rfc9074.original   rfc9074.txt 
Network Working Group C. Daboo Internet Engineering Task Force (IETF) C. Daboo
Internet-Draft Apple Request for Comments: 9074 Apple
Updates: 5545 (if approved) K. Murchison, Ed. Updates: 5545 K. Murchison, Ed.
Intended status: Standards Track Fastmail Category: Standards Track Fastmail
Expires: September 4, 2021 March 3, 2021 ISSN: 2070-1721 August 2021
VALARM Extensions for iCalendar "VALARM" Extensions for iCalendar
draft-ietf-calext-valarm-extensions-07
Abstract Abstract
This document defines a set of extensions to the iCalendar VALARM This document defines a set of extensions to the iCalendar "VALARM"
component to enhance use of alarms and improve interoperability component to enhance the use of alarms and improve interoperability
between clients and servers. between clients and servers.
This document updates RFC5545. This document updates RFC 5545.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This is an Internet Standards Track document.
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
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working documents as Internet-Drafts. The list of current Internet-
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Internet-Drafts are draft documents valid for a maximum of six months This document is a product of the Internet Engineering Task Force
and may be updated, replaced, or obsoleted by other documents at any (IETF). It represents the consensus of the IETF community. It has
time. It is inappropriate to use Internet-Drafts as reference received public review and has been approved for publication by the
material or to cite them other than as "work in progress." Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
This Internet-Draft will expire on September 4, 2021. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc9074.
Copyright Notice Copyright Notice
Copyright (c) 2021 IETF Trust and the persons identified as the Copyright (c) 2021 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction
2. Conventions Used in This Document . . . . . . . . . . . . . . 3 2. Conventions Used in This Document
3. Extensible syntax for VALARM . . . . . . . . . . . . . . . . 3 3. Extensible Syntax for VALARM
4. Alarm Unique Identifier . . . . . . . . . . . . . . . . . . . 5 4. Alarm Unique Identifier
5. Alarm Related To . . . . . . . . . . . . . . . . . . . . . . 6 5. Alarm Related To
6. Alarm Acknowledgement . . . . . . . . . . . . . . . . . . . . 6 6. Alarm Acknowledgement
6.1. Acknowledged Property . . . . . . . . . . . . . . . . . . 7 6.1. Acknowledged Property
7. Snoozing Alarms . . . . . . . . . . . . . . . . . . . . . . . 8 7. Snoozing Alarms
7.1. Relationship Type Property Parameter . . . . . . . . . . 9 7.1. Relationship Type Property Parameter
7.2. Example . . . . . . . . . . . . . . . . . . . . . . . . . 9 7.2. Example
8. Alarm Proximity Trigger . . . . . . . . . . . . . . . . . . . 13 8. Alarm Proximity Trigger
8.1. Proximity Property . . . . . . . . . . . . . . . . . . . 14 8.1. Proximity Property
8.2. Example . . . . . . . . . . . . . . . . . . . . . . . . . 15 8.2. Example
9. Security Considerations . . . . . . . . . . . . . . . . . . . 16 9. Security Considerations
10. Privacy Considerations . . . . . . . . . . . . . . . . . . . 16 10. Privacy Considerations
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17 11. IANA Considerations
11.1. Property Registrations . . . . . . . . . . . . . . . . . 17 11.1. Property Registrations
11.2. Relationship Types Registry . . . . . . . . . . . . . . 17 11.2. Relationship Types Registry
11.3. Proximity Value Registry . . . . . . . . . . . . . . . . 17 11.3. Proximity Values Registry
12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 18 12. References
13. References . . . . . . . . . . . . . . . . . . . . . . . . . 18 12.1. Normative References
13.1. Normative References . . . . . . . . . . . . . . . . . . 18 12.2. Informative References
13.2. Informative References . . . . . . . . . . . . . . . . . 19 Acknowledgements
Appendix A. Change History (To be removed by RFC Editor before Authors' Addresses
publication) . . . . . . . . . . . . . . . . . . . . 19
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 22
1. Introduction 1. Introduction
The iCalendar [RFC5545] specification defines a set of components The iCalendar specification [RFC5545] defines a set of components
used to describe calendar data. One of those is the "VALARM" used to describe calendar data. One of those is the "VALARM"
component which appears as a sub-component of "VEVENT" and "VTODO" component, which appears as a subcomponent of the "VEVENT" and
components. The "VALARM" component is used to specify a reminder for "VTODO" components. The "VALARM" component is used to specify a
an event or task. Different alarm actions are possible, as are reminder for an event or task. Different alarm actions are possible,
different ways to specify how the alarm is triggered. as are different ways to specify how the alarm is triggered.
As iCalendar has become more widely used and as client-server As iCalendar has become more widely used and as client-server
protocols such as CalDAV [RFC4791] have become more prevalent, protocols, such as Calendaring Extensions to WebDAV (CalDAV)
several issues with "VALARM" components have arisen. Most of these [RFC4791], have become more prevalent, several issues with "VALARM"
relate to the need to extend the existing "VALARM" component with new components have arisen. Most of these relate to the need to extend
properties and behaviors to allow clients and servers to accomplish the existing "VALARM" component with new properties and behaviors to
specific tasks in an interoperable manner. For example, clients allow clients and servers to accomplish specific tasks in an
typically need a way to specify that an alarm has been dismissed by a interoperable manner. For example, clients typically need a way to
calendar user, or has been "snoozed" by a set amount of time. To specify that an alarm has been dismissed by a calendar user or has
date, this has been done through the use of custom "X-" properties been "snoozed" by a set amount of time. To date, this has been done
specific to each client implementation, leading to poor through the use of custom "X-" properties specific to each client
interoperability. implementation, leading to poor interoperability.
This specification defines a set of extensions to "VALARM" components This specification defines a set of extensions to "VALARM" components
to cover common requirements for alarms not currently addressed in to cover common requirements for alarms not currently addressed in
iCalendar. Each extension is defined in a separate section below. iCalendar. Each extension is defined in a separate section below.
For the most part, each extension can be supported independently of For the most part, each extension can be supported independently of
the others, though in some cases one extension will require another. the others; though, in some cases, one extension will require
In addition, this specification describes mechanisms by which clients another. In addition, this specification describes mechanisms by
can interoperably implement common features such as "snoozing". which clients can interoperably implement common features, such as
"snoozing".
2. Conventions Used in This Document 2. Conventions Used in This Document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in "OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here. capitals, as shown here.
The notation used in this memo to (re-)define iCalendar elements is
the ABNF notation of [RFC5234] as used by [RFC5545]. Any syntax
elements shown below that are not explicitly defined in this
specification come from iCalendar [RFC5545].
When XML element types in the namespaces "DAV:" and When XML element types in the namespaces "DAV:" and
"urn:ietf:params:xml:ns:caldav" are referenced in this document "urn:ietf:params:xml:ns:caldav" are referenced in this document
outside of the context of an XML fragment, the string "DAV:" and outside of the context of an XML fragment, the string "DAV:" and
"CALDAV:" will be prefixed to the element type names respectively. "CALDAV:" will be prefixed to the element type names, respectively.
3. Extensible syntax for VALARM 3. Extensible Syntax for VALARM
Section 3.6.6 of [RFC5545] defines the syntax for "VALARM" components Section 3.6.6 of [RFC5545] defines the syntax for "VALARM" components
and properties within them. However, as written, it is hard to and properties within them. However, as written, it is hard to
extend this by adding, e.g., a new property common to all types of extend this, e.g., by adding a new property common to all types of
alarm. Since many of the extensions defined in this document need to alarms. Since many of the extensions defined in this document need
extend the base syntax, an alternative form for the base syntax is to extend the base syntax, an alternative form for the base syntax is
defined here, with the goal of simplifying specification of the defined here, with the goal of simplifying specification of the
extensions while augmenting the existing functionality defined in extensions while augmenting the existing functionality defined in
[RFC5545] to allow for nested sub-components (as required by [RFC5545] to allow for nested subcomponents (as required by proximity
proximity alarm triggers (Section 8)). alarm triggers (Section 8)).
A "VALARM" calendar component is re-defined by the following A "VALARM" calendar component is redefined by the following notation:
notation:
alarmcext = "BEGIN" ":" "VALARM" CRLF alarmcext = "BEGIN" ":" "VALARM" CRLF
*alarmprop *alarm-subcomp *alarmprop *alarm-subcomp
"END" ":" "VALARM" CRLF "END" ":" "VALARM" CRLF
alarmprop = ( alarmprop = (
; the following are REQUIRED, ; the following are REQUIRED
; but MUST NOT occur more than once ; but MUST NOT occur more than once
action / trigger / action / trigger /
; one set of action properties MUST be ; one set of action properties MUST be
; present and MUST match the action specified ; present and MUST match the action specified
; in the ACTION property ; in the ACTION property
actionprops / actionprops /
; the following are OPTIONAL, ; the following are OPTIONAL
; and MAY occur more than once ; and MAY occur more than once
x-prop / iana-prop x-prop / iana-prop
) )
actionprops = *audiopropext / *disppropext / *emailpropext actionprops = *audiopropext / *disppropext / *emailpropext
audiopropext = ( audiopropext = (
; 'duration' and 'repeat' are both OPTIONAL, ; 'duration' and 'repeat' are both OPTIONAL
; and MUST NOT occur more than once each, ; and MUST NOT occur more than once each,
; but if one occurs, so MUST the other ; but if one occurs, so MUST the other
duration / repeat / duration / repeat /
; the following is OPTIONAL, ; the following is OPTIONAL
; but MUST NOT occur more than once ; but MUST NOT occur more than once
attach attach
) )
disppropext = ( disppropext = (
; the following are REQUIRED, ; the following are REQUIRED
; but MUST NOT occur more than once ; but MUST NOT occur more than once
description / description /
; 'duration' and 'repeat' are both OPTIONAL, ; 'duration' and 'repeat' are both OPTIONAL
; and MUST NOT occur more than once each, ; and MUST NOT occur more than once each,
; but if one occurs, so MUST the other ; but if one occurs, so MUST the other
duration / repeat duration / repeat
) )
emailpropext = ( emailpropext = (
; the following are all REQUIRED, ; the following are all REQUIRED
; but MUST NOT occur more than once ; but MUST NOT occur more than once
description / summary / description / summary /
; the following is REQUIRED, ; the following is REQUIRED
; and MAY occur more than once ; and MAY occur more than once
attendee / attendee /
; 'duration' and 'repeat' are both OPTIONAL, ; 'duration' and 'repeat' are both OPTIONAL
; and MUST NOT occur more than once each, ; and MUST NOT occur more than once each,
; but if one occurs, so MUST the other ; but if one occurs, so MUST the other
duration / repeat duration / repeat
; the following is OPTIONAL, ; the following is OPTIONAL
; and MAY occur more than once ; and MAY occur more than once
attach attach
) )
alarm-subcomp = ( alarm-subcomp = (
; the following are OPTIONAL, ; the following are OPTIONAL
; and MAY occur more than once ; and MAY occur more than once
x-comp / iana-comp x-comp / iana-comp
) )
4. Alarm Unique Identifier 4. Alarm Unique Identifier
This extension adds a "UID" property to "VALARM" components to allow This extension adds a "UID" property to "VALARM" components to allow
a unique identifier to be specified. The value of this property can a unique identifier to be specified. The value of this property can
then be used to refer uniquely to the "VALARM" component. then be used to refer uniquely to the "VALARM" component.
The "UID" property defined here follows the definition in The "UID" property defined here follows the definition in
Section 3.8.4.7 of [RFC5545] with the security and privacy updates in Section 3.8.4.7 of [RFC5545] with the security and privacy updates in
Section 5.3 of [RFC7986]. In particular it MUST be a globally unique Section 5.3 of [RFC7986]. In particular, it MUST be a globally
identifier that does not contain any security- or privacy-sensitive unique identifier that does not contain any security- or privacy-
information. sensitive information.
The "VALARM" component defined in Section 3 is extended here as: The "VALARM" component defined in Section 3 is extended here as:
alarmprop =/ ( alarmprop =/ (
; the following is OPTIONAL, ; the following is OPTIONAL
; but MUST NOT occur more than once ; but MUST NOT occur more than once
uid uid
) )
5. Alarm Related To 5. Alarm Related To
It is often convenient to relate one or more "VALARM" components to It is often convenient to relate one or more "VALARM" components to
other "VALARM" components (e.g., see Section 7). This can be other "VALARM" components (e.g., see Section 7). This can be
skipping to change at page 6, line 32 skipping to change at line 267
defined in Section 3.8.4.5 of [RFC5545] to enable its use with defined in Section 3.8.4.5 of [RFC5545] to enable its use with
"VALARM" components. Specific types of relationships between "VALARM" components. Specific types of relationships between
"VALARM" components can be identified by registering new values for "VALARM" components can be identified by registering new values for
the "RELTYPE" property parameter defined in Section 3.2.15 of the "RELTYPE" property parameter defined in Section 3.2.15 of
[RFC5545]. [RFC5545].
The "VALARM" component defined in Section 3 is extended here as: The "VALARM" component defined in Section 3 is extended here as:
alarmprop =/ ( alarmprop =/ (
; the following is OPTIONAL, ; the following is OPTIONAL
; and MAY occur more than once ; and MAY occur more than once
related related
) )
6. Alarm Acknowledgement 6. Alarm Acknowledgement
There is currently no way for a "VALARM" component to indicate There is currently no way for a "VALARM" component to indicate
whether it has been triggered and acknowledged. With the advent of a whether it has been triggered and acknowledged. With the advent of a
standard client/server protocol for calendaring and scheduling data standard client/server protocol for calendaring and scheduling data
([RFC4791]) it is quite possible for an event with an alarm to exist ([RFC4791]), it is quite possible for an event with an alarm to exist
on multiple clients in addition to the server. If each of those is on multiple clients in addition to the server. If each of those is
responsible for performing the action when an alarm triggers, then responsible for performing the action when an alarm triggers, then
multiple "alerts" are generated by different devices. In such a multiple "alerts" are generated by different devices. In such a
situation, a calendar user would like to be able to "dismiss" the situation, a calendar user would like to be able to "dismiss" the
alarm on one device and have it automatically dismissed on the others alarm on one device and have it automatically dismissed on the
too. others, too.
Also, with recurring events that have alarms, it is important to know Also, with recurring events that have alarms, it is important to know
when the last alarm in the recurring set was acknowledged, so that when the last alarm in the recurring set was acknowledged so that the
the client can determine whether past alarms have been missed. client can determine whether past alarms have been missed.
To address these needs, this specification adds an "ACKNOWLEDGED" To address these needs, this specification adds an "ACKNOWLEDGED"
property to "VALARM" components to indicate when the alarm was last property to "VALARM" components to indicate when the alarm was last
acknowledged (or sent, if acknowledgement is not possible). This is acknowledged (or sent, if acknowledgement is not possible). This is
defined by the syntax below. defined by the syntax below.
alarmprop =/ ( alarmprop =/ (
; the following is OPTIONAL, ; the following is OPTIONAL
; but MUST NOT occur more than once ; but MUST NOT occur more than once
acknowledged acknowledged
) )
6.1. Acknowledged Property 6.1. Acknowledged Property
Property Name: ACKNOWLEDGED Property Name: ACKNOWLEDGED
Purpose: This property specifies the UTC date and time at which the Purpose: This property specifies the UTC date and time at which the
corresponding alarm was last sent or acknowledged. corresponding alarm was last sent or acknowledged.
Value Type: DATE-TIME Value Type: DATE-TIME
Property Parameters: IANA and non-standard property parameters can Property Parameters: IANA and nonstandard property parameters can be
be specified on this property. specified on this property.
Conformance: This property can be specified within "VALARM" calendar Conformance: This property can be specified within "VALARM" calendar
components. components.
Description: This property is used to specify when an alarm was last Description: This property is used to specify when an alarm was last
sent or acknowledged. This allows clients to determine when a sent or acknowledged. This allows clients to determine when a
pending alarm has been acknowledged by a calendar user so that any pending alarm has been acknowledged by a calendar user so that any
alerts can be dismissed across multiple devices. It also allows alerts can be dismissed across multiple devices. It also allows
clients to track repeating alarms or alarms on recurring events or clients to track repeating alarms or alarms on recurring events or
to-dos to ensure that the right number of missed alarms can be to-dos to ensure that the right number of missed alarms can be
tracked. tracked.
Clients SHOULD set this property to the current date-time value in Clients SHOULD set this property to the current date-time value in
UTC when a calendar user acknowledges a pending alarm. Certain UTC when a calendar user acknowledges a pending alarm. Certain
kinds of alarms, such as email-based alerts, might not provide kinds of alarms, such as email-based alerts, might not provide
feedback as to when the calendar user sees them. For those kinds feedback as to when the calendar user sees them. For those kinds
of alarms, the client SHOULD set this property when the alarm is of alarms, the client SHOULD set this property when the alarm is
triggered and the action successfully carried out. triggered and the action is successfully carried out.
When an alarm is triggered on a client, clients can check to see When an alarm is triggered on a client, clients can check to see
if an "ACKNOWLEDGED" property is present. If it is, and the value if an "ACKNOWLEDGED" property is present. If it is, and the value
of that property is greater than or equal to the computed trigger of that property is greater than or equal to the computed trigger
time for the alarm, then the client SHOULD NOT trigger the alarm. time for the alarm, then the client SHOULD NOT trigger the alarm.
Similarly, if an alarm has been triggered and an "alert" presented Similarly, if an alarm has been triggered and an "alert" has been
to a calendar user, clients can monitor the iCalendar data to presented to a calendar user, clients can monitor the iCalendar
determine whether an "ACKNOWLEDGED" property is added or changed data to determine whether an "ACKNOWLEDGED" property is added or
in the alarm component. If the value of any "ACKNOWLEDGED" changed in the alarm component. If the value of any
property in the alarm changes and is greater than or equal to the "ACKNOWLEDGED" property in the alarm changes and is greater than
trigger time of the alarm, then clients SHOULD dismiss or cancel or equal to the trigger time of the alarm, then clients SHOULD
any "alert" presented to the calendar user. dismiss or cancel any "alert" presented to the calendar user.
Format Definition: This property is defined by the following Format Definition: This property is defined by the following
notation: notation:
acknowledged = "ACKNOWLEDGED" *acknowledgedparam ":" datetime CRLF acknowledged = "ACKNOWLEDGED" *acknowledgedparam ":" datetime CRLF
acknowledgedparam = ( acknowledgedparam = (
; the following is OPTIONAL, ; the following is OPTIONAL
; and MAY occur more than once ; and MAY occur more than once
(";" other-param) (";" other-param)
) )
Example: The following is an example of this property: Example: The following is an example of this property:
ACKNOWLEDGED:20090604T084500Z ACKNOWLEDGED:20090604T084500Z
7. Snoozing Alarms 7. Snoozing Alarms
Users often want to "snooze" an alarm, and this specification defines Users often want to "snooze" an alarm, and this specification defines
a standard approach to accomplish that. a standard approach to accomplish that.
To "snooze" an alarm that has been triggered, clients MUST do the To "snooze" an alarm that has been triggered, clients MUST do the
following: following:
1. Set the "ACKNOWLEDGED" property (see Section 6.1) on the 1. Set the "ACKNOWLEDGED" property (see Section 6.1) on the
triggered alarm. triggered alarm.
2. Create a new "VALARM" component (the "snooze" alarm) within the 2. Create a new "VALARM" component (the "snooze" alarm) within the
parent component of the triggered alarm (i.e., as a "sibling" parent component of the triggered alarm (i.e., as a "sibling"
component of the triggered alarm). component of the triggered alarm).
A. The new "snooze" alarm MUST be set to trigger at the user's a. The new "snooze" alarm MUST be set to trigger at the user's
chosen "snooze" interval after the original alarm triggered. chosen "snooze" interval after the original alarm is
Clients SHOULD use an absolute "TRIGGER" property with a triggered. Clients SHOULD use an absolute "TRIGGER" property
"DATE-TIME" value specified in UTC. with a "DATE-TIME" value specified in UTC.
B. The new "snooze" alarm MUST have a "RELATED-TO" property (see b. The new "snooze" alarm MUST have a "RELATED-TO" property (see
Section 5) with a value set to the "UID" property value of Section 5) with a value set to the "UID" property value of
the original "VALARM" component that was triggered. If the the original "VALARM" component that was triggered. If the
triggered "VALARM" component does not already have a "UID" triggered "VALARM" component does not already have a "UID"
property, the client MUST add one. The "RELATED-TO" property property, the client MUST add one. The "RELATED-TO" property
added to the new "snooze" alarm MUST include a "RELTYPE" added to the new "snooze" alarm MUST include a "RELTYPE"
property parameter with a value set to "SNOOZE" (see property parameter with a value set to "SNOOZE" (see
Section 7.1). Section 7.1).
3. When the "snooze" alarm is triggered, the client MUST do the 3. When the "snooze" alarm is triggered, the client MUST do the
following: following:
A. Update the "ACKNOWLEDGED" property on the original related a. Update the "ACKNOWLEDGED" property on the original related
alarm. alarm.
B. If the "snooze" alarm is itself "snoozed", the client MUST b. If the "snooze" alarm is itself "snoozed", the client MUST
remove the "snooze" alarm component, and return to step 2. remove the "snooze" alarm component and return to step 2.
Otherwise, if the "snooze" alarm is dismissed, the client Otherwise, if the "snooze" alarm is dismissed, the client
MUST do one of the following: MUST do one of the following:
+ Set the "ACKNOWLEDGED" property on the "snooze" alarm. * Set the "ACKNOWLEDGED" property on the "snooze" alarm.
+ Remove the "snooze" alarm component. * Remove the "snooze" alarm component.
Note that regardless of the final disposition of the "snooze" alarm Note that regardless of the final disposition of the "snooze" alarm
when triggered, the original "VALARM" component is left unchanged when triggered, the original "VALARM" component is left unchanged
other than updating its "ACKNOWLEDGED" property. other than updating its "ACKNOWLEDGED" property.
7.1. Relationship Type Property Parameter 7.1. Relationship Type Property Parameter
This specification adds the "SNOOZE" relationship type for use with This specification adds the "SNOOZE" relationship type for use with
the "RELTYPE" property defined in Section 3.2.15 of [RFC5545]. This the "RELTYPE" property defined in Section 3.2.15 of [RFC5545]. This
is used when relating a "snoozed" "VALARM" component to the original is used when relating a "snoozed" "VALARM" component to the original
alarm that the "snooze" was generated for. alarm that the "snooze" was generated for.
7.2. Example 7.2. Example
The following example shows the snoozing, re-snoozing, and dismissal The following example shows the "snoozing", "re-snoozing", and
of an alarm. Note that the encompassing VCALENDAR component has been dismissal of an alarm. Note that the encompassing "VCALENDAR"
omitted for brevity and that the line-breaks surrounding the VALARM component has been omitted for brevity and that the line breaks
components are for clarity only and would not be present in the surrounding the "VALARM" components are for clarity only and would
actual iCalendar data. not be present in the actual iCalendar data.
Assume that we have the following event with an alarm set to trigger Assume that we have the following event with an alarm set to trigger
15 minutes before the meeting: 15 minutes before the meeting:
BEGIN:VEVENT BEGIN:VEVENT
CREATED:20210302T151004Z CREATED:20210302T151004Z
UID:AC67C078-CED3-4BF5-9726-832C3749F627 UID:AC67C078-CED3-4BF5-9726-832C3749F627
DTSTAMP:20210302T151004Z DTSTAMP:20210302T151004Z
DTSTART;TZID=America/New_York:20210302T103000 DTSTART;TZID=America/New_York:20210302T103000
DTEND;TZID=America/New_York:20210302T113000 DTEND;TZID=America/New_York:20210302T113000
skipping to change at page 10, line 25 skipping to change at line 449
BEGIN:VALARM BEGIN:VALARM
UID:8297C37D-BA2D-4476-91AE-C1EAA364F8E1 UID:8297C37D-BA2D-4476-91AE-C1EAA364F8E1
TRIGGER:-PT15M TRIGGER:-PT15M
DESCRIPTION:Event reminder DESCRIPTION:Event reminder
ACTION:DISPLAY ACTION:DISPLAY
END:VALARM END:VALARM
END:VEVENT END:VEVENT
When the alarm is triggered, the user decides to snooze it for 5 When the alarm is triggered, the user decides to "snooze" it for 5
minutes. The client acknowledges the original alarm and creates a minutes. The client acknowledges the original alarm and creates a
new "snooze" alarm as a sibling of, and relates it to, the original new "snooze" alarm as a sibling of, and relates it to, the original
alarm (note that both VALARMs reside within the same "parent" alarm (note that both occurrences of "VALARM" reside within the same
VEVENT): "parent" VEVENT):
BEGIN:VEVENT BEGIN:VEVENT
CREATED:20210302T151004Z CREATED:20210302T151004Z
UID:AC67C078-CED3-4BF5-9726-832C3749F627 UID:AC67C078-CED3-4BF5-9726-832C3749F627
DTSTAMP:20210302T151516Z DTSTAMP:20210302T151516Z
DTSTART;TZID=America/New_York:20210302T103000 DTSTART;TZID=America/New_York:20210302T103000
DTEND;TZID=America/New_York:20210302T113000 DTEND;TZID=America/New_York:20210302T113000
SUMMARY:Meeting SUMMARY:Meeting
BEGIN:VALARM BEGIN:VALARM
skipping to change at page 11, line 31 skipping to change at line 481
BEGIN:VALARM BEGIN:VALARM
UID:DE7B5C34-83FF-47FE-BE9E-FF41AE6DD097 UID:DE7B5C34-83FF-47FE-BE9E-FF41AE6DD097
TRIGGER;VALUE=DATE-TIME:20210302T152000Z TRIGGER;VALUE=DATE-TIME:20210302T152000Z
RELATED-TO;RELTYPE=SNOOZE:8297C37D-BA2D-4476-91AE-C1EAA364F8E1 RELATED-TO;RELTYPE=SNOOZE:8297C37D-BA2D-4476-91AE-C1EAA364F8E1
DESCRIPTION:Event reminder DESCRIPTION:Event reminder
ACTION:DISPLAY ACTION:DISPLAY
END:VALARM END:VALARM
END:VEVENT END:VEVENT
When the "snooze" alarm is triggered, the user decides to snooze it When the "snooze" alarm is triggered, the user decides to "snooze" it
again for an additional 5 minutes. The client once again again for an additional 5 minutes. The client once again
acknowledges the original alarm, removes the triggered "snooze" acknowledges the original alarm, removes the triggered "snooze"
alarm, and creates another new "snooze" alarm as a sibling of, and alarm, and creates another new "snooze" alarm as a sibling of, and
relates it to, the original alarm (note the different UID for the new relates it to, the original alarm (note the different UID for the new
snooze alarm): "snooze" alarm):
BEGIN:VEVENT BEGIN:VEVENT
CREATED:20210302T151004Z CREATED:20210302T151004Z
UID:AC67C078-CED3-4BF5-9726-832C3749F627 UID:AC67C078-CED3-4BF5-9726-832C3749F627
DTSTAMP:20210302T152026Z DTSTAMP:20210302T152026Z
DTSTART;TZID=America/New_York:20210302T103000 DTSTART;TZID=America/New_York:20210302T103000
DTEND;TZID=America/New_York:20210302T113000 DTEND;TZID=America/New_York:20210302T113000
SUMMARY:Meeting SUMMARY:Meeting
BEGIN:VALARM BEGIN:VALARM
skipping to change at page 13, line 34 skipping to change at line 547
RELATED-TO;RELTYPE=SNOOZE:8297C37D-BA2D-4476-91AE-C1EAA364F8E1 RELATED-TO;RELTYPE=SNOOZE:8297C37D-BA2D-4476-91AE-C1EAA364F8E1
DESCRIPTION:Event reminder DESCRIPTION:Event reminder
ACTION:DISPLAY ACTION:DISPLAY
ACKNOWLEDGED:20210302T152507Z ACKNOWLEDGED:20210302T152507Z
END:VALARM END:VALARM
END:VEVENT END:VEVENT
8. Alarm Proximity Trigger 8. Alarm Proximity Trigger
VALARMs are currently triggered when a specific date-time is reached. Currently, a "VALARM" is triggered when a specific date-time value is
It is also desirable to be able to trigger alarms based on location, reached. It is also desirable to be able to trigger alarms based on
e.g. when arriving at or departing from a particular location. location, e.g., when arriving at or departing from a particular
location.
This specification adds the following elements to "VALARM" components This specification adds the following elements to "VALARM" components
to indicate when an alarm can be triggered based on location. to indicate when an alarm can be triggered based on location.
"PROXIMITY" property - indicates that a location based trigger is "PROXIMITY" property: indicates that a location-based trigger is to
to be used and which action is used for the trigger be used and which action is used for the trigger
"VLOCATION" component(s) [I-D.ietf-calext-eventpub-extensions] - "VLOCATION" component(s) [RFC9073]: used to indicate the actual
used to indicate the actual location(s) to trigger off of, location(s) to trigger off of, specified with a URL property
specified with a URL property containing a geo: URI [RFC5870] containing a 'geo' URI [RFC5870], which allows for two or three
which allows for two or three coordinate values with an optional coordinate values with an optional uncertainty
uncertainty
alarmprop =/ ( alarmprop =/ (
; the following is OPTIONAL, ; the following is OPTIONAL
; but MUST NOT occur more than once ; but MUST NOT occur more than once
proximity / proximity /
) )
alarm-subcomp =/ ( alarm-subcomp =/ (
; the following is OPTIONAL, ; the following is OPTIONAL
; and MAY occur more than once, but only ; and MAY occur more than once but only
; when a PROXIMITY property is also present ; when a PROXIMITY property is also present
locationc locationc
) )
Typically, when a "PROXIMITY" property is used there is no need to Typically, when a "PROXIMITY" property is used, there is no need to
specify a time-based trigger using the "TRIGGER" property. However, specify a time-based trigger using the "TRIGGER" property. However,
since "TRIGGER" is defined as a required property for a "VALARM" since "TRIGGER" is defined as a required property for a "VALARM"
component, for backwards compatibility it has to be present, but component, for backwards compatibility, it has to be present but
ignored. To indicate a "TRIGGER" that is to be ignored, clients ignored. To indicate a "TRIGGER" that is to be ignored, clients
SHOULD use a value a long time in the past. A value of SHOULD use a value a long time in the past. A value of
"19760401T005545Z" has been commonly used for this purpose. "19760401T005545Z" has been commonly used for this purpose.
8.1. Proximity Property 8.1. Proximity Property
Property Name: PROXIMITY Property Name: PROXIMITY
Purpose: This property indicates that a location based trigger is Purpose: This property indicates that a location-based trigger is
applied to an alarm. applied to an alarm.
Value Type: TEXT Value Type: TEXT
Property Parameters: IANA and non-standard property parameters can Property Parameters: IANA and nonstandard property parameters can be
be specified on this property. specified on this property.
Conformance: This property can be specified within "VALARM" calendar Conformance: This property can be specified within "VALARM" calendar
components. components.
Description: This property is used to indicate that an alarm has a Description: This property is used to indicate that an alarm has a
location-based trigger. Its value identifies the action that will location-based trigger. Its value identifies the action that will
trigger the alarm. trigger the alarm.
When the property value is set to "ARRIVE", the alarm is triggered When the property value is set to "ARRIVE", the alarm is triggered
when the calendar user agent arrives in the vicinity of one or when the calendar user agent arrives in the vicinity of one or
more locations. When set to "DEPART", the alarm is triggered when more locations. When set to "DEPART", the alarm is triggered when
the calendar user agent departs from the vicinity of one or more the calendar user agent departs from the vicinity of one or more
locations. Each location which MUST be specified with a locations. Each location MUST be specified with a "VLOCATION"
"VLOCATION" component. Note that the meaning of "vicinity" in component. Note that the meaning of "vicinity" in this context is
this context is implementation defined. implementation defined.
When the property value is set to "CONNECT", the alarm is When the property value is set to "CONNECT", the alarm is
triggered when the calendar user agent connects to a automobile to triggered when the calendar user agent connects to an automobile
which is has been paired via Bluetooth(R) [BTcore]. When set to to which it has been paired via Bluetooth [BTcore]. When set to
"DISCONNECT", the alarm is triggered when the calendar user agent "DISCONNECT", the alarm is triggered when the calendar user agent
disconnects from a automobile to which it has been paired via disconnects from an automobile to which it has been paired via
Bluetooth(R). Note that neither current implementations of Bluetooth. Note that neither current implementations of proximity
proximty alarms nor this document have a mechanism to target a alarms nor this document have a mechanism to target a particular
particular automobile. Such a mechanism may be specified in a automobile. Such a mechanism may be specified in a future
future extension. extension.
Format Definition: This property is defined by the following Format Definition: This property is defined by the following
notation: notation:
proximity = "PROXIMITY" *proximityparam ":" proximityvalue CRLF proximity = "PROXIMITY" *proximityparam ":" proximityvalue CRLF
proximityparam = ( proximityparam = (
; the following is OPTIONAL, ; the following is OPTIONAL
; and MAY occur more than once ; and MAY occur more than once
(";" other-param) (";" other-param)
) )
proximityvalue = "ARRIVE" / "DEPART" / proximityvalue = "ARRIVE" / "DEPART" /
"CONNECT" / "DISCONNECT" / iana-token / x-name "CONNECT" / "DISCONNECT" / iana-token / x-name
8.2. Example 8.2. Example
The following example shows a VALARM component with a proximity The following example shows a "VALARM" component with a proximity
trigger set to trigger when the device running the calendar user trigger set to trigger when the device running the calendar user
agent leaves the vicinity defined by the URL property in the agent leaves the vicinity defined by the URL property in the
VLOCATION component. Note use of the "u=" parameter with the "geo" "VLOCATION" component. Note use of the "u=" parameter with the 'geo'
URI to define the uncertainty of the location determination. URI to define the uncertainty of the location determination.
BEGIN:VALARM BEGIN:VALARM
UID:77D80D14-906B-4257-963F-85B1E734DBB6 UID:77D80D14-906B-4257-963F-85B1E734DBB6
ACTION:DISPLAY ACTION:DISPLAY
TRIGGER;VALUE=DATE-TIME:19760401T005545Z TRIGGER;VALUE=DATE-TIME:19760401T005545Z
DESCRIPTION:Remember to buy milk DESCRIPTION:Remember to buy milk
PROXIMITY:DEPART PROXIMITY:DEPART
BEGIN:VLOCATION BEGIN:VLOCATION
UID:123456-abcdef-98765432 UID:123456-abcdef-98765432
NAME:Office NAME:Office
URL:geo:40.443,-79.945;u=10 URL:geo:40.443,-79.945;u=10
END:VLOCATION END:VLOCATION
END:VALARM END:VALARM
9. Security Considerations 9. Security Considerations
In addition to the security properties of iCalendar (see Section 7 of In addition to the security properties of iCalendar (see Section 7 of
[RFC5545]), VALARMs, if not monitored properly, can be used to [RFC5545]), a "VALARM", if not monitored properly, can be used to
disturb users and/or leak personal information. For instance, an disturb users and/or leak personal information. For instance, an
undesirable audio alert could cause embarassment. An unwanted undesirable audio alert could cause embarrassment; an unwanted
display alert could be considered an annoyance. Or an email alert display alert could be considered an annoyance; or an email alert
could be used to leak a user's location to a third party or to send could be used to leak a user's location to a third party or to send
unsolicited email to multiple users. Therefore, CalDAV clients and unsolicited email to multiple users. Therefore, CalDAV clients and
servers that accept iCalendar data from a third party (e.g. via iTIP servers that accept iCalendar data from a third party (e.g., via
iCalendar Transport-Independent Interoperability Protocol (iTIP)
[RFC5546], a subscription feed, or a shared calendar) SHOULD remove [RFC5546], a subscription feed, or a shared calendar) SHOULD remove
all VALARMs from the data prior to storing in their calendar system. each "VALARM" from the data prior to storing in their calendar
system.
Security considerations related to unique identifiers for VALARMs are Security considerations related to unique identifiers for "VALARM"
discussed in Section 4. are discussed in Section 4.
10. Privacy Considerations 10. Privacy Considerations
Proximity VALARMs, if not used carefully, can leak a user's past, A proximity "VALARM", if not used carefully, can leak a user's past,
present, or future location. For instance, storing an iCalendar present, or future location. For instance, storing an iCalendar
resource containing proxmity VALARMs to a shared calendar on CalDAV resource containing proximity "VALARM"s to a shared calendar on
server can expose to anyone that has access to that calendar the CalDAV server can expose to anyone that has access to that calendar
user's intent to leave from or arrive at a particular location at the user's intent to leave from or arrive at a particular location at
some future time. Furthermore, if a CalDAV client updates the shared some future time. Furthermore, if a CalDAV client updates the shared
iCalendar resource with an ACKNOWLEDGED property when the alarm is iCalendar resource with an "ACKNOWLEDGED" property when the alarm is
triggered, will leak the exact date and time that the user left from triggered, this will leak the exact date and time that the user left
or arrived at the location. Therefore, CalDAV clients that implement from or arrived at the location. Therefore, CalDAV clients that
proximity alarms SHOULD give users the option of storing and/or implement proximity alarms SHOULD give users the option of storing
acknowledging the alarms on the local device only and not storing the and/or acknowledging the alarms on the local device only and not
alarm and/or acknowledgment on a remote server. storing the alarm and/or acknowledgement on a remote server.
Privacy considerations related to unique identifiers for VALARMs are Privacy considerations related to unique identifiers for "VALARM" are
discussed in Section 4. discussed in Section 4.
11. IANA Considerations 11. IANA Considerations
11.1. Property Registrations 11.1. Property Registrations
This document defines the following new iCalendar properties to be This document defines the following new iCalendar properties that
added to the registry defined in Section 8.2.3 of [RFC5545] and have been added to the "Properties" registry defined in Section 8.2.3
located here: <https://www.iana.org/assignments/icalendar#properties> of [RFC5545] and located here: <https://www.iana.org/assignments/
icalendar>.
+--------------+---------+----------------------+ +==============+=========+=======================+
| Property | Status | Reference | | Property | Status | Reference |
+--------------+---------+----------------------+ +==============+=========+=======================+
| ACKNOWLEDGED | Current | RFCXXXX, Section 6.1 | | ACKNOWLEDGED | Current | RFC 9074, Section 6.1 |
| PROXIMITY | Current | RFCXXXX, Section 8.1 | +--------------+---------+-----------------------+
+--------------+---------+----------------------+ | PROXIMITY | Current | RFC 9074, Section 8.1 |
+--------------+---------+-----------------------+
Table 1: Additions to the Properties Registry
11.2. Relationship Types Registry 11.2. Relationship Types Registry
This document defines the following new iCalendar relationship type This document defines the following new iCalendar relationship type
to be added to the registry defined in Section 8.3.8 of [RFC5545] and that has been added to the "Relationship Types" registry defined in
located here: <https://www.iana.org/assignments/ Section 8.3.8 of [RFC5545] and located here:
icalendar#relationship-types> <https://www.iana.org/assignments/icalendar>.
+-------------------+---------+----------------------+ +===================+=========+=======================+
| Relationship Type | Status | Reference | | Relationship Type | Status | Reference |
+-------------------+---------+----------------------+ +===================+=========+=======================+
| SNOOZE | Current | RFCXXXX, Section 7.1 | | SNOOZE | Current | RFC 9074, Section 7.1 |
+-------------------+---------+----------------------+ +-------------------+---------+-----------------------+
11.3. Proximity Value Registry Table 2: Addition to the Relationship Types Registry
This document creates a new iCalendar registry for values of the 11.3. Proximity Values Registry
"PROXIMITY" property located here: <https://www.iana.org/assignments/
icalendar#proximity-values> A new iCalendar registry for values of the "PROXIMITY" property has
been created and is located here: <https://www.iana.org/assignments/
icalendar>.
Additional values MAY be used, provided the process described in Additional values MAY be used, provided the process described in
Section 8.2.1 of [RFC5545] is used to register them, using the Section 8.2.1 of [RFC5545] is used to register them, using the
template in Section 8.2.6 of [RFC5545]. template in Section 8.2.6 of [RFC5545].
The following table has been used to initialize the Proximity Value The following table has been used to initialize the Proximity Value
Registry. Registry.
+------------+---------+----------------------+ +============+=========+=======================+
| Value | Status | Reference | | Value | Status | Reference |
+------------+---------+----------------------+ +============+=========+=======================+
| ARRIVE | Current | RFCXXXX, Section 8.1 | | ARRIVE | Current | RFC 9074, Section 8.1 |
| DEPART | Current | RFCXXXX, Section 8.1 | +------------+---------+-----------------------+
| CONNECT | Current | RFCXXXX, Section 8.1 | | DEPART | Current | RFC 9074, Section 8.1 |
| DISCONNECT | Current | RFCXXXX, Section 8.1 | +------------+---------+-----------------------+
+------------+---------+----------------------+ | CONNECT | Current | RFC 9074, Section 8.1 |
+------------+---------+-----------------------+
12. Acknowledgments | DISCONNECT | Current | RFC 9074, Section 8.1 |
+------------+---------+-----------------------+
This specification came about via discussions at the Calendaring and
Scheduling Consortium. Also, thanks to the following for providing
feedback: Bernard Desruisseaux, Mike Douglass, Jacob Farkas, Jeffrey
Harris, Ciny Joy, Barry Leiba, and Daniel Migault.
13. References Table 3: Initial Contents of the Proximity
Values Registry
13.1. Normative References 12. References
[I-D.ietf-calext-eventpub-extensions] 12.1. Normative References
Douglass, M., "Event Publishing Extensions to iCalendar",
draft-ietf-calext-eventpub-extensions-18 (work in
progress), January 2021.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234,
DOI 10.17487/RFC5234, January 2008,
<https://www.rfc-editor.org/info/rfc5234>.
[RFC5545] Desruisseaux, B., Ed., "Internet Calendaring and [RFC5545] Desruisseaux, B., Ed., "Internet Calendaring and
Scheduling Core Object Specification (iCalendar)", Scheduling Core Object Specification (iCalendar)",
RFC 5545, DOI 10.17487/RFC5545, September 2009, RFC 5545, DOI 10.17487/RFC5545, September 2009,
<https://www.rfc-editor.org/info/rfc5545>. <https://www.rfc-editor.org/info/rfc5545>.
[RFC5870] Mayrhofer, A. and C. Spanring, "A Uniform Resource [RFC5870] Mayrhofer, A. and C. Spanring, "A Uniform Resource
Identifier for Geographic Locations ('geo' URI)", Identifier for Geographic Locations ('geo' URI)",
RFC 5870, DOI 10.17487/RFC5870, June 2010, RFC 5870, DOI 10.17487/RFC5870, June 2010,
<https://www.rfc-editor.org/info/rfc5870>. <https://www.rfc-editor.org/info/rfc5870>.
[RFC7986] Daboo, C., "New Properties for iCalendar", RFC 7986, [RFC7986] Daboo, C., "New Properties for iCalendar", RFC 7986,
DOI 10.17487/RFC7986, October 2016, DOI 10.17487/RFC7986, October 2016,
<https://www.rfc-editor.org/info/rfc7986>. <https://www.rfc-editor.org/info/rfc7986>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>. May 2017, <https://www.rfc-editor.org/info/rfc8174>.
13.2. Informative References [RFC9073] Douglass, M., "Event Publishing Extensions to iCalendar",
RFC 9073, DOI 10.17487/RFC9073, August 2021,
<https://www.rfc-editor.org/info/rfc9073>.
12.2. Informative References
[BTcore] Bluetooth Special Interest Group, "Bluetooth Core [BTcore] Bluetooth Special Interest Group, "Bluetooth Core
Specification Version 5.0", December 2016, Specification Version 5.0 Feature Overview", December
<https://www.bluetooth.com/specifications/bluetooth-core- 2016, <https://www.bluetooth.com/bluetooth-resources/
specification>. bluetooth-5- go-faster-go-further/>.
[RFC4791] Daboo, C., Desruisseaux, B., and L. Dusseault, [RFC4791] Daboo, C., Desruisseaux, B., and L. Dusseault,
"Calendaring Extensions to WebDAV (CalDAV)", RFC 4791, "Calendaring Extensions to WebDAV (CalDAV)", RFC 4791,
DOI 10.17487/RFC4791, March 2007, DOI 10.17487/RFC4791, March 2007,
<https://www.rfc-editor.org/info/rfc4791>. <https://www.rfc-editor.org/info/rfc4791>.
[RFC5546] Daboo, C., Ed., "iCalendar Transport-Independent [RFC5546] Daboo, C., Ed., "iCalendar Transport-Independent
Interoperability Protocol (iTIP)", RFC 5546, Interoperability Protocol (iTIP)", RFC 5546,
DOI 10.17487/RFC5546, December 2009, DOI 10.17487/RFC5546, December 2009,
<https://www.rfc-editor.org/info/rfc5546>. <https://www.rfc-editor.org/info/rfc5546>.
Appendix A. Change History (To be removed by RFC Editor before Acknowledgements
publication)
Changes in ietf-06:
1. Corrected timestamps in snooze example.
2. Editorial changes from Benjamim Kaduk.
Changes in ietf-05:
1. Updated to use VLOCATION components rather than (deprecated)
STRUCTURED-LOCATION properties for proximity alarms.
2. Reorganized and clarified the process of snoozing an alarm and
added an example.
3. Noted that there is currently no mechanism for specifying a
particular automobile for CONNECT/DISCONNECT proximity alarms.
4. Replaced the term "spam" with new wording in Security
Considerations.
5. Addressed IESG comments from Benjamim Kaduk.
6. Addressed IESG comments from Robert Wilton.
7. Addressed IESG comments Alissa Cooper.
Changes in ietf-04:
1. Addressed security review comments from Valery Smyslov.
2. Addressed Genart review comments from Roni Even.
3. Added text addressing management of Proximity Value Registry.
Changes in ietf-03:
1. Fixed ABNF to be properly extended.
2. Addressed AD review comments from Barry Leiba.
Changes in ietf-02:
1. Addressed some WGLC comments from Daniel Migault.
Changes in ietf-01:
1. Reintroduced the RELATED-TO property for VALARMs and the SNOOZE
value for the RELTYPE property parameter.
2. Add Privacy Considerations section.
Changes in ietf-00:
1. Submitted as CALEXT draft.
Changes in daboo-05:
1. Added Murchison as editor.
2. Updated keywords boilerplate.
3. Added reference to UID security/privacy recommendations.
4. Removed default alarms.
5. Removed ALARM-AGENT property.
6. Added text about using TRIGGER value in the past in addition to
ACTION:NONE to have a default alarm be ignored.
7. Removed text about related alarms.
8. Removed URL alarm action.
9. Added reference to draft-ietf-calext-eventpub-extensions for
STRUCTURED-LOCATION.
10. Added CONNECT and DISCONNECT PROXIMITY property values.
11. Added Security Considerations.
12. Editorial fixes.
Changes in daboo-04:
1. Changed "ID" to "AGENT-ID".
2. Add more text on using "ACKNOWLEDGED" property.
3. Add "RELATED-TO" as a valid property for VALARMs.
4. Add "SNOOZE" relationship type for use with VALARMs.
5. State that "TRIGGER" is typically ignored in proximity alarms.
6. Added "PROXIMITY" value registry.
7. Added a lot more detail on default alarms including new action
and property.
Changes in daboo-03: none - resubmission of -02
Changes in daboo-02:
1. Updated to 5545 reference.
2. Clarified use of absolute trigger in UTC in snooze alarms
3. Snooze alarms should be removed when completed
4. Removed status and replaced last-triggered by acknowledged
property
5. Added location-based trigger
6. IANA registry tables added
Changes in daboo-01:
1. Removed DESCRIPTION as an allowed property in the URI alarm.
2. Added statement about what to do when ALARM-AGENT is not present.
3. Allow multiple ALARM-AGENT properties to be present.
4. Removed SNOOZE-UNTIL - snoozing now accomplished by creating a
new VALARM.
5. Remove VALARM by reference section.
6. Added more detail to CalDAV default alarms. This specification came about via discussions at The Calendaring and
Scheduling Consortium. Also, thanks to the following for providing
feedback: Bernard Desruisseaux, Mike Douglass, Jacob Farkas, Jeffrey
Harris, Ciny Joy, Barry Leiba, and Daniel Migault.
Authors' Addresses Authors' Addresses
Cyrus Daboo Cyrus Daboo
Apple Inc. Apple Inc.
1 Infinite Loop 1 Infinite Loop
Cupertino, CA 95014 Cupertino, CA 95014
USA United States of America
Email: cyrus@daboo.name Email: cyrus@daboo.name
URI: http://www.apple.com/ URI: http://www.apple.com/
Kenneth Murchison (editor) Kenneth Murchison (editor)
Fastmail US LLC Fastmail US LLC
1429 Walnut St, Suite 1201 Suite 1201
Philadephia, PA 19102 1429 Walnut St
USA Philadelphia, PA 19102
United States of America
Email: murch@fastmailteam.com Email: murch@fastmailteam.com
URI: http://www.fastmail.com/ URI: http://www.fastmail.com/
 End of changes. 102 change blocks. 
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