RFC 4324
Calendar Access Protocol (CAP)
Pages: 131
Experimental
Experimental
Part 1 of 5 – Pages 1 to 19
Network Working Group D. Royer Request for Comments: 4324 IntelliCal, LLC Category: Experimental G. Babics Oracle S. Mansour eBay December 2005 Calendar Access Protocol (CAP) Status of This Memo This memo defines an Experimental Protocol for the Internet community. It does not specify an Internet standard of any kind. Discussion and suggestions for improvement are requested. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (2005).Abstract
The Calendar Access Protocol (CAP) described in this memo permits a Calendar User (CU) to utilize a Calendar User Agent (CUA) to access an iCAL-based Calendar Store (CS). At the time of this writing, three vendors are implementing CAP, but it has already been determined that some changes are needed. In order to get implementation experience, the participants felt that a CAP specification is needed to preserve many years of work. Many properties in CAP which have had many years of debate, can be used by other iCalendar protocols.
Table of Contents
1. Introduction ....................................................5 1.1. Formatting Conventions .....................................5 1.2. Related Documents ..........................................6 1.3. Definitions ................................................7 2. Additions to iCalendar .........................................11 2.1. New Value Types (Summary) ................................14 2.1.1. New Parameters (summary) .............................14 2.1.2. New or Updated Properties (summary) ..................14 2.1.3. New Components (summary) .............................17 2.2. Relationship of RFC-2446 (ITIP) to CAP ...................18 3. CAP Design .....................................................20 3.1. System Model ..............................................20 3.2. Calendar Store Object Model ...............................20 3.3. Protocol Model ............................................21 3.3.1. Use of BEEP, MIME, and iCalendar .....................22 4. Security Model .................................................23 4.1. Calendar User and UPNs ....................................23 4.1.1. UPNs and Certificates ................................24 4.1.2. Anonymous Users and Authentication ...................25 4.1.3. User Groups ..........................................25 4.2. Access Rights .............................................26 4.2.1. Access Control and NOCONFLICT ........................26 4.2.2. Predefined VCARs .....................................26 4.2.3. Decreed VCARs ........................................28 4.3. CAP Session Identity ......................................28 5. CAP URL and Calendar Address ...................................29 6. New Value Types ................................................30 6.1. Property Value Data Types .................................30 6.1.1. CAL-QUERY Value Type .................................30 6.1.1.1. [NOT] CAL-OWNERS() ..............................36 6.1.1.2. CURRENT-TARGET() ................................37 6.1.1.3. PARAM() .........................................37 6.1.1.4. SELF() ..........................................38 6.1.1.5. STATE() .........................................38 6.1.1.6. Use of Single Quote .............................38 6.1.1.7. Comparing DATE and DATE-TIME Values .............39 6.1.1.8. DTEND and DURATION ..............................40 6.1.1.9. [NOT] LIKE ......................................40 6.1.1.10. Empty vs. NULL .................................41 6.1.1.11. [NOT] IN .......................................41 6.1.1.12. DATE-TIME and TIME Values in a WHERE Clause ....42 6.1.1.13. Multiple Contained Components ..................43 6.1.1.14. Example, Query by UID ..........................43 6.1.1.15. Query by Date-Time Range .......................43 6.1.1.16. Query for All Unprocessed Entries ..............44 6.1.1.17. Query with Subset of Properties by Date/Time ...44
6.1.1.18. Query with Components and Alarms in A Range ....45
6.1.2. UPN Value Type .......................................45
6.1.3. UPN-FILTER Value .....................................46
7. New Parameters .................................................48
7.1. ACTION Parameter ..........................................48
7.2. ENABLE Parameter ..........................................48
7.3. ID Parameter ..............................................49
7.4. LATENCY Parameter .........................................50
7.5. LOCAL Parameter ...........................................50
7.6. LOCALIZE Parameter ........................................51
7.7. OPTIONS Parameter .........................................52
8. New Properties .................................................52
8.1. ALLOW-CONFLICT Property ...................................52
8.2. ATT-COUNTER Property ......................................53
8.3. CALID Property ............................................54
8.4. CALMASTER Property ........................................54
8.5. CAP-VERSION Property ......................................55
8.6. CARID Property ............................................55
8.7. CAR-LEVEL Property ........................................56
8.8. COMPONENTS Property .......................................56
8.9. CSID Property .............................................58
8.10. DECREED Property .........................................58
8.11. DEFAULT-CHARSET Property .................................59
8.12. DEFAULT-LOCALE Property ..................................60
8.13. DEFAULT-TZID Property ....................................61
8.14. DEFAULT-VCARS Property ...................................62
8.15. DENY Property ............................................62
8.16. EXPAND property ..........................................63
8.17. GRANT Property ...........................................64
8.18. ITIP-VERSION Property ....................................64
8.19. MAX-COMP-SIZE Property ...................................65
8.20. MAXDATE Property .........................................65
8.21. MINDATE Property .........................................66
8.22. MULTIPART Property .......................................66
8.23. NAME Property ............................................67
8.24. OWNER Property ...........................................68
8.25. PERMISSION Property ......................................68
8.26. QUERY property ...........................................69
8.27. QUERYID property .........................................70
8.28. QUERY-LEVEL Property .....................................70
8.29. RECUR-ACCEPTED Property ..................................71
8.30. RECUR-LIMIT Property .....................................71
8.31. RECUR-EXPAND Property ....................................72
8.32. RESTRICTION Property .....................................72
8.33. SCOPE Property ...........................................73
8.34. STORES-EXPANDED Property .................................74
8.35. TARGET Property ..........................................74
8.36. TRANSP Property ..........................................75
9. New Components .................................................76 9.1. VAGENDA Component .........................................76 9.2. VCALSTORE Component .......................................78 9.3. VCAR Component ............................................80 9.4. VRIGHT Component ..........................................82 9.5. VREPLY Component ..........................................83 9.6. VQUERY Component ..........................................83 10. Commands and Responses ........................................85 10.1. CAP Commands (CMD) .......................................85 10.2. ABORT Command ............................................88 10.3. CONTINUE Command .........................................89 10.4. CREATE Command ...........................................90 10.5. DELETE Command ...........................................96 10.6. GENERATE-UID Command .....................................98 10.7. GET-CAPABILITY Command ..................................100 10.8. IDENTIFY Command ........................................103 10.9. MODIFY Command ..........................................105 10.10. MOVE Command ...........................................110 10.11. REPLY Response to a Command ............................112 10.12. SEARCH Command .........................................113 10.13. SET-LOCALE Command .....................................116 10.14. TIMEOUT Command ........................................118 10.15. Response Codes .........................................118 11. Object Registration ..........................................120 11.1. Registration of New and Modified Entities ...............120 11.2. Post the Item Definition ................................120 11.3. Allow a Comment Period ..................................120 11.4. Release a New RFC .......................................120 12. BEEP and CAP .................................................120 12.1. BEEP Profile Registration ...............................120 12.2. BEEP Exchange Styles ....................................123 12.3. BEEP Connection Details .................................123 13. IANA Considerations ..........................................125 14. Security Considerations ......................................125 Appendix A. Acknowledgements ....................................127 Appendix B. References ..........................................127 Appendix B.1. Normative References ..........................127 Appendix B.2. Informative References ........................128
1. Introduction
This document specifies the Calendar Access Protocol (CAP). CAP permits a Calendar User (CU) to utilize a Calendar User Agent (CUA) to access an iCAL-based Calendar Store (CS) and manage calendar information. In particular, the document specifies how to query, create, modify, and delete iCalendar components (e.g., events, to- dos, or daily journal entries). It further specifies how to search for available busy time information. Synchronization with CUAs is not covered, but it is believed to be possible using CAP. At the time of this writing, three vendors are implementing CAP. It has already been determined that some changes are needed. In order to get implementation experience, the participants felt that a CAP specification is needed to preserve many years of work. Many properties in CAP can be used by other iCalendar protocols and have had many years of debate. CAP is specified as a BEEP (Block Extensible Exchange Protocol) "profile" [BEEP] [BEEPGUIDE]. Many aspects of the protocol (e.g., authentication and privacy) are provided within BEEP. The protocol data units of CAP leverage the standard iCalendar format iCAL [iCAL] to convey calendar-related information. CAP can also be used to store and fetch iCalendar Transport- Independent Interoperability Protocol (iTIP) objects [iTIP]. iTIP objects used are exactly as defined in [iTIP]. When iCalendar objects are transferred between the CUA and a CS, some additional properties and parameters may be added; the CUA is responsible for correctly generating iCalendar objects to non-CAP processes. The definition of new components, properties, parameters, and value types are broken into two parts. The first part summarizes and defines the new objects. The second part provides detail and ABNF for those objects. The ABNF rules for CAP, as for other iCalendar specifications, are order-independent. That is, properties in a component may occur in any order, and parameters in any property may occur in any order.1.1. Formatting Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY" and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. Calendaring and scheduling roles are referred to in quoted-strings of text with the first character of each word in upper case. For example, "Organizer" refers to a role of a "Calendar User" (CU)
within the protocol defined by [iTIP]. Calendar components defined by [iCAL] are referred to with capitalized, quoted-strings of text. All iCalendar components should start with the letter "V". For example, "VEVENT" refers to the event calendar component, "VTODO" refers to the to-do component, and "VJOURNAL" refers to the daily journal component. Scheduling methods defined by [iTIP] are referred to with capitalized, quoted-strings of text. For example, "REPLY" refers to the method for replying to a "REQUEST". CAP commands are referred to by upper-case, quoted-strings of text, followed by the word "command". For example, '"CREATE" command' refers to the command for creating a calendar entry, '"SEARCH" command' refers to the command for reading calendar components. CAP commands are named using the "CMD" property. Properties defined by this memo are referred to with capitalized, quoted-strings of text, followed by the word "property". For example, '"ATTENDEE" property' refers to the iCalendar property used to convey the calendar address that has been invited to a "VEVENT" or "VTODO" component. Property parameters defined by this memo are referred to with capitalized, quoted-strings of text, followed by the word "parameter". For example, "PARTSTAT" parameter refers to the iCalendar property parameter used to specify the participation status of an attendee. Enumerated values defined by this memo are referred to with capitalized text, either alone or followed by the word "value". Object states defined by this memo are referred to with capitalized, quoted-strings of text, followed by the word "state". For example, '"BOOKED" state' refers to an object in the booked state. Within a query, the different parts are referred to as a "clause" and its value as "clause value" and the clause name will be in uppercase enclosed in quotes, for example, 'The "SELECT" claus' or 'if the "SELECT" clause value contains ...'. In tables, the quoted-string text is specified without quotes in order to minimize the table length.1.2. Related Documents
Implementers will need to be familiar with several other memos that, along with this one, describe the Internet calendaring and scheduling standards. These documents are as follows.
[iCAL] (RFC2445) specifies the objects, data types, properties and
property parameters used in the protocols, along with the
methods for representing and encoding them.
[iTIP] (RFC2446) specifies an interoperability protocol for
scheduling between different installations.
[iMIP] (RFC2447) specifies the Internet email binding for [iTIP].
[GUIDE] (RFC3283) is a guide to implementers and describes the
elements of a calendaring system, how they interact with each
other, how they interact with end users, and how the standards
and protocols are used.
This memo does not attempt to repeat the specification of concepts
and definitions from these earlier memos. Where possible, references
are made to the memo that provides the specification of these
concepts and definitions.
1.3 Definitions
UNPROCESSED, BOOKED, DELETED - A conceptual state of an object in
the calendar store. There are three conceptual states:
"UNPROCESSED" state, "BOOKED" state, and marked for deletion,
which is the "DELETED" state. How the implementation stores the
state of any object is not a protocol issue and is not discussed.
An object can be said to be booked, unprocessed, or marked for
deletion.
1. An "UNPROCESSED" state scheduling object has been stored in
the calendar store but has not been acted on by a CU or CUA.
All scheduled entries are [iTIP] objects. No [iTIP] objects
in the store are in the "BOOKED" state. To retrieve any
[iTIP] object, simply do a query asking for any objects that
are stored in the "UNPROCESSED" state.
2. A "BOOKED" state entry is stored with the "CREATE" command.
It is an object that has been acted on by a CU or CUA and
there has been a decision to store an object. To retrieve any
booked object, simply do a query asking for any objects that
were stored in the "BOOKED" state.
3. A "DELETED" state entry is created by sending a "DELETE"
command with the "OPTION" parameter value set to "MARK". To
retrieve any deleted object, simply do a query asking for any
objects that were stored in the "DELETED" state. By default
objects marked for delete are not returned. The CUA must
specifically ask for marked-for-deletion objects. You cannot
ask for components in the "DELETED" state and in other states
in the same "VQUERY" component, as there would be no way to
distinguish between them in the reply.
Calendar - A collection of logically related objects or entities
each of which may be associated with a calendar date and possibly
time of day. These entities can include calendar properties or
components. In addition, a calendar might be related to other
calendars with the "RELATED-TO" property. A calendar is
identified by its unique calendar identifier. The [iCAL] defines
the initial calendar properties, calendar components and
properties that make up the contents of a calendar.
Calendar Access Protocol (CAP) - The Internet protocol that permits
a CUA to access and manipulate calendars residing on a Calendar
Store. (This memo.)
Calendar Access Rights (VCAR) - The mechanism for specifying the CAP
operations ("PERMISSION") that a particular calendar user ("UPN",
defined below) is granted or denied permission to perform on a
given calendar object ("SCOPE"). The calendar access rights are
specified with a "VCAR" component. (Section 9.3)
Calendar Address - Also see Calendar URL, which is the same as a CAP
address. The calendar address can also be the value to the
"ATTENDEE" and "ORGANIZER" properties, as defined in [iCAL].
Calendar URL - A calendar URL is a URL, defined in this memo,
that specifies the address of a CS or Calendar.
Component - Any object that conforms to the iCalendar object format
and that is either defined in an Internet Draft, registered with
IANA, or is an experimental object that is prefixed with "x-".
Some types of components include calendars, events, to-dos,
journals, alarms, and time zones. A component consists of
properties and possibly other contained components. For example,
an event may contain an alarm component.
Container - This is a generic name for VCALSTORE or VAGENDA.
Properties - An attribute of a particular component. Some
properties are applicable to different types of components. For
example, the "DTSTART" property is applicable to the "VEVENT",
"VTODO", and "VJOURNAL" components. Other components are
applicable only to an individual type of calendar component. For
example, the "TZURL" property may only be applicable to the
"VTIMEZONE" components.
Calendar Identifier (CALID) - A globally unique identifier
associated with a calendar. Calendars reside within a CS. See
Qualified Calendar Identifier and Relative Calendar Identifier.
All CALIDs start with "cap:".
Calendar Policy - A CAP operational restriction on the access or
manipulation of a calendar. These may be outside the scope of the
CAP protocol. An example of an implementation or site policy is,
"events MUST be scheduled in unit intervals of one hour".
Calendar Property - An attribute of a calendar ("VAGENDA"). The
attribute applies to the calendar, as a whole. For example, the
"CALSCALE" property specifies the calendar scale (e.g., the
"GREGORIAN" value) for the all entries within the calendar.
Calendar Store (CS) - The data and service model definitions for a
Calendar Store as defined in this memo. This memo does not
specify how the CS is implemented.
Calendar Server - An implementation of a Calendar Store (CS) that
manages one or more calendars.
Calendar Store Identifier (CSID) - The globally unique identifier
for an individual CS. A CSID consists of the host and port
portions of a "Common Internet Scheme Syntax" part of a URL, as
defined by [URL]. The CSID excludes any reference to a specific
calendar. (Section 8.9)
Calendar Store Components - Components maintained in a CS specify a
grouping of calendar store-wide information.
Calendar Store Properties - Properties maintained in a Calendar
Store represent store-wide information.
Calendar User (CU) - An entity (often biological) that uses a
calendaring system.
Calendar User Agent (CUA) - The client application that a CU
utilizes to access and manipulate a calendar.
CAP Session - An open communication channel between a CUA and a CS.
If the CAP session is authenticated, the CU is "authenticated" and
it is an "authenticated CAP session".
Contained Component / Contained Properties - A component or property
that is contained inside of another component. For example, a
"VALARM" component may be contained inside a "VEVENT" component,
and a "TRIGGER" property could be a contained property of a
"VALARM" component.
Delegate - A CU (sometimes called the delegatee) who has been
assigned participation in a scheduled component (e.g., VEVENT) by
one of the attendees in the scheduled component (sometimes called
the delegator). An example of a delegate is a team member told to
go to a particular meeting in place of another invitee who is
unable to attend.
Designate - A CU who is authorized to act on behalf of another CU.
An example of a designate is an assistant.
Experimental - The CUA and CS may implement experimental extensions
to the protocol. They might also have experimental components,
properties, and parameters. These extensions MUST start with "x-"
(or "X-") and should include a vendor prefix (such as "x-
myvendor-"). There is no guarantee that these experimental
extensions will interoperate with other implementations. There is
no guarantee that they will not interact in unpredictable ways
with other vendor experimental extensions. There is no guarantee
that the same specific experimental extension is not used by
multiple vendors in incompatible ways. Implementations should
limit sending those extensions to other implementations.
Object - A generic name for any component, property, parameter, or
value type to be used in iCalendar.
Overlapped Booking - A policy that indicates whether or not
components with a "TRANSP" property not set to "TRANSPARENT-
NOCONFLICT" or "OPAQUE-NOCONFLICT" value can overlap one another.
When the policy is applied to a calendar it indicates whether or
not the time span of any component (VEVENT, VTODO, ...) in the
calendar can overlap the time span of any other component in the
same calendar. When applied to an individual object, it indicates
whether or not any other component's time span can overlap that
individual component. If the CS does not allow overlapped
booking, then the CS is unwilling to allow any overlapped bookings
within any calendar or entry in the CS.
Owner - One or more CUs or UGs that are listed in the "OWNER"
property in a calendar. There can be more than one owner.
Qualified Calendar Identifier (Qualified CALID) - A CALID in which
both the scheme and CSID of the CAP URI are present.
Realm - A collection of calendar user accounts, identified by a
string. The name of the Realm is only used in UPNs. In order to
avoid namespace conflict, the Realm SHOULD be postfixed with an
appropriate DNS domain name (e.g., the foobar Realm could be
called foobar.example.com).
Relative Calendar Identifier (Relative CALID) - An identifier for an
individual calendar in a calendar store. It MUST be unique within
a calendar store. A Relative CALID consists of the "URL path" of
the "Common Internet Scheme Syntax" portion of a URL, as defined
by [URI] and [URLGUIDE].
Session Identity - A UPN associated with a CAP session. A session
gains an identity after successful authentication. The identity
is used in combination with VCAR to determine access to data in
the CS.
User Group (UG) - A collection of Calendar Users and/or User Groups.
These groups are expanded by the CS and may reside either locally
or in an external database or directory. The group membership may
be fixed or dynamic over time.
Username - A name that denotes a Calendar User within a Realm. This
is part of a UPN.
User Principal Name (UPN) - A unique identifier that denotes a CU or
a group of CUs. (Section 6.1.2)
2. Additions to iCalendar
Several new components, properties, parameters, and value types are
added in CAP. This section summarizes those new objects.
This memo extends the properties that can go into 'calprops' as
defined in [iCAL] section 4.6 page 51, to allow [iTIP] objects
transmitted between a CAP aware CUA and the CS to contain the
"TARGET" and "CMD" properties. This memo also adds to the [iCAL]
ABNF to allow IANA and experimental extensions. This memo does not
address how a CUA transmits [iTIP] or [iMIP] objects to non-CAP
programs. What follows is ABNF, as described in [ABNF].
calprops= 2*(
; 'prodid' and 'version' are both REQUIRED,
; but MUST NOT occur more than once.
;
prodid /version /
;
; These are optional, but MUST NOT occur
; more than once.
;
calscale /
method /
cmd /
;
; Target is optional, and may occur more
; than once.
;
target / other-props )
;
other-props = *(x-prop) *(iana-prop) *(other-props)
;
iana-prop = ; Any property registered by IANA directly or
; included in an RFC that may be applied to
; the component and within the rules published.
;
x-prop = ; As defined in [iCAL].
;
methodp = ; As defined in [iCAL].
;
prodid = ; As defined in [iCAL].
;
calscale = ; As defined in [iCAL].
;
Another change is that the 'component' part of the 'icalbody' ABNF as
described in [iCAL] section 4.6 is optional when sending a command,
as shown in the following updated ABNF:
icalbody = calprops component
; If the "VCALENDAR" component contains the "CMD"
; property then the 'component' is optional:
;
/ calprops ; Which MUST include a "CMD" property
;
component = ; As defined in [iCAL].
In addition, a problem exists with the control of "VALARM" components
and their "TRIGGER" properties. A CU may wish to set its own alarms
(local alarms) on components. These local alarms are not to be
forwarded to other CUs, CUAs, or CSs. Similarly, the "SEQUENCE"
property and the "ENABLE" parameter in local alarms are not to be
forwarded to other CUs, CUAs, or CSs. Therefore, for the protocol
between a CUA and a CS, the following changes from [iCAL] section
4.6.6 page 67 apply to the CAP protocol:
alarmc = "BEGIN" ":" "VALARM" CRLF
alarm-seq
other-props
(audioprop / dispprop / emailprop / procprop)
"END" ":" "VALARM" CRLF
;
emailprop = ; As defined in [iCAL]
;
procprop = ; As defined in [iCAL]
;
dispprop = ; As defined in [iCAL]
;
audioprop = ; As defined in [iCAL]
;
alarm-seq = "SEQUENCE" alarmseqparams ":" posint0 CRLF
;
alarmseqparams = other-params [";" local-param] other-params
;
; Where DIGIT is defined in [iCAL]
;
posint0 = 1*DIGIT
posint1 = posintfirst 1*DIGIT
;
; A number starting with 1 through 9.
;
posintfirst = %x31-39
;
other-params = *(";" xparam) *(";" iana-params)
*(";" other-params)
;
iana-params = ; Any parameter registered by IANA directly or
; included in an RFC that may be applied to
; the property and within the rules published.
;
xparam ; As defined in [iCAL].
;
The CUA adds a "SEQUENCE" property to each "VALARM" component as it
books the component. This property, along with the "LOCAL" and
"ENABLE" parameters, allows the CUA to uniquely identify any VALARM
in any component. The CUA should remove those before forwarding to
non-CAP-aware CUAs.
In addition, if a CUA wished to ignore a "TRIGGER" property in a
"VALARM" component that was supplied to it by the "Organizer", the
CUA needs a common way to tag that trigger as disabled. So the
following is a modification to [iCAL] section 4.8.6.3 page 127:
trigger = "TRIGGER" 1*(";" enable-param) (trigrel / trigabs)
;
trigrel = ; As defined in [iCAL].
;
trigabs = ; As defined in [iCAL].
See Section 7.2 and Section 7.5.
2.1. New Value Types (Summary)
UPN: The UPN value type is a text value type restricted to only UPN
values (see Section 6.1.2).
UPN-FILTER: Like the UPN value type, but also includes filter rules
that allow wildcards (see Section 6.1.3).
CALQUERY: The "CAL-QUERY" value type is a query syntax that is used
by the CUA to specify the rules that apply to a CAP command (see
Section 6.1.1).
2.1.1. New Parameters (summary)
ACTION - The "ACTION" parameter informs the endpoint if it should
abort or ask to continue on timeout. (Section 7.1)
ENABLE - The "ENABLE" parameter in CAP is used to tag a property in
a component as disabled or enabled. (Section 7.2)
ID - The "ID" parameter specifies a unique identifier to be used for
any outstanding commands.
LATENCY - The "LATENCY" parameter supplies the timeout value for
command completion to the other endpoint. (Section 7.4)
LOCAL - The "LOCAL" parameter in CAP is used to tag a property in a
component to signify that the component is local or to be
distributed. (Section 7.5)
LOCALIZE - The "LOCALIZE" parameter specifies the locale to be used
in error and warning messages.
OPTIONS - The "OPTIONS" parameter passes optional information for
the command being sent.
2.1.2. New or Updated Properties (summary)
ALLOW-CONFLICT - Some entries in a calendar might not be valid if
other entries were allowed to overlap the same time span.
(Section 8.1)
ATT-COUNTER - When storing a "METHOD" property with the "COUNTER"
method, there needs to be a way to remember the "ATTENDEE" value
that sent the COUNTER. (Section 8.2)
CAP-VERSION - The version of CAP that the implementation supports.
(Section 8.5)
CAR-LEVEL - The level of calendar access supported. (Section 8.7)
COMPONENTS - The list of components supported. (Section 8.8)
CSID - The Calendar Store IDentifier (CSID) uniquely identifies a
CAP server. (Section 8.9)
CALID - Each calendar within a CS needs to be uniquely identifiable.
The "CALID" property identifies a unique calendar within a CS. It
can be a full CALID or a relative CALID. (Section 8.3)
CALMASTER - The "CALMASTER" property specifies the contact
information for the CS. (Section 8.4)
CARID - Access rights can be saved and fetched by unique ID - the
"CARID" property. (Section 8.6)
CMD - The CAP commands, as well as replies are transmitted using the
"CMD" property. (Section 10.1)
DECREED - Some access rights are not changeable by the CUA. When
that is the case, the "DECREED" property value in the "VCAR"
component will be "TRUE". (Section 8.10)
DEFAULT-CHARSET - The list of charsets supported by the CS. The
first entry is the default for the CS. (Section 8.11)
DEFAULT-LOCALE - The list of locales supported by the CS. The first
entry in the list is the default locale. (Section 8.12)
DEFAULT-TZID - This is the list of known timezones supported. The
first entry is the default. (Section 8.13)
DEFAULT-VCARS - A list of the "CARID" properties that will be used
to create new calendars. (Section 8.14)
DENY - The UPNs listed in the "DENY" property of a "VCAR" component
will be denied access, as described in the "VRIGHT" component.
(Section 8.15)
EXPAND - This property tells the CS if the query reply should expand
components into multiple instances. The default is "FALSE" and is
ignored for CSs that cannot expand recurrence rules. (Section
8.16)
GRANT - The UPNs listed in the "GRANT" property of a "VCAR"
component will be allowed access as described in the "VRIGHT"
component. (Section 8.17)
ITIP-VERSION - The version of [iTIP] supported. (Section 8.18)
MAXDATE - The maximum date supported by the CS. (Section 8.20)
MAX-COMP-SIZE - The largest component size allowed in the
implementation including attachments in octets. (Section 8.19)
MINDATE - The minimum date supported by the CS. (Section 8.21)
MULTIPART - Passed in the capability messages to indicate which MIME
multipart types the sender supports. (Section 8.22)
NAME - The "NAME" property is used to add locale-specific
descriptions into components. (Section 8.23)
OWNER - Each calendar has at least one "OWNER" property. (xref
target="OWNER"/>) Related to the "CAL-OWNERS()" query clause.
(Section 6.1.1.1)
PERMISSION - This property specifies the permission being granted or
denied. Examples are the "SEARCH" and "MODIFY" values. (Section
8.25)
QUERY - Used to hold the CAL-QUERY (Section 8.26) for the component.
QUERYID - A unique id for a stored query. (Section 8.27)
QUERY-LEVEL - The level of the query language supported. (Section
8.28)
RECUR-ACCEPTED - If the implementation support recurrence rules.
(Section 8.29)
RECUR-EXPAND - If the implementation support expanding recurrence
rules. (Section 8.31)
RECUR-LIMIT - Any maximum limit on the number of instances the
implementation will expand recurring objects. (Section 8.30)
REQUEST-STATUS - The [iCAL] "REQUEST-STATUS" property is extended to include new error numbers. RESTRICTION - In the final check when granting calendar access requests, the CS test the results of a command for the value of the "RESTRICTION" property in the corresponding "VRIGHT" component, to determine if the access meets that restriction. (Section 8.32) SCOPE - The "SCOPE" property is used in "VRIGHT"s component to select the subset of data that may be acted upon when checking access rights. (Section 8.33) SEQUENCE - When the "SEQUENCE" property is used in a "VALARM" component, it uniquely identifies the instances of the "VALARM" within that component. STORES-EXPANDED - Specifies if the implementation stores recurring objects expanded or not. (Section 8.34) TARGET - The new "VCALENDAR" component property "TARGET" (Section 8.35) is used to specify which calendar(s) will be the subject of the CAP command. TRANSP - This is a modification of the [iCAL] "TRANSP" property and it allows more values. The new values are related to conflict control. (Section 8.36)2.1.3. New Components (summary)
VAGENDA - CAP allows the fetching and storing of the entire contents of a calendar. The "VCALENDAR" component is not sufficient to encapsulate all of the needed data that describes a calendar. The "VAGENDA" component is the encapsulating object for an entire calendar. (Section 9.1) VCALSTORE - Each CS contains one or more calendars (VAGENDAs), the "VCALSTORE" component is the encapsulating object that can hold all of the "VAGENDA" components along with any components and properties that are unique to the store level. (Section 9.2) VCAR - Calendar Access Rights are specified and encapsulated in the new iCalendar "VCAR" component. The "VCAR" component holds some new properties and at least one "VRIGHT" component. (Section 9.3) VRIGHT - This component encapsulates a set of instructions to the CS to define the rights or restrictions needed. (Section 9.4)
VREPLY - This component encapsulates a set of data that can consist
of an arbitrary number of properties and components. Its contents
are dependent on the command that was issued. (Section 9.5)
VQUERY - The search operation makes use of a new component, called
"VQUERY" and a new value type "CAL-QUERY" (Section 6.1.1). The
"VQUERY" component is used to fetch objects from the CS. (Section
9.6)
2.2. Relationship of RFC-2446 (ITIP) to CAP
[iTIP] describes scheduling methods that result in indirect
manipulation of components. In CAP, the "CREATE" command is used to
deposit entities into the store. Other CAP commands, such as
"DELETE", "MODIFY", and "MOVE" command values, provide direct
manipulation of components. In the CAP calendar store model,
scheduling messages are conceptually kept separate from other
components by their state.
All scheduling operations are as defined in [iTIP]. This memo makes
no changes to any of the methods or procedures described in [iTIP].
In this memo, referring to the presence of the "METHOD" property in
an object is the same as saying an [iTIP] object.
A CUA may create a "BOOKED" state object by depositing an iCalendar
object into the store. This is done by depositing an object that
does not have a "METHOD" property. The CS then knows to set the
state of the object to the "BOOKED" state. If the object has a
"METHOD" property, then the object is stored in the "UNPROCESSED"
state.
If existing "UNPROCESSED" state objects exist in the CS for the same
UID (UID is defined in [iCAL]), then a CUA may wish to consolidate
the objects into one "BOOKED" state object. The CUA would fetch the
"UNPROCESSED" state objects for that UID and process them in the CUA
as described in [iTIP]. Then, if the CUA wished to book the UID, the
CUA would issue a "CREATE" command to create the new "BOOKED" state
object in the CS, followed by a "DELETE" command to remove any
related old [iTIP] objects from the CS. It might also involve the
CUA sending some [iMIP] objects or contacting other CSs and
performing CAP operations on those CSs.
The CUA could also decide not to book the object. In this case, the
"UNPROCESSED" state objects could be removed from the CS, or the CUA
could set those objects to the marked-for-delete state. The CUA
could also ignore objects for later processing.
The marked-for-delete state is used to keep the object around so that the CUA can process duplicate requests automatically. If a duplicate [iTIP] object is deposited into the CS and there exists identical marked-for-delete objects, then a CUA acting on behalf of the "OWNER" can silently drop those duplicate entries. Another purpose for the marked-for-delete state is so that, when a CU decides they do not wish to have the object show in their calendar, the CUA can book the object by changing the "PARTSTAT" parameter to "DECLINED" in the "ATTENDEE" property that corresponds to their UPN. Then the CUA can perform [iTIP] processing such as sending back a decline, and then mark that object as marked-fo-delete. The CUA might be configurable to automatically drop any updates for that object, knowing the CU has already declined. When synchronizing with multiple CUAs, the marked-for-delete state could be used to inform the synchronization process that an object is to be deleted. How synchronization is done is not specified in this memo. Several "UNPROCESSED" state entries can be in the CS for the same UID. However, once consolidated, only one object exists in the CS and that is the booked object. The other objects MUST be removed or have their state changed to "DELETED". There MUST NOT be more than one "BOOKED" state object in a calendar for the same "UID". The "ADD" method value may create multiple objects in the "BOOKED" state for the same UID; however, for the purpose of this memo, they are the same object and simply have multiple "VCALENDAR" components. For example, if you were on vacation, you could have received a "REQUEST" method to attend a meeting and several updates to that meeting. Your CUA would have to issue "SEARCH" commands to find them in the CS using CAP, process them, and determine the final state of the object from a possible combination of user input and programmed logic. Then the CUA would instruct the CS to create a new booked object from the consolidated results. Finally, the CUA could do a "DELETE" command to remove the related "UNPROCESSED" state objects. See [iTIP] for details on resolving multiple [iTIP] scheduling entries.