................................................64 Code...........................................69
9. Author's Address...................................................64 References.........................................................69
10. Examples..........................................................65 Acknowledgments...................................................70
11. Author's Address..................................................70
12. iCalendar Object Examples.........................................71

1. Introduction

   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 groupware applications. This specification is intended to
   progress the level of interoperability possible between dissimilar
   calendaring and scheduling applications. This specification defines a
   MIME content type for exchanging electronic calendaring and
   scheduling information. The Internet Calendaring and Scheduling Core
   Object Specification, or iCalendar Object, iCalendar, allows for the capture and
   exchange of information normally stored within a calendaring and
   scheduling application; such as a Personal Information Manager or a
   Group Scheduling product.

   The format is suitable as an exchange format between applications or
   systems. The format is defined in terms of a MIME content type. This

Dawson/Stenerson                   4             Expires September 1997
   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 specification also provides for the definition of usage profiles
   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 appointments, to-dos and to-dos.
   journal entries. The

Dawson/Stenerson                   4                Expires August 1997 usage profiles can be used to define other
   calendaring and scheduling operations such a requesting for and
   replying with free/busy time data.

   The specification also includes a formal grammar for the content type
   to aid in the implementation of parsers and to serve as the
   definitive reference when ambiguities or questions arise in
   interpreting the descriptive prose definition of the specification.

1.1     Definitions

   Date

2. Basic Grammar and time terminology is used in every day conversations.
   However, there are precise definitions of many Conventions

   This document makes use of these terms that
   are both a descriptive prose and a more formal
   notation for defining the calendaring and scheduling format.

   The notation used by in this memo.

1.1.1   Calendar Scale

   The particular type document is the augmented BNF notation of calendar
   [RFC 822]. Readers intending on implementing this format defined in general use. For example,
   Gregorian, Buddhist Era, Japanese Emperor Era, Chinese Lunar,
   Islamic, and Jewish Calendars.

1.1.2   Coordinate Universal Time (UTC)

   The time scale maintained by the Bureau International de l'Heure
   (International Time Bureau) that forms
   this document should be familiar with this notation in order to
   properly interpret the basis specifications of a coordinated
   dissemination this document.

   All numeric and hexadecimal values used in this document are given in
   decimal notation. All names of standard frequencies properties, property parameters,
   enumerated property values and time signals. UTC is often
   incorrectly referred to property parameter values are case-
   insensitive. However, all other property values are case-sensitive,
   unless otherwise stated.

        Note: All indented editorial notes, such as GMT.

1.1.3   Daylight Saving Time (DST)

   An adjustment to local this one, are
        intended to accommodate annual changes in provide the number of
   daylight hours. DST reader with additional information that
        is also known as Advanced Time, Summer Time, or
   Legal Time. Daylight saving time adjustments in the southern
   hemisphere are opposite not essential to those in the northern hemisphere.

1.1.4   Gregorian Calendar

   A calendar scale in general use beginning in 1582. It was introduced building of a conformant implementation
        of the specifications of this document. The information is
        provided to correct an error in highlight a particular feature or characteristic of
        the Julian Calendar scale. specifications.

   The Gregorian
   Calendar scale format for the iCalendar Object is based on a solar calendar consisting the syntax of common
   years made up of 365 days and leap years made up of 366 days; both
   divided into 12 sequential months.

   Initially, this memo addresses specification of calendar information
   in terms the
   [MIME DIR] content type. While the iCalendar Object is not a profile
   of the Gregorian calendar scale.

1.1.5   Local Time

   The clock time in public use in [MIME DIR] content type, it does reuse a locale. Local time is often
   referenced by number of the customary name for
   elements from the time zone in which it is
   located. The relationship between local time [MIME DIR] specification.

3. Definitions

   Date and UTC is based on the
   offset(s) that time, as well as, calendaring and scheduling terminology are
   used in use for a particular time zone. In general, the
   formula is as follows: every day conversations. However, there are precise
   definitions of many of these terms that are used by this memo.

Dawson/Stenerson                   5             Expires August September 1997
        local time = UTC + (offset)

1.1.6   Standard

3.1 Alarm

   Also called a reminder. An activity that is an asynchronous mechanism
   for providing feedback for a pending or past event or to-do.

3.2 Busy Time

   Introduced by Sir Sanford Fleming and others around 1870, standard

   A period of time is of time on a scheme for dividing the world into zones calendar where the same
   time would there is already
   scheduled one or more events or that is otherwise not available for
   scheduling.

3.3 Calendar Component

   One of a number of entities that may be kept. The original proposal was to divide the world
   into 24 zones, each found within a calendar
   object. In particular, a calendar may be composed of calendar
   properties and event, to-do, journal, free/busy, time zone having or alarm
   calendar components. Calendar components are identified by unique
   delimiters within a width calendar object. Calendar components provide an
   organized collection of 15 degrees component properties.

3.4 Calendar Date

   A particular day of longitude.
   The center zone was originally the meridian passing through
   Greenwich, England, called Greenwich Mean Time (GMT). The time in the
   zones was decremented by one hour per zone going westwards and was
   incremented by one hour per zone going eastwards from GMT. Changes
   have been made to the original proposal to accommodate political
   boundaries. In addition, some countries and regions specify 30 or 45
   minute offsets, rather than the full 60 minute offset. Standard time
   is also known as Winter Time in some regions.

   GMT and UTC are generally equivalent. However, a calendar year identified by international
   agreement, its position within
   the GMT term is discouraged in favor year.

3.5 Calendar Object

   An entity consisting of the term UTC for
   all general time keeping.

1.1.7   Time Zone an organized collection of calendar
   properties and calendar components. The particular time zone that a location's time is expressed in. A
   time zone calendar object is unambiguously defined by the set of time measurement
   rules determined identified
   by unique delimiters.

3.6 Calendar Properties

   Attributes that apply to the governing body for the given location. These
   rules describe at calendar object as a minimum whole. For example,
   the base offset from UTC, often referred iCalendar version used to as format the Standard Time offset. Optionally, if Daylight time is
   observed, calendar object, an
   identifier of the rules will specify product that created the Daylight time offset and either
   a set of rules describing calendar object, the transition
   calendar scale used to represent the calendar information and from Daylight time or
   absolute dates describing the movement
   zone information.

3.7 Calendar Scale

   The particular type of calendar in general use. For example,
   Gregorian, Buddhist Era, Japanese Emperor Era, Chinese Lunar,
   Islamic, and out of Daylight time.
   It is important to note Jewish Calendars.

3.8 Component Properties

   Attributes that these rules are not static. Time zones
   may also have a local customary name. However, not all time zones
   have a special name for their time. The customary names for time
   zones are often abbreviated. However, not all time zone abbreviations
   are unique. can only appear within one or more calendar
   components. For example, AST may mean Atlantic Standard Time, Alaska
   Standard Time, the due date can only appear within a to-do
   calendar component. The start date and event Aleutian Standard Time. Each of these are
   different offsets from UTC. Nevertheless, customary names for time
   zones are in use in various parts of the world.

2.      TEXT/CALENDAR Registration Information

        [Editor NOTE: This form will be changed to reflect the revision applies to both the MIME memos when event
   and the respective RFC becomes available.]

     To: ietf-types@uninett.no

     Subject: Registration of MIME content type text/calendar.

     MIME media type name: text

     MIME subtype name: calendar

     Required parameters: PROFILE to-do component.

Dawson/Stenerson                   6             Expires August September 1997
     Optional parameters: CHARSET

     Additional required content header fields: CONTENT-ID, MESSAGE-ID

     Optional content header fields: CONTENT-LANGUAGE, TRANSFER-ENCODING

     Encoding considerations: This MIME content type does not introduce
     any new encoding considerations beyond those defined in [RFC 2045].

     Security considerations:

3.9 Coordinate Universal Time (UTC)

   The calendaring and scheduling information
     based on this MIME content type may include references to Uniform
     Resource Locators time scale maintained by the Bureau International de l'Heure
   (International Time Bureau) that may be programmed resources. In addition,
     this information may contain direct references to executable
     programs intended forms the basis of a coordinated
   dissemination of standard frequencies and time signals. UTC is often
   incorrectly referred to be used as program-based alarms for an event GMT.

3.10 Daylight Saving Time (DST)

   An adjustment to local to accommodate annual changes in the number of
   daylight hours. DST is also known as Advanced Time, Summer Time, or to-do. Implementers
   Legal Time. Daylight saving time adjustments in the southern
   hemisphere are opposite to those in the northern hemisphere.

3.11 Event

   A calendar component that defines a scheduled activity, minimally
   specified by a start and users end calendar date and time of day and a
   description.

3.12 Free Time

   A period of time available on a calendar.

3.13 Gregorian Calendar

   A calendar scale in general use beginning in 1582. It was introduced
   to correct an error in the Julian Calendar scale. The Gregorian
   Calendar scale is based on a solar calendar consisting of common
   years made up of 365 days and leap years made up of 366 days; both
   divided into 12 sequential months.

        Note: Initially, this memo addresses specification should be
     aware of calendar
        information in terms of the network security implications Gregorian calendar scale.

3.14 Journal

   A calendar component that defines a collection of accepting information
   intended for human presentation and parsing
     such information.

     Interoperability considerations: This MIME content type is intended
     to provide interoperability minimally specified by a
   calendar date and one or more descriptions.

3.15 Local Time

   The clock time in public use in a locale. Local time is often
   referenced by the customary name for the time zone in which it is
   located. The relationship between calendaring local time and scheduling
     products. It UTC is heavily based on the earlier [VCAL] industry
     specification.

     Intended Usage: COMMON

     Published specification: This document.

     Person & email address to contact
   offset(s) that are in use for further information:

        Frank Dawson
        6544 Battleford Drive
        Raleigh, NC 27613-3502
        919-676-9515 (Telephone)
        919-676-9564 (Facsimile)
        fdawson@earthlink.net (Internet Mail)

        Derik Stenerson
        One Microsoft Way
        Redmond, WA  98052-6399
        206-936-5522 (Telephone)
        206-936-7329 (Facsimile)
        deriks@microsoft.com (Internet Mail)

3.      Intended Use

        [Editor NOTE: The reference to [RFC 1521] and [MIME-REG] will be
        changed to reflect the revision to the MIME memos when the
        respective RFC becomes available.]

   This memo is meant to serve as the basis for registration of a MIME
   content type per [RFC1521]. It is defined using particular time zone. In general, the MIME content type
   registration from [MIME-REG]. The proposed content type value
   formula is
   "TEXT/CALENDAR". This string would label a media type containing as follows:

        local time = UTC + (offset)

Dawson/Stenerson                   7             Expires August September 1997
   calendaring and scheduling information encoded primarily as text
   characters formatted in a manner outlined below. The media type is
   useful for conveying inter-personal calendaring and scheduling
   information between systems and applications.

3.16 Period

   A subtype duration of the standard MIME _TEXT_ media type was chosen time, specified as the
   form for this content type because it provides either a known defined length of time or
   by its beginning and reasonable
   fallback for legacy systems that are required in an enterprise that
   also includes MIME based user agents that support this content type.
   Legacy systems that do not understand end points.

3.17 Recurrence Rule

   A notation used to represent repeating occurrences, or the _TEXT/CALENDAR_ content
   type will render these MIME entities as they would _TEXT/PLAIN_
   content type. This will provide exceptions
   to such a minimal level repetition of support for
   calendaring and scheduling information an event or a to-do. The recurrence rule can
   also be used in legacy systems (i.e., the
   ability to display the text tagged calendaring and scheduling content
   information). specification of a time zone description. This is
   document defines a vital requirement particular notation used in recurrence rules
   within this specification.

3.18 Reminder

   See Alarm.

3.19 Repeating Event or To-do

   An event or to-do that repeats for any mail enabled,
   enterprise application; as there are still over 7 million existing
   legacy electronic mail user agents at this time.

   The calendaring and scheduling media type is specified as an
   independent content type in order that it can be conveyed either as a
   single MIME message entity or as one MIME entity in a multi-part MIME
   message. Additionally, the calendaring and scheduling information or more additional
   occurrences. The recurrence may be defined in with discrete dates and
   times and/or with a multi-part message containing references to other
   MIME body parts holding additional data related to recurrence rule.

3.20 Standard Time

   Introduced by Sir Sanford Fleming and others around 1870, standard
   time is a scheme for dividing the event, to-do,
   or free/busy world into zones where the same
   time information.

3.1     Published specification would be kept. The following characteristics are specific original proposal was to this MIME content type.

3.1.1   Existing Message Header Fields

   The MIME Calendar Content Type may utilize any of divide the message header
   fields defined by [RFC 822], [RFC 2045], and [RFC 1766]. A number world
   into 24 zones, each zone having a width of
   these message header fields are especially useful to the iCalendar
   Object. These include the following header fields defined in either
   [RFC 822], [RFC 2045], and [RFC 1766].

3.1.1.1 Content-Type Header Field 15 degrees of longitude.
   The [RFC 2045] Content-Type header field is used to identify center zone was originally the
   iCalendar Object. meridian passing through
   Greenwich, England, called Greenwich Mean Time (GMT). The value of this property must be _text/calendar_ time in order to correspond to the media type defined
   zones was decremented by this document.
   This header field is required for MIME entities conforming to this
   content type.

3.1.1.1.1       CHARSET Header Field Parameter

   The [RFC 2045] CHARSET Content-Type header field parameter is used one hour per zone going westwards and was
   incremented by one hour per zone going eastwards from GMT. Changes
   have been made to
   identify an alternate character set the original proposal to accommodate political
   boundaries. In addition, some countries and regions specify 30 or 45
   minute offsets, rather than the default US-ASCII used full 60 minute offset. Standard time
   is also known as Winter Time in some regions.

   GMT and UTC are generally equivalent. However, by international
   agreement, the iCalendar Object. This header field parameter GMT term is optional discouraged in favor of the term UTC for
   MIME entities conforming to this content type.

Dawson/Stenerson                   8                Expires August 1997

3.1.1.2 Content-ID Header Field
   all general time keeping.

3.21 Time Zone

   The [RFC 2045] Content-ID header field particular time zone that time in a particular location is used
   expressed in. A time zone is unambiguously defined by the iCalendar
   Object to provide a persistent, globally unique identifier set of time
   measurement rules determined by the governing body for the given
   location. These rules describe at a MIME
   Calendar Object within a MIME message entity. This header field is
   required for multi-part MIME entities containing an iCalendar Object
   that conforms to this content type. In minimum the event that base offset from UTC,
   often referred to as the iCalendar
   Object Standard Time offset. Optionally, if
   Daylight Savings Time is transported in a MIME message containing observed, the rules will specify the
   Daylight Savings Time offset and either a single body,
   then set of rules describing the Message-ID header field is required.

3.1.1.3 Content-Language

   The [RFC 1766] Content-Language header field is used
   transition to provide an
   alternate default language for the MIME Calendar Object. The default
   language is _en-US_. This header field and from Daylight Savings Time or absolute dates
   describing the movement in and out of Daylight Savings Time. It is optional for MIME entities
   conforming
   important to this content type.

3.1.1.4 Message-ID Header Field note that these rules are not static. Time zones may

Dawson/Stenerson                   8             Expires September 1997
   also have a local customary name. However, not all time zones have a
   special name for their time. The [RFC 2045] Message-ID header field customary names for time zones are
   often abbreviated. However, not all time zone abbreviations are
   unique. For example, AST may mean Atlantic Standard Time, Alaska
   Standard Time, and even Aleutian Standard Time. Each of these are
   different offsets from UTC. Nevertheless, customary names for time
   zones are in use in various parts of the world.

3.22 To-do

   A calendar component that defines an action item and is used minimally
   specified by the iCalendar
   Object to provide a persistent, globally unique identifier for a MIME
   message containing an effective calendar date and time of day, a single body part consisting due
   calendar date and time of day, a iCalendar
   Object. This header field priority and a description.

4. TEXT/CALENDAR Registration Information

   The Calendaring and Scheduling Core Object Specification is required intended
   for use as a single body part MIME
   message conforming to this content type. In However, the event that implementation of the
   iCalendar Object
   specification is transported in no way limited solely as a body part within a multi-part MIME message, the Content-ID header field must be specified. content type.

   The
   Message-ID header field following text is used to unambiguously refer intended to register this specification as the
   iCalendar Object within a
   MIME entity.

3.1.1.5 Transfer-Encoding Header Field

   The [RFC 2045] Transfer-Encoding header field is used to provide an
   alternate transfer encoding for the iCalendar Object. The default
   transfer encoding is _7BIT_. This header field is required for a content type "text/calendar".

     To: ietf-types@uninett.no

     Subject: Registration of MIME
   entity conforming to this content type when any other encoding text/calendar.

     MIME media type name: text

     MIME subtype name: calendar

     Required parameters: profile

     The "profile" parameter is used in to convey the iCalendar Object.

3.1.2   Additional Content Type Parameter

   In addition scheduling usage to
     which the existing content type parameters defined by [RFC
   2045] calendaring and [RFC 1766], this document defines scheduling information pertains. It also
     is an additional content
   type identifier for the set of properties that the iCalendar
     Object will consist of. The parameter is intended to be used by as a
     guide to applications interpreting the iCalendar Object.

3.1.2.1 Profile

   The MIME Calendar Object defines information contained within
     the Profile content type parameter.
   This parameter is body part. It should NOT be used to specify a usage exclude or require
     particular pieces of information unless the identified profile
     definition specifically calls for the iCalendar
   Object. The value of this parameter consists of a type and behavior. Unless
     specifically forbidden by a subtype
   value pair. The type value is used to specify either particular profile definition, a EVENT, TODO,
   or FREE-BUSY
     text/calendar content type may contain any set of MIME Calendar properties
     permitted by the Calendaring and Scheduling Core Object profile.
     Specification.

     The subtype value
   is used to specify the scheduling operation being conveyed by for the "profile" parameter is defined as follows:

        profile type. For example, the EVENT and TODO type values might have
   a subtype value of REQUEST, to convey an event or to-do request
   message, REPLY, to convey an event or to-do reply message, MODIFY, to = component "-" usage

        component       = "EVENT" / "event" / "TODO" / "todo"
                        / "JOURNAL" / "journal" / "FREEBUSY"
                        / "freebusy" / x-token  / iana-comp

Dawson/Stenerson                   9             Expires August September 1997
   convey an event or to-do modification message, CANCEL, to convey an
   event
        usage   = "REQUEST" / "request" / "REPLY" / "reply"
                / "CANCEL" / "cancel" / "x-token / iana-usage

        x-token = <The two characters "X-" or to-do cancellation message, DELEGATE, to convey an event or
   to-do delegation message; or the BUSYFREE type value might have a
   subtype value "x-" followed, with
                   no intervening white space, by any atom, where
                   atom is from section 3.3 of REQUEST, to convey a free-busy time request message
   , or REPLY, to convey a free-busy time data message. [RFC 822]>

        iana-comp = <A publicly defined extension component,
                     registered with IANA, as specified by this
                     document>

        iana-usage = <A publicly defined extension usage,
                      registered with IANA, as specified by this
                      document>

     Optional parameters: charset

     The "charset" parameter
   value is defined by in [RFC 2046] for other body
     parts. It is used to identify the following BNF:

     profile := ((_EVENT_ / _    _)                              TODO   _-_ type1) / (_FREEBUSY_ _-_ type2)

     type1 :=   <any IANA values default character set used within
     the body part. Note that alternate character sets can be specified
     on a per-value basis using the "charset" property parameter defined by an iCalendar Object usage
     profile or an _X-_ type of non-standard value>

     type2 :=   <any IANA value
     in [MIME DIR].

     Optional content header fields: Any header fields defined by an iCalendar Object usage
     profile or an _X-_ type of non-standard value>

   The following is an example of this [RFC
     2045].

     Encoding considerations: This MIME content type parameter for a
   profile does not introduce
     any new encoding types beyond those defined in [RFC 2045]. Note
     that specifies an event request message, such as each property in a request
   for a meeting or appointment:

     CONTENT-TYPE:TEXT/CALENDAR;PROFILE=EVENT-REQUEST

   The following is an example of this the content type parameter entity may also have an inline
     encoding for a
   profile that specifies a to-do delegation message, such the body part as delegating a task whole (i.e., inline encoding are
     performed first, then Content-Transfer-Encoding is applied to another individual:

     CONTENT-TYPE:TEXT/CALENDAR;PROFILE=TODO-DELEGATE the
     entire body part). This means that content values may end up
     encoded twice.

     Security considerations: The following is an example of calendaring and scheduling information
     based on this MIME content type parameter for a
   profile may include references to Uniform
     Resource Locators that specifies a free-busy time request, such may be programmed resources. In addition,
     this information may contain direct references to executable
     programs intended to be used as when
   searching for a free time procedure-based alarms for a meeting:

     CONTENT-TYPE:TEXT/CALENDAR;PROFILE=FREEBUSY-REQUEST an event
     or to-do. Implementers and users of this specification should be
     aware of the network security implications of accepting and parsing
     such information.

     Interoperability considerations: This MIME content type parameter is required for MIME entities conforming
   to this content type. Other memos are expected intended
     to address specific
   usage profiles provide interoperability between calendaring and define values for scheduling
     products. It is heavily based on the earlier [VCAL] industry
     specification.

     Intended Usage: COMMON

     Published specification: This remainder of this property.

3.1.3   Content Syntax Considerations document.

     Author/Change controllers:

Dawson/Stenerson                   10            Expires September 1997
        Frank Dawson
        6544 Battleford Drive
        Raleigh, NC 27613-3502
        919-676-9515 (Telephone)
        919-676-9564 (Facsimile)
        fdawson@earthlink.net (Internet Mail)

        Derik Stenerson
        One Microsoft Way
        Redmond, WA  98052-6399
        206-936-5522 (Telephone)
        206-936-7329 (Facsimile)
        deriks@microsoft.com (Internet Mail)

5. iCalendar Object Specification

   The following general considerations are specific to sections define the syntax used details of a Calendaring and
   Scheduling Core Object Specification. This information is intended to format the text
   be an integral part of the body MIME content type registration. In
   addition, this information for may be used independent of such content
   registration. In particular, this specification has direct
   applicability for use as a calendaring and scheduling exchange format
   in file-, memory- or network-based transport mechanisms.

5.1 Syntax Considerations

   The content type.

3.1.3.1 Property

   A property information associated with an iCalendar Object is
   formatted using a syntax similar to that defined by [MIME DIR]. That
   is, the definition content information consists of an individual attribute describing an
   event one or a to-do associated with the MIME Calendar Object. A property
   takes the following form:

     property :=        propname *(_;_ propparm) _:_ propvalue

   as shown more CRLF-separated
   lines in the following example:

     DTSTART:19960415T083000-05:00 format:

     contentline = [group "."] name [";" paramlist] ":" value CRLF
     ;Folding permitted on content lines.

     group      = atom          ;As defined in [RFC 822]

     name       = x-name / iana-name    ;An iCalendar attribute/property

     x-name     = <The two characters "X-" or "x-" followed, with no
                   intervening white space, by any atom>

     iana-name  = <A publicly defined name, registered with IANA>

     paramlist  = parameter / paramlist ";" parameter

     parameter  = encodingparm
                / valuetypeparm         ;If not present => inline value
                / charsetparm
                / languageparm
                / [parmtype "="] parmvalues

     encodingparm = "encoding" "=" encodetype

Dawson/Stenerson                   10                   11            Expires August September 1997
   A property takes the form of one or more lines of text. The
   specification of property names and property parameters is case
   insensitive. The property name can be one of a set of pre-defined or
   non-standard strings. The property name must appear
     encodetype = "8bit"                ;From [RFC 2045]
                / "7bit"                ;From [RFC 2045]
                / "base64"              ;From [RFC 2045]
                / "quoted-printable"    ;From [RFC 2045]

     valuetypeparm = "value" "=" valuetype

     valuetype  = "url"
                / "text"
                / "date"
                / "time"
                / "date-time"
                / "period"
                / "duration"
                / "boolean"
                / "integer"
                / "float"
                / "rfc822-address"
                / "utc-offset"
                / x-token
                / iana-value

     iana-value = <A publicly defined extension value type, registered
                   with IANA, as the first
   characters on a line. In the previous example, _DTSTART_ is the name
   of the Start Date/Time property. Property values are specified as
   strings. In the previous example, _19960415T083000-05:00_ is the
   formatted value for the Start Date/Time property.

   The property by this document>

     charsetparm = "charset" "=" charset ;As defined in [RFC 2047]

     languageparm = "language" "=" language ;As defined in [RFC 1766]

     parmtype   = x-token / iana-ptype

     iana-ptype = <A publicly defined extension parameter expressions are type,
                   registered with IANA, as specified by this document>

     parmvalues = parmvalue / parmvalues "," parmvalue

     parmvalue  = x-name / iana-pvalue

     iana-pvalue = <A publicly defined extension parameter value,
                    registered with IANA, as either a
   name=value or a specified by this document>

     value string. The parameter      = url / text / date / time/ date-time / period /
                / duration / boolean / integer / float / rfc822-address
                / utc-offset / x-token / iana-value

     iana-value = <A publicly defined property value string can be
   specified alone data type,
                   registered with IANA, as defined in those cases where the value is unambiguous. For
   example a complete property parameter specification might be:

     DESCRIPTION;ENCODING=QUOTED-PRINTABLE:Don't forget to order Girl=
      Scout cookies from Stacey today!

   A valid short version of the same property parameter specification
   might be:

     DESCRIPTION;QUOTED-PRINTABLE:Don't forget to order Girl=
      Scout cookies from Stacey today!

3.1.3.2 Delimiters

   Individual lines within this document>

5.1.1 Content Lines

   Individual lines within the iCalendar Object body are delimited by the
   [RFC 822] line break, which is a CRLF sequence (ASCII decimal 13,
   followed by ASCII decimal 10). Line should not be longer than 76
   characters, excluding the line break.

Dawson/Stenerson                   12            Expires September 1997
   Long lines of text can be split into a multiple-line representation
   using the RFC 822 _folding_ a line "folding" technique. That is, wherever there may be linear white space (NOT simply LWSP-
   chars), a line split is
   desired a CRLF immediately followed by at least one LWSP-char may must instead be
   inserted.

   For example the line:

     DESCRIPTION:This is a long description that exists on a long line.

   Can be represented as:

     DESCRIPTION:This is a long description
      that exists on a long line.

   The process of moving from this folded multiple-line representation
   of a property definition
   to its single line representation is called
   _unfolding_. "unfolding". Unfolding is
   accomplished by regarding removing the CRLF immediately followed by a LWSP-char as equivalent to the LWSP-char.

   It is recommended that folding be limited to higher-level syntactic
   breaks in structured components of the property definition.

   A LWSP-
   char.

   An intentional formatted text line break in a property value, value must
   also be specified by a (RFC 822) line break, which is a CRLF
   sequence. However, since the CRLF sequence is used to delimit a line,
   property values with imbedded formatted line breaks (i.e., multiple lines) hard line
   breaks) must be encoded using an alternate encoding of either Quoted-Printable quoted-
   printable or
   Base64, base64, as defined in [RFC 2045].

Dawson/Stenerson                   11               Expires August 1997
   For example, in the Quoted-Printable

   The quoted-printable encoding of the multiple lines of formatted text
   are separated with a Quoted-Printable quoted-printable CRLF sequence of
   _=0D_ "=0D" followed
   by _=0A_ "=0A" followed by a Quoted-Printable soft line break sequence of _=_. Quoted-Printable
   "=". Quoted-printable lines of text must also be limited to less than
   76 characters. The 76 characters does not include the CRLF [RFC 822]
   line break sequence. For example a multiple line DESCRIPTION value
   of:

     Project XYZ Final Review
     Conference Room - 3B
     Come Prepared.

   Would be represented in a Quoted-Printable encoding as:

     DESCRIPTION; QUOTED-PRINTABLE:Project XYZ Final Review=0D=0A=
     Conference Room - 3B=0D=0A=
     Come Prepared.

   Property

   White space characters (i.e., HTAB and SPACE characters, ASCII
   decimal 9 and 32) to the left of a "value" may freely surround any
   symbol. This means that if a "value" begins with a white space
   character, it must be encoded using either the base64 or quoted-
   printable encoding methods.

5.1.2 List and Field Separators

   Where a property parameter sub-strings are delimited by value consists of a field delimiter,
   specified list of values, each
   value must be separated by the Semi-colon a COMMA character (ASCII decimal 59). 44). A Semi-
   colon

Dawson/Stenerson                   13            Expires September 1997
   COMMA character in a property parameter value must be escaped with a
   Backslash
   BACKSLASH character (ASCII decimal 92).

   Compound

   Structured property values are delimited must have their components separated by a field delimiter,
   specified
   SEMICOLON character (ASCII decimal 59). In addition, lists of
   property parameters must be separated by the Semi-colon a SEMICOLON character (ASCII
   decimal 59). A Semi-
   colon SEMICOLON character in a component of a compound property value or property
   parameter value must be escaped with a Backslash BACKSLASH character (ASCII
   decimal 92).

3.1.3.3 Property Value Transfer Encoding

   The default transfer encoding for

   For example, in the iCalendar Object following properties a SEMICOLON is _7BIT_. The
   default transfer encoding can be overridden for an individual used to
   separate property value by using the _ENCODING_ parameters and property parameter. This
   parameter value can be either _7BIT_, _BASE64_, _QUOTED-PRINTABLE_,
   or _8BIT_. This parameter may be fields. A COMMA is
   used on any property. to separate values.

     ATTENDEE;RSVP=YES;ROLE=ATTENDEE:"J.Smith" <jsmith@host.com)
     RDATE;VALUE=DATE:19970304,19970504,19970704,19970904

5.1.3 Grouping

   The MIME TRANSFER-ENCODING header field can be group construct is used to specify a
   default transfer encoding other than 7BIT (e.g., 8BIT).

3.1.3.4 Property Value Character Set group related properties together. The default character set for a iCalendar Object
   group name is ASCII. The
   default character set can a syntactic convention used to indicate that all
   property names prefaced with the same group name should be overridden for processed
   together when displayed by an individual application. It has no other
   significance. Implementations that do not understand or support
   grouping may simply strip off any text before the PERIOD character
   (ASCII decimal 46) and present the property and value by using the _CHARSET_ as normal.

   The following provides an example of property parameter. This grouping. The first
   start, end and busy time are grouped together with a label "GROUPA".
   The second start, end and busy time are grouped together with a label
   "GROUPB".

     GROUPA.DTSTART:19970101T000000-0500
     GROUPA.DTEND:19970101T235959-0500
     GROUPA.BUSYTIME;VALUE=PERIOD-START:19970101T000000-0500/PT8H30M,
      19970101T100000-0500/PT2H,19970101T150000-0500/PT20H59M59S
     GROUPB.DTSTART:19970102T000000-0500
     GROUPB.DTEND:19970102T235959-0500
     GROUPB.BUSYTIME;VALUE=PERIOD-START=19970102T000000-5000/PT10H,
      19970102T130000-0500/PT6H

5.1.4 Multiple Values

   Each attribute or property
   parameter defined in the iCalendar Object may be used on any property. However, have
   multiple values, if allowed in the use definition of this
   parameter on some properties may not make sense.

   Any character set registered with the Internet Assigned Numbers
   Authority (IANA) can specific
   property. 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 specified by this noted that some properties
   support encoding multiple values in a single property parameter. For
   example, ISO 8859-8 or by separating
   the Latin/Hebrew character set is specified
   by:

     DESCRIPTION;CHARSET=ISO-8859-8:... values with a COMMA (ASCII decimal 44).

Dawson/Stenerson                   12                   14            Expires August September 1997

5.1.5 Character Set

   The MIME CHARSET "charset" property parameter on the CONTENT-TYPE header field can should be used to specify a default identify character set
   sets other than ASCII (e.g., UTF-
   8).

3.1.3.5 Property Value Language

   The default language for a iCalendar Object is _en-US_ (US English). "US-ASCII". The default language "charset" property parameter can be overridden for an individual property
   value by using
   used to change the _LANGUAGE_ property parameter. default character set on a per-value basis. The values for this
   value of the charset property are parameter is any IANA registered
   character set.

        Note: For transport in a string consistent with RFC 1766, Tags for MIME entity, the
   Identification of Languages. This property "charset" Content-Type
        parameter may be used on
   any property. However, to set the use of this default character set for the
        entire body part.

5.1.6 Language

   The "language" property parameter on some properties,
   such as PHOTO, LOGO, SOUND, TEL, may not make sense. Canadian French
   would should be specified by this used to identify data in
   alternate languages. The default language is "us-EN". The value of
   the language property parameter by the following:

     SUMMARY;LANGUAGE=fr-CA:...

   The is that defined in [RFC 1766].

        Note: For transport in a MIME LANGUAGE parameter on entity, the CONTENT-TYPE Content-Language
        header field can may be used to specify a set the default language other than US English (e.g., fr-
   CA).

3.1.3.6 Property Value Data Type

   In order for the
        entire body part.

5.1.7 Content Encoding

   The "encoding property parameter should be used to more fully specify an
   alternate encoding for a value. If the semantics of this content type and value contains a <CR>
   character (ASCII decimal 10) or <LF> character (ASCII decimal 13), it
   must be encoded using either base64 or quoted-printable, since
   <CR><LF> is used to facilitate its automated processing, separate lines in the specification iCalendar Object itself.

5.1.8 Binary Content

   There is no support for inline encoding of each
   property defined by binary information in an
   iCalendar Object. Binary information is associated with the iCalendar
   Object identifies the valid data
   types and the default data type for through the property value. In addition,
   within an instance use of this content type a property may explicitly
   convey the data type information through uniform resource locator (URL) reference
   to the DATATYPE property
   parameter. binary information.

5.1.9 Recurrence Set

   Recurring events and to-dos are supported by this specification. The STRING data type for
   recurrence within the DESCRIPTION property would iCalendar Object may be specified by the following:

     DESCRIPTION;DATATYPE=STRING:Weekly Staff Meeting

   If as either a
   list of discrete date and time values or as a recurrence rule. The
   full recurrence set is generated by considering the DATATYPE property parameter initial DTSTART
   along with the RRULE, RDATE, EXDATE and EXRULE properties contained
   within the iCalendar object. Multiple instances of the RRULE and
   EXRULE properties may also be specified to define more sophisticated
   recurrence sets. The final recurrence set is not generated by gathering
   all of the start date-times generated by any of the specified on a property,
   then RRULE
   and RDATE properties, and excluding any start date and times which
   fall within the default data type for union of start date and times generated by any
   specified EXRULE and EXDATE properties. This implies that start date
   and times within exclusion related properties (i.e., EXDATE and
   EXRULE) take precedence over those specified by inclusion properties
   (i.e., RDATE and RRULE).

Dawson/Stenerson                   15            Expires September 1997
   The recurrence rule used in the iCalendar Object is defined in the
   RRULE component property.

5.1.10 Data Types

   The "value" property parameter is assumed. Usage
   profiles for this content type that introduce new properties must
   specify an optional property parameter. It
   is used to identify the default data type for each newly defined property. and format of the property value.
   The following data types are used within this content type definition include the
   following:

              Property Data       Description
                   Type

                  AALARM          Indicates an
                                  audio alarm
                                  value, as
                                  specified by
                                  this
                                  document.

Dawson/Stenerson                   13               Expires August 1997
                 BOOLEAN          Indicates the iCalendar Object.

5.1.10.1 URL

   The "url" data type is used to identify values that contain a
                                  Boolean value
                                  string uniform
   resource locator (URL) type of
                                  either TRUE
                                  or FALSE.

                   CID            Indicates a
                                  string
                                  identifier
                                  value reference to the property value. This
   data type might be used to reference binary information, for values
   that are large, or otherwise undesirable to include directly in the
                                  content
                                  identifier of
                                  another MIME
                                  entity within
   iCalendar Object. The data type is defined by the current
                                  message.

                  DALARM          Indicates a
                                  display alarm
                                  value, as
                                  specified following notation:

     url        = <As defined by
                                  this
                                  document.

                DATE-TIME         Indicates [RFC 1738]>

   Any IANA registered URL type may be used. These include, but are not
   limited to, those for FTP and HTTP protocols, file access, content
   identifier and message identifier.

   For example, the following is an
                                  ISO 8601
                                  formatted
                                  date/time
                                  string value.

                 DST-RULE         Indicates URL for a
                                  daylight
                                  saving time
                                  rule value as
                                  specified local file:

     file:///my-report.txt

5.1.10.2 Text

   The "text" data type is used to identify values that contain human
   readable text. The character set and language in
                                  this
                                  document.

                 D-T-LIST         Indicates which the text is
   represented is controlled by the charset and language property
   parameters. The data type is defined by the following notation:

     CHAR       = <Any character in the selected character set>

     text       = <Any CHAR, including bare CR & bare LF but not
                   including CRLF>

5.1.10.3 Date

   The "date" data type is used to identify values that contain a
                                  list of ISO
                                  8601
                                  formatted
                                  date/time
                                  string
                                  values.

                 DURATION         Indicates an
                                  ISO 8601
                                  formatted
                                  duration or
                                  period
   calendar date. The format is expressed as the [ISO 8601] complete
   representation, basic format for a calendar date. The text format
   specifies a four-digit year, two-digit month, and two-digit day of
                                  time value.
   the month. There are no separator characters between the year, month
   and day component text. The data type is defined by the following
   notation:

     DIGIT      =<any ASCII decimal digit>      ;0-9

     date-fullyear      = 4DIGIT
     date-month         = 2DIGIT        ;01-12
     date-mday          = 2DIGIT        ;01-28, 01-29, 01-30, 01-31

Dawson/Stenerson                   14                   16            Expires August September 1997
                  FLOAT           Indicates
                                        ;based on month/year
     full-date          = date-fullyear date-month date-mday

     date       = fulldate *["," fulldate]

   For example, the following represents July 14, 1997:

     19970714

5.1.10.4 Time

   The "time" data type is used to identify values that contain a
                                  string
                                  representatio
                                  n time
   of day. The format is expressed as the [ISO 8601] complete
   representation, basic format for a
                                  floating
                                  point value.

                FLOAT-LIST        Indicates a
                                  list of
                                  string
                                  representatio
                                  ns time of
                                  floating
                                  point values.

                 INTEGER          Indicates a
                                  numeric
                                  string
                                  representatio
                                  n day. The text format
   consists of an
                                  integer
                                  value.

               INTEGER-LIST       Indicates a
                                  list of
                                  numeric
                                  string
                                  representatio
                                  ns two-digit 24-hour of an
                                  integer
                                  value.

                  MALARM          Indicates a
                                  mail alarm
                                  value, as
                                  specified by
                                  this
                                  document.

                   MID            Indicates a
                                  string
                                  identifier
                                  value for an
                                  external
                                  message.

                  PALARM          Indicates a
                                  procedure
                                  alarm value,
                                  as specified
                                  by this
                                  document.

Dawson/Stenerson                   15               Expires August 1997
                 RFC822-          Indicates a
                 ADDRESS          RFC 822
                                  formatted
                                  address
                                  specification
                                  string value.

                  RRULE           Indicates a
                                  recurrence
                                  rule grammar
                                  string value
                                  as specified the day, two-digit minute in this
                                  document.

                  STRING          Indicates a
                                  text string
                                  value the
   hour, and two-digit seconds in the
                                  current
                                  character
                                  set.

               STRING-LIST        Indicates a
                                  list minute. If seconds of text
                                  string values
                                  in the
                                  current
                                  character
                                  set.

               TIME-OFFSET        Indicates minute
   are not supported by an
                                  ISO 8601
                                  formatted
                                  time offset
                                  value

                   URL            Indicates a
                                  RFC 1738
                                  formatted
                                  Uniform
                                  Resource
                                  Locator
                                  string.

   The property values consisting of lists of implementation, then a particular data type
   (i.e., STRING-LIST) are semi-colon separated string value of list items.

3.1.3.7 Date and Time

   The date and time values "00" should
   be specified for all iCalendar Object properties are
   formatted as a string consistent with the ISO 8601 representation for

Dawson/Stenerson                   16               Expires August 1997
   combinations seconds component. Fractions of dates and times. Either the basic an hour, minute
   or extended second are not supported by this format. This format is allowed. The use of UTC, rather than local time, should be used
   when ever possible in order to avoid time zone ambiguities. Where
   represent local time, local time is specified, the inclusion of the with UTC offset should also
   be included to avoid time zone ambiguities. The format for the
   complete, representation of a date and UTC time. UTC
   time value is represented identified by a LATIN CAPITAL LETTER Z suffix character
   (ASCII decimal 90), the following ABNF:

     date-time =        (date / UTC designator, appended to the time. The
   local time / (date _T_ time))

     date =     year month day
     year =     <four digits representing the century and year>
     month =    [_-_] <digits representing the month in with UTC offset is expressed as a local time, suffixed
   with the year>
     day =      [_-_] <digits representing signed offset from UTC. The UTC offset is express as the day of 2-
   digit hours and 2-digit minutes difference from UTC. It is expressed
   as positive, with an optional leading PLUS SIGN character (ASCII
   decimal 43), if the month>

     time =     hour minute second [fraction](utc-sign / utc-offset)
     hour =     <digits representing a period of local time is ahead of 60 minutes>
     minute =   [_:_] <digits representing UTC. It is expressed as a period of time of 60
                seconds>
     second =   [_:_] <digits representing
   negative, with a basic measurement unit
                of leading HYPEN-MINUS character (ASCII decimal 45), if
   the local time in is behind UTC. Local time has neither the International System of Units as UTC
   designator nor the UTC offset suffix text. The data type is defined
                in ISO 31-1>
     fraction
   by the following notation:

     DIGIT      =<any ASCII decimal digit>      ;0-9

     time-hour          = _,_ <digits representing fraction of a second>
     utc-sign 2DIGIT        ;00-24
     time-minute        = _Z_
     utc-offset 2DIGIT        ;00-60
     time-second        = [_+_ 2DIGIT        ;00-59
     time-numzone       = ("+" / _-_] hour [_:_] minute
        ;_+_ if offset is after UTC and _-_ if offset is before UTC

   The basic complete representation does not include the _-_ date
   separator nor the _:_ "-") time-hour time-minute
     time-zone          = "Z" / time-numzone
     full-time          = time-hour time-minute time-second [time-zone]

     time separator. The extended complete
   representation does include the separators.       = fulltime *["," fulltime]

   For example, the following represents 8:30 AM on April 15, 1996 local time EST would be
   written as:

     19960415T083000-05:00

   And the same time in UTC based New York, five hours
   behind UTC, in local time would be written as:

     19960415T133000Z

   The same date and local time represented in the extended completed
   representation would be written as:

     1996-04-15T08:30:00-05:00

   And the same time with UTC offset. In
   addition, 1:30 PM in UTC based time would be written as:

     1996-04-15T13:30:00Z

   Where a value needs to specify is illustrated:

     083000
     083000-0500
     133000Z

   There are cases when a sequence of date and floating time values,
   then the property value is intended within a string made up of a list of date and
   time values, separated by the field separator, a Semi-Colon (ASCII
   decimal 59). property
   value. For example: example, an event may be defined that indicates that an

Dawson/Stenerson                   17            Expires August September 1997
     19960101T090000Z;19960201T090000Z;19960301T090000Z;...

3.1.3.8 Time Duration

   The values for
   individual will be busy from 11:00 AM to 1:00 PM every day. In these
   cases, a local time duration or periods may be specified. The recipient of time for all an iCalendar
   Object properties are formatted with a property value consisting of a local time, without any
   relative time zone information, should interpret the value as being
   fixed to the recipient's locale and time zone. In most cases, a string consistent fixed
   time is desired. To properly communicate a fixed time in a property
   value, either UTC, local time with UTC offset, or local time with the ISO
   8601 representation for duration of time. A given duration of a
   period of
   time zone calendar component must be specified.

5.1.10.5 Date-Time

   The "date-time" data type is represented by used to identify values that contain a character string consisting of the
   designator _P_, optionally including the number of years followed by
   the designator _Y_, optionally including the number of months
   followed by the designator _M_, optionally including the number
   precise calendar date and time of
   weeks followed by the designator _W_, optionally including day. The format is expressed as the number
   [ISO 8601] complete representation, basic format for a calendar date
   and time of days followed by the designator _D_. day. The sequence can also contain text format is a time component preceded by the designator _T_, optionally including
   the number concatenation of hours the "date",
   followed by the designator _H_, optionally
   including the number of minutes LATIN CAPITAL LETTER T character (ASCII decimal 84)
   time designator, followed by the designator _M_,
   optionally including the number of seconds followed "time" format defined above. The
   data type is defined by the designator
   _S_. following notation:

     date-time  = date "T" time ;As specified above in date and time

   The following ABNF describes represents July 14, 1997, at 1:30 PM in UTC and the representation of ISO 8601
   periods
   equivalent time in New York (five hours behind UTC), expressed as a
   local time and local time with UTC offset:

     19970714T133000Z
     19970714T083000
     19970714T083000-0500

5.1.10.6 Duration

   The "duration" data type is used to identify properties that contain
   a duration of time: time. The format is expressed as the [ISO 8601] basic
   format for the duration = _P_ (yr-period / tm-period / (yr-period tm-period))
        ;Duration needs to include at least one component of year or
        ;time periods

     yr-period time. The format can represent durations
   in terms of years, months, days, hours, minutes, and seconds. The
   data type is defined by the following notation:

     DIGIT      =<any ASCII decimal digit>      ;0-9

     dur-second =        [yr-parm] [mo-parm] / wk-parm
     yr-parm 1*DIGIT "S"
     dur-minute =          _Y_ <digits representing the number of years>
     mo-parm 1*DIGIT "M" [dur-second]
     dur-hour   =          _M_ <digits representing the number of months>
     wk-parm 1*DIGIT "H" [dur-minute]
     dur-time   =          _W_ <digits representing the number of weeks>

     tm-period "T" (dur-hour / dur-minute / dur-second)

     dur-week   =        _T_ [hr-parm] [mn-parm] [sc-parm]
     hr-parm 1*DIGIT "W"
     dur-day    =          _H_ <digits representing the number of hours>
     mn-parm 1*DIGIT "D"
     dur-month  =          _M_ <digits representing the number of minutes>
     sc-parm 1*DIGIT "M" [dur-day]
     dur-year   =          _S_ <digits representing the number of seconds> 1*DIGIT "Y" [dur-month]
     dur-date   = (dur-day / dur-month / dur-year) [dur-time]

     duration   = "P" (dur-date / dur-time / dur-week)

   For example:

     P6W

   represents a period of six weeks;

     PT15M

   represents a period of 15 minutes;

     PT1H30M

   represents a period of 1 hour and thirty minutes; or

     P2Y10M15DT10H30M20S

   represents example, a period duration of 2 years, 10 years, 3 months, 15 days, 10 5 hours, 30
   minutes,
   minutes and 20 seconds. seconds would be:

Dawson/Stenerson                   18            Expires August September 1997

3.1.3.9 Value Location

   The default location
     P10Y3M15DT5H30M20S

5.1.10.7 Period of the property values Time

   The "period" data type is inline with the
   property. However, for some properties, such as those used to identify values that specify
   multimedia values, it is more efficient in contain a MIME message to organize
   the property value as
   precise period of time. There are two forms of a separate MIME entity. The property parameter
   _VALUE_ can period of time.

   A period of time may be specified to override identified by it start and its end. This
   format is expressed as the _INLINE_ location [ISO 8601] complete representation, basic
   format for "date-time" start of the
   property value. In period, followed by a SOLIDUS
   character (ASCII decimal 47), followed by the case "date-time" of the iCalendar Object being transported
   within a MIME email message, end
   of the property value can be specified as
   being located period. For example, the period starting at 10 AM in Seattle
   (eight hours behind UTC) on January 1, 1997 and ending at 11 PM in
   Seattle on January 1, 1997 would be:

     19970101T100000-0800/19970101T230000-0800

   A period of time may also be defined by a separate MIME entity with the _CONTENT-ID_ value;
   or _CID_ for shorthand. In this case, the property value start and a duration of
   time. The format is expressed as the
   Content-ID [ISO 8601] complete
   representation, basic format for the MIME entity within the multi-part message that
   contains "date-time" start of the property value. The value can also be specified as being
   contained within an another, external message using period,
   followed by a SOLIDUS character (ASCII decimal 47), followed by the _MESSAGE-ID_
   value, or _MID_
   [ISO 8601] basic format for shorthand. In addition, the property value can be
   specified as being located out on the Internet using "duration" of the _URL_ value.
   In this case, period. For example,
   the property value period start at 10 AM in Seattle (eight hours behind UTC) on
   January 1, 1997 and lasting 5 hours and 30 minutes would be:

     19970101T100000-0800/P5H30M

   The data type is defined by the Uniform Resource Locator following notation:

     period-explicit = date-time "/" date-time
     ;ISO 8601 complete representation basic format for
   the Internet resource containing the property value. This property
   parameter may a period of time
     ;consisting of a start and end. The start must be used on any property. However, before the use of this
   parameter on some properties may not make sense; end.

     period-start = date-time "/" duration
     ;ISO 8601 complete representation basic format for example the
   Version, Time Zone, Status, Priority, Mail Reminder, etc. properties.

   The following specifies a value located out on the Internet:

     ATTACH;VALUE=URL:http://www.abc.com/dir_photos/my_photo.gif

   The following specifies period of time
     ;consisting of a value located out in the content start and duration of another
   message:

     ATTACH;VALUE=MID:<960120.aaCB@host1.com>

3.1.3.10        Binary Property Values time.

     period     = period-explicit / period-start

5.1.10.8 Boolean

   The iCalendar Object supports inclusion of binary information, such
   as computer graphic images (e.g., IMAGE/JPEG), digital audio (e.g.,
   AUDIO/BASIC), or video graphic images (e.g., VIDEO/MPEG). As
   specified above the binary information can be referenced with a
   Uniform Reference Locator (URL), referenced within an external MIME
   message, referenced within a particular MIME message body part, or
   placed inline. Inline binary information "boolean" data type is included as a property
   value after being binary encoded using Base 64 (default) or Quoted-
   Printable transfer encoding.

3.1.3.11        Recurrence Rule Grammar

   Recurring events within the iCalendar Object may be specified as used to identify properties that contain
   either a list of discrete date and time values "true" or as a recurrence
   rule using a grammar. "false" boolean value. These values are case
   insensitive. The basic recurrence rule grammar used by this
   specification data type is defined in a separate section of this specification.
   The grammar defines a recurrence rule that that is based on the prior
   work of by the X.400 API Association's Calendaring and Scheduling
   Subcommittee. It is also based on prior work following notation:

     boolean    = "TRUE" / "FALSE"

   For example, any of the IETF Chronos
   Working Group. Refer to section 3.3. following are equivalent:

     TRUE
     true
     TrUe

Dawson/Stenerson                   19            Expires August September 1997

3.1.4   Body Delimiter Properties

5.1.10.9 Integer

   The body information of a iCalendar Object "integer" data type is defined by a series of
   body fields or properties. This section defines the properties that
   can be used in MIME entities conforming to this content type.

3.1.4.1 Calendar Object identify properties that contain a
   signed integer value. The body of valid range for "integer" is -2147483648 to
   2147483647. If the iCalendar Object sign is identified within not specified, then the body of value is assumed
   to be positive. If the property permits, multiple "integer" values
   may be specified using a
   MIME entity COMMA character (ASCII decimal 44) separator
   character. The data type is defined by the appearance of the Begin Calendar Object Delimiter:

     BEGIN:VCALENDAR following notation:

     DIGIT      =<any ASCII decimal digit>      ;0-9

     integer    = ["+" / "-"] *DIGIT

   For example:

     1234567890
     -1234567890
     +1234567890
     432109876

5.1.10.10 Float

   The sentinel string must appear as the first characters in the body
   of the MIME entity and as "float" data type is used to identify properties that contain a
   real value number value. If the first characters on property permits, multiple "float"
   values may be specified using a line. COMMA character (ASCII decimal 44)
   separator character. The body information of the iCalendar Object data type is terminated defined by the
   appearance of the End Calendar Object Delimiter as the first
   characters on a line:

     END:VCALENDAR following
   notation:

     DIGIT      =<any ASCII decimal digit>      ;0-9

     float      = ["+" / "-"] *DIGIT ["." *DIGIT]

   For example:

     1000000.0000001
     1.333
     -3.14

5.1.10.11 RFC 822 Address

   The iCalendar Object "rfc822-address" data type is used to identify properties that
   contain a container for calendar components. These
   can include either event or to-do components. address. The body phrase component of a iCalendar
   Object will generally contain a single calendar event or to-do
   component. However, the body address may include multiple event
   be used to match an unknown address with an otherwise known
   individual, group, or to-do
   components. This resource. The data type is as defined by the case for free-busy time reply messages that
   contain multiple free time intervals in individual calendar
   components.

   The Begin
   following notation:

     rfc822-address     = addr-spec / [phrase] "<" addr-spec ">"

     addr-spec  = local-part "@" domain         ;RFC 822 address
     local-part = WORD *("." WORD)
     domain     = domain-ref *("." domain-ref)
     domain-ref = ATOM

Dawson/Stenerson                   20            Expires September 1997
     phrase     = 1*WORD
     WORD       = ATOM / quoted-string
     quoted-string = <"> *(qtext/quoted-pair) <"> ; Regular qtext or
                                                  ;   quoted chars.
     qtext      = <any CHAR excepting <">,        ; => may be folded
                  "\" & CR, and End Calendar Object Delimiter properties are required
   in including linear-white-space>
     quoted-pair ="\" CHAR                        ; may quote any char
     CHAR       = <any a MIME entity conforming to this content type. character from the selected character set>
     ATOM       = 1*<any CHAR except specials, SPACE and CTLs>

5.1.10.12 UTC Offset

   The "utc -offset" data type for
   these properties is a STRING.

3.1.4.2 Event Component

   An Event Component is a grouping of calendaring and scheduling used to identify properties that defines a component that represents a scheduled
   amount of time on a calendar. For example, it may be
   contain an activity;
   such as a one-hour, department meeting offset from 8 AM UTC to 9 AM, tomorrow or
   a free/busy time interval.

   An individual Event Component is identified within a MIME Calendaring
   and Scheduling Content Type by the appearance of the delimiter:

     BEGIN:VEVENT

   The sentinel string must appear as the first characters on a line. local time. The Event Component data type is terminated with the appearance of defined by
   the following delimiter string as the first characters on a line

     END:VEVENT

Dawson/Stenerson                   20               Expires August 1997
   The Event Component can not be nested within another Event or To-do
   Component. If Event components need to be related to each other or to
   a To-do Component, they can specify a relationship with notation:

     utc-offset = time-numzone  ;As defined above in time data type

   For example, the RELATED-
   TO property.

   The Begin and End Event Component Delimiter properties following are required UTC offsets for a MIME entity containing an event component New York (five hours
   behind UTC) and conforming to
   this content type. Geneva (one hour ahead of UTC):

     -0500      ;New York
     +0100      ;Geneva

5.2 iCalendar Object

   The data type for these properties is a STRING.

3.1.4.3 To-do Component

   A To-do Component Calendaring and Scheduling Core Object is a grouping collection of
   calendaring and scheduling
   properties that define information. Typically, this information
   will consist of a component that represents an action-item or
   assignment. For example, it single iCalendar Object. However, multiple
   iCalendar Objects may be an item of work assigned to an
   individual; such as _turn in travel expense today_.

   An individual To-do Component is identified within a MIME Calendaring sequentially, grouped together. The first
   line and Scheduling Content Type by the appearance last line of the delimiter:

     BEGIN:VTODO

   The sentinel string iCalendar Object must appear as the first characters on contain a line.

   The To-do Component is terminated with the appearance pair of the
   following
   iCalendar Object delimiter string as the first characters on strings. The syntax for a line

     END:VTODO vCalendar Object
   is as follows:

     icalobject = "BEGIN" ":" "VCALENDAR" CRLF
                  icalbody
                  "END" ":" "VCALENDAR" CRLF [icalobject]

   The To-do Component can not be nested within another To-do or Event
   Component. If To-do components need to be related to each other or to
   an Event Component, they can specify following is a relationship with simple example of an iCalendar Object:

     BEGIN:VCALENDAR
     VERSION:2.0
     PRODID:-//hacksw/handcal//NONSGML v1.0//EN
     BEGIN:VEVENT
     DTSTART:19970714T120000-0500
     DTEND:19970714T235959-0500
     DESCRIPTION:Bastile Day Party
     END:VEVENT
     END:VCALENDAR

Dawson/Stenerson                   21            Expires September 1997

5.3 Property

   A property is the RELATED-
   TO property.

   The Begin and End To-do Component Delimiter properties are required
   for definition of an individual attribute describing a MIME entity containing
   calendar property or a to-do component and conforming to calendar component. A property takes the
   following form:

     property   = [group "."] propname [";" parmlist] ":" value CRLF

     propname   = <any properties defined in this
   content type. document>
                / iana-prop / x-token

     x-token    = <The two characters "X-" or "x-" followed, with no
                   intervening white space, by any atom>

     iana-prop  = <A publicly defined extension property, registered
                   with IANA, as specified by this document>

   The data type for these properties following is an example of a STRING.

3.1.5   Calendar Object Properties

   The following property:

     DTSTART:19960415T083000-05:00

   This document places no imposed ordering of properties may appear between the Begin Calendar Object
   Delimiter within an
   iCalendar Object.

   Property names, parameter names and either the Begin Event Component Delimiter or the Begin
   To-do Component Delimiter. These properties define body field parameter values
   that apply (i.e.,
   everything to the complete calendar object.

3.1.5.1 Calendar Content Profile

   This property is identified by the property name PROFILE. This
   property defines the usage profile associated with left of the calendar
   object. When used in ":" on a MIME message entity, line) are case insensitive.
   For example, the value of this property MUST be name "DUE" is the same as the Content-Type profile parameter
   value. This property can only appear once within "due" and "Due".

5.4 Calendar Components

   The body of the iCalendar
   Object.

Dawson/Stenerson                   21               Expires August 1997 Object consists of a sequence of calendar
   properties and one or more calendar components. The calendar property value might include
   properties are attributes that apply to the following usage profile
   values:

              Profile Parameter     Description
              Type/Subtype Value

              EVENT-REQUEST         Make calendar as a request for an
                                    event

              EVENT-REPLY           Reply to an event
                                    request

              EVENT-COUNTER         Make whole. The
   calendar components are collections of properties that with a counter proposal
                                    to the event request

              EVENT-DECLINECOUNTER  Decline the counter
                                    proposal to
   particular calendar semantic. For example, the event
                                    request

              EVENT-MODIFY          Modify calendar component may
   specify a an event, a subset to-do, journal entry, time zone information, or
   free/busy time information, or alarm.

   The body of the
                                    details of an existing
                                    event request

              EVENT-REPLACE         Replace iCalenar Object is defined by the current
                                    event request with following notation:

     icalbody   = calprops 1*component

     calprops   = [calscale] [geo] prodid [profile] [profile-version]
                  [source] [name] version

     component  = 1*(eventc / todoc / journalc / freebusyc /
                / timezonec)

5.4.1 Event Component

   An Event Calendar Component is a
                                    complete set grouping of
                                    information

              EVENT-CANCEL          Cancel an existing
                                    event request

              EVENT-DELEGATE        Delegate component properties and
   an existing
                                    event request

              EVENT-RESEND          Request optional alarm calendar component that represent a duplicate scheduled
   amount of
                                    the current event
                                    request information

              TODO-REQUEST          Assign time on a to-do calendar. For example, it may be an activity;

Dawson/Stenerson                   22            Expires August September 1997
              TODO-REPLY            Reply to a to-do
                                    assignment

              TODO-COUNTER          Make a counter proposal
                                    for the to-do request

              TODO-DECLINECOUNTER   Decline
   such as a counter
                                    proposal for one-hour, department meeting from 8:00 AM to 9:00 AM,
   tomorrow.

   An Event Component is defined by the to-do
                                    request

              TODO-MODIFY           Modify following notation:

     eventc     = "BEGIN" ":" "VEVENT" CRLF
                  *eventprop *alarmc
                  "END" ":" "VEVENT" CRLF

     eventprop  = *attach *attendee *categories [class]
                / [created] description dtend dtstart *exdate
                / *exrule *last-mod [location] [priority]
                / *related *resources *rdate *rrule
                / [resp-seq] / [seq] [status] [summary] [transp]
                / [uid] *url

   The Event Component can not be nested within another Calendar
   Component. Event components may be related to each other or to a subset of To-
   do or Journal Calendar Component with the
                                    details of RELATED-TO property.

   The following is an existing
                                    to-do assignment

              TODO-REPLACE          Replace example of the current to-
                                    do request with Event Calendar Component:

     BEGIN:VEVENT
     DTSTART:19970903T083000-0800
     DTEND:19970903T110000-0500
     DESCRIPTION:Annual Employee Review
     CLASS:PRIVATE
     CATEGORIES:BUSINESS,HUMAN RESOURCES
     END:VEVENT

5.4.2 To-do Component

   A To-do Calendar Component is a
                                    complete set grouping of
                                    information

              TODO-CANCEL           Cancel component properties and
   an existing to-
                                    do

              TODO-DELEGATE         Delegate optional alarm calendar component that represent an existing
                                    to-do

              TODO-RESEND           Request a duplicate of
                                    the current to-do
                                    request information

              FREEBUSY-REQUEST      Free/busy time request

              FREEBUSY-REPLY        Reply to an existing
                                    free/busy time request
                                    with free/busy time
                                    data

   Other values action-item or
   assignment. For example, it may be an item of work assigned to an
   individual; such as "turn in travel expense today".

   A To-do Component is defined by the following notation:

     todoc      = "BEGIN" ":" "VTODO" CRLF
                  *todoprop *alarmc
                  "END" ":" "VTODO" CRLF

     todoprop   = *attach *attendee *categories [class] [completed]
                / [created] description dtstart due *exdate
                / *exrule *last-mod [location] priority
                / *related *resources *rdate *rrule [resp-seq]
                / [seq] [status] [summary] [transp] [uid] *url

   The To-do Component can not be nested within another Calendar
   Component. If To-do components need to be related to each other usage profiles of this content
   type. or to
   an Event or Journal Calendar Component, they can specify a
   relationship with the RELATED-TO property.

Dawson/Stenerson                   23            Expires August September 1997
   This property is optional for MIME entities conforming to this
   content type. In the event that this property
   The following is not specified, the
   recipient an example of a MIME Calendaring and Scheduling Content Type should
   assume the calendar object is for an _event/request_. The data type
   for this property is STRING.

3.1.5.2 To-do Calendar Scale

   This property Component:

     BEGIN:VTODO
     DTSTART:19970415T083000-0500
     DUE:19970415T235959-0500
     DESCRIPTION:1996 Income Tax Preparation
     CLASS:CONFIDENTIAL
     CATEGORIES:FAMILY,FINANCE
     PRIORITY:1
     STATUS:NEEDS ACTION
     END:VEVENT

5.4.3 Journal Component

   A Journal Calendar Component is identified by the property name CALENDAR. This
   property defines the a grouping of component properties
   that represent one or more descriptive text on a particular calendar scale used
   date. For example, it may be a journal entry of individual telephone
   contacts for the calendar information
   specified in day or an ordered list of accomplishments for the iCalendar Object. This specification
   day.

   A Journal Component is based on defined by the
   Gregorian calendar scale. following notation:

     journalc   = "BEGIN" ":" "VJOURNAL" CRLF
                  *jourprop
                  "END" ":" "VJOURNAL" CRLF

     jourprop   = *attach *categories [class] [created] description
                / dtstart *last-mod *related [resp-seq] [seq] [uid] *url

   The Gregorian calendar scale is assumed if
   this property is Journal Component can not specified in the iCalendar Object. It is
   expected that other calendar scales will be defined in nested within another Calendar
   Component. If Journal Components need to be related to each other
   specifications or by future versions of this specification.
   to an Event or To-Do Calendar Component, they can specify a
   relationship with the RELATED-TO property.

   The following is an example of this property:

     CALENDAR:GREGORIAN

   The data type the Journal Calendar Component:

     BEGIN:VJOURNAL
     DTSTART:19970317T083000
     DESCRIPTION:1. Staff meeting: Participants include Joe, Lisa
      and Bob. Aurora project plans were reviewed. There is currently
      no budget reserves for this property project. Lisa will escalate to
      management. Next meeting on Tuesday.
      2. Telephone Conference: ABC Corp. sales representative called
      to discuss new printer. Promised to get us a demo by Friday.
      3. Henry Miller (Handsoff Insurance): Car was totaled by tree.
      Is looking into a loaner car. 654-2323 (tel).
     END:VJOURNAL

5.4.4 Free/Busy Component

   A Free/Busy Calendar Component is STRING.

3.1.5.3 Daylight Savings Rule

   This property a grouping of component properties
   that represent free or busy time information. Typically, this
   component exists in an iCalendar Object that is identified being used to either
   request or return free or busy time information.

Dawson/Stenerson                   24            Expires September 1997
   A Free/Busy Component is defined by the property name DAYLIGHT. following notation:

     freebusyc  = "BEGIN" ":" "VFREEBUSY" CRLF
                  *fbprop
                  "END" ":" "VFREEBUSY" CRLF

     fbprop     = *attendee [created] [duration] [dtend] [dtstart]
                / *freebusy *last-mod *related [resp-seq] [seq] [uid]
                / *url

   The Free/Busy Component can not be nested within another Calendar
   Component. Free/Busy components may be related to each other with the
   RELATED-TO property. Multiple Free/Busy Calendar Components may be
   specified within a iCalendar Object. This
   property defines permits the effective daylight savings grouping of
   Free/Busy information into logical collections, such as monthly
   groups of busy time rule information.

   The Free/Busy Calendar Component is intended for
   calendar information specified use in profiles
   involving requests for free time, requests for busy time, requests
   for both free and busy, and the iCalendar Object. More than one
   DAYLIGHT properties associated replies.

   Free/Busy information can be specified for expressed using the FREEBBUSY property.
   This property provides a series terse representation of future DST rules
   for the time zone.

   Many locations adjust their standard time forward periods. One or backward by one
   hour,
   more FREEBUSY properties may be specified in order the FREE/BUSY Calendar
   Component to accommodate seasonal changes describe the Free/Busy information.

   Optionally, the DTSTART and DTEND properties may be specified to
   express the start and end date and time for Free/Busy information in number
   the Free/Busy Calendar Component. When present in a Free/Busy
   Calendar Component, they should be specified prior to any FREEBUSY
   properties. In a free time request, these properties may be used in
   combination with the DURATION property to express a request for a
   duration of free time within a given window of time.

   The recurrence properties (RRULE, EXRULE, RDATE, EXDATE) are not
   permitted within a Free/Busy Calendar Component. Any recurring events
   are resolved into their individual busy time periods using the
   FREEBUSY property.

   The following is an example of a Free/Busy Calendar Component:

     BEGIN:VFREEBUSY
     DTSTART:19971015T050000Z
     DTEND:19971016T050000Z
     FREEBUSY;VALUE=PERIOD-START:19971015T050000Z/PT8H30M,
      19971015T160000Z/PT5H30M, 19971015T223000Z/PT6H30M
     END:VFREEBUSY

5.4.5 Alarm Component

   An Alarm Calendar Component is a grouping of component properties
   that is a reminder or alarm for an event or a to-do. The Alarm
   Calendar Component may only be specified in an event or to-do

Dawson/Stenerson                   25            Expires September 1997
   calendar component. For example, it may define a reminder for a
   pending event or an overdue to-do.

   An Alarm Component is defined by the following notation:

     alarmc     = "BEGIN" ":" "VALARM" CRLF
                  *alarmprop
                  "END" ":" "VALARM" CRLF

     alarmprop  = *attach [created] [description] dtstart duration
                / *last-mod *related repeat [summary] *url

   The Alarm Component can only appear within either an Event or To-Do
   Calendar Component. Alarm Components can not be nested.

   The following is an example of the Alarm Calendar Component:

     BEGIN:VALARM
     DTSTART:19970317T133000Z
     REPEAT:4
     DURATION:PT15M
     CATEGORIES:DISPLAY,AUDIO
     ATTACH:file:///mmedia/sounds/bell1.wav
     DESCRIPTION:Breakfast meeting with executive team at 8:30 AM
     END:VALARM

5.4.6 Timezone Component

   A time zone is unambiguously defined by the set of time measurement
   rules determined by the governing body for a given geographic area.
   These rules describe at a minimum the base offset from UTC for the
   time zone, often referred to as the Standard Time offset. Many
   locations adjust their Standard Time forward or backward by one hour,
   in order to accommodate seasonal changes in number of daylight
   hours. hours,
   often referred to as Daylight Saving Time. Some locations adjust
   their time by a fraction of an hour. Standard time Time is also known as
   Winter Time. Daylight savings time Saving Time is also known as Advanced Time,
   Summer Time, or Legal Time in certain countries. The property value consists of a sequence of components that define a
   rule for the observance of daylight savings time. The value consists
   of effective start date for the DST rule, followed by the daylight
   savings time flag, followed by following table
   shows the daylight savings changes in time offset from
   UTC, followed by zone rules for the date eastern United States.

     Effective  Transition Rule
     Date       (Date/Time)                     Offset  Abbreviation

     1967-*     last Sun in October, 02:00      -0500   EDT

     1967-1973  last Sun in April, 02:00        -0400   EST

     1974-1974  Jan 6, 02:00                    -0400   EST

     1975-1975  Feb 23, 02:00                   -0400   EST

     1976-1986  last Sun in April, 02:00        -0400   EST

     1987-*     first Sun in April, 02:00       -0400   EST

Dawson/Stenerson                   26            Expires September 1997
   Interoperability between two calendaring and time of scheduling applications,
   especially for recurring events and to-dos, is dependent on the transition from standard
   time
   ability to daylight savings time, followed by the capture and convey date and time information in an
   unambiguous format. The specification of the
   transition from daylight savings current time zone
   information is integral to standard time, followed by
   the customary standard time designation, followed by the customary
   daylight savings time designation. this behavior.

   The effective start date for the
   DST rule allows for the specification of Time Zone Calendar Component is a series grouping of future DST component
   properties that define a time zone description. The time zone
   description specifies the effective Standard Time or Daylight Savings
   Time rules for a given particular time zone. The daylight savings time flag is TRUE if
   daylight savings time is observed, otherwise it is FALSE and no Timezone Component can not
   be nested within other
   components are specified. Calendar Components. The daylight savings time offset value is Time Zone Component
   may be specified in a manner consistent with ISO 8601. The property value multiple times. If the Time Zone Component is
   a signed numeric indicating
   missing, the number of hours and possibly minutes
   from UTC. recipient should assume all local times are relative to
   the recipient's time zone. The date and time that the daylight savings time begins and
   ends is Time Zone Component should be
   specified in a manner consistent with ISO 8601 date and time

Dawson/Stenerson                   24               Expires August 1997
   format. The standard time and daylight savings time designations
   correspond to the customary character designations.

   The iCalendar Object before any other Calendar
   Components.

   A Time Zone Component is defined by the following are examples of this property:

     DAYLIGHT:19960407;TRUE;-06;19960407T025959;19961027T010000;EST;EDT

     DAYLIGHT:FALSE

     DAYLIGHT:19960407;TRUE;-09;19960407T115959;19961027T100000;PST;PDT

   This property notation:

     timezonec  = "BEGIN" ":" "VTIMEZONE" CRLF
                  *tzprop
                  "END" ":" "VTIMEZONE" CRLF

     tzprop     = [created] [daylight] [dtend] dtstart [rdate / rrule]
                  [tzname] tzoffset [tztrans] [uid]

   The Time Zone component is optional especially important for MIME entities conforming to this
   content type. In correct
   interpretation of recurring events and to-dos. If the iCalendar
   Object contains an event or to-do component that this property is not specified, has a recurring date
   pattern (i.e., includes the
   recipient of RRULE property) or a MIME Calendaring list of date and Scheduling Content Type should
   assume the same daylight savings
   local time rule as values (i.e., includes the recipient location.
   The data type RDATE property), one or more
   Time Zone components must be specified, such that for this property is DST-RULE.

3.1.5.4 Geographic Position

   This property is identified by the property name GEO. This property
   specifies information related to the global position given range
   of the _home_
   system that created the MIME calendar object. The property value
   specifies longitude and latitude. The longitude represents recurrence (i.e., the
   location east and west earliest instance to latest instance),
   there is valid time zone information for all instances. In other
   words, if all of the prime meridian as a positive or
   negative real number, respectively. The latitude represents the
   location north and south instances of the equator as a positive or negative
   real number, respectively. The following is an example of this
   property:

     GEO:37.24,-17.87

   This property pattern is optional for MIME entities conforming to this
   content type. The default data type for this property is FLOAT-LIST.
   Optionally, the data type for this property may entirely within one
   offset observance, (e.g., all are in Standard Time), only one Time
   Zone Calendar Component need be URL. The URL present. If a time zone transition is
   crossed, then other Time Zone Components are needed. Further, if
   there are known changes to the resource location rules for the geographical position value.

3.1.5.5 Product Identifier

   This time zone, even more
   Time Zone Components are needed.

   Each Time Zone Component consists of several properties. The CREATED
   property is identified by the property name PRODID. This
   property specifies the identifier for the product a DATE-TIME value that created indicates when the
   MIME calendar object. The vendor of time zone
   description was created; the implementation should assure
   that this DAYLIGHT property is a globally unique identifier; using some technique such
   as an ISO 9070 FPI value. The following is an example of this
   property:

     PRODID:-//ABC Corporation//NONSGML My Product//EN

   This BOOLEAN value
   indicating Standard Time (FALSE) or Daylight Savings Time (TRUE); the
   DSTART property is required for MIME entities conforming to this
   content type. The default data type a DATE-TIME value indicating the effective start
   for this property is STRING.
   Optionally, the data type may be URL. The URL time zone information; the DTEND property is a DATE-TIME
   value indicating the resource
   location effective end date for the product identifier value.

Dawson/Stenerson                   25               Expires August 1997

3.1.5.6 Time Zone

   This time zone
   information; the TZOFFSET property is identified by a UTC-OFFSET value indicating
   the property name TZ. This property
   specifies UTC offset for the standard time zone of the _home_ system that created (Standard Time or Daylight Savings
   Time); the MIME calendar object. The TZTRANS property value is specified in a manner
   consistent with ISO 8601. The property TIME value is a signed numeric indicating the number time of hours and possibly minutes from UTC. Time
   zones east of UTC are positive numbers. Time zones west of UTC are
   negative numbers. The following are examples of this property:

     TZ:-0500

     TZ:+05:30

   This property is optional for MIME entities conforming
   day after which the transition to this
   content type. If this the time zone occurs; the TZNAME
   property is missing, the recipient should
   assume all local times are relative to customary name for the recipients time zone. The
   data type for this zone; the RRULE property
   is TIME-OFFSET. Optionally, a TEXT property indicating the data type recurrence rule for the transition

Dawson/Stenerson                   27            Expires September 1997
   to this time zone or alternatively, the RDATE property may be STRING.

3.1.5.7 Version

   This is a DATE-TIME
   property specifies the identifier corresponding to indicating the highest
   version number of individual dates and times that the MIME Calendaring
   transition takes effect; and Scheduling Content Type
   specification supported by the implementation that created UID is a TEXT value indicating a
   globally unique identifier for the MIME
   calendar object. time zone.

   The value default for DAYLIGHT is FALSE or Standard Time.

   The following are examples of this property must be 2.0 the Time Zone Calendar Component:

     BEGIN:VTIMEZONE
     DAYLIGHT:FALSE
     DTSTART:19670101T000000
     RRULE;BYDAY=-1SU;BYMONTH=10:YEARLY
     TZTRANS:020000
     TZOFFSET:-0500
     TZNAME:EST
     END:VTIMEZONE

     BEGIN:VTIMEZONE
     DAYLIGHT:TRUE
     DTSTART:19870101T000000
     RRULE;BYDAY=1SU;BYMONTH=4:YEARLY
     TZTRANS:020000
     TZOFFSET:-0400
     TZNAME:EDT
     END:VTIMEZONE

5.4.7 Calendar Properties

   The Calendar Properties are attributes that apply to correspond the iCalendar
   Object, as a whole. These properties do not appear within a Calendar
   Component. They should be specified after the BEGIN:VCALENDAR
   properties and prior to this specification.. any Calendar Component.

5.4.7.1 Calendar Scale

   This property is identified by the property name VERSION. The
   following is an example of this property:

     VERSION:2.0 CALSCALE. This
   property is required defines the calendar scale used for MIME entities conforming to this
   content type. the calendar information
   specified in the iCalendar Object. This property must appear within specification is based on the MIME
   Gregorian calendar
   object. scale. The data type for Gregorian calendar scale is assumed if
   this property is FLOAT.

3.1.6   Event and To-do Component Properties 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 specification.

   The property is defined by the following notation:

     calscale   = "CALSCALE" ":" calvalue CRLF

     calvalue   = "GREGORIAN" / iana-scale

     iana-scale = <Any other designator for a calendar scale
                   registered with IANA>

   The following properties apply to either is an event or to-do calendar
   object component.

3.1.6.1 Attachment example of this property:

Dawson/Stenerson                   28            Expires September 1997
     CALSCALE:GREGORIAN

   The data type for this property is TEXT.

5.4.7.2 Geographic Position

   This property is identified by the property name ATTACH. The GEO. This property
   defines an attached object
   specifies information related to the MIME calendar object. For example,
   a document to be reviewed at a scheduled event or global position of the process steps
   for a to-do. entity
   represented by the iCalendar Object. The property value can be a text string, specifies
   longitude and latitude. The longitude represents the location east
   and west of the prime meridian as a reference to
   another message body part positive or negative real number,
   respectively. The latitude represents the location north and south of
   the equator as a reference to a URL corresponding to a
   document.

   Multiple attachments may be specified positive or negative real number, respectively.

   The property is defined by including multiple ATTACH
   properties within the MIME calendaring entity.

Dawson/Stenerson                   26               Expires August 1997 following notation:

     geo        = "GEO" ":" geovalue CRLF

     geovalue   = (float ";" float )/ url

   The following are examples is an example of this property:

     ATTACH;VALUE=CONTENT-ID:<jsmith.part3.960817T083000.
        xyzMail@host1.com>

     ATTACH;VALUE=URL:file://xyzCorp.com/pub/reports/r-960812.ps

   This property is optional for MIME entities conforming to this
   content type.

     GEO:37.24,-17.87

   The default data type for this property is MID. The FLOAT. Optionally, the
   data type for this property may alternatively be specified to be CID, URL, or STRING URL. The URL is the resource
   location for the geographical position value.

3.1.6.2 Attendee

5.4.7.3 Product Identifier

   This property is identified by the property name ATTENDEE. The PRODID. This
   property defines an attendee to a group event or to-do. The default
   property value is an (RFC 822) address. The property may include
   property parameters TYPE, for specifies the type of attendee, ROLE, identifier for the
   role of the attendee in the event or to-do; STATUS, for product that created the status
   iCalendar Object. The vendor of the attendee's participation implementation should assure that
   this is a globally unique identifier; using some technique such as an
   ISO 9070 FPI value. This calendar property must be specified in the event or to-do, RSVP, for
   indicating whether the favor of a reply
   iCalendar Object but can only appear once.

   The property is requested, EXPECT, to
   indicate the expectation of the attendee's participation defined by the
   originator, and MEMBER, to indicate following notation:

     prodid     = "prodid" ":" pidvalue CRLF

     pidvalue   = (text / url)
     ;Any text that describes the group product and version
     ;and that is generally assured of being unique.>

   The following is an example of this property:

     PRODID:-//ABC Corporation//NONSGML My Product//EN

   The default data type for this property is TEXT. Optionally, the attendee
   belongs to.

   Multiple attendees data
   type may be specified URL. The URL is the resource location for the product
   identifier value.

Dawson/Stenerson                   29            Expires September 1997

5.4.7.4 Profile

   This property is identified by including multiple ATTENDEE
   properties within the MIME calendaring entity.

   The property value may reference a vCard object. name PROFILE. This provides
   property defines the usage profile associated with the calendar
   object. When used in a
   useful mechanism to allow more than just MIME message entity, the address value of the attendee
   to be referenced.

   The TYPE this
   property must be the same as the Content-Type profile parameter for each attendee
   value. This property can have only appear once within the following
   values:

Dawson/Stenerson                   27               Expires August 1997
              Property            Description
              Value

              INDIVIDUAL          Indicates
                                  attendee iCalendar
   Object.

   The property is
                                  an
                                  individual.

              GROUP               Indicates
                                  attendee defined by the following notation:

     profile    = "PROFILE" ": profvalue CRLF

     profvalue  = " component "-" action

     component  = "EVENT" / "TODO" / "JOURNAL" / "FREEBUSY"
                / iana-component / x-token

     action     = <Any IANA registered iCalendar action type.>

     iana-component = <Any other component registered with IANA>

   The following is a
                                  group an example of
                                  individuals.

              RESOURCE            Indicates
                                  attendee is a
                                  resource.

              UNKNOWN             Indicates
                                  attendee type
                                  is unknown.

   The ROLE this property parameter for each attendee can have when the following
   values:

              Property            Description
              Value

              ATTENDEE            Indicates an
                                  attendee at iCalendar
   Object is used to request a meeting:

     PROFILE:EVENT-REQUEST

   In the event or
                                  to-do

              ORGANIZER           Indicates
                                  organizer of
                                  the event,
                                  but that this property is not owner

              OWNER               Indicates
                                  owner of specified, the
                                  event or to-
                                  do.

Dawson/Stenerson                   28               Expires August 1997
              DELEGATE            Indicates a
                                  delegate of
                                  another
                                  attendee. usage profile
   is undefined. The default value data type for this property parameter is ATTENDEE.

   The STATUS TEXT.

5.4.7.5 Profile Version

   This property parameter for each attendee can have the
   following values:

              Property            Description
              Value

              ACCEPTED            Indicates to-
                                  do was
                                  accepted by
                                  attendee

              NEEDS ACTION        Indicates
                                  event or to-
                                  do requires
                                  action by
                                  attendee

              SENT                Indicates
                                  event or to-
                                  do was sent
                                  out to
                                  attendee

              TENTATIVE           Indicates
                                  event is
                                  tentatively
                                  accepted identified by
                                  attendee

              CONFIRMED           Indicates
                                  attendee has
                                  confirmed
                                  their
                                  attendance at the event

              DECLINED            Indicates
                                  event or to-

Dawson/Stenerson                   29               Expires August 1997
                                  do has been
                                  rejected by
                                  attendee

              COMPLETED           Indicates to-
                                  do has been
                                  completed by
                                  attendee

              DELEGATED           Indicates
                                  event or to-
                                  do has been
                                  delegated by property name PROFILE-VERSION.
   This property specifies the attendee identifier corresponding to another

              CANCELED            Indicates the
                                  event or to-
                                  do has been
                                  canceled
                                  and/or this
                                  attendee has
                                  been removed
                                  from the list highest
   version number of attendees.

   The default value the usage profile that was used in constructing the
   iCalendar Object. Values for this property parameter is NEEDS ACTION. are to be defined by
   registering an iCalendar usage profiles.

   The RSVP property parameter for each attendee can have is defined by the following
   values:

              Property           Description
              Value

              YES                Indicates a
                                 reply is
                                 requested

              NO                 Indicates a
                                 reply notation:

     prof-version = "PROFILE-VERSION" ":" profvalue CRLF

     profvalue  = iana-prfver / x-token

     iana-prfver = <A IANA registered iCalendar profile identifier>

   The following is not
                                 requested. an example of this property:

     PROFILE-VERSION:IPCS-1.0

   The default value data type for this property parameter is NO. TEXT.

Dawson/Stenerson                   30            Expires August September 1997
   The EXPECT

5.4.7.6 Source

   This property parameter for each attendee can have the
   following values:

              Property           Description
              Value

              FYI                Indicates
                                 request is
                                 for your
                                 information.

              REQUIRE            Indicates
                                 presence is
                                 definitely
                                 required.

              REQUEST            Indicates
                                 presence is
                                 being
                                 requested

              IMMEDIATE          Indicates an
                                 immediate
                                 response
                                 needed.

   The default value for this identified by the property parameter is FYI.

   The MEMBER name SOURCE. This
   property parameter value is an (RFC 822) address that
   represents defined by the group or distribution list. [MIME DIR] specification. The following is an example of this property's use property
   identifies the URL for the source of the iCalendar Object. The source
   will usually be a to-do:

     ATTENDEE;ROLE=OWNER;STATUS=COMPLETED:jsmith@host1.com resource on a calendaring and scheduling service.

   The following is an example of this property used for specifying
   multiple attendees to an event:

     ATTENDEE;ROLE=OWNER;STATUS=CONFIRMED:John Smith <jsmith@host1.com>
     ATTENDEE;ROLE=ATTENDEE;STATUS=TENTATIVE:Henry Cabot
     <hcabot@host2.com>
     ATTENDEE;ROLE=DELEGATE;STATUS=CONFIRMED:Jane Doe <jdoe@host1.com> is defined by the following notation:

     source     = "SOURCE" ":" url CRLF

   The following is an example of this property with the value specified
   as an URL reference to a vCard that contains the information about
   the attendee:

Dawson/Stenerson                   31               Expires August 1997
     ATTENDEE;ROLE=ATTENDEE;STATUS=CONFIRMED;VALUE=URL:
       http://www.xyz.com/~myvcard.vcf

   This property is optional for MIME entities conforming to this
   content type. property:

     SOURCE:http://xyz.corp.com/corp-cals/1997-events.or4

   The default data type for this property is RFC822-
   ADDRESS. Optionally, the data type for this property may be URL, MID,
   or CID; in which case the value is a location or message that
   contains information that is to be used to specify the attendee.

3.1.6.3 Audio Reminder URL.

5.4.7.7 Source Name

   This property is identified by the property name AALARM. The NAME. This property
   defines an audio reminder for the MIME calendar object. An audio
   reminder
   is an alarm that is sounded for a calendar component.. defined by the [MIME DIR] specification. The value property identifies
   the displayable, presentation name for the audio reminder consists source of the Run Time, or the
   date and time that the reminder iCalendar
   Object. The source name is a useful text to be executed; Snooze Time, or associate in the duration user-
   interface of time after the Run Time that the reminder is to be
   dormant prior to being repeated; Repeat Count, or an application with the number of times
   that value in the reminder SOURCE property.

   The property is to be repeated; and the Audio Content, or the
   digital sound to be played when defined by the reminder is executed. following notation:

     name       = "NAME" ":" text CRLF

   The following are some examples is an example of this property:

     AALARM;TYPE=WAVE;VALUE=URL:19960415T235959; ; ;
     file:///mmedia/taps.wav

     AALARM;TYPE=WAVE;VALUE=CONTENT-
     ID:19960903T060000;PT15M;4;<jsmith.part2.=
      960901T083000.xyzMail@host1.com>

   The property has the following additional property parameters:

              Property           Description
              Parameter
              Values

              TYPE

              - - Any IANA       Indicates a
              registered         MIME audio
              audio              content
              content type       type.
              value - -

              WAVE               Indicates
                                 the WAVE
                                 format for
                                 audio
                                 content.

Dawson/Stenerson                   32               Expires August 1997
              AIFF               Indicates
                                 the AIFF
                                 format for
                                 audio
                                 content.

   The Reminder properties are primarily provided as a means for
   allowing the capture of alarm information when accessing a calendar
   system. It may not be an appropriate property to send in an event or
   to-do request.

   This property is optional

     NAME:1997 Events Calendar for MIME entities conforming to this
   content type. XYZ Corporation

   The default data type for this property is AALARM.
   Optionally, the data type may be specified to be CID, MID, or URL.

3.1.6.4 Categories TEXT.

5.4.7.8 Version

   This property is identified by the property name CATEGORIES. VERSION. This
   property defines specifies the categories for identifier corresponding to the MIME calendar component. More
   than one category may be specified as a list highest
   version number of categories separated the MIME Calendaring and Scheduling Content Type
   specification supported by the Semi-Colon character (ASCII decimal 59). implementation that created the
   iCalendar Object. The following are some examples value of this property:

     CATEGORIES:APPOINTMENT;EDUCATION

     CATEGORIES:MEETING

   Some of the possible values for property must be "2.0" to
   correspond to this specification. This calendar property might include must appear
   within the
   following:

              Some Possible

              Property Values

              APPOINTMENT

              BUSINESS

              EDUCATION

              HOLIDAY

              MEETING

              MISCELLANEOUS

Dawson/Stenerson                   33               Expires August 1997
              NON-WORKING-HOURS

              NOT-IN-OFFICE

              PERSONAL

              PHONE CALL

              SICK DAY

              SPECIAL OCCASION

              TRAVEL

              VACATION

   This iCalendar Object but can only appear once.

   The property is optional for MIME entities conforming to defined by the following notation:

     version    = "VERSION" ":" vervalue CRLF

     vervalue   = "2.0" / x-token

   The following is an example of this
   content type. property:

     VERSION:2.0

Dawson/Stenerson                   31            Expires September 1997
   The data type for this property is STRING-LIST.

3.1.6.5 Classification TEXT.

5.5 Component Properties

   The following properties apply to either an event or to-do calendar
   object component.

5.5.1.1 Attachment

   This property is identified by the property name CLASS. This ATTACH. The property
   defines the access classification for
   provides the MIME capability to associate an external object with a
   calendar component.

   A calendar event/to-do access classification is only one component of
   the general security system within For example, a calendar application. It
   provides document to be reviewed at a method of capturing
   scheduled event or the scope description of the access the calendar
   owner intends process steps for information a to-do.
   The property may only be specified within an individual event, to-do, or journal
   calendar entry.
   The access classification of components. This property may be specified multiple times
   within an individual MIME calendaring entity iCalendar Object.

   The property is
   useful when measured along with the other security components of a
   calendar system (e.g., user authorization, access rights, access
   role, etc.). Hence, the semantics of the individual access
   classifications can not be completely defined by this specification.
   Additionally, due to the _blind_ nature of most exchange processes
   using this specification, these entity classifications can not serve
   as an enforcement statement for a system receiving a MIME calendar
   object . Rather, they provide a method for capturing the intention of
   the calendar owner for the access to the MIME calendar object
   component. following notation:

     attach     = [group "."] "ATTACH" ":" url CRLF

   The following is an example are examples of this property:

     CLASS:PUBLIC

     ATTACH:<jsmith.part3.960817T083000.xyzMail@host1.com>

     ATTACH://xyzCorp.com/pub/reports/r-960812.ps

   The property can have the following values:

Dawson/Stenerson                   34               Expires August 1997
                Property         Description
                  Value

                 PUBLIC          Indicates
                                 general,
                                 public
                                 access.

                 PRIVATE         Indicates
                                 restricted,
                                 private
                                 access.

              CONFIDENTIAL       Indicates
                                 very
                                 restricted,
                                 confidential
                                 access.

   The default value for this property is PUBLIC.

   This property is optional for MIME entities conforming to this
   content type. The data type for this data type for this property is STRING.

3.1.6.6 Date/Time Created URL.

5.5.1.2 Attendee

   This property is identified by the property name DCREATED. This ATTENDEE. The
   property specifies the date and time that the MIME defines an attendee within a calendar component
   was created component. The
   property may only be specified within the originating event, to-do and free/busy
   calendar system. This components.

   The property has the property parameters TYPE, for the type of
   attendee, ROLE, for the intended role of the attendee; STATUS, for
   the status of the attendee's participation; RSVP, for indicating
   whether the favor of a reply is not
   necessarily requested; EXPECT, to indicate the same date and time that
   expectation of the MIME calendar object was
   created. The date attendee's participation by the originator; and time value is
   MEMBER, to indicate the local or UTC based time
   expressed in group that the complete representation, basic or extended format as attendee belongs to.

   Multiple attendees may be specified in ISO 8601. by including multiple ATTENDEE
   properties within the MIME calendaring entity.

   The following is an example of this property:

     DCREATED:19960329T083000-0500

   This property data type default is optional for MIME entities conforming to this
   content type. RFC822-ADDRESS. The property data
   type for this property is DATE-TIME.

3.1.6.7 Date/Time Completed may also be set to URL. This property is identified by provides a useful mechanism to
   allow more than just the property name COMPLETED. This
   property defines address of the date and time that attendee to be referenced.
   For example, the to-do was actually
   completed. The date and time property value may refer to a URL.

   The property is expressed in defined by the complete
   representation, basic following notation:

Dawson/Stenerson                   32            Expires September 1997
     attendee   = [group "."] "ATTENDEE" [";" attparamlist] ":"
                  (rfc822-address / URL) CRLF
     ;Value must match default or extended format as specified in ISO 8601.
   The time can either be explicit data type

     attparamlist       = attparam / attparamlist ";" attparam
                        / paramlist / paramlist ";" attparam
                        / paramlist ";" attparamlist ";" attparam

     attparam   = typeparm / roleparm / statusparm / rsvpparm
                / expectparm / memberparm

     typeparm   = "TYPE" "="
                ("INDIVIDUAL"   ; An individual
                / "GROUP"       ; A group of individuals
                / "RESOURCE"    ; A physical resource
                / "ROOM"        ; A room resource
                / "UNKNOWN")    ; Otherwise not known
     ;Default value is UNKNOWN

     roleparm   = "ROLE" "="
                ("ATTENDEE"     ; Indicates a regular attendee
                / "OWNER"       ; Indicates owner of event or to-do
                / "ORGANIZER"   ; Indicates organizer of event or to-do
                / "DELEGATE")   ; Indicates delegate to event or to-do
     ;Default is ATTENDEE

     statusparm = "STATUS" "="
                ("NEEDS-ACTION" ; Indicates event or to-do needs action
                / "ACCEPTED"    ; Indicates event or to-do accepted
                / "DECLINED"    ; Indicates event or to-do not accepted
                / "TENTATIVE"   ; Indicates event or to-do tentatively
                ; accepted. Status may change in local the future.
                / "COMPLETED"   ; Indicates to-do was completed.
                ; COMPLETED property has date/time completed.
                / "DELEGATED"   ; Indicateds event or UTC based time. to-do delegated
                ; to another ATTENDEE
                / "CANCELED")   ; Indicates event or to-do canceled for
                ; ATTENDEE
     ;Default is NEEDS-ACTION

     rsvpparm   = "RSVP" "=" ("YES" / "NO")
     ;Default is NO

     expectparm = "EXPECT" "="
                ("FYI"          ; Indicates request is for your info
                / "REQUIRE"     ; Indicates presence is required
                / "REQUEST"     ; Indicates presence is requested
                / "IMMEDIATE")  ; Indicates an immediate response needed
     ;Default is FYI

     memberparm = rfc822-address ; Indicates a group or mailing list

   The following is an example of this property: property's use for a to-do:

Dawson/Stenerson                   35                   33            Expires August September 1997
     COMPLETED:19960401T235959Z

   This property
     ATTENDEE;ROLE=OWNER;STATUS=COMPLETED:jsmith@host1.com

   The following is optional an example of this property used for MIME entities conforming specifying
   multiple attendees to this
   content type. The data type for this property is DATE-TIME.

3.1.6.8 Description

   This property is identified by the property name DESCRIPTION. This
   property provides a more complete description of the MIME calendar
   component, than that provided by the SUMMARY property. an event:

     ATTENDEE;ROLE=OWNER;STATUS=CONFIRMED:John Smith <jsmith@host1.com>
     ATTENDEE;ROLE=ATTENDEE;STATUS=TENTATIVE:Henry Cabot
      <hcabot@host2.com>
     ATTENDEE;ROLE=DELEGATE;STATUS=CONFIRMED:Jane Doe <jdoe@host1.com>

   The following is an examples example of the property with formatted line breaks in the
   property value:

     DESCRIPTION;ENCODING=QUOTED-PRINTABLE:Meeting to provide technical=
      review for _Phoenix_ design.=0D=0A=
     Happy Face Conference Room. Phoenix design team=
      must attend this meeting. RSVP to team leader.

   The following is an examples of the property with folding of long
   lines:

     DESCRIPTION:Last draft of the new novel is value specified
   as an URL reference to be completed
       for a vCard that contains the editor's proof today.

   This property is required for MIME entities conforming to this
   content type. information about
   the attendee:

     ATTENDEE;ROLE=ATTENDEE;STATUS=CONFIRMED;VALUE=URL:
      http://www.xyz.com/~myvcard.vcf

   The default data type for this property is STRING. Optionally,
   the RFC822-ADDRESS. The data
   type may be URL, MID, reset to URL; in which case the value is a location or CID.

3.1.6.9 Display Reminder
   message that contains the information that is to be used to specify
   the attendee address.

5.5.1.3 Categories

   This property is identified by the property name DALARM. The CATEGORIES. This
   property defines a display reminder for the MIME calendar component. A display
   reminder is an alarm that is popped up into the user interface or
   otherwise visually displayed categories for a calendar component. The value for the display reminder consists of
   property may be specified within the Run Time, event, to-do or the
   date and time that the reminder is to journal calendar
   component with an arbitrary text value. The property may also be executed; Snooze Time, or
   specified within the duration alarm property with a value of time after the Run Time that the reminder is to alarm
   category. More than one category may be
   dormant prior to being repeated; Repeat Count, or the number specified as a list of times
   that
   categories separated by the reminder COMMA character (ASCII decimal 44).

   The properties is to be repeated; and the Display String, or the
   text to be displayed when defined by the reminder is executed. following notation:

     categories = "CATEGORIES" [";" paramlist] ":" catvalue CRLF

     catvalue   = cat1value [,cat1value] / cat2value [, cat2value]

     cat1value  = "APPOINTMENT" / "BUSINESS" / "EDUCATION" / "HOLIDAY"
                / "MEETING" / "MISCELLANEOUS" / "NON-WORKING HOURS"
                / "NOT IN OFFICE" / "PERSONAL" / "PHONE CALL"
                / "SICK DAY" / "SPECIAL OCCASION" / "TRAVEL"
                / "VACATION" / word
     ;Used in event and to-do components only

     cat2value  = "AUDIO" / "DISPLAY" / "EMAIL" / "PROCEDURE"
                / x-token / iana-word
     ;Used in alarm component only

   The following is an example are examples of this property:

     DALARM:19960415T235000-0800;PT5M;2;Your Taxes Are Due !!! property in an event, to-do or
   journal calendar component:

     CATEGORIES:APPOINTMENT,EDUCATION

Dawson/Stenerson                   34            Expires September 1997
     CATEGORIES:MEETING

   The Reminder properties following are primarily provided as a means for
   allowing the capture examples of alarm information when accessing a calendar
   system. It may not be an appropriate this property to send in an event or
   to-do request.

   This property is optional for MIME entities conforming to this
   content type. alarm calendar
   component:

     CATEGORIES:AUDIO,DISPLAY

     CATEGORIES:PROCEDURE

   The default data type for this property is DALARM.
   Optionally, the data type may be specified to be CID, MID, or URL.

Dawson/Stenerson                   36               Expires August 1997

3.1.6.10        Due Date/Time TEXT.

5.5.1.4 Classification

   This property is identified by the property name DUE. CLASS. This property
   defines the date and time that the to-do is due to be completed. The
   date and time value is expressed in the complete representation,
   basic or extended format as specified in ISO 8601. access classification for a calendar component. The time can
   either
   property may only be specified in local an event, to-do or UTC based time. Alternatively, the value journal calendar
   component. The property may only be
   a duration of time, expressed in the ISO 8601 format as specified in
   section 3.1.3.8. In this case, the end once.

   An access classification is relative to only one component of the start general
   security system within a calendar application. It provides a method
   of capturing the scope of the access the MIME calendar component. owner intends for
   information within an individual calendar entry. The following is access
   classification of an example of this
   property:

     DUE:19960401T235959Z

   This property individual iCalendar component is required for MIME entities consisting useful when
   measured along with the other security components of a to-do calendar component that conforms to this content type. The default
   data type for this property is DATE-TIME. Optionally,
   system (e.g., user authorization, access rights, access role, etc.).
   Hence, the data type
   may semantics of the individual access classifications can not
   be specified as a DURATION.

3.1.6.11        Duration

   This property is identified completely defined by this specification alone. Additionally, due
   to the property name DURATION. The
   property specifies an interval or duration "blind" nature of time. This property most exchange processes using this
   specification, these access classifications can
   be used with the DTSTART property to specify a relative duration for not serve as an event (e.g., event starts at 8:00 am and lasts
   enforcement statement for one hour). The
   property can also be used in constructing a free-busy time request
   (e.g., find free time periods system receiving an iCalendar Object .
   Rather, they provide a method for capturing the intention of 15 minute duration, or longer). the
   calendar owner for the access to the calendar component.

   The property is defined by the following notation:

     class      = "CLASS" [";" paramlist] ":" classvalue CRLF

     classvalue = "PUBLIC" / "PRIVATE" / "CONFIDENTIAL" / x-token
     ;Default is an example of this property that specifies an interval
   of time of 1 hour and zero minutes and zero seconds:

     DURATION:PT1H0M0S PUBLIC

   The following is an example of this property that specifies an
   interval of time of 15 minutes.

     DURATION:PT15M

   This property is optional for MIME entities conforming to this
   content type. property:

     CLASS:PUBLIC

   The data type for this property is DURATION.

3.1.6.12        End TEXT.

5.5.1.5 Date/Time Created

   This property is identified by the property name DTEND. CREATED. This
   property
   defines specifies the date and time that the event component will end. calendar information
   was created. The property may be specified in any of the calendar
   components. The property may only be specified once. The date and
   time value is expressed in the complete representation, basic or
   extended format as specified in ISO 8601. The time can either be in
   local or an UTC based time. Alternatively, the value may be a duration
   of time, expressed in the ISO 8601 format as specified in section
   3.1.3.8. In this case, the end value.

Dawson/Stenerson                   35            Expires September 1997
   The property is relative to the start of the MIME
   calendar component. Events may have an end date/time but no start
   date/time. In that case, defined by the event does not take up any time. following notation:

     created    = "CREATED" ":" date-time CRLF

   The following is an example of this property:

     DTEND:19960401T235959Z

Dawson/Stenerson                   37               Expires August 1997
   This property is required for MIME entities conforming to this
   content type.

     CREATED:19960329T133000Z

   The default data type for this property is DATE-TIME.
   The data type may alternatively be specified as a DURATION.

3.1.6.13        Exception Date/Times

5.5.1.6 Date/Time Completed

   This property is identified by the property name EXDATE. COMPLETED. This
   property defines the list of date/time exceptions for date and time that a recurring
   MIME calendar to-do was actually
   completed. The property may be specified once in a to-do component.
   The date and time values is expressed in the
   complete representation, basic format as specified in ISO 8601. The
   times can either be in local or a UTC based time. value.

   The property is defined by the following notation:

     completed  = "COMPLETED" ":" date-time CRLF

   The following is an example of this property:

     EXDATE:19960402T010000Z;19960403T010000Z;19960404T010000Z

     COMPLETED:19960401T235959Z

   This property is optional for MIME entities conforming to this
   content type. The data type for this property is D-T-LIST.
   Optionally, the data type may be URL; in which case the value is the
   location where a list of exception dates can be found. This latter
   case is a useful method for conveying dynamic exceptions dates, such
   as holidays, for a recurring event or to-do.

3.1.6.14        Exception Rule DATE-TIME.

5.5.1.7 Daylight

   This property is identified by the property name EXRULE. DAYLIGHT. This
   property defines may only be specified in a rule Time Zone Calendar Component.
   This property specifies whether Daylight Saving Time (i.e., value is
   TRUE) or repeating pattern Standard Time (i.e., value is FALSE) is in effect for an exception to a
   recurring MIME calendaring entity, based on the Basic Recurrence Rule
   Grammar of the [XAPIA].
   time zone. The default value for the is FALSE or Standard Time.

   The property is a pattern
   specification for defined by the recurrence exception. following notation:

     daylight   = "DAYLIGHT" ":" boolean CRLF
     ;Default value is FALSE

   The following are some
   examples is an example of this property:

     EXRULE:W2 TU TH #2         // Except every other week, on Tuesday
                                // and Thursday for 4 occurrences

     EXRULE:D1 #10              // Except daily for 10 occurrences

     EXRULE:YM1 6 7 #8          // Except yearly

     DAYLIGHT:TRUE              ;Specifies DST in June and July for 8
                                // occurrences

   This property is optional for MIME entities conforming to this
   content type. effect in time zone

   The data type for this property is RRULE.

3.1.6.15        Last Modified BOOLEAN.

5.5.1.8 Description

   This property is identified by the property name LAST-MODIFIED. The DESCRIPTION. This
   property specifies provides a more complete description of the date and time calendar
   component, than that provided by the MIME SUMMARY property. The property
   must be specified in the event, to-do and journal calendar component
   was last revised.

Dawson/Stenerson                   36            Expires September 1997
   components. The property may be specified multiple times only within
   a journal calendar component.

   The property is defined by the following notation:

     description = "DESCRIPTION" [";" paramlist] text CRLF

   The following is an example examples of the property with formatted line
   breaks in the property value:

     DESCRIPTION;ENCODING=QUOTED-PRINTABLE:Meeting to provide technical=
      review for "Phoenix" design.=0D=0A=
     Happy Face Conference Room. Phoenix design team=
      must attend this property:

     LAST-MODIFIED:19960817T133000Z

   This meeting. RSVP to team leader.

   The following is an examples of the property with folding of long
   lines:

     DESCRIPTION:Last draft of the new novel is optional for MIME entities conforming to this
   content type. be completed
       for the editor's proof today.

   The data type for this property is DATE-TIME.

Dawson/Stenerson                   38               Expires August 1997

3.1.6.16        Location TEXT.

5.5.1.9 Due Date/Time

   This property is identified by the property name LOCATION. The DUE. This property
   defines the intended location for the MIME calendar
   component.

   The property value may reference a vCard object. This provides date and time that a
   useful mechanism to-do is expected to specify a location be completed.
   The time can either be in terms of its electronic
   business card. local time, local time with UTC offset or
   UTC time. The property must be specified in a to-do calendar
   component, but may only be specified once.

   The property is defined by the following are some examples notation:

     due        = "DUE" ":" date-time CRLF

   The following is an example of this property:

     LOCATION:Conference Room - F123, Bldg. 002         // or

     LOCATION;VALUE=URL:http://www.xyzcorp.com/~jsmith.vcf

   This property is optional for MIME entities conforming to this
   content type.

     DUE:19960401T235959Z

   The default data type for this property is STRING.
   Optionally the DATE-TIME. The data type
   may URL, MID, or CID.

3.1.6.17        Mail Reminder be reset to DURATION.

5.5.1.10 Duration

   This property is identified by the property name MALARM. DURATION. The
   property
   defines specifies a duration of time. The property may be specified
   in an email address that is event calendar component in order to be sent specify a reminder for duration of the MIME
   calendar component. A mail reminder is
   event, instead of an electronic mail address
   that will explicit end date/time. The property may be sent a display string as an alarm for
   specified in a free/busy calendar
   component.

   The value for the procedure reminder consists of the Run Time, or the
   date and time that the reminder is component in order to be executed; Snooze Time, or specify the duration
   amount of free time after the Run Time that the reminder is to being requested. The property may be
   dormant prior specified in
   an alarm calendar component in order to being repeated; Repeat Count, or the number of times
   that specify the reminder period between
   repeating alarms.

   The property is to be repeated; Email Address, or defined by the (RFC 822)
   email address that is to be sent the reminder, Subject, or the
   textual subject of the note, and the Note, or the textual reminder
   string that is to be sent to the email address.

   The following following notation:

Dawson/Stenerson                   37            Expires September 1997
     duration   = "DURATION" ":" duration CRLF

   The following is an example of this property:

     MALARM:19960416T000000-0500;PT1H;24;IRS@us.gov;My Payment;
        The Check Is In The Mail!

   The Reminder properties are primarily provided as a means for
   allowing the capture of alarm information when accessing a calendar
   system. It may not be an appropriate property to send in that specifies an event or
   to-do request.

   This property is optional for MIME entities conforming to this
   content type. The default data type for this property is MALARM.
   Optionally, the data type may be URL, MID, or CID.

Dawson/Stenerson                   39               Expires August 1997

3.1.6.18        Number Recurrences

   This property is identified by the property name RNUM. The property
   defines the number of times the calendar entry will reoccur. The
   value is equal to the number
   interval of recurrences that are specified by the
   union time of the Recurrence Dates, Recurrence Rule, Exception Dates, 1 hour and
   Exception Rule property values. zero minutes and zero seconds:

     DURATION:PT1H0M0S

   The following is an example of this
   property:

     RNUM:3

   In the event property that this value does not match the computed number specifies an
   interval of
   recurrences, it will be ignored and the computed number time of
   recurrences will be used.

   This property is optional for MIME entities conforming to this
   content type. 15 minutes.

     DURATION:PT15M

   The data type for this property is INTEGER.

3.1.6.19        Priority DURATION.

5.5.1.11 Start Date/Time

   This property is identified by the property name PRIORITY. The DTSTART. This
   property may be specified within the event, free/busy, and time zone
   calendar components.

   Within the event calendar component, this property defines the priority start
   date and time for the MIME event. The property is required in event
   calendar component. components. The
   value time can either be in local time, local time
   with UTC offset or UTC time. The local time is an alphanumeric. A value of zero (ASCII decimal 48)
   specifies an undefined priority. only to be used to
   specify date and time values that do not need to be fixed. A value of one (ASCII decimal 49) is
   recipient must assume their own time zone for data and time values
   that do not include time zone information. Events may have a start
   date/time but no end date/time. In that case, the highest priority. A value of two (ASCII decimal 50) is event does not take
   up any time.

   Within the second
   highest priority. Subsequent numbers specify free/busy calendar component, this property defines the
   start date and time for the free or busy time information. The time
   must be specified in local time with UTC offset or UTC time.

   Within the time zone calendar component, this property defines the
   effective start date and time for a decreasing ordinal
   priority. time zone specification. This
   property is required within time zone calendar components. The time
   must be specified as a UTC time.

   The property is defined by the following notation:

     dtstart    = "DTSTART" ":" date-time CRLF

   The following is an example of this property:

     PRIORITY:2

   This property is optional for MIME entities conforming to this
   content type.

     DTSTART:19960401T235959-0600

   The default data type for this property is STRING.
   Optionally the data type may be specified to be INTEGER.

3.1.6.20        Procedure Reminder DATE-TIME.

5.5.1.12 End Date/Time

   This property is identified by the property name PALARM. The DTEND. This property
   defines a procedure reminder for
   may be specified within the MIME event, free/busy, and time zone calendar component. A
   procedure reminder is a procedure, or application executable that
   will be run as an alarm for a
   components.

Dawson/Stenerson                   38            Expires September 1997
   Within the event calendar component.

   While component, this property has many useful purposes, implementers should be
   aware of defines the security implications of sending a MIME calendaring
   entity containing this property. end
   date and time for the event. The security implications are
   similar to those associated with active messages within electronic
   mail. property is required in event
   calendar components. The value for the procedure reminder consists of the Run Time, or the
   date and time that the reminder is to can either be executed; Snooze Time, in local time, local time
   with UTC offset or
   the duration of UTC time. The local time after the Run Time that the reminder is only to be
   dormant prior used to being repeated; Repeat Count, or the number of times
   specify date and time values that the reminder is do not need to be repeated; fixed. A
   recipient must assume their own time zone for data and time values
   that do not include time zone information. Events may have an end
   date/time but no start date/time. In that case, the Procedure Name, or event does not
   take up any time.

   Within the
   path to free/busy calendar component, this property defines the procedure to be run when
   end date and time for the reminder is executed.
   Parameters are passed to free or busy time information. The time
   must be specified in local time with UTC offset or UTC time.

   Within the procedure by concatenating to time zone calendar component, this property defines the

Dawson/Stenerson                   40               Expires August 1997
   Procedure Name value
   effective end date and time for a Question-Mark (ASCII decimal 63) followed by time zone specification. This
   property is required within time zone calendar components. The time
   must be specified as a
   string representation of UTC time.

   The property is defined by the parameters. following notation:

     dtend      = "DTEND" ":" date-time CRLF

   The following is an example of this property:

     PALARM;VALUE=URL:19960415T235000-0500;PT5M;2;file:///myapps/
        shockme.exe?HARD

     DTEND:19960401T235959Z

   The Reminder properties are primarily provided as a means data type for
   allowing the capture of alarm information when accessing a calendar
   system. It may not be an appropriate this property to send in an event or
   to-do request.

   This property is optional for MIME entities conforming to this
   content type. The default data type for this property is PALARM.
   Optionally, the data type may be URL, MID, or CID.

3.1.6.21        Related To is DATE-TIME.

5.5.1.13 Exception Date/Times

   This property is identified by the property name RELATED-TO. The
   property is used to represent relationships or references between
   this MIME calendar component and another. The EXDATE. This
   property value consists
   of defines the persistent, globally unique identifier list of another MIME
   calendar component. This value would be represented in a MIME
   calendar component by the UID property.

   A linked relationship can be specified by date/time exceptions for a series of components that
   each, in turn, refer to their parent recurring
   event or to-do component. A group relationship The times can either be specified by a number of components that all refer to one
   common parent component.

   Changes to a calendar component referenced by this property may
   impact the related calendar component. For example, if a group event
   changes its start or end date or time, then the related, dependent
   events will need to have their start and end dates changed in a
   corresponding way. This local time,
   local time with UTC offset or UTC time.

   The property is intended only to provide
   information on the relationship of calendar components. It is up to defined by the target calendar system to maintain this relationship. following notation:

     exdate     = "EXDATE" ":" date-time *["," date-time] CRLF

   The following is an example of this property:

     RELATED-TO:<jsmith.part7.19960817T083000.xyzMail@host3.com>

     RELATED-TO:19960401-080045-4000F192713-0052

   This property is optional for MIME entities conforming to this
   content type.

     EXDATE:19960402T010000Z;19960403T010000Z;19960404T010000Z

   The default data type for this property is STRING.
   Optionally, the data type may be URL, MID, or CID.

3.1.6.22        Recurrence Date/Times DATE-TIME.

5.5.1.14 Exception Rule

   This property is identified by the property name RDATE. EXRULE. This
   property defines the list of date/times a rule or repeating pattern for an exception to a
   recurring MIME calendar
   component. event or to-do. This property may appear along with only be specified in the RRULE property to
   event and to-do calendar components.

Dawson/Stenerson                   41                   39            Expires August September 1997
   define an aggregate set of repeating occurrences. When they both
   appear in an iCalendar Object, the recurring events are defined by
   the union of occurrences
   This property is defined by both the RDATE and RRULE. The
   date and time same property values is expressed in the complete representation,
   basic format and parameters
   as specified in ISO 8601. The times can either be in
   local or UTC based time. for the RRULE property. The number of recurring date/times property is
   specified defined by the Number Recurrences property.
   following notation:

     exrule     = "EXRULE" [";" rparamlist] ":" rvalue CRLF

   The following is an
   example are examples of this property:

     RDATE:19960402T010000Z;19960403T010000Z;19960404T010000Z

   This property is optional property. Except every other week,
   on Tuesday and Thursday for MIME entities conforming to this
   content type. 4 occurrences:

     EXRULE;COUNT=4;INTERVAL=2;BYDAY=TU,TH:WEEKLY

   Except daily for 10 occurrences:

     EXRULE;COUNT=10:DAILY

   Except yearly in June and July for 8 occurrences:

     EXRULE;COUNT=8;BYMONTH=6,7:YEARLY

   The default data type for this property is D-T-LIST.
   Optionally, the data type may be URL; in which case the value is the
   location where a list of recurring dates can be found. This latter
   case is a useful method for conveying dynamic recurring dates, such
   as schedules, for a recurring event or to-do.

3.1.6.23        Recurrence Rule TEXT.

5.5.1.15 Free/Busy Time

   This property is identified by the property name RRULE. This FREEBUSY. The
   property defines one or more free or busy time intervals. These time
   periods may be specified as either a rule start and end date-time or repeating pattern for a recurring MIME calendar
   component, based on the Basic Recurrence Rule Grammar of [XAPIA].
   start date-time and duration.

   The
   value for the property date and time is either local time with UTC offset or a pattern specification for the recurrence.
   This UTC
   value.

   The FREEBUSY property may appear along with include the RDATE TYPE property parameter to define an
   aggregate set of repeating occurrences. When they both appear in an
   iCalendar Object,
   specify the recurring events are defined information defines a free or busy time interval. The
   property may also include the STATUS property parameter to specify
   the type of busy time. The STATUS parameter may be utilized by the union
   application reading the busy time information in order to provide a
   richer view of
   occurrences the information.

   The property is defined by both the RDATE and RRULE. following notation:

     freebusy   = "FREEBUSY" [";" fbparmlist] ":" fbvalue CRLF

     fbparmlist = fbparam / paramlist ";" fbparam
                / fbparam ";" fbparmlist

     fbparam    = fbtype / fbstatus

     fbtype     = "TYPE" "=" ("FREE" or "BUSY")
     ;Default is BUSY

     fbstatus   = "STATUS" "="
                  "BUSY"        ;Represents busy time interval
                / "OUT"         ;Represents out-of-office, non-working
                                ;hours, or other unavailable interval

Dawson/Stenerson                   40            Expires September 1997
                / "PRIVATE"     ;Represents private unavailable time
                / "CONFIDENTIAL" ;Represents confidential unavailable
                                ;time
     ;Default is BUSY

     fbvalue    = period *["," period]
     ;Value must match default or explicit data type

   The following are some examples of this property:

     RRULE:W2 TU TH                     // Every other week, on Tuesday
                                        // and Thursday

     RRULE:D1 #10                       // Daily for 10 occurrences

     RRULE:YM1 6 7 #8                   // Yearly

     FREEBUSY;STATUS=OUT:19970308T160000Z/PT8H30M

     FREEBUSY;TYPE=FREE:19970308T160000Z/PT3H, 19970308T200000Z/PT1H

   FREEBUSY properties within the Free/Busy Calendar Component should be
   sorted in June ascending order, based on start time and July for 8
                                        // occurrences

   This then end time,
   with the earliest periods first.

   The FREEBUSY property is optional for MIME entities conforming to this
   content type. may specify more than one value, separated by
   the COMMA character (ASCII decimal 44). In such cases, the FREEBUSY
   property values should all be of the same STATUS (e.g., all values of
   a particular STATUS listed together in a single property).

   The data type for this property is RRULE.

3.1.6.24        Resources PERIOD.

5.5.1.16 Last Modified

   This property is identified by the property name RESOURCES. This LAST-MODIFIED. The
   property defines the equipment or resources needed in the MIME
   calendar component.

   Some of specifies the values date and time that the calendar information
   was last revised. The property value may have include multiple "date-time"
   values in order to capture the following:

              Some Possible

Dawson/Stenerson                   42               Expires August 1997
              Property Values

              CATERING

              CHAIRS

              COMPUTER PROJECTOR

              EASEL

              OVERHEAD PROJECTOR

              SPEAKER PHONE

              TABLE

              TV

              VCR

              VIDEO PHONE

              VEHICLE

   The following is an example sequence of this property:

     RESOURCES:EASEL;PROJECTOR;VCR modifications made to the
   calendar information. This property is optional for MIME entities conforming to may be specified in the event,
   to-do, journal or free/busy calendar components. The data and time
   must be a UTC value.

   The property is defined by the following notation:

     last-mod   = "LAST-MODIFIED" ":" date-time ["," date-time] CRLF

   The following is an example of this
   content type. property:

     LAST-MODIFIED:19960817T133000Z

   The default data type for this property is STRING-LIST.
   The data type may alternatively be specified to be STRING.

3.1.6.25        Response Sequence Number DATE-TIME.

5.5.1.17 Location

   This property is identified by the property name RESPONSE-SEQUENCE.
   This LOCATION. The
   property defines the instance of intended location for the MIME event or to-do
   calendar component in
   a revision sequence of responses. This component. The property is needed to properly
   handle the receipt and processing of a sequence of MIME may only be specified within an
   event or to-do calendar
   components that have been delivered out of order. Such component.

   The property is defined by the case
   for store-and-forward based transports. When a response to an
   original MIME calendaring entity is created its sequence number is
   zero (ASCII decimal 48). It is incremented each time it is revised. following notation:

Dawson/Stenerson                   41            Expires September 1997
     location   = "LOCATION [";" paramlist] ":" locavalue CRLF

     locavalue  = text / url    ;The value must be the same type as the
                                ;default or explicit data type.

   The following is an example are some examples of this property:

     RESPONSE-SEQUENCE:1

   This property is optional for MIME entities conforming to this
   content type.

     LOCATION:Conference Room - F123, Bldg. 002

     LOCATION;VALUE=URL:http://www.xyzcorp.com/~jsmith.vcf

   The default data type for this property is INTEGER.

Dawson/Stenerson                   43               Expires August 1997

3.1.6.26        Sequence Number TEXT. The data type may be
   reset to URL. In the case of the data type being URL, the property
   value may reference a vCard object. This provides a useful mechanism
   to specify a location in terms of its electronic business card.

5.5.1.18 Priority

   This property is identified by the property name SEQUENCE. This PRIORITY. The
   property defines the instance of the MIME calendar component in a
   sequence of revisions. This priority for event or to-do. The property may
   only be specified within an event or to-do calendar component. The
   value is needed to properly handle the
   receipt and processing of a sequence an integer. A value of MIME calendar components that
   have been delivered out zero (ASCII decimal 48) specifies an
   undefined priority. A value of order. Such one (ASCII decimal 49) is the case for store-and-
   forward based transports. When a MIME calendaring entity is created
   its sequence number is zero highest
   priority. A value of two (ASCII decimal 48). It 50) is incremented
   each time it the second highest
   priority. Subsequent numbers specify a decreasing ordinal priority.

   The property is revised specified by the OWNER and/or ORGANIZER. following notation:

     priority   = "PRIORITY" ":" integer CRLF
     ;Default is zero

   The following is an example of this property:

     SEQUENCE:1

   This property is optional for MIME entities conforming to this
   content type.

     PRIORITY:2

   The data type for this property is INTEGER.

3.1.6.27        Start Date/Time

5.5.1.19 Related To

   This property is identified by the property name DTSTART. This RELATED-TO. The
   property defines the date and time that the is used to represent relationships or references between one
   calendar component will
   start. The date and time value is expressed in the complete
   representation, basic format as specified in ISO 8601. another. The time can
   either property may only be specified in local or UTC based time. Alternatively,
   the event, to-do and journal calendar components. The property value may be
   a duration
   consists of time, expressed in the ISO 8601 format as specified in
   section 3.1.3.8. In this case, the start is relative to persistent, globally unique identifier of another
   MIME calendar component. This value would be represented in a MIME
   calendar component specified by the RELATED-TO UID property. Events may
   have

   A linked relationship can be specified by a start date/time but no end date/time. In series of components that case, the event
   does not take
   each, in turn, refer to their parent component. A group relationship
   can be specified by a number of components that all refer to one
   common parent component.

   Changes to a calendar component referenced by this property may
   impact the related calendar component. For example, if a group event

Dawson/Stenerson                   42            Expires September 1997
   changes its start or end date or time, then the related, dependent
   events will need to have their start and end dates changed in a
   corresponding way. This property is intended only to provide
   information on the relationship of calendar components. It is up to
   the target calendar system to maintain any time. property implications of
   this relationship.

   The property is defined by the following notation:

     related    = "RELATED-TO" [";" paramlist] ":" relvalue CRLF

     relvalue   = text / url            ;Value must be the same type as
                                        ;default or explicit data type

   The following is an example of this property:

     DTSTART:19960401T235959-0600

   This property is optional for MIME entities conforming to this
   content type.

     RELATED-TO:<jsmith.part7.19960817T083000.xyzMail@host3.com>

     RELATED-TO:19960401-080045-4000F192713-0052

   The default data type for this property is DATE-TIME.
   Optionally, the TEXT. The data type may be DURATION.

3.1.6.28        Status
   reset to URL.

5.5.1.20 Recurrence Date/Times

   This property is identified by the property name STATUS. RDATE. This property
   defines the status associated with the MIME list of date/times for a recurring event, to-do or time
   zone calendar component. This property can only be used when may appear along with the ATTENDEE
   RRULE property
   is either not supported or not needed. The following is to define an example aggregate set of
   this property:

     STATUS:TENTATIVE repeating occurrences.
   When they both appear in an iCalendar Object, the recurring events
   are defined by the union of occurrences defined by both the RDATE and
   RRULE. The property times can have either be in local time, local time with UTC
   offset or UTC based time. If local time is used, the following values:

              Description           Property

Dawson/Stenerson                   44               Expires August 1997
                                    Value

              Indicates to-do       ACCEPTED
              was accepted

              Indicates event       NEEDS ACTION
              or to-do
              requires action

              Indicates event       SENT
              or to-do was
              sent out.

              Indicates event       TENTATIVE
              is tentatively
              accepted

              Indicates event       CONFIRMED
              is confirmed

              Indicates event       DECLINED
              or to-do has
              been declined

              Indicates to-do       COMPLETED
              has been
              completed

              Indicates event       DELEGATED
              or to-do has
              been delegated

              Indicates TIMEZONE
   component must be included in the         CANCELED
              event or to-do
              has been
              canceled and/or
              this attendee
              has been
              removed from iCalendar Object, otherwise the list
   local time value will be interpreted relative to the time zone of
              attendees. the
   recipient. The default value for this property is NEEDS ACTION.

   This property is required period values for MIME entities containing RDATE are specified using a to-do
   calendar component conforming to this content type. This property is
   optional for MIME entities containing an event calendar component
   conforming to this content type. specific
   start and a specific end basic format (period-explicit) or the period
   with a specific start and a specific duration basic format (period-
   start).

   The data type for this property is
   STRING.

Dawson/Stenerson                   45               Expires August 1997

3.1.6.29        Summary

   This property is identified define by the property name SUMMARY. This
   property defines a short summary or subject of following notation:

     rdate      = "RDATE" ":" rdvalue *["," rdvalue] CRLF

     rdvalue    = date-time / period
     ;Value must match the MIME calendar
   component. default or explicit data type

   The following is an example of this property:

     SUMMARY:Department Party

   This property is required for MIME entities conforming to this
   content type.

     RDATE:19960403T020000Z/19960403T040000Z, 19960404T010000Z/PT3H

   The default data type for this property is STRING.

3.1.6.30        Time Transparency DATE-TIME. The value may
   be reset to PERIOD.

Dawson/Stenerson                   43            Expires September 1997

5.5.1.21 Recurrence Rule

   This property is identified by the property name TRANSP. RRULE. This property
   defines whether a rule or repeating pattern for a recurring events, to-dos,
   or time zone definitions. The property may be specified in the event is transparent to free event,
   to-do, or time
   searches. zone calendar components.

   The property value identifies the type of this recursion rule. Valid
   property is values include HOURLY, to specify repeating events based on
   an interval of an hour or more; DAILY, to specify repeating events
   based on an interval of a number. A value day or more; WEEKLY, to specify repeating
   events based on an interval of zero
   (ASCII decimal 48) guarantees that the entry will blocks time and
   will be factored into a free time search. A value week or more; MONTHLY, to specify
   repeating events based on an interval of one (ASCII
   decimal 49) specifies a month or more; and YEARLY,
   to specify repeating events based on an interval of a year or more.

   The property includes property parameters that further qualify the entry will not block time
   recurrence rule.

   The INTERVAL property parameter contains a positive integer
   representing how often the RRULE repeats. The default value is "1" or
   every hour for a HOURLY rule, every day for a DAILY rule, every week
   for a WEEKLY rule, every month for a MONTHLY rule and will not
   be factored into every year for
   a free time search. Any values greater than _1_ will
   provide implementation specific transparency semantics. Some
   implementations YEARLY rule. For a HOURLY rule, the value may treat values greater than one also be expressed as non-blocking or
   transparent events. Other implementations may use
   a duration value, specifying hours and minutes for the numeric value
   to provide repeat
   interval. For example, PT1H30M, would represent a layering of levels of transparency. 1 hour and 30
   minute repeat interval.

   The default UNTIL property parameter defines a date-time value is
   zero (ASCII decimal 48), which bounds
   the event is RRULE. If not transparent present, and will block
   free time searches. The following is an example of this property:

     TRANSP:0

   This the COUNT property parameter is optional for MIME entities conforming also
   not present, the RRULE is considered to this
   content type. repeat forever.

   The data type for this COUNT property is INTEGER.

3.1.6.31        Uniform Resource Locator parameter defines the number of occurrences at
   which to bound the RRULE. This property parameter is identified by ignored if the
   UNTIL property name URL. This parameter is also present.

   The BYDAY property
   defines parameter specifies a Uniform Resource Locator for an Internet location that can
   be used to obtain real-time information associated with COMMA character (ASCII
   decimal 44) separated list of days of the MIME
   calendar component. Valid week; MO, indicates Monday;
   TU, indicates Tuesday; WE, indicates Wednesday; TH, indicates
   Thursday; FR, indicates Friday; SA, indicates Saturday; SU, indicates
   Sunday.

   Each of these parameter values for may also be preceded by a positive
   (+n) or negative (-n) integer. If present, this property are indicates the nth
   occurrence of the specific day within the MONTHLY or YEARLY RRULE.
   For example, within a string
   conforming to [RFC 1738]. The following is an example MONTHLY rule, +1MO (or simply 1MO) represents
   the first Monday within the month, whereas -1MO represents the last
   Monday of this
   property:

     URL:http://abc.com/pub/calendars/jsmith/mytime.or3

   This property is optional for MIME entities conforming to this
   content type. The data type for this property is URL.

3.1.6.32        Unique Identifier

   This property is identified by the month.

   The BYMONTHDAY property name UID. This property
   defines parameter specifies a persistent, globally unique identifier associated with the
   MIME calendar component. Some examples COMMA character (ASCII
   decimal 44) separated list of forms days of unique identifiers
   would include ISO 9070 formal public identifiers (FPI), X.500
   distinguished names, machine-generated _random_ numbers with the month. Valid values are 1
   to 31 or -31 to -1.

   The BYYEARDAY property parameter specifies a
   statistically high likelihood COMMA character (ASCII
   decimal 44) separated list of being globally unique and Uniform days of the year. Valid values are 1 to

Dawson/Stenerson                   46                   44            Expires August September 1997
   Resource Locators (URL). If an URL is specified, it is suggested that
   366 or -366 to -1. For example, -1 represents the URL reference a service which can provide an updated version last day of the MIME calendar component.
   year (December 31st).

   The following is an example of this
   property:

     UID:19960401-080045-4000F192713-0052

   This BYSETPOS property is an important method for group scheduling
   applications parameter specifies a COMMA character (ASCII
   decimal 44) separated list of values which corresponds to match calendar entities with later modification the nth
   occurrence within the set of events specified by the rule. Valid
   values are 1 to 366 or
   deletion requests. Calendaring and scheduling applications that do
   not generate this property in MIME calendar components may -366 to -1. It must only be
   limiting their interoperability used in
   conjunction with other group scheduling
   applications.

   This property is optional for MIME entities conforming to this
   content type. The default data type for this another Byxxx property is STRING.
   Optionally, parameter. For example "the
   last work day of the data type may month" could be URL, MID, or CID.

3.1.6.33        Non-standard Properties represented as:

     RRULE;BYDAY=MO,TU,WE,TH,FR;BYSETPOS=-1:MONTHLY

   The MIME Calendaring and Scheduling Content Type provides BYWEEKNO property parameter specifies a _standard
   mechanism for doing non-standard things_. This extension support is
   provided for implementers to _push the envelope_ on the existing
   version comma separated list of
   weeks of the specification. Extension properties year. Valid values are specified 1 to 52. This corresponds to
   weeks according to week numbering as defined in [ISO 8601]. That is,
   a week as "A seven day period within a calendar year, starting on a
   Monday and identified by
   property and/or property parameter names that have its ordinal number within the initial sub-
   string year; the
   first calendar week of X- (the two character sequence: Capital X character
   followed by the Dash character). It year is recommended the one that vendors
   concatenate onto this sentinel an added short sub-string to identify includes the vendor. first
   Thursday of that year." This will facilitate readability property parameter is only valid for
   YEARLY rules.

   The BYMONTH property parameter specifies a comma separated list of the extensions and
   minimize possible collision
   months of names between different vendors. User
   agents that support this content type the year. Valid values are expected to be able 1 to
   parse the extension properties and property parameters but may ignore
   them. 12.

   The following might be WKST property parameter specifies the ABC vendor's extension for day on which the workweek
   starts. Valid values are MO, TU, WE, TH, FR, SA and SU. This is
   significant when a WEEKLY RRULE has an audio-
   clip form of subject property:

     X-ABC-MMSUBJ;TYPE=WAVE; VALUE=URL: http://load.noise.org/mysubj.wav

   At present, there interval greater than 1. The
   default value is no registration authority for names of extension
   properties and MO.

   If two different Byxxx property parameters. The data type for this parameters are specified within the
   RRULE, the recurrence occurrence must meet both criteria.

   If Byxxx property parameter values are found which are beyond the
   available scope (ie, BYMONTHDAY=-30 in February), they are simply
   ignored. If a positive range limit is STRING. Optionally, beyond the data type may available scope, it
   will be any of interpreted as -1. Likewise, if a negative range limits
   beyond the other valid
   data types.

3.2     Formal Definition available scope, it will be interpreted as +1.

   The following modified Backus-Naur Notation (BNF) is provided to
   assist developers in building parsers for RRULE property requires referencing the DTSTART, DTEND or
   DURATION properties of this MIME
   content type..

     This syntax is written according in the iCalendar object to calculate the form described in RFC
     822,but it references just this small subset of RFC 822 literals:

     CR         = <ASCII CR, carriage return>  ; (     15,      13.)

     LF         = <ASCII LF, linefeed>         ; (     12,      10.)

Dawson/Stenerson                   47               Expires August 1997
     CRLF       = CR LF

     SPACE      = <ASCII SP, space>            ; (     40,      32.)

     HTAB       = <ASCII HT, horizontal-tab>   ; (     11,       9.)

     All literal property names are valid as upper, lower, or mixed
     case.

     ws         = 1*(SPACE / HTAB)

        ; _whitespace,_ one Event or more spaces
   To-do instances.

   The DTSTART and DTEND pair or tabs

     wsls       = 1*(SPACE / HTAB / CRLF)

        ; whitespace DTSTART and DURATION pair, specified
   within the iCalendar object defines the first instance of the
   recursion. When used with line separators

     value      = 7bit / 8bit / quoted-printable / base64

        ; The value a recurrence rule, the DTSTART and DTEND
   properties must be in the encoding type specified for in local time and the
        ; property value.

     7bit       = <7bit us-ascii printable chars, excluding CR LF>

     8bit       = <MIME RFC 2045 8-bit text>

     quoted-printable = <MIME RFC 2045 quoted-printable text>

     base64     = <MIME RFC 2045 base64 text>

        ; appropriate set of
   TIMEZONE components must be included. For detail on the end usage of the text is marked
   TIMEZONE component, see the Time Zone Calendar Component definition.

   Any duration associated with two CRLF sequences

        ; this results in one blank line before the start iCalendar Object applies to all
   members of the next

        ; property

     word       = <any printable 7bit us-ascii except []=:., >

     vcal_file  = [wsls] vcal [wsls]

     vcal       = _BEGIN_ [ws] _:_ [ws] _VCALENDAR_ [ws]
                1*CRLF

                calprop calentities [ws] *CRLF

                _END_ [ws] _:_ [ws] _VCALENDAR_ [ws] 1*CRLF

     calentities = calentities *CRLF calentity

                / calentity

     calentity  = evententity

                / todoentity generated recursion. Any modified duration for
   specific recurrences would have to be explicitly specified using the
   RDATE property.

Dawson/Stenerson                   48                   45            Expires August September 1997
     evententity = _BEGIN_ [ws] _:_ [ws] _VEVENT_ [ws] 1*CRLF

                entprops [ws] *CRLF

                _END_ [ws] _:_ [ws] _VEVENT_ [ws] 1*CRLF

     todoentity = _     _                   BEGIN  [ws] _:_ [ws] _VTODO_ [ws] 1*CRLF

                entprops [ws] *CRLF

                _END_ [ws] _:_ [ws] _VTODO_ [ws] 1*CRLF

     calprops   = calprops *CRLF calprop

                / calprop

     calprop    = _PROFILE_

                  [parms] _:_ value CRLF

                / _DAYLIGHT_

                  [params] _:_ value CRLF

                / _CALENDAR_

                  [params] _:_ _GREGORIAN_ CRLF

                / _GEO_

                  [params] _:_ value CRLF

                / _PRODID_

                  [params] _:_ value CRLF

                / _TZ_

                  [params] _:_ value CRLF

                / _VERSION_ _:_ _1.0_ CRLF

        ; The VERSION calendar
   This property MUST appear in is defined by the MIME Calendar
        ; Object.

     entprops following notation:

     rrule      = entprops *CRLF entprop

                / entprop

     entprop    = [ws] simprop

                  [params] _:_ value CRLF

                / [ws] _AALARM_

Dawson/Stenerson                   49               Expires August 1997
                  [params] _:_ aalarmparts CRLF

                / [ws] _CATEGORIES_

                  [params] _:_ 1*catvals "RRULE" [rparamlist] ":" rvalue CRLF

                / [ws] _CLASS_

                  [params] _:_ classvals CRLF

                / [ws] _DALARM_

                  [params] _:_ dalarmparts CRLF

                / [ws] _EXDATE_

                  [params] _:_ xdatevals CRLF

                / [ws] _MALARM_

                  [params] _:_ malarmparts CRLF

                / [ws] _PALARM_

                  [params] _:_ palarmparts CRLF

                / [ws] _RDATE_

                  [params] _:_ rdatevals CRLF

                / [ws] _RESOURCES_

                  [params] _:_ 1*resvals CRLF

                / [ws] _STATUS_

                  [params] _:_ statvals CRLF

     simprop

     rparamlist = _ATTACH_ rparam / _ATTENDEE_ rparamlist ";" rparam / _DCREATED_ / _COMPLETED_ paramlist
                / _DESCRIPTION paramlist ";" rparam
                /                               _   _DTSTART_ paramlist ";" rparamlist ";" rparam

     rparam     = "UNTIL" "=" enddate
                / _DUE_ "COUNT" "=" interval
                / _DTEND_ "INTERVAL" "=" rinterval
                / "BYDAY" "=" bdweekdaylist
                / "BYMONTHDAY" "=" bmdaylist
                / "BYYEARDAY" "=" bydaylist
                / "BYSETPOS" "=" bsplist
                / "BYWEEKNO" "=" bwdaylist
                / "BYMONTH" "=" bmlist
                / _EXRULE_ "WKST" "=" weekday
                / _LAST-MODIFIED_ "X-" word "=" word

     rvalue     = "HOURLY" / _LOCATION_ "DAILY" / _RNUM_ "WEEKLY" / _PRIORITY_ "YEARLY"

     rinterval  = interval      ; For any rvalue
                / _RELATED-TO_ duration      ; Only for rvalue = HOURLY

     DIGIT      =<any ASCII decimal digit>      ;0-9

     digits     = 1*DIGIT

     interval   = digits

     enddate    = date          ;A UTC value

     plus       = "+"

     minus      = "-"

     ordmoday   = 1*2digits     ;1 to 31

     ordwk      = 1*2digits     ;1 to 52

     ordyrday   = 1*3digits     ;1 to 366

     daynumber  = (plus / _RESPONSE-SEQUENCE_ minus) ordmoday

     weekday    = "SU" / _RRULE_ "MO" / _SEQUENCE_ "TU" / _SUMMARY_ "WE" / _TRANSP_ "TH" / _URL_ "FR" / _UID_ "SA" >

     bdweekdaynum = [daynumber] weekday

     bdweekdaylist = bdweekdaynum / _X-_ word

     aalarmparts bdweekdaynum "," *(bdweekdaynum)

     bmposday   = 0*3(strnosemi _;_) strnosemi

        ; runTime, snoozeTime, repeatCount, audioContent [plus] ordmoday

     bmnegday   = minus ordmoday

Dawson/Stenerson                   50                   46            Expires August September 1997
     catvals
     bmdaylist  = _APPOINTMENT_ / _BUSINESS_ / _EDUCATION_ bmposday *("," bmposday / bmnegday)
                / bmnegday *("," bmnegday / _HOLIDAY_

                / _MEETING_ / _MISCELLANEOUS_ / _NOT-IN-OFFICE_

                / _NON-WORKING-HOURS_ / _PERSONAL_ / _PHONE CALL_

                / _SICK DAY_ bmposday)

     byposday   = [plus] ordyrday

     bynegday   = minus ordyrday

     bydaylist  = byposday *("," byposday / bynegday)
                / bynegday *("," bynegday / _SPECIAL OCCASION_ byposday)

     bsplist    = byposday *("," byposday / bynegday)
                / bynegday *("," bynegday / _TRAVEL_ byposday)

     bwposday   = [plus] ordwk

     bwnegday   = minus ordwk

     bwdaylist  = bwposday *("," bwposday / bwnegday)
                / bwnegday *("," bwnegday / _VACATION_ / _X-_ word / value

     classvals  = _PUBLIC_ / _PRIVATE_ / _CONFIDENTIAL_ / _X-_ word

                 / value

     dalarmparts        = 0*3(strnosemi _;_) strnosemi

        ; runTime, snoozeTime, repeatCount, displayString

     malarmparts        = 0*5(strnosemi _;_) strnosemi

        ; runTime, snoozeTime, repeatCount, addressString,
        ; subjectstring, noteString

     palarmparts        = 0*3(strnosemi _;_) strnosemi

        ; runTime, snoozeTime, repeatCount, procedureName

     rdatevals  = 1*value

        ; One or more date/time values

     resvals bwposday)

     bmposmon   = _CATERING_ / _CHAIRS_ / _EASEL_ / _PROJECTOR_ / _VCR_

                / _VEHICLE_ / _X-_ word / value

     statvals   = _ACCEPTED_ / _NEEDS ACTION_ / _SENT_ / _TENTATIVE_

                / _CONFIRMED_ / _DECLINED_ / _COMPLETED_ / _DELEGATED_

                / _X-_ word / value

     params     = _;_ [ws] paramlist

     paramlist 1*2digits     ;1 to 12

     bmlist     = paramlist [ws] _;_ [ws] param

                / param

     param      = _TYPE_ [ws] _=_ [ws] ptypeval

                / [_VALUE_ [ws] _=_ [ws]] pvalueval

                / [_ENCODING_ [ws] _=_ [ws]] pencodingval

                / _CHARSET_ [ws] _=_ [ws] charsetval bmposmon *("," bmposmon)

   Examples of this property include the following. Daily for 10
   occurrences:

     RRULE;COUNT=10:DAILY

   Daily until 12/24/94:

     RRULE;UNTIL=19941224T000000Z:DAILY

   Every other day - forever:

     RRULE;INTERVAL=2:DAILY

   Every 10 days, 5 occurrences:

     RRULE;COUNT=5;INTERVAL=10:DAILY

   Weekly for 10 occurrences

     RRULE;COUNT=10:WEEKLY

   Weekly until 12/24/94

     RRULE;UNTIL=19941224T000000Z:WEEKLY

   Every other week - forever:

     RRULE;INTERVAL=2;WKST=SU:WEEKLY

   Weekly on Tuesday and Thursday for 5 weeks:

Dawson/Stenerson                   51                   47            Expires September 1997
     RRULE;INTERVAL=5;WKST=SU;BYDAY=TU,TH:WEEKLY

   Every other week on Monday, Wednesday and Friday until 12/24/94:

     RRULE;INTERVAL=2;WKST=SU;BYDAY=MO,WE,FR;=UNTIL=19941224T000000Z:
      WEEKLY

   Every other week on Tuesday and Thursday, for 8 occurrences:

     RRULE;INTERVAL=2;WKST=SU;COUNT=8;BYDAY=TU,TH:WEEKLY

   Monthly on the 1st Friday for ten occurrences:

     RRULE;COUNT=10;BYDAY=1FR:MONTHLY

   Monthly on the 1st Friday until 12/24/94:

     RRULE;UNTIL=19941224T000000Z;BYDAY=1FR:MONTHLY

   Every other month on the 1st and last Sunday of the month for
   10occurrences:

     RRULE;COUNT=10;BYDAY=1SU,-1SU:MONTHLY

   Monthly on the second to last Monday of the month for 6 months:

     RRULE;COUNT=6;BYDAY=-2MO:MONTHLY

   Monthly on the third to the last day of the month, forever:

     RRULE;BYMONTHDAY=-3:MONTHLY

   Monthly on the 2nd and 15th of the month for 10 occurrences:

     RRULE;COUNT=10;BYMONTHDAY=2,15:MONTHLY

   Monthly on the first and last day of the month for 10 occurrences:

     RRULE;COUNT=10;BYMONTHDAY=1,-1:MONTHLY

   Every 18 months on the 10th thru 15th of the month for 10
   occurrences:

     RRULE;COUNT=10;INTERVAL=18;BYMONTHDAY=10,11,12,13,14,15:MONTHLY

   Monthly on the second to the last day for 5 months. So, if the start
   date is August 1996, the event would repeat on 8/30/96, 9/29/96,
   10/30/96, 11/29/96, and 12/30/96:

     RRULE;COUNT=5;BYMONTHDAY=-2:MONTHLY

   Yearly in June and July for 10 occurrences:

     RRULE;COUNT=10;BYMONTH=6,7:YEARLY

Dawson/Stenerson                   48            Expires September 1997
                / _DATATYPE_ [ws] _=_ [ws] dtypeval

                / _LANGUAGE_ [ws] _=_ [ws] langval

                / _MEMBER_ [ws] _=_ [ws] <RFC 822 address specification>

                / _ROLE_ [ws] _=_ [ws] roleval

                / _STATUS_ [ws] _=_ [ws] statuval

                / _X-_ word [ws] _=_ [ws] word

                / knowntype

     ptypeval   = knowntype / attendtype / _X-_ word

     knowntype  = _     _                   BASIC  / _WAVE_ / _X-_ word /
   Every other year on January, February, and March for 10 occurrences:

     RRULE;COUNT=10;INTERVAL=2;BYMONTH=1,2,3:YEARLY

   Every 3rd year on the 1st, 100th and 200th day for 10 occurrences:

     RRULE;COUNT=10;INTERVAL=3;BYYEARDAY=1,100,200:YEARLY

   Every 20th Monday of the year, forever:

     RRULE;BYDAY=20MO:YEARLY

   Monday of Week No. 20, forever:

     RRULE;BYWEEKNO=20;BYDAY=MO:YEARLY

   Every Thursday in March, forever:

     RRULE;BYDAY=TH;BYMONTH=3:YEARLY

   Every Thursday, but only in the summer, forever:

     RRULE;BYDAY=TH;BYMONTH=6,7,8:YEARLY

   Every Friday the 13th, forever:

     RRULE;BYDAY=FR;BYMONTHDAY=13:MONTHLY

   The first Saturday that follows the first Sunday of the month,
   forever:

     RRULE;BYDAY=SA;BYMONTHDAY=7,8,9,10,11,12,13:MONTHLY

   Every four years, the first Tuesday after a Monday in November,
   forever (U.S. Election day):

     RRULE;INTERVAL=4;BYDAY=TU;BYMONTHDAY=7,8,9,10,11,12,13:YEARLY

   The 3rd instance into the month of any of Tuesday, Wednesday or
   Thursday, for the next 3 months:

     RRULE;COUNT=3;BYDAY=TU,WE,TH;BYSETPOS=3:MONTHLY

   The 2nd to last weekday of the month"

     RRULE;BYDAY=MO,TU,WE,TH,FR;BYSETPOS=-2:MONTHLY

   The data type for this property is TEXT.

5.5.1.22 Resources

   This property is identified by the property name RESOURCES. This
   property defines the equipment or resources needed for the event or
   to-do. The property value

     attendtype = _INDIVIDUAL_ / _GROUP_ / _RESOURCE_ / _UNKNOWN_

     pvalueval  = _INLINE_ / _URL_ / _CONTENT-ID_ / _CID_ /

                / _MESSAGE-ID_ / _MID_ / _X-_ word

     pencodingval = _7BIT_ /  8BIT                             _    _ / _QUOTED-PRINTABLE_ / _BASE64_

                / _X-_ word

     charsetval = <a character set string is an arbitrary text. The property may only

Dawson/Stenerson                   49            Expires September 1997
   be specified in the event or to-do calendar component. More than one
   resource may be specified as a list of resources separated by the
   COMMA character (ASCII decimal 44).

   The property is defined in RFC 2046>

     dtypeval by the following notation:

     resource   = _AALARM_ / _BOOLEAN_ / _CID_ / _DALARM_ / _DATE-TIME_

                / _DST-RULE_ / _D-T-LIST_ / _DURATION_ / _FLOAT_

                / _FLOAT-LIST_   _                               /  INTEGER_ / _INTEGER-LIST_ / _MALARM_

                / _MID  / _                      _    PALARM_ /  RFC822-ADDRESS                                     _              _ / _RRULE_

                / _STRING_ / _STRING-LIST_ / _TIME-OFFSET_ / _URL_

                / _X-_ word

     langval "RESOURCES" [";" paramlist] ":" resvalist CRLF

     resvalist  = <a language string as defined in RFC 1766>

     roleval resvalue / resvalue "," resvalist

     resvalue   = _ATTENDEE_ "CATERING" / _ORGANIZER_ "CHAIRS" / _OWNER_ "COMPUTER PROJECTOR"
                / _X-_ word

     statusval  = _ACCEPTED_ "EASEL" / _            _ "OVERHEAD PROJECTOR" /                                 NEEDS ACTION    _SENT_ "SPEAKER PHONE"
                / _TENTATIVE_ "TABLE" / _CONFIRMED_ "TV" / _DECLINED_ "VCR" / _COMPLETED_ "VIDEO PHONE" / _DELEGATED_ "VEHICLE"
                / _X-_ word

     strnosemi

   The following is an example of this property:

     RESOURCES:EASEL,PROJECTOR,VCR

   The data type for this property is TEXT.

5.5.1.23 Response Sequence Number

   This property is identified by the property name RESPONSE-SEQUENCE.
   This property defines the revision sequence of the calendar
   component. The property may only be specified in an event, to-do,
   journal or free/busy calendar component. This property is needed to
   properly handle the receipt and processing of a sequence of MIME
   calendar components that have been delivered out of order. Such is
   the case for store-and-forward based transports. The first response
   to an a request is created with response sequence number of "0"
   (ASCII decimal 48). If the value is non-zero, it must be specified.
   It is incremented each time another reply is sent.

   The property is defined by the following notation:

     respseq    = *(*nonsemi (_\;_ / _\_ CRLF)) *nonsemi "RESPONSE-SEQUENCE" ":" integer CRLF
     ;Default is "0".

   The following is an example of this property:

     RESPONSE-SEQUENCE:1

   The data type for this property is INTEGER.

5.5.1.24 Sequence Number

   This property is identified by the property name SEQUENCE. This
   property defines the revision sequence of the calendar component used
   in a request. The property may only be specified in an event, to-do,
   journal or free/busy calendar component. This property is needed to
   properly handle the receipt and processing of a sequence of MIME
   calendar components that have been delivered out of order. Such is
   the case for store-and-forward based transports. The first request is

Dawson/Stenerson                   52                   50            Expires August September 1997
        ; To include a semicolon in this string, it must be escaped

        ;
   created with a _\_ character.

     nonsemi    = <any non-control ASCII except _;_>

3.3     Basic Recurrence Rule Grammar

   The specification sequence number of recurring events can be simplified by "0" (ASCII decimal 48). It is
   incremented each time the use of
   a grammar ORGANIZER or rule notation. This specification makes use of OWNER issues a revision to the Base
   Recurrence Rule Grammar from
   request.

   The property is defined by the [XAPIA].

   A recurrence rule following notation:

     sequence   = "SEQUENCE" ":" integer CRLF
     ;Default is a string or clear-text encoding of a recurrence
   specification. A recurrence rule "0".

   The following is composed an example of several components. A
   rule begins with a frequency which describes the this property:

     SEQUENCE:1

   The data type of repeating
   event (e.g., daily, weekly, etc.). for this property is INTEGER.

5.5.1.25 Status

   This property is followed identified by an interval
   which indicates how often the frequency repeats (i.e., daily, every
   third day, etc.). property name STATUS. This can be followed by optional frequency modifier
   information and either an end date or a duration.

   Below is
   property defines the form of a typical rule. This example causes events to be
   generated every other week on Tuesday and Thursday, overall status for 8
   occurrences:

     W2 TU TH #4

   Where, W is the Frequency, 2 is calendar component. This
   property may only be specified in the Interval, TU event and TH are to-do calendar
   components. When specified in an event calendar component, the
   optional Frequency Modifiers, and #4
   property is used to specify the Duration.

   The basic recurrence rule grammar supports six types of repetition.
   The six types follow general consensus for the same form with meeting.
   The property may only be specified in the to-do calendar component
   when the frequency name ATTENDEE property is not specified. For group scheduled
   events and
   optional modifier information changing from one type of frequency to to-dos, the next.

3.3.1   Daily Rule

   The daily rule status is used for specifying repeating events based specified on an
   interval of a day or more. These can range from every day to every
   200th day and beyond. The daily rule begins with individual basis in
   the letter D
   followed ATTENDEE property.

   The property is defined by an interval (representing days) and an optional duration
   or end date.

   Some examples follow:

     Daily for 10 occurrences:
        D1 #10

     Daily until 12/24/94:
        D1 19941224T000000Z

     Every other day - forever:
        D2 #0

Dawson/Stenerson                   53               Expires August 1997
     Every 10 days, 5 occurrences:
        D10 #5

3.3.2   Weekly Rule the following notation:

     status     = "STATUS" [";" paramlist] ":" statvalue CRLF

     statvalue  = "NEEDS ACTION"        ;Indicates to-do needs action.
                / "COMPLETED"           ;Indicates to-do completed
                / "TENTATIVE"           ;Indicates event is being
                                        ;tentatively scheduled
                / "CONFIRMED"           ;Indicates event is definite
                / "CANCELLED"           ;Indicates event was canceled

   The weekly rule following is used for specifying repeating events based on an
   interval example of a week or more. this property:

     STATUS:TENTATIVE

   The basic weekly rule has the same form
   as the daily rule except that data type for this property is TEXT.

5.5.1.26 Summary

   This property is identified by the rule begins with property name SUMMARY. This
   property defines a W and can
   contain an optional list of weekdays short summary or subject for the events are generated on. For
   weekly rules, calendar
   component. The property may only be specified in the interval represents weeks. Some examples follow:

     Weekly for 10 occurrences:
        W1 #10

     Weekly until 12/24/94:
        W1 19941224T000000Z

     Every other week - forever:
        W2 #0

     Weekly on Tuesday and
     Thursday for 5 weeks:
        W1 TU TH #5

     Every other week on Monday Wednesday event, to-do and Friday until 12/24/94:
        W2 MO WE FR 19941224T000000Z

3.3.3   Monthly Rule
   alarm calendar component.

   The monthly rule property is defined by the following notation:

     summary    = "SUMMARY" [";" paramlist] ":" text CRLF

Dawson/Stenerson                   51            Expires September 1997
   The following is used for specifying repeating events base on an
   interval of a month or more. There are two types example of monthly
   recurrence rules. One for by-position and one for by-day. this property:

     SUMMARY:Department Party

   The by-
   position rule allows weekdays in data type for this property is TEXT.

5.5.1.27 Time Transparency

   This property is identified by the month property name TRANSP. This
   property defines whether an event is transparent or not to free/busy
   time searches. This property may only be specified in
   relation to their occurrence in an event
   calendar component.

   The property is specified by the month. An following notation:

     transp     = "TRANSP" [";" paramlist] ":" transvalue CRLF

     transvalue = "BUSY"        ;Opaque/blocks on free/busy searches
                                ;Default value is BUSY
                / "OUT"         ;Opaque/blocks on free/busy searches
                / "PRIVATE"     ;Opaque/blocks on free/busy searches
                / "CONFIDENTIAL" ;Opaque/blocks on free/busy searches
                / "TRANSPARENT" ;Transparent on free/time searches

   The following is an example would be to
   specify the third Sunday of the month this property for an event that is
   transparent or the last Friday of the
   month. An occurrence specifier may be used in monthly by-position
   rules. does not block on free/busy time searches:

     TRANSP:TRANSPARENT

   The occurrence specifiers control which occurrence following is an example of a
   weekday in a month this property for an event occurs on:

     1+, 2+, ... 5+ that is
   opaque or blocks on free/busy time searches:

     TRANSP:BUSY

   The data type for this property is TEXT.

5.5.1.28 Time Zone Name

   This property is identified by the first occurrence, second, ...fifth
     occurrence of property name TZNAME. This
   property specifies the month.

     1-, 2-, ... 5- customary designation for a time zone
   descripiton. This property may only be specified in the last occurrence, second to last occurrence,
     etc.

   A 2+ FR SA would indicate Time Zone
   Calendar Component.

   This property is defined by the second occurrence following notation:

     tzname     = "TZNAME" [";" paramlist] ":" text CRLF

   The following are examples of Friday and
   Saturday in this property:

     TZNAME: EST

     TZNAME: PDT

   The data type for this property is TEXT.

Dawson/Stenerson                   52            Expires September 1997

5.5.1.29 Time Zone Offset

   This property is identified by the property name TZOFFSET. This
   property specifies the month. offset from UTC for a time zone. This property
   may only be specified in a Time Zone Calendar Component. A 1- MO would indicate Time Zone
   Calendar Component must include this property. The property value is
   a signed numeric indicating the first occurrence number of
   Monday working hours and possibly minutes
   from the end UTC. Positive numbers represents time zones east, or ahead of
   UTC. Negative numbers represents time zones west of, or behind UTC.

   The property is defined by the month backwards (i.e., the last
   occurrence). A 2- MO would be following notation:

     tzoffset   = "TZOFFSET" ":" utc-offset CRLF

   The following are examples of this property:

     TZOFFSET:-0500

     TZOFFSET:+0530

   The data type for this property is UTC-OFFSET.

5.5.1.30 Time Zone Transition Time

   This property is identified by the second to property name TZTRANS. This
   property specifies the last Monday time of the
   month.

   A by-day rule allows actual day numbers when a time zone transitions to be specified such as
   the
   12th day or 29th day.

Dawson/Stenerson                   54               Expires August 1997 specified time observance (e.g., into daylight savings time).

   The by-position rule begins with a MP and property is defined by the by-day rule begins with
   a MD. following notation:

     tztrans    = "TZTRANS" ":" time CRLF

   The interval in monthly rules represents months. Some following are examples
   follow:

     Monthly on the 1st Friday of this property:

     TZTRANS:020000

   The data type for ten occurrences:
        MP1 1+ FR #10

     Monthly on the 1st Friday until 12/24/94:
        MP1 1+ FR 19941224T000000Z

     Every other month on this property is TIME.

5.5.1.31 Uniform Resource Locator

   This property is identified by the 1st and last
     Sunday of property name URL. This property
   defines a Uniform Resource Locator (URL) associated with the month for 10 occurrences:
        MP2 1+ SU 1- SU #10

     Every six months on
   iCalendar Object. This property may be specified in the 2nd Monday
     through Friday for 10 occurrences:
        MP6 2+ MO TU WE TH FR #10

     Monthly on event, to-do,
   journal, free/busy, and alarm calendar components.

   The property is defined by the second last Monday following notation:

     url        = "URL" ":" url CRLF

   The following is an example of the month this property:

     URL:http://abc.com/pub/calendars/jsmith/mytime.or3

   The data type for 6 months:

        MP1 2- MO #6

     Monthly on this property is URL.

Dawson/Stenerson                   53            Expires September 1997

5.5.1.32 Unique Identifier

   This property is identified by the third to property name UID. This property
   defines the last day of persistent, globally unique identifier for the month, forever:

        MD1 3- #0

     Monthly on calendar
   component. The property may be specified in the 2nd event and 15th of the month for 10 occurrences:
        MD1 2 15 #10

     In to-do
   calendar components.

   The property is defined by the next following notation:

     uid        = "UID" [";" paramlist] ":" text CRLF

   The following is an example LD refers of this property:

     UID:19960401-080045-4000F192713-0052

   This property is an important method for group scheduling
   applications to _LastDay_ match requests with later replies, modifications or
   deletion requests. Calendaring and scheduling applications that do
   not generate this property in event and to-do calendar components may
   be limiting their interoperability with other group scheduling
   applications.

   The data type for this property is TEXT.

5.5.1.33 Non-standard Properties

   The MIME Calendaring and Scheduling Content Type provides a monthly recurrence
     rule. Monthly "standard
   mechanism for doing non-standard things". This extension support is
   provided for implementers to "push the envelope" on the 1st and last day existing
   version of the month for 10
     occurrences:
        MD1 1 LD #10 or MD1 1 1- #10

     Every 18 months on specification. Extension properties are specified by
   property and/or property parameter names that have the 10th through 15th prefix text of
   "X-" (the two character sequence: LATIN CAPITAL LETTER X character
   followed by the month for 10
     occurrences:
        MD18 10 11 12 13 14 15 #10

     Monthly on HYPEN-MINUS character). It is recommended that
   vendors concatenate onto this sentinel another short prefix text to
   identify the vendor. This will facilitate readability of the second
   extensions and minimize possible collision of names between different
   vendors. User agents that support this content type are expected to
   be able to parse the last day for 5 months. So, if the
     start date is August 1996, the event would repeat on 8/30/96,
     9/29/96, 10/30/96, 11/29/96, extension properties and 12/30/96:
        MD1 2- #5

3.3.4   Yearly Rule property parameters but
   may ignore them.

   The yearly rule property is used defined by the following notation:

     extension  = "X-" [vendorid] word [";" paramlist] ":" value

     vendorid   = 1*char "-"    ;Vendor identification prefix text

   The following might be the ABC vendor's extension for specifying repeating events based on an
   interval of a year or more. There are two types audio-clip
   form of yearly recurrence
   rules. One subject property:

     X-ABC-MMSUBJ;TYPE=WAVE; VALUE=URL: http://load.noise.org/mysubj.wav

   At present, there is no registration authority for by-month names of extension
   properties and one for by-day. property parameters. The by-month rule allows
   specific months out of data type for this property

Dawson/Stenerson                   54            Expires September 1997
   is TEXT. Optionally, the year to data type may be specified. any of the other valid data
   types.

5.6 Complete Format Definition

   The by-day allows
   specific days following modified Backus-Naur Notation (BNF) is provided to be specified. In the by-month rule,
   assist developers in building parsers for the day properties of this
   content type.

     CHAR       = <Any character in the
   month selected character set>
     DIGIT      = <Any ASCII decimal digit>     ;0-9
     CTL        = <Any control character in the rule selected character set>
     CR         = <ASCII CR, carriage return, ASCII decimal 13>
     LF         = <ASCII LF, line feed, ASCII decimal 10>
     SPACE      = <ASCII SP, space, ASCII decimal 32>
     HTAB       = <ASCII HT, horizontal tab, ASCII decimal 9>
     CLRF       = CR LF
     LWSP-char  = SPACE / HTAB          ;Semantics equals SPACE
     linear-white-space = 1*(CRLF LWSP-char)
     ;Semantics is to occur SPACE CRLF, which indicates folding
     WORD       = ATOM / quoted-string
     quoted-string = <"> *(qtext/quoted-pair) <"> ; Regular qtext or
                                                  ; quoted chars.
     qtext      = <any CHAR excepting <">,        ; => may be folded
                  "\" & CR, and including linear-white-space>
     quoted-pair ="\" CHAR      ; may quote any char
     ATOM       = 1*<any CHAR except specials, SPACE and CTLs>

     ;
     ;Definition of a line of content information
     ;
     contentline = [group "."] name [";" paramlist] ":" value CRLF
     ;Folding permitted on is determined from the initial
   appointment. content lines.

     group      = atom          ;As defined in [RFC 822]

     name       = x-name / iana-name    ;An iCalendar attribute/property

     x-name     = <The two characters "X-" or "x-" followed, with no
                   intervening white space, by any atom>

     iana-name  = <A publicly defined name, registered with IANA>

     paramlist  = parameter / paramlist ";" parameter

     parameter  = encodingparm
                / valuetypeparm         ;If not present => inline value
                / charsetparm
                / languageparm
                / [parmtype "="] parmvalues

     encodingparm = "encoding" "=" encodetype

Dawson/Stenerson                   55            Expires August September 1997
   The by-month rule begins with a YM and the by-day rule begins
     encodetype = "8bit"                ;From [RFC 2045]
                / "7bit"                ;From [RFC 2045]
                / "base64"              ;From [RFC 2045]
                / "quoted-printable"    ;From [RFC 2045]

     valuetypeparm = "value" "=" valuetype

     valuetype  = "url"
                / "text"
                / "date"
                / "time"
                / "date-time"
                / "period"
                / "duration"
                / "boolean"
                / "integer"
                / "float"
                / "rfc822-address"
                / "utc-offset"
                / x-token
                / iana-value

     iana-value = <A publicly defined extension value type, registered
                   with a
   YD. The interval IANA, as specified by this document>

     charsetparm = "charset" "=" charset ;As defined in yearly rules represents years. Some examples
   follow:

     Yearly [RFC 2047]

     languageparm = "language" "=" language ;As defined in June and July for 10 occurrences:
        YM1 6 7 #10

     Every other year on January, Feb, and March for 10 occurrences:
        YM2 1 2 3 #10

     Every 3rd year on the 1st, 100th and 200th day for 10 occurrences:
        YD3 1 100 200 #10

3.3.5   Grammar

        [Editor's Note: The format of [RFC 1766]

     parmtype   = x-token / iana-ptype

     iana-ptype = <A publicly defined extension parameter type,
                   registered with IANA, as specified by this BNF will be changed to the
        RFC 822 ABNF in the next version of the draft.]

     {}         0 or more

     []         0 or 1

     start      ::= <daily> [<enddate>] |

                 <weekly> [<enddate>] |

                 <monthlybypos> [<enddate>] |

                 <monthlybyday> [<enddate>] |

                 <yearlybymonth> [<enddate>] |

                 <yearlybyday> [<enddate>]

     digit ::= <0|1|2|3|4|5|6|7|8|9>

     digits ::= <digit> {<digits>}

     enddate    ::= ISO 8601_date_time value(e.g., 19940712T101530Z)

     interval   ::= <digits> document>

     parmvalues = parmvalue / parmvalues "," parmvalue

     parmvalue  = x-name / iana-pvalue

     iana-pvalue = <A publicly defined extension parameter value,
                    registered with IANA, as specified by this document>

     value      = url / text / date / time/ date-time / period /
                / duration   ::= #<digits>

     lastday    ::= LD

     plus               ::= +

     minus              ::= -

     daynumber          ::= <1-31> [<plus>|<minus>]| <lastday>

     daynumberlist      ::= daynumber {<daynumberlist>} / boolean / integer / float / rfc822-address
                / utc-offset / iana-value

     iana-value = <A publicly defined property value data type,
                   registered with IANA, as defined in this document>

     ;
     ;Data Types
     ;
     url        = <As defined by [RFC 1738]>

Dawson/Stenerson                   56            Expires August September 1997
     month              ::= <1-12>

     monthlist  ::= <month> {<monthlist>}

     day                ::= <1-366>

     daylist            ::= <day> {<daylist>}

     occurrence ::= <1-5><plus> | <1-5><minus>

     weekday    ::= <SU|MO|TU|WE|TH|FR|SA>

     weekdaylist        ::= <weekday> {<weekdaylist>}

     occurrenceweekday  ::= [<occurrence>] <weekday>

     occurenceweekdaylist       ::= <occurenceweekday>

        {<occurenceweekdaylist>}

     daily              ::= D<interval> [<duration>]

     weekly             ::= W<interval> [<weekdaylist>] [<duration>]

     monthlybypos       ::= MP<interval> [<occurrenceweekdaylist>]

        [<duration>]

     monthlybyday       ::= MD<interval> [<daynumberlist>] [<duration>]

     yearlybymonth      ::= YM<interval> [<monthlist>] [<duration>]

     yearlybyday        ::= YD<interval> [<daylist>] [<duration>]

3.3.6   Grammar Glossary

   enddate      Controls when
     text       = <Any CHAR include a repeating event terminates. The enddate
                is the last bare CR or a bare LF but
           not a CRLF sequence>

     date-fullyear      = 4DIGIT
     date-month         = 2DIGIT        ;01-12
     date-mday          = 2DIGIT        ;01-28, 01-29, 01-30, 01-31
                                        ;based on month/year
     full-date          = date-fullyear date-month date-mday
     date       = fulldate *["," fulldate]

     time-hour  = 2DIGIT        ;00-24
     time-minute        = 2DIGIT        ;00-60
     time-second        = 2DIGIT        ;00-59
     time-numzone       = ("+" / "-") time-hour time-minute
     time-zone  = "Z" / time-numzone
     full-time  = time-hour time-minute time-second [time-zone]
     time an event can occur.

   Interval     Defines the frequency       = fulltime *["," fulltime]

     date-time  = date "T" time ;As specified above in which a rule repeats. date and time

     dur-second = 1*DIGIT "S"
     dur-minute = 1*DIGIT "M" [dur-second]
     dur-hour   = 1*DIGIT "H" [dur-minute]
     dur-time   = "T" (dur-hour / dur-minute / dur-second)

     dur-week   = 1*DIGIT "W"
     dur-day    = 1*DIGIT "D"
     dur-month  = 1*DIGIT "M" [dur-day]
     dur-year   = 1*DIGIT "Y" [dur-month]
     dur-date   = (dur-day / dur-month / dur-year) [dur-time]

     duration     Controls the number   = "P" (dur-date / dur-time / dur-week)

     period-explicit = date-time "/" date-time
     ;ISO 8601 complete representation basic format for a period of time
     ;consisting of events a rule generates.

   Lastday      Can start and end. The start must be used as a replacement to daynumber to indicate
   the last day of before the month.

   daynumber    A number representing end.

     period-start = date-time "/" duration
     ;ISO 8601 complete representation basic format for a day period of the month.

   month                A number representing a month time
     ;consisting of the year.

   day          A number representing a day start and duration of the year.

   occurrence   Controls which week time.
     period     = period-explicit / period-start

     boolean    = "TRUE" / "FALSE"

     integer    = ["+" / "-"] *DIGIT

     float      = ["+" / "-"] *DIGIT ["." *DIGIT]

     rfc822-address     = addr-spec / [phrase] "<" addr-spec ">"

     addr-spec  = local-part "@" domain         ;RFC 822 address
     local-part = WORD *("." WORD)
     domain     = domain-ref *("." domain-ref)

Dawson/Stenerson                   57            Expires September 1997
     domain-ref = ATOM
     phrase     = 1*WORD

     utc-offset = time-numzone  ;As defined above in time

     ;
     ;Definition of an iCalendar Object
     ;
     icalobject = "BEGIN" ":" "VCALENDAR" CRLF
                  icalbody
                  "END" ":" "VCALENDAR" CRLF [icalobject]

     ;
     ;Definition of an iCalendar Property
     ;
     property   = [group "."] propname [";" parmlist] ":" value CRLF

     propname   = <any properties defined in this document>
                / iana-prop / x-token

     x-token    = <The two characters "X-" or "x-" followed, with no
                   intervening white space, by any atom>

     iana-prop  = <A publicly defined extension property, registered
                   with IANA, as specified by this document>

     ;
     ;Definition of the month a particular weekday
   event occurs. Calendar Components and Calendar Properties
     ;
     icalbody   = calprops 1*component

     calprops   = [calscale] [geo] prodid [profile] [prof-version]
                  [source] [name] version

     component  = 1*(eventc / todoc / journalc / freebusyc /
                / timezonec)

     ;Event Component
     eventc     = "BEGIN" ":" "VEVENT" CRLF
                  *eventprop *alarmc
                  "END" ":" "VEVENT" CRLF

     eventprop  = *attach *attendee *categories [class]
                / [created] description dtend dtstart *exdate
                / *exrule *last-mod [location] [priority]
                / *related *resources *rdate *rrule
                / [resp-seq] / [seq] [status] [summary] [transp]
                / [uid] *url

     ;To-do Component
     todoc      = "BEGIN" ":" "VTODO" CRLF
                  *todoprop *alarmc
                  "END" ":" "VTODO" CRLF

Dawson/Stenerson                   57                   58            Expires August September 1997
   weekday      A symbol representing a day
     todoprop   = *attach *attendee *categories [class] [completed]
                / [created] description dtstart due *exdate
                / *exrule *last-mod [location] priority
                / *related *resources *rdate *rrule [resp-seq]
                / [seq] [status] [summary] [transp] [uid] *url

     ;Journal Component
     journalc   = "BEGIN" ":" "VJOURNAL" CRLF
                  *jourprop
                  "END" ":" "VJOURNAL" CRLF

     jourprop   = *attach *categories [class] [created] description
                / dtstart *last-mod *related [resp-seq] [seq] [uid] *url

     ;Free/Busy Component
     freebusyc  = "BEGIN" ":" "VFREEBUSY" CRLF
                  *fbprop
                  "END" ":" "VFREEBUSY" CRLF

     fbprop     = *attendee [created] [duration] [dtend] [dtstart]
                / *freebusy *last-mod *related [resp-seq] [seq] [uid]
                / *url

     ;Alarm Component
     alarmc     = "BEGIN" ":" "VALARM" CRLF
                  *alarmprop
                  "END" ":" "VALARM" CRLF

     alarmprop  = *attach [created] [description] dtstart duration
                / *last-mod *related repeat [summary] *url

     ;Time Zone Component
     timezonec  = "BEGIN" ":" "VTIMEZONE" CRLF
                  *tzprop
                  "END" ":" "VTIMEZONE" CRLF

     tzprop     = [created] [daylight] [dtend] dtstart [rdate / rrule]
                  [tzname] tzoffset [tztrans] [uid]

     ;
     ;Definition of the week.

   daily                Defines a rule that repeats on a daily basis.

   weekly               Defines a rule that repeats on a weekly basis.

   monthlybypos Defines a rule that repeats on a monthly basis on a
   relative day and week.

   monthlybyday Defines a rule that repeats on a monthly basis on an
   absolute day.

   yearlybymonth        Defines Calendar Properties
     ;
     calscale   = "CALSCALE" ":" calvalue CRLF
     calvalue   = "GREGORIAN" / iana-scale
     iana-scale = <Any other designator for a rule calendar scale
                   registered with IANA>

     geo                = "GEO" ":" geovalue CRLF
     geovalue   = (float ";" float )/ url

     prodid     = "prodid" ":" pidvalue CRLF
     pidvalue   = (guid-text / url)
     ;Any text that repeats on specific months
   of describes the year.

   yearlybyday  Defines a rule product and version
     ;and that repeats on specific days is generally assured of the
   year.

3.3.7   Policies

   1.      The duration portion being unique.>

Dawson/Stenerson                   59            Expires September 1997
     profile    = "PROFILE" ": profvalue CRLF
     profvalue  = " component "-" action
     component  = "EVENT" / "TODO" / "JOURNAL" / "FREEBUSY"
                / iana-component / x-token
     action     = <Any IANA registered iCalendar action type.>
     iana-component = <Any other component registered with IANA>

     prof-version       = "PROFILE-VERSION" ":" profvalue CRLF
     profvalue  = iana-prfver / x-token
     iana-prfver = <A IANA registered iCalendar profile identifier>

     source     = "SOURCE" ":" url CRLF

     name               = "NAME" ":" text CRLF

     version    = "VERSION" ":" vervalue CRLF
     vervalue   = "2.0" / x-token

     ;Component Properties
     attach     = [group "."] "ATTACH" ":" url CRLF

     attendee   = [group "."] "ATTENDEE" [";" attparamlist] ":"
                  (rfc822-address / url) CRLF

     attparamlist               = attparam / attparamlist ";" attparam
                        / paramlist / paramlist ";" attparam
                        / paramlist ";" attparamlist ";" attparam

     attparam   = typeparm / roleparm / statusparm / rsvpparm
                / expectparm / memberparm

     typeparm   = "TYPE" "="
                ("INDIVIDUAL"   ; An individual
                / "GROUP"       ; A group of individuals
                / "RESOURCE"    ; A physical resource
                / "ROOM"        ; A room resource
                / "UNKNOWN")    ; Otherwise not known
     ;Default value is UNKNOWN

     roleparm   = "ROLE" "="
                ("ATTENDEE"     ; Indicates a rule defines the total number regular attendee
                / "OWNER"       ; Indicates owner of events
     the rule generates, including the first event.

   2.      Information, event or to-do
                / "ORGANIZER"   ; Indicates organizer of event or to-do
                / "DELEGATE")   ; Indicates delegate to event or to-do
     ;Default is ATTENDEE

     statusparm = "STATUS" "="
                ("NEEDS-ACTION" ; Indicates event or to-do needs action
                / "ACCEPTED"    ; Indicates event or to-do accepted
                / "DECLINED"    ; Indicates event or to-do not contained accepted
                / "TENTATIVE"   ; Indicates event or to-do tentatively
                ; accepted. Status may change in the rule, necessary future.
                / "COMPLETED"   ; Indicates to-do was completed.
                ; COMPLETED property has date/time completed.

Dawson/Stenerson                   60            Expires September 1997
                / "DELEGATED"   ; Indicateds event or to-do delegated
                ; to determine the
     next another ATTENDEE
                / "CANCELED")   ; Indicates event time and date or to-do canceled for
                ; ATTENDEE
     ;Default is derived from the Start Time entry
     attribute.

   3.      If NEEDS-ACTION

     rsvpparm   = "RSVP" "=" ("YES" / "NO")
     ;Default is NO

     expectparm = "EXPECT" "="
                ("FYI"          ; Indicates request is for your info
                / "REQUIRE"     ; Indicates presence is required
                / "REQUEST"     ; Indicates presence is requested
                / "IMMEDIATE")  ; Indicates an end date and a duration immediate response needed
     ;Default is specified FYI

     memberparm = rfc822-address ; Indicates a group or mailing list

     categories = "CATEGORIES" [";" paramlist] ":" catvalue CRLF

     catvalue   = cat1value [,cat1value] / cat2value [, cat2value]

     cat1value  = "APPOINTMENT" / "BUSINESS" / "EDUCATION" / "HOLIDAY"
                / "MEETING" / "MISCELLANEOUS" / "NON-WORKING HOURS"
                / "NOT IN OFFICE" / "PERSONAL" / "PHONE CALL"
                / "SICK DAY" / "SPECIAL OCCASION" / "TRAVEL"
                / "VACATION" / word
     ;Used in the rule, the
     recurring event ceases when the end date and to-do components
     cat2value  = "AUDIO" / "DISPLAY" / "EMAIL" / "PROCEDURE"
                / x-token / iana-word
     ;Used in alarm component

     class      = "CLASS" [";" paramlist] ":" classvalue CRLF
     classvalue = "PUBLIC" / "PRIVATE" / "CONFIDENTIAL" / x-token
     ;Default is reached PUBLIC

     created    = "CREATED" ":" date-time CRLF

     completed  = "COMPLETED" ":" date-time CRLF

     daylight   = "DAYLIGHT" ":" boolean CRLF
     ;Default value is FALSE

     description = "DESCRIPTION" [";" paramlist] text CRLF

     due        = "DUE" ":" date-time CRLF

     duration   = "DURATION" ":" duration CRLF

     dtstart    = "DTSTART" ":" date-time CRLF

     dtend      = "DTEND" ":" date-time CRLF

     exdate     = "EXDATE" ":" date-time *["," date-time] CRLF

Dawson/Stenerson                   61            Expires September 1997
     exrule     = "EXRULE" [";" rparamlist] ":" rvalue CRLF

     freebusy   = "FREEBUSY" [";" fbparmlist] ":" fbvalue CRLF

     fbparmlist = fbparam / paramlist ";" fbparam
                / fbparam ";" fbparmlist
     fbparam    = fbtype / fbstatus

     fbtype     = "TYPE" "=" ("FREE" or the number
     of events indicated in the duration occur; whichever comes first.

   4.      If the duration "BUSY")
     ;Default is BUSY

     fbstatus   = "STATUS" "="
                  "BUSY"        ;Represents busy time interval
                / "OUT"         ;Represents out-of-office, non-working
                                ;hours, or an end date other unavailable interval
                / "PRIVATE"     ;Represents private unavailable time
                / "CONFIDENTIAL" ;Represents confidential unavailable
                                ;time
     ;Default is not established in BUSY

     fbvalue    = period ["," period]
     ;Value must match default or explicit data type

     last-mod   = "LAST-MODIFIED" ":" date-time ["," date-time] CRLF

     location   = "LOCATION [";" paramlist] ":" locavalue CRLF
     locavalue  = text / url    ;The value must be the rule
     (e.g., D4) same type as the event occurs twice. That is D4
                                ;default or explicit data type.

     priority   = "PRIORITY" ":" integer CRLF
     ;Default is equivalent to D4
     #2.

   5.      A duration of #0 means repeat this event forever.

   6.      Using the occurrence specifier 5+ (e.g. 5th Friday) or 5- (e.g.
     5th from last Friday) in a month that does not contain 5 weeks
     does not generate an event and thus does not count against zero

     related-to = "RELATED-TO" [";" paramlist] ":" relvalue CRLF
     relvalue   = text / url            ;Value must be the
     duration. The same applies to providing a day of the month that
     does not occur in the month. For example the 30th type as
                                        ;default or 31st .

   7.      The start time and date of an entry explicit data type

     rdate      = "RDATE" ":" rdvalue *["," rdvalue] CRLF
     rdvalue    = date-time / period
     ;Value must be synchronized with one match default or explicit data type

     ;
     ;Definition of the repeating events defined by its recurrence rule. The
     following is not allowed:

        Initial Appointment Date:       7/1/94 (Friday)
        Recurrence Rule:                W1 MO TH #5

     The following is acceptable:

        Initial Appt Date:      7/1/94 (Friday)
        Recurrence Rule:                W1 MO FR #5 or W1 #5 rule
     ;rrule     = "RRULE" [rparamlist] ":" rvalue CRLF

     rparamlist = rparam / rparamlist ";" rparam / paramlist
                / paramlist ";" rparam
                / paramlist ";" rparamlist ";" rparam

     rparam     = "UNTIL" "=" enddate
                / "COUNT" "=" interval
                / "INTERVAL" "=" rinterval
                / "BYDAY" "=" bdweekdaylist
                / "BYMONTHDAY" "=" bmdaylist
                / "BYYEARDAY" "=" bydaylist

Dawson/Stenerson                   62            Expires September 1997
                / "BYSETPOS" "=" bsplist
                / "BYWEEKNO" "=" bwdaylist
                / "BYMONTH" "=" bmlist
                / "WKST" "=" weekday
                / "X-" word "=" word

     rvalue     = "HOURLY" / "DAILY" / "WEEKLY" / "YEARLY"

     rinterval  = interval      ; For any rvalue
                / duration      ; Only for rvalue = HOURLY

     digits     = 1*digit

     interval   = digits

     enddate    = date          ;A UTC value

     plus       = "+"

     minus      = "-"

     ordmoday   = 1*2digits     ;1 to 31

     ordwk      = 1*2digits     ;1 to 52

     ordyrday   = 1*3digits     ;1 to 366

     daynumber  = (plus / minus) ordmoday

     weekday    = "SU" / "MO" / "TU" / "WE" / "TH" / "FR" / "SA" >

     bdweekdaynum = [daynumber] weekday

     bdweekdaylist = bdweekdaynum / bdweekdaynum "," *(bdweekdaynum)

     bmposday   = [plus] ordmoday

     bmnegday   = minus ordmoday

     bmdaylist  = bmposday *("," bmposday / bmnegday)
                / bmnegday *("," bmnegday / bmposday)

     byposday   = [plus] ordyrday

     bynegday   = minus ordyrday

     bydaylist  = byposday *("," byposday / bynegday)
                / bynegday *("," bynegday / byposday)

     bsplist    = byposday *("," byposday / bynegday)
                / bynegday *("," bynegday / byposday)

     bwposday   = [plus] ordwk

Dawson/Stenerson                   58                   63            Expires August September 1997
   8.      If the optional <occurrencelist> and <weekdaylist> information
     bwnegday   = minus ordwk

     bwdaylist  = bwposday *("," bwposday / bwnegday)
                / bwnegday *("," bwnegday / bwposday)

     bmposmon   = 1*2digits     ;1 to 12

     bmlist     = bmposmon *("," bmposmon)

     resource   = "RESOURCES" [";" paramlist] ":" resvalist CRLF
     resvalist  = resvalue / resvalue "," resvalist
     resvalue   = "CATERING" / "CHAIRS" / "COMPUTER PROJECTOR"
                / "EASEL" / "OVERHEAD PROJECTOR" / "SPEAKER PHONE"
                / "TABLE" / "TV" / "VCR" / "VIDEO PHONE" / "VEHICLE"
                / word

     respseq    = "RESPONSE-SEQUENCE" ":" integer CRLF
     ;Default is
     missing from a <monthlybypos> occurrence the information "0".

     sequence   = "SEQUENCE" ":" integer CRLF
     ;Default is
     derived from the entry attributes. The <occurrence> used in the
     recurring "0".

     status     = "STATUS" [";" paramlist] ":" statvalue CRLF

     statvalue  = "NEEDS ACTION"        ;Indicates to-do needs action.
                / "COMPLETED"           ;Indicates to-do completed
                / "TENTATIVE"           ;Indicates event is a count from the beginning of the month to the
     entry date and the <weekday> used is the day of the week the entry
     is being
                                        ;tentatively scheduled to occur on.

   9.      If the <monthlybypos> occurrence or <monthlybyday> occurrence does
     not list a week day (e.g., SU or day 10) in the rule, the week day
     is established from the entry attribute information. As an example
     the rule MP1 #3 used in an entry with a start date of 7/20/94
     (which
                / "CONFIRMED"           ;Indicates event is the third Wednesday of the month) repeats definite
                / "CANCELLED"           ;Indicates event was canceled

     summary    = "SUMMARY" [";" paramlist] ":" text CRLF

     transp     = "TRANSP" [";" paramlist] ":" transvalue CRLF
     transvalue = "BUSY"        ;Opaque/blocks on 8/17/94
     which free/busy searches
                                ;Default value is the third Wednesday BUSY
                / "OUT"         ;Opaque/blocks on free/busy searches
                / "PRIVATE"     ;Opaque/blocks on free/busy searches
                / "CONFIDENTIAL" ;Opaque/blocks on free/busy searches
                / "TRANSPARENT" ;Transparent on free/time searches

     tzname     = "TZNAME" [";" paramlist] ":" text CRLF

     tzoffset   = "TZOFFSET" ":" utc-offset CRLF

     tztrans    = "TZTRANS" ":" time CRLF

     url        = "URL" ":" url CRLF

     uid        = "UID" [";" paramlist] ":" text CRLF

     extension  = "X-" [vendorid] word [";" paramlist] ":" value
     vendorid   = 1*char "-"    ;Vendor identification prefix text

Dawson/Stenerson                   64            Expires September 1997
     ;End of the month.

4. grammar

6. Registration of Content Type Profiles

   This section defines procedures by which usage profiles for the MIME
   Calendaring and Scheduling Content Type are registered with the IANA
   and made available to the Internet community. Note that non-IANA
   profiles may be used by bilateral agreement, provided the associated
   profile names follow the "X-" convention defined above in section
   3.1.6.33.

   The procedures defined here are designed to allow public comment and
   review of new profiles, while posing only a small impediment to the
   definition of new profiles.

   Registration of a new profile is accomplished by the following steps.

4.1

6.1 Define the profile

   A profile is defined by completing the following template.

     To: ietf-calendar@imc.org

     Subject: Registration of text/calendar MIME profile XXX

     Profile name:

     Profile purpose:

     Profile type-subtype:

     Profile special notes (optional):

     Intended usage: (one of COMMON, LIMITED USE or OBSOLETE)

   The explanation of what goes in each field in the template follows.

   Profile name: The name of the profile as it will be generally
   referred to in public. This name is required in the profile.

Dawson/Stenerson                   59               Expires August 1997

   Profile purpose: The purpose of the profile (e.g., to schedule
   document management updates, etc.). Give a short but clear
   description. This description is required in the profile.

   Profile type-subtype: The type-subtypes of the profile as they will
   appear in the text/calendar MIME Content-Type Profile parameter. This
   list of type-subtype values is required in the profile.

   Profile properties: The list of MIME Calendaring and Scheduling
   Content Type properties associated with the profile. This list of
   properties that are included in the profile. If a property is
   required by the profile, it should noted in this section. Other types
   not mentioned in the profile definition may also be present. Note

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   that any new properties referenced by the profile must be defined
   separately as described in section .

   Profile special notes: Any special notes about the profile, how it is
   to be used, etc. This section is not required in the profile.

4.2

6.2 Post the profile definition

   The profile description must be posted to the IETF Calendaring and
   Scheduling Working Group discussion list, ietf-calendar@imc.org.

4.3

6.3 Allow a comment period

   Discussion on the new profile must be allowed to take place on the
   list for a minimum of two weeks. Consensus must be reached on the
   profile before submitting the profile for approval.

4.4

6.4 Submit the profile for approval

   Once the two-week comment period has elapsed, and the proposer is
   convinced consensus has been reached on the profile, the registration
   application should be submitted to the Profile Reviewer for approval.

   The Profile Reviewer is appointed to the Application Area Directors
   and may either accept or reject the profile registration. An accepted
   registration should be passed on by the Profile Reviewer to the IANA
   for inclusion in the official IANA profile registry. The registration
   may be rejected for any of the following reasons. 1) Insufficient
   comment period; 2) Consensus not reached; 3) Technical deficiencies
   raised on the list or elsewhere have not been addressed. The Profile
   Reviewer's decision to reject a profile may be appealed by the
   proposer to the IESG, or the objections raised can be addressed by
   the proposer and the profile resubmitted.

4.5

6.5 Profile Change Control

   Existing profiles may be changed using the same process by which they
   were registered.

   1.      Define the change

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   2.      Post the change

   3.      Allow a comment period

   4.      Submit the profile for approval

   Note that the original author or any other interested party may
   propose a change to an existing profile, but that such changes should
   only be proposed when there are serious omissions or errors in the
   published specification. The Profile Reviewer may object to a change
   if it is not backwards compatible, but is not required to do so.

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   Profile definitions can never be deleted from the IANA registry, but
   profiles which are no longer believed to be useful can be declared
   OBSOLETE by a change to their "intended use" field.

4.6

6.6 Registration of New Content Type Properties

   This section defines procedures by which new properties for the MIME
   Calendaring and Scheduling Content Type are registered with the IANA.
   Note that non-IANA properties may be used by bilateral agreement,
   provided the associated properties names follow the "X-" convention
   defined above in section 3.1.6.33.

   The procedures defined here are designed to allow public comment and
   review of new properties, while posing only a small impediment to the
   definition of new properties.

   Registration of a new property is accomplished by the following
   steps.

4.6.1

6.6.1 Define the property

   A property is defined by completing the following template.

     To: ietf-calendar@imc.org

     Subject: Registration of text/calendar MIME property XXX

     Property name:

     Property purpose:

     Property data type(s):

     Property encoding:

     Property special notes (optional):

     Intended usage: (one of COMMON, LIMITED USE or OBSOLETE)

   The meaning of each field in the template is as follows.

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   Property name: The name of the property, as it will appear in the
   body of an text/calendar MIME Content-Type "property: value" line to
   the left of the colon ":".

   Property purpose: The purpose of the property (e.g., to indicate a
   delegate for the event or to-do, etc.). Give a short but clear
   description.

   Property data type(s): Any of the valid data types for the property
   value needs to be specified. The default data type also needs to be
   specified. If a new data type is specified, it needs to be declared
   in this section.

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   Property encoding: The encodings permitted for the property value.
   This description must be precise and must not violate the general
   encoding rules defined in this document.

   Property special notes: Any special notes about the property, how it
   is to be used, etc.

4.6.2

6.6.2 Post the Property definition

   The property description must be posted to the new property
   discussion list, ietf-calendar@imc.org.

4.6.3

6.6.3 Allow a comment period

   Discussion on the new property must be allowed to take place on the
   list for a minimum of two weeks. Consensus must be reached on the
   property before proceeding to the next step.

4.6.4

6.6.4 Submit the property for approval

   Once the two-week comment period has elapsed, and the proposer is
   convinced consensus has been reached on the property, the
   registration application should be submitted to the Profile Reviewer
   for approval. The Profile Reviewer is appointed to the Application
   Area Directors and may either accept or reject the property
   registration. An accepted registration should be passed on by the
   Profile Reviewer to the IANA for inclusion in the official IANA
   profile registry. The registration may be rejected for any of the
   following reasons. 1) Insufficient comment period; 2) Consensus not
   reached; 3) Technical deficiencies raised on the list or elsewhere
   have not been addressed. The Profile Reviewer's decision to

   reject a property may be appealed by the proposer to the IESG, or the
   objections raised can be addressed by the proposer and the property
   resubmitted.

4.7     Content Type

6.7 Property Change Control

   Existing properties may be changed using the same process by which
   they were registered.

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        1.           Define the change

        2.           Post the change

        3.           Allow a comment period

        4.           Submit the property for approval

   Note that the original author or any other interested party may
   propose a change to an existing property, but that such changes
   should only be proposed when there are serious omissions or errors in
   the published specification. The Profile Reviewer may object to a

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   change if it is not backwards compatible, but is not required to do
   so.

   Property definitions can never be deleted from the IANA registry, but
   properties which are no longer believed to be useful can be declared
   OBSOLETE by a change to their "intended use" field.

5.

7. File extension

   The file extension of _vcs_ "vcs" is to be used to designate a file
   containing calendaring and scheduling information consistent with
   this MIME content type.

6.

8. Macintosh File Type Code

   The file type code of _vcal_ "vcal" 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.

7.      Bibliography

9. References

   The following document are referred to within this document.

   [ISO 8601] ISO 8601, Data "Data elements and interchange formats_
   Information interchange_Representation of dates and times, times",
   International Organization for Standardization, June, 1988. This
   standard is also addressed by the Internet Draft document
   ftp://ds.internic.net/internet-drafts/draft-newman-datetime-00.txt.

   [ISO 9070] ISO/IEC 9070, Information "Information Technology_SGML Support
   Facilities_Registration Procedures for Public Text Owner Identifiers,
   Identifiers", Second Edition, International Organization for
   Standardization, April, 1991.

   [MIME-REG] Freed, N.,  Postel,  J.,  "Multipurpose

   [MIME DIR] Howes, T., Smith, M., "A MIME Content-Type for Directory
   Information", Internet-draft-ietf-asid-mime-direct-05.txt, March,
   1997.

   [RFC 822] Crocker, D., "Standard for the Format of ARPA Internet  Mail
   Extensions (MIME) - Part Four: Registration Procedures", Internet-
   Draft draft-ietf-822ext-mime-reg-02.txt, December 1995. Text
   Messages", STD 11, RFC 822, August 1982.

   [RFC 1738] T. Berners-Lee and L. Masinter , _Universal Berners-Lee, T., Masinter, L., McCahill, M., "Uniform
   Resource
   Locator_, Locators (URL)", RFC 1738, Xerox Corporation, University of Minnesota, December 1994.

Dawson/Stenerson                   63               Expires August 1997

   [RFC 1766] H. Alvestrand, _Tags H., "Tags for the Identification of Languages_,
   UNINETT, RFC 1766,
   Languages", March 1995.

   [RFC 1872] Levinson, E., "The MIME Multipart/Related Content-type,"
   RFC 1872, December 1995.

   [RFC 2045] Freed, N., Borenstein, N., and N. Freed, "Multipurpose " Multipurpose Internet Mail
   Extensions (MIME) - Part One: Format of Internet Message Bodies", RFC
   2045, November 1996.

Dawson/Stenerson                   69            Expires September 1997
   [RFC 2046] Borenstein N., and N. Freed, "Multipurpose N., Borenstein, N., " Multipurpose Internet Mail
   Extensions (MIME) - Part Two: Media Types", RFC 2046, November 1996.

   [RFC 2047] Moore, K., "Multipurpose Internet Mail Extensions (MIME) -
   Part Three: Message Header Extensions for Non-ASCII Text", RFC 2047,
   November 1996.

   [RFC 2048] Freed, N., J. Klensin, J. Postel, "Multipurpose Internet
   Mail Extensions (MIME) - Part Four: Registration Procedures", RFC
   2048, January 1997.

   [US-ASCII] Coded "Coded Character Set--7-bit American Standard Code for
   Information Interchange, Interchange", ANSI X3.4-1986.

   [VCARD] Internet Mail Consortium, "vCard - The Electronic Business
   Card Version 2.1", http://www.versit.com/pdi/vcard-21.txt, September
   18, 1996.

   [VCAL] MIME calendaring entity Internet Mail Consortium, "vCalendar - The Electronic
   Calendaring and Scheduling Exchange
   Format, Versit Consortium, Format",
   http://www.imc.org/pdi/vcal-10.txt, September 18, 1996.

   [XAPIA] XAPIA "XAPIA CSA, Calendaring and Scheduling Application
   Programming Interface (CSA) Version 1.0, 1.0", X.400 API Association,
   November 15, 1994.

8.

10. Acknowledgments

   A hearty thanks to the IETF Calendaring and Scheduling Working Group
   and also the following individuals who have participated in the
   drafting, review and discussion of this memo:

   Roland Alden, Harald T. Alvestrand, Denis Bigorgne, John Binici, Bill
   Bliss, Andre Courtemanche, Dave Crocker, Alec Dun, Ross Finlayson,
   Randell Flink, Ned Freed, Patrik Falstrom, Chuck Grandgent, Mark
   Handley, Steve Hanna, Paul B. Hill, Mark Horton, Bruce Kahn, C.
   Harald Koch, Theodore Lorek, Keith Moore, Cecil Murray, Chris Newman,
   Ralph Patterson, Pete Resnick, Keith Rhodes, Robert Ripberger, Andras
   Salamar, Vinod Seraphin, Ken Shan, Andrew Shuman, William P. Spencer,
   Mark Towfiq, Robert Visnov, James L. Weiner, Mike Weston, William
   Wyatt.

9.
   Wyatt, Steve Silverberg.

11. Author's Address

   The following address information is provided in a MIME-VCARD,
   Electronic Business Card, format.

   The authors of this draft are:

     BEGIN:VCARD
     FN:Frank Dawson
     ORG:Lotus Development Corporation
     ADR;WORK;POSTAL;PARCEL:;;6544 Battleford Drive;
       Raleigh;NC;27613-3502;USA

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     TEL;WORK;MSG:+1-919-676-9515
     TEL;WORK;FAX:+1-919-676-9564
     EMAIL;INTERNET:fdawson@earthlink.net
     URL:http://home.earthlink.net/~fdawson
     END:VCARD

Dawson/Stenerson                   64               Expires August 1997

     BEGIN:VCARD
     FN:Derik Stenerson
     ORG:Microsoft Corporation
     ADR;WORK;POSTAL;PARCEL:;;One Microsoft Way;
       Redmond;WA;98052-6399;USA
     TEL;WORK;MSG:+1-206-936-5522
     TEL;WORK;FAX:+1-206-936-7329
     EMAIL;INTERNET:deriks@Exchange.Microsoft.com
     END:VCARD

   The iCalendar Object is a result of the work of the Internet
   Engineering Task Force Calendaring and Scheduling Working Group. The
   chairman of that working group is:

     BEGIN:VCARD
     FN:Anik Ganguly
     ORG:OnTime, Inc.
     ADR;WORK;POSTAL;PARCEL:10 Floor;;21700 Northwestern Highway;
       Southfield;MI;48075;USA
     TEL;WORK;MSG:+1-810-559-5955
     TEL;WORK;FAX:+1-810-559-5034
     EMAIL;INTERNET:anik@ontime.com
     END:VCARD

10.

12. iCalendar Object Examples

   The following examples are provided as an informational source of
   illustrative MIME entities containing data iCalendar Objects consistent with this MIME content type.

   The following is an example of a MIME message with a single body part
   consisting of a text/calendar content type. The message specifies a
   meeting request between the originator and recipient of the message.

     TO:jsmith@host1.com
     FROM:jdoe@host1.com
     MIME-VERSION:2.0
     MESSAGE-ID:<19960704 08:30:00 EDT xyz@host1.com>
     CONTENT-TYPE:text/calendar;PROFILE=request,event

     BEGIN:VCALENDAR
     PROFILE:event-request
     VERSION:2.0
     BEGIN:VEVENT
     DTSTART:19960918T143000Z
     DTEND:19960920T220000Z
     CATEGORIES:CONFERENCE;PROJECT

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     SUMMARY:Networld+Interop Conference
     DESCRIPTION;ENCODING=QUOTED-PRINTABLE:Networld+Interop Conference=
      and Exhibit=0D=0A=
     Atlanta World Congress Center=0D=0A=
     Atlanta, Georgia

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     END:VEVENT
     END:VCALENDAR

   The following example message issues a meeting request that does not
   require any reply. The message is sent as a singular _text/calendar_ "text/calendar"
   content type, body part.

     From: jsmith@host1.com
     To: ietf-calendar@imc.org
     Subject: First IETF-Calendar Working Group Meeting
     MIME-Version: 2.0
     Message-ID: <id1@host1.com>
     Content-Type: text/calendar;Profile=event,request

     BEGIN:VCALENDAR
     PROFILE:event-request
     DAYLIGHT:TRUE;-06:00;19960407T025959;19961027T010000;EST;EDT
     PRODID:-//RDU Software//NONSGML HandCal//EN
     TZ:-05:00
     VERSION:2.0
     BEGIN:VEVENT
     ATTENDEE;EXPECT=REQUEST:ietf-calendar@imc.org
     DESCRIPTION:First IETF-Calendaring and Scheduling Working Group
       Meeting
     CATEGORIES:MEETING
     CLASS:PUBLIC
     DCREATED:19961022T083000
     CREATED:19961022T083000
     SUMMARY:IETF Calendaring Working Group Meeting
     DTSTART:19961210T210000Z
     DTEND:19961210T220000Z
     LOCATION:San Jose, CA - Fairmont Hotel
     UID:guid-1.host1.com
     END:VEVENT
     END:VCALENDAR

   The following is an example of a MIME message with a single body part
   consisting of a text/calendar content type. The message specifies a
   meeting request between the originator and recipient of the message.

     TO:jsmith@host1.com
     FROM:jdoe@host1.com
     MIME-VERSION:1.0
     MESSAGE-ID:<19970322 08:30:00 EDT xyz@host1.com>
     CONTENT-TYPE:text/calendar;PROFILE=event-request

     BEGIN:VCALENDAR
     PROFILE:event-request
     VERSION:2.0
     PRODID:-//ABC Corporation//NONSGML My Product//EN
     BEGIN:VEVENT
     SEQUENCE:0

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     UID:19970324-080045-4000F192713-0052
     ATTENDEE;EXPECT=REQUEST:jsmith@host1.com
     DTSTART:19970324T123000Z
     DTEND:19970324T210000Z
     CATEGORIES:CONFERENCE;PROJECT
     CLASS:PUBLIC
     SUMMARY:Calendaring Interop Conference
     DESCRIPTION;ENCODING=QUOTED-PRINTABLE:Calendaring Interop=
      Conference and Exhibit=0D=0A=
      Atlanta, Georgia
     LOCATION:Atlanta World Congress Center
     ATTACH;VALUE=URL:file://xyzCorp.com/conf/bkgrnd.ps
     END:VEVENT
     END:VCALENDAR

   Example of a reply to the above request, accepting the meeting.

     TO:jdoe@host1.com
     FROM:jsmith@host1.com
     MIME-VERSION:1.0
     MESSAGE-ID:<19970322 08:30:00 EDT xyz@host1.com>
     CONTENT-TYPE:text/calendar;PROFILE=event-reply

     BEGIN:VCALENDAR
     PROFILE:event-reply
     VERSION:2.0
     PRODID:-//ABC Corporation//NONSGML My Product//EN
     BEGIN:VEVENT
     SEQUENCE:0
     RESPONSE-SEQUENCE:0
     UID:19970324-080045-4000F192713-0052
     ATTENDEE;STATUS=CONFIRMED;EXPECT=REQUEST:jsmith@host1.com
     END:VEVENT
     END:VCALENDAR

   An example of a meeting cancelation:

     TO:jsmith@host1.com
     FROM:jdoe@host1.com
     MIME-VERSION:1.0
     MESSAGE-ID:<19970322 08:30:00 EDT xyz@host1.com>
     CONTENT-TYPE:text/calendar;PROFILE=event-cancel

     BEGIN:VCALENDAR
     PROFILE:event-cancel
     VERSION:2.0
     PRODID:-//ABC Corporation//NONSGML My Product//EN
     BEGIN:VEVENT
     UID:19970324-080045-4000F192713-0052
     END:VEVENT
     END:VCALENDAR

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