Calendaring and Scheduling                                      D. Royer
Internet-Draft                                           INET-Consulting
Expires: July 12, November 14, 2004                                     G. Babics
                                                                  Oracle
                                                                 P. Hill
                                              Massachusetts Institute of
                                                              Technology
                                                              S. Mansour
                                                            AOL/Netscape
                                                        January 12,
                                                            May 16, 2004

                     Calendar Access Protocol (CAP)
                        draft-ietf-calsch-cap-12
                        draft-ietf-calsch-cap-13

Status of this Memo

   This document is an Internet-Draft and is in full conformance with
   all provisions of Section 10 of RFC2026.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups. Note that other
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   http://www.ietf.org/shadow.html.

   This Internet-Draft will expire on July 12, November 14, 2004.

Copyright Notice

   Copyright (C) The Internet Society (2004). All Rights Reserved.

Abstract

   The Calendar Access Protocol (CAP) is an Internet protocol described
   in this memo that permits a Calendar User (CU) to utilize a Calendar
   User Agent (CUA) to access an [iCAL] based Calendar Store (CS).

   The CAP definition is based on requirements identified by the
   Internet Engineering Task Force (IETF) Calendaring and Scheduling
   (CALSCH) Working Group. More information about the IETF CALSCH
   Working Group activities can be found on the IMC web site at http://
   www.imc.org/ietf-calendar and at the IETF web site at http://
   www.ietf.org/html.charters/calsch-charter.html [1]. Refer to the
   references within this memo for further information on how to access
   these various documents.

Table of Contents

   1.      Introduction . . . . . . . . . . . . . . . . . . . . . .    5
   1.1     Formatting Conventions . . . . . . . . . . . . . . . . .    5
   1.2     Related Documents  . . . . . . . . . . . . . . . . . . .    6
   1.3     Definitions  . . . . . . . . . . . . . . . . . . . . . .    7
   2.      Additions to iCalendar . . . . . . . . . . . . . . . . .   12
   2.1     New Value Types (summary)  . . . . . . . . . . . . . . .   14
   2.1.1   New Parameters (summary) . . . . . . . . . . . . . . . .   14
   2.1.2   New or Updated Properties (summary)  . . . . . . . . . . . . . . . .   15
   2.1.3   New Components (summary) . . . . . . . . . . . . . . . .   17
   2.2     Relationship of RFC-2446 (ITIP) and 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 . . . . . . . . . . . . . . . . . . . . .   24
   4.1     Calendar User and UPNs . . . . . . . . . . . . . . . . .   24
   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 . . . . . . . . . . . . . . . . . .   29
   5.      CAP URL and Calendar Address . . . . . . . . . . . . . .   31
   6.      New Value Types  . . . . . . . . . . . . . . . . . . . .   33
   6.1     Property Value Data Types  . . . . . . . . . . . . . . .   33
   6.1.1   CAL-QUERY Value Type . . . . . . . . . . . . . . . . . .   33
   6.1.2   UPN Value Type . . . . . . . . . . . . . . . . . . . . .   48
   6.1.3   UPN-FILTER Value . . . . . . . . . . . . . . . . . . . .   49
   7.      New Parameters . . . . . . . . . . . . . . . . . . . . .   52
   7.1     ACTION Parameter . . . . . . . . . . . . . . . . . . . .   52
   7.2     ENABLE Parameter . . . . . . . . . . . . . . . . . . . .   52
   7.3     ID Parameter . . . . . . . . . . . . . . . . . . . . . .   53
   7.4     LATENCY Parameter  . . . . . . . . . . . . . . . . . . .   54
   7.5     LOCAL Parameter  . . . . . . . . . . . . . . . . . . . .   55
   7.6     LOCALIZE Parameter . . . . . . . . . . . . . . . . . . .   55
   7.7     OPTIONS Parameter  . . . . . . . . . . . . . . . . . . .   56
   8.      New Properties . . . . . . . . . . . . . . . . . . . . .   58
   8.1     ALLOW-CONFLICT Property  . . . . . . . . . . . . . . . .   58
   8.2     ATT-COUNTER Property . . . . . . . . . . . . . . . . . .   58
   8.3     CALID Property . . . . . . . . . . . . . . . . . . . . .   59
   8.4     CALMASTER Property . . . . . . . . . . . . . . . . . . .   60
   8.5     CAP-VERSION Property . . . . . . . . . . . . . . . . . .   60
   8.6     CARID Property . . . . . . . . . . . . . . . . . . . . .   61
   8.7     CAR-LEVEL Property . . . . . . . . . . . . . . . . . . .   61
   8.8     COMPONENTS Property  . . . . . . . . . . . . . . . . . .   62
   8.9     CSID Property  . . . . . . . . . . . . . . . . . . . . .   64
   8.10    DECREED Property . . . . . . . . . . . . . . . . . . . .   64
   8.11    DEFAULT-CHARSET Property . . . . . . . . . . . . . . . .   65
   8.12    DEFAULT-LOCALE Property  . . . . . . . . . . . . . . . .   66
   8.13    DEFAULT-TZID Property  . . . . . . . . . . . . . . . . .   67
   8.14    DEFAULT-VCARS Property . . . . . . . . . . . . . . . . .   68
   8.15    DENY Property  . . . . . . . . . . . . . . . . . . . . .   69
   8.16    EXPAND property  . . . . . . . . . . . . . . . . . . . .   69
   8.17    GRANT Property . . . . . . . . . . . . . . . . . . . . .   70
   8.18    ITIP-VERSION Property  . . . . . . . . . . . . . . . . .   71
   8.19    MAX-COMP-SIZE Property . . . . . . . . . . . . . . . . .   71
   8.20    MAXDATE Property . . . . . . . . . . . . . . . . . . . .   72
   8.21    MINDATE Property . . . . . . . . . . . . . . . . . . . .   73
   8.22    MULTIPART Property . . . . . . . . . . . . . . . . . . .   73
   8.23    NAME Property  . . . . . . . . . . . . . . . . . . . . .   74
   8.24    OWNER Property . . . . . . . . . . . . . . . . . . . . .   75
   8.25    PERMISSION Property  . . . . . . . . . . . . . . . . . .   75
   8.26    QUERY property . . . . . . . . . . . . . . . . . . . . .   76
   8.27    QUERYID property . . . . . . . . . . . . . . . . . . . .   77
   8.28    REQUEST-STATUS property  . . . . . . . . . . . . . . . .   78
   8.29    QUERY-LEVEL Property . . . . . . . . . . . . . . . . . .   79
   8.30    RECUR-ACCEPTED Property  . . . . . . . . . . . . . . . .   79
   8.31    RECUR-LIMIT Property . . . . . . . . . . . . . . . . . .   80
   8.32    RECUR-EXPAND Property  . . . . . . . . . . . . . . . . .   81
   8.33    RESTRICTION Property . . . . . . . . . . . . . . . . . .   81
   8.34    SCOPE Property . . . . . . . . . . . . . . . . . . . . .   82
   8.35    STORES-EXPANDED Property . . . . . . . . . . . . . . . .   83
   8.36    TARGET Property  . . . . . . . . . . . . . . . . . . . .   84
   8.37    TRANSP Property  . . . . . . . . . . . . . . . . . . . .   84
   9.      New Components . . . . . . . . . . . . . . . . . . . . .   86
   9.1     VAGENDA Component  . . . . . . . . . . . . . . . . . . .   86
   9.2     VCALSTORE Component  . . . . . . . . . . . . . . . . . .   88
   9.3     VCAR Component . . . . . . . . . . . . . . . . . . . . .   89
   9.4     VRIGHT Component . . . . . . . . . . . . . . . . . . . .   92
   9.5     VREPLY Component . . . . . . . . . . . . . . . . . . . .   93
   9.6     VQUERY Component . . . . . . . . . . . . . . . . . . . .   93
   10.     Commands and Responses . . . . . . . . . . . . . . . . .   95
   10.1    CAP Commands (CMD) . . . . . . . . . . . . . . . . . . .   95
   10.1.1  Bounded Latency  . . . . . . . . . . . . . . . . . . . .   96
   10.2    ABORT Command  . . . . . . . . . . . . . . . . . . . . .   98
   10.3    CONTINUE Command . . . . . . . . . . . . . . . . . . . .   99
   10.4    CREATE Command . . . . . . . . . . . . . . . . . . . . .  100
   10.5    DELETE Command . . . . . . . . . . . . . . . . . . . . .  105
   10.6    GENERATE-UID Command . . . . . . . . . . . . . . . . . .  108
   10.7    GET-CAPABILITY Command . . . . . . . . . . . . . . . . .  110
   10.8    IDENTIFY Command . . . . . . . . . . . . . . . . . . . .  112
   10.9    MODIFY Command . . . . . . . . . . . . . . . . . . . . .  115
   10.10   MOVE Command . . . . . . . . . . . . . . . . . . . . . .  119
   10.11   REPLY Response to a Command  . . . . . . . . . . . . . .  121
   10.12   SEARCH Command . . . . . . . . . . . . . . . . . . . . .  122
   10.12.1 Searching for VFREEBUSY  . . . . . . . . . . . . . . . .  125
   10.13   SET-LOCALE Command . . . . . . . . . . . . . . . . . . .  126
   10.14   TIMEOUT Command  . . . . . . . . . . . . . . . . . . . .  127
   10.15   Response Codes . . . . . . . . . . . . . . . . . . . . .  128
   11.     Object Registration  . . . . . . . . . . . . . . . . . .  131
   11.1    Registration of New and Modified Entities  . . . . . . .  131
   11.2    Post the item definition . . . . . . . . . . . . . . . .  131
   11.3    Allow a comment period . . . . . . . . . . . . . . . . .  131
   11.4    Release a new RFC  . . . . . . . . . . . . . . . . . . .  131
   12.     BEEP and CAP . . . . . . . . . . . . . . . . . . . . . .  132
   12.1    BEEP Profile Registration  . . . . . . . . . . . . . . .  132
   12.2    BEEP Exchange Styles . . . . . . . . . . . . . . . . . .  134
   12.3    BEEP connection details  . . . . . . . . . . . . . . . .  134
   13.     IANA Considerations  . . . . . . . . . . . . . . . . . .  135  137
   14.     Security Considerations  . . . . . . . . . . . . . . . .  136  138
           Authors' Addresses . . . . . . . . . . . . . . . . . . .  137  139
   A.      Acknowledgments  . . . . . . . . . . . . . . . . . . . .  139  141
   B.      Bibliography . . . . . . . . . . . . . . . . . . . . . .  140  142
           Intellectual Property and Copyright Statements . . . . .  142  144

1. Introduction

   This document specifies how a Calendar CUA interacts with a CS to
   manage calendar information. In particular, it 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 and believed to be possible using CAP.

   CAP is specified as a [BEEP] "profile". As such, many aspects of the
   protocol (e.g., authentication and privacy) are provided within
   [BEEP].  The protocol data units leverage the standard iCalendar
   format [iCAL] to convey calendar related information.

   CAP can also be used to store and fetch [iTIP] objects and when those
   objects are used in this memo, they mean exactly the same as defined
   in [iTIP]. When iCalendar objects are transferred between the CUA and
   a CS, some additional properties and parameters may be added and the
   CUA is responsible for correctly generating iCalendar objects to non
   CAP processes.

   The definition of new components, properties, parameter's, and value
   types are broken into two parts. The first part summarizes and
   defines the new objects. The second part provides the detail and any
   ABNF for those objects. The ABNF in CAP as in other iCalendar
   specifications is 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 [RFCWORDS].

   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. Example, The "SELECT" clause 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:

   [iCAL] -  (RFC2445) Which specifies the objects, data types,
      properties and property parameters used in the protocols, along
      with the methods for representing and encoding them.

   [iTIP] -  (RFC2446) Which specifies an interoperability protocol for
      scheduling between different installations.

   [iMIP] -  (RFC2447) Which specifies the Internet email binding for
      [iTIP].

   [GUIDE] -  (RFC3283),  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 other memos. Where possible, references
   are made to the memo that provides for the specification of these
   concepts and definitions.

1.3 Definitions

   BOOKED -  An object in the calendar store has one of three conceptual
      states. It is in the "UNPROCESSED" state, "BOOKED" state, or
      marked for deletion which is the "DELETED" state. How the
      implementation stores the state of any object is not a protocol
      issues and is not discussed. An object can be said to be booked,
      unprocessed, or marked for delete.

      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. All [iTIP] objects
          in the store are not 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 delete objects. You can not
          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 standard 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")
      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 - they are one in the same
      for CAP addresses. 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 of 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 definition 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 calendar 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. A "VALARM"
      component for example may be contained inside of 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 Attendee 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 also might 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 my
      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 which 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 which 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 CU. (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.

   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]

   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

   In addition a problem exists with the control of "VALARM" components
   and their "TRIGGER" properties. A CU may wish to set their own alarm
   (local alarms) on components. These local alarms are not to be
   forwarded to other CUs, CUAs, or CSs as are the "SEQUENCE" property
   and the "ENABLE" parameter. So for the protocol between a CUA and a
   CS, the following changes apply to the CAP protocol from [iCAL]
   section 4.6.6 page 67:

     alarmc     = "BEGIN" ":" "VALARM" CRLF
               alarm-seq
                  other-props
               (audioprop / dispprop / emailprop / procprop)
               "END" ":" "VALARM" CRLF

    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-param)

    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 allow 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)

   Section 7.2 and Section 7.5.

2.1 New Value Types (summary)

   UPN The UPN value type is text value type restricted to only UPN
      values. (Section 6.1.2)

   UPN-FILTER Like the UPN value type, but also includes filter rules
      that allow wildcards. (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. (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 the implementation supports.
      (Section 8.5)

   CAR-LEVEL -  The level of calendar access level 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 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 can not expand recurrence rules. (Section
      8.16)

   GRANT -  The UPNs listed in the "GRANT" property of a "VCAR"
      component will 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()" (Section 6.1.1.1)
      query clause.

   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
      8.29)
   RECUR-ACCEPTED -  If the implementation support recurrence rules.
      (Section 8.30)

   RECUR-EXPAND -  If the implementation support expanding recurrence
      rules. (Section 8.32)

   RECUR-LIMIT -  Any maximum limit on the number of instances the
      implementation will expand recurring objects. (Section 8.31)

   REQUEST-STATUS -  The [iCAL] "REQUEST-STATUS" property is extended to
      include new error numbers. (Section 8.28)

   RESTRICTION -  In the final check when granting calendar access
      requests, the CS test the results to the value of the
      "RESTRICTION" property in the corresponding "VRIGHT" component to
      determine if the access meets that restriction. (Section 8.33)

   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 8.34)

   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
      object expanded or not. (Section 8.35)

   TARGET -  The new "VCALENDAR" component property "TARGET" (Section
      8.36) is used to specify which calendar(s) will be the subject of
      the CAP command.

   TRANSP -  This is a modification the [iCAL] "TRANSP" property and it
      allows more values. The new values are related to conflict
      control. (Section 8.37)

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
      that define the rights or restrictions needed. (Section 9.4)

   VREPLY -  This component encapsulates a set of data that can consist
      of an arbitrary amounts of properties and components. Its contents
      is 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) and CAP

   [iTIP] describes scheduling methods which 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 then a CUA may wish to consolidate the objects in to 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. And it might also involve having the CUA send 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 which case the
   "UNPROCESSED" state objects could be removed from the CS or the CUA
   could set those object 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; changing the "PARTSTAT" parameter to
   "DECLINED" in the "ATTENDEE" property that corresponds to their UPN.
   Then perform an [iTIP] processing such as sending back a decline.
   Then mark that object as marked for delete. Their 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, then only one object exists in the CS
   and that is the booked object. The others 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 all in the "BOOKED" state for the same UID, however for the
   purpose of this memo, they are the same object that 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, determine what 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.

3. CAP Design

3.1 System Model

   The system model describes the high level components of a calendar
   system and how they interact with each other.

   CAP is used by a CUA to send commands to and receive responses from a
   CS.

   The CUA prepares a [MIME] encapsulated command, sends it to the CS,
   and receives a [MIME] encapsulated response. The calendaring related
   information within these messages are represented by iCalendar
   objects. In addition the "GET-CAPABILITY" command can be sent from
   the CS to the CUA.

   There are two distinct protocols in operation to accomplish this
   exchange. [BEEP] is the transport protocol used to move these
   encapsulations between a CUA and a CS. CAP's [BEEP] profile defines
   the application protocol where the content and semantics of the
   messages sent between the CUA and the CS are specified.

3.2 Calendar Store Object Model

   [iCAL] describes components such as events, todos, alarms, and
   timezones. [CAP] requires additional object infrastructure. In
   particular,  detailed definitions of the containers for events and
   todos (calendars), access control objects, and a query language.

   The conceptual model for a calendar store is shown below. The
   calendar store (VCALSTORE - Section 9.2) contains "VCAR"s, "VQUERY"s,
   "VTIMEZONE"s, "VAGENDA"s and calendar store properties.

   Calendars (VAGENDAs) contain "VEVENT"s, "VTODO"s, "VJOURNAL"s,
   "VCAR"s, "VTIMEZONE"s, "VFREEBUSY", "VQUERY"s and calendar
   properties.

   The component "VCALSTORE" is used to denote the a root of the
   calendar store and contains all of the calendars.

   Calendar Store

   VCALSTORE
   |
   +-- properties
   +-- VCARs
   +-- VQUERYs
   +-- VTIMEZONEs
   +-- VAGENDA
   |     |
   |     +--properties
   |     +--VEVENTs
   |     |    |
   |     |    +--VALARMs
   |     +--VTODOs
   |     |    |
   |     |    +--VALARMs
   |     +--VJOURNALs
   |     +--VCARs
   |     +--VTIMEZONEs
   |     +--VQUERYs
   |     +--VFREEBUSYs
   |     |
   |     |   ...
   .
   .
   +-- VAGENDA
   .     .
   .     .
   .     .

   Calendars within a Calendar Store are identified by their unique
   Relative CALID.

3.3 Protocol Model

   CAP uses [BEEP] as the transport and authentication protocol.

   The initial charset MUST BE UTF-8 for the session in an unknown
   locale. If the CS supplied the [BEEP] 'localize' attribute in the
   [BEEP] 'greeting' then the CUA may tell the CS to switch locales for
   the session by issuing the "SET-LOCALE" CAP command and supplying one
   of the locales supplied by the [BEEP] 'localize' attribute. If
   supplied the first locale in the [BEEP] 'localize' attribute is the
   default locale of the CS. The locale is switched only after a
   successful reply.

   The "DEFAULT-CHARSET" property of the CS contains the list of
   charsets supported by the CS with the first value being the default
   for new calendars. If the CUA wishes to switch to one of those
   charsets for the session, the CUA issues the "SET-LOCALE" command.
   The CUA would have to first perform a "GET-CAPABILITY" command on the
   CS to get the list of charsets supported by the CS. The charset is
   switched only after a successful reply.

   The CUA may switch locales and charsets as needed. There is no
   requirement that a CS support multiple locales or charsets.

3.3.1 Use of BEEP, MIME and iCalendar

   CAP uses the [BEEP] application protocol over TCP. (refer to [BEEP]
   and [BEEPTCP] for more information). The default port that the CS
   listens for connections is on user port 1026.

   The [BEEP] data exchanged in CAP is a iCalendar MIME content that
   fully conforms to [iCAL] iCalendar format.

   This example tells the CS to generate and return 10 UIDs to be used
   by the CUA. Note throughout this memo, 'C:' refers to what the CUA
   sends, 'S:' refers to what the CS sends, 'I:' refers to what the
   initiator sends, and 'L:' refers to what the listener sends. Where
   initiator and listener are used as defined in [BEEP].

   C: MSG 1 2 . 432 62
   C: Content-Type: text/calendar
   C:
   C: BEGIN:VCALENDAR
   C: VERSION:2.0
   C: PRODID:-//someone's prodid
   C: CMD;ID=unique-per-cua-123;OPTIONS=10:GENERATE-UID
   C: END:VCALENDAR

   NOTE: The following examples will not include the [BEEP] header and
   footer information. Only the iCalendar objects that are sent between
   the CUA and CS will be shown as the [BEEP] payload boundaries are
   independent of CAP.

   The commands listed below are used to manipulate or access the data
   on the calendar store:

   ABORT -  Sent to halt the processing of some of the commands.
      (Section 10.2)

   CONTINUE -  Sent to continue processing a command that has had its
      specified timeout time reached. (Section 10.3)

   CREATE -  Create a new object on the CS. Initiated by the CUA only.
      (Section 10.4)
   SET-LOCALE -  Tell the CS to use any named locale and charset
      supplied. Initiated by the CUA only. (Section 10.13)

   DELETE -  Delete objects from the CS. Initiated by the CUA only. Can
      also be used to mark an object for deletion. (Section 10.5)

   GENERATE-UID -  Generate one or more unique ids. Initiated by the CUA
      only. (Section 10.6)

   GET-CAPABILITY - Query the capabilities the other end point of the
      session. (Section 10.7)

   IDENTIFY -  Set a new identity for the session. Initiated by the CUA
      only. (Section 10.8)

   MODIFY -  Modify components. Initiated by the CUA only. (Section
      10.9)

   MOVE -  Move components to another container. Initiated by the CUA
      only. (Section 10.10)

   REPLY -  When replying to a command, the "CMD" value will be set to
      "REPLY" so that it will not be confused with a new command.
      (Section 10.11)

   SEARCH -  Search for components. Initiated by the CUA only. (Section
      10.12)

   TIMEOUT -  Sent when a specified amount of time has lapsed and a
      command has not finished. (Section 10.14)

4. Security Model

   The [BEEP] transport performs all session authentication.

4.1 Calendar User and UPNs

   A CU is an entity that can be authenticated. It is represented in CAP
   as a UPN, which is a key part of access rights.  The UPN
   representation is independent of the authentication mechanism used
   during a particular CUA/CS interaction. This is because UPNs are used
   within VCARs. If the UPN were dependent on the authentication
   mechanism, a VCAR could not be consistently evaluated. A CU may use
   one mechanism while using one CUA but the same CU may use a different
   authentication mechanism when using a different CUA, or while
   connecting from a different location.

   The user may also have multiple UPNs for various purposes.

   Note that the immutability of the user's UPN may be achieved by using
   SASL's authorization identity feature. (The transmitted authorization
   identity may be different than the identity in the client's
   authentication credentials.) [SASL, section 3]. This also permits a
   CU to authenticate using their own credentials, yet request the
   access privileges of the identity for which they are proxying SASL.
   Also, the form of authentication identity supplied by a service like
   TLS may not correspond to the UPNs used to express a server's access
   rights, requiring a server specific mapping to be done. The method by
   which a server determines a UPN, based on the authentication
   credentials supplied by a client, is implementation specific. See
   [BEEP] for authentication details; [BEEP] relies on SASL.

4.1.1 UPNs and Certificates

   When using X.509 certificates for purposes of CAP authentication, the
   UPN should appear in the certificate. Unfortunately there is no
   single correct guideline for which field should contain the UPN.

   From RFC-2459, section 4.1.2.6 (Subject):

      If subject naming information is present only in the
      subjectAlt-Name extension (e.g., a key bound only to an email
      address or URI), then the subject name MUST be an empty sequence
      and the subjectAltName extension MUST BE critical.

      Implementations of this specification MAY use these comparison
      rules to process unfamiliar attribute types (i.e., for name
      chaining). This allows implementations to process certificates
      with unfamiliar attributes in the subject name.

      In addition, legacy implementations exist where an RFC 2822 name
      is embedded in the subject distinguished name as an EmailAddress
      attribute.  The attribute value for EmailAddress is of type
      IA5String to permit inclusion of the character '@', which is not
      part of the PrintableString character set. EmailAddress attribute
      values are not case sensitive (e.g., "fanfeedback@redsox.com" is
      the same as "FANFEEDBACK@REDSOX.COM").

      Conforming implementations generating new certificates with
      electronic mail addresses MUST use the rfc822Name in the subject
      alternative name field (see sec. 4.2.1.7 of [X509CRL]) to describe
      such identities. Simultaneous inclusion of the EmailAddress
      attribute in the subject distinguished name to support legacy
      implementations is deprecated but permitted.

   Since no single method of including the UPN in the certificate will
   work in all cases, CAP implementations MUST support the ability to
   configure what the mapping will be by the CS administrator.
   Implementations MAY support multiple mapping definitions, for
   example, the UPN may be found in either the subject alternative name
   field, or the UPN may be embedded in the subject distinguished name
   as an EmailAddress attribute.

   Note: If a CS or CUA is validating data received via [iMIP], if the
   "ORGANIZER" or "ATTENDEE" properties said (e.g.) "ATTENDEE;CN=Joe
   Random User:MAILTO:juser@example.com" then the email address should
   be checked against the UPN. This is so the "ATTENDEE" property cannot
   be changed to something misleading like "ATTENDEE;CN=Joe Rictus
   User:MAILTO:jrictus@example.com" and have it pass validation. Note
   that it is the email addresses that miscompare, the CN miscompare is
   irrelevant.

4.1.2 Anonymous Users and Authentication

   Anonymous access is often desirable. For example an organization may
   publish calendar information that does not require any access control
   for viewing or login. Conversely, a user may wish to view
   unrestricted calendar information without revealing their identity.

4.1.3 User Groups

   A User Group is used to represent a collection of CUs or other UGs
   that can be referenced in VCARs. A UG is represented in CAP as a UPN.
   The CUA cannot distinguish between a UPN that represents a CU or a
   UG.

   UGs are expanded as necessary by the CS. The CS MAY expand a UG
   (including nested UGs) to obtain a list of unique CUs. Duplicate UPNs
   are filtered during expansion.

   How the UG expansion is maintained across commands is implementation
   specific. A UG may reference a static list of members, or it may
   represent a dynamic list. Operations SHOULD recognize changes to UG
   membership.

   CAP does not define commands or methods for managing UGs.

4.2 Access Rights

   Access rights are used to grant or deny access to calendars,
   components, properties, and parameters in a CS to a CU. CAP defines a
   new component type called a Calendar Access Right (VCAR).
   Specifically, a "VCAR" component grants, or denies, UPNs the right to
   search and write components, properties, and parameters on calendars
   within a CS.

   The "VCAR" component model does not put any restriction on the
   sequence in which the object and access rights are created. That is,
   an object associated with a particular "VCAR" component might be
   created before or after the actual "VCAR" component is defined. In
   addition, the "VCAR" and "VEVENT" components might be created in the
   same iCalendar object and passed together in a single object.

   All rights MUST BE denied unless specifically granted.

   If two rights specified in "VCAR" components are in conflict, the
   right that denies access always takes precedence over the right that
   grants access. Any attempt to create a "VCAR" component that
   conflicts with a "VCAR" components with a "DECREED" property set to
   the "TRUE" value must fail.

4.2.1 Access Control and NOCONFLICT

   The "TRANSP" property can take on values "TRANSPARENT-NOCONFLICT" and
   "OPAQUE-NOCONFLICT" that prohibit other components from overlapping
   it. This setting overrides access. The "ALLOW-CONFLICT" CS, Calendar
   or component setting may also prevent overlap, returning an error
   code "6.3".

4.2.2 Predefined VCARs

   Predefined calendar access CARIDs that MUST BE implemented are:

   CARID:READBUSYTIMEINFO -  Specifies the "GRANT" and "DENY" rules that
      allow UPNs to search "VFREEBUSY" components. An example definition
      for this VCAR is:

    BEGIN:VCAR
    CARID:READBUSYTIMEINFO
    BEGIN:VRIGHT
    GRANT:*
    PERMISSION:SEARCH
    SCOPE:SELECT * FROM VFREEBUSY WHERE STATE() = 'BOOKED'
    END:VRIGHT
    END:VCAR

   CARID:REQUESTONLY -  Specifies the "GRANT" and "DENY" rules to UPNs
      other than the owner of the calendar the ability to write new
      objects with the property "METHOD" property set to the "REQUEST"
      value. This CARID allows the owner to specify which UPNs are
      allowed to make scheduling requests. An example definition for
      this VCAR is:

    BEGIN:VCAR
    CARID:REQUESTONLY
    BEGIN:VRIGHT
    GRANT:NON CAL-OWNERS()
    PERMISSION:CREATE
    RESTRICTION:SELECT VEVENT FROM VAGENDA WHERE METHOD = 'REQUEST'
    RESTRICTION:SELECT VTODO FROM VAGENDA WHERE METHOD = 'REQUEST'
    RESTRICTION:SELECT VJOURNAL FROM VAGENDA WHERE METHOD = 'REQUEST'
    END:VRIGHT
    END:VCAR

   CARID:UPDATEPARTSTATUS -  Grants to authenticated users the right to
      modify the instances of the "ATTENDEE" property set to one of
      their calendar addresses in any components for any booked
      component containing an "ATTENDEE" property. This allows (or
      denies) a CU the ability to update their own participation status
      in a calendar where they might not otherwise have "MODIFY" command
      access. They are not allowed to change the "ATTENDEE" property
      value. An example definition for this VCAR is (This example only
      affects the "VEVENT" components):

    BEGIN:VCAR
    CARID:UPDATEPARTSTATUS
    BEGIN:VRIGHT
    GRANT:*
    PERMISSION:MODIFY
    SCOPE:SELECT ATTENDEE FROM VEVENT
     WHERE ATTENDEE = SELF()
     AND ORGANIZER = CURRENT-TARGET()
     AND STATE() = 'BOOKED'
    RESTRICTION:SELECT * FROM VEVENT
     WHERE ATTENDEE = SELF()
    END:VRIGHT
    END:VCAR

   CARID:DEFAULTOWNER -  Grants to any owner the permission they have
      for the target. An example definition for this VCAR is:

    BEGIN:VCAR
    CARID:DEFAULTOWNER
    BEGIN:VRIGHT
    GRANT:CAL-OWNERS()
    PERMISSION:*
    SCOPE:SELECT * FROM VAGENDA
    END:VRIGHT
    END:VCAR

4.2.3 Decreed VCARs

   A CS MAY choose to implement and allow persistent immutable VCARs
   that may be configured by the CS administrator. A reply from the CS
   may dynamically create "VCAR" components that are decreed depending
   on the implementation. To the CUA any "VCAR" component with the
   "DECREED" property set to "TRUE" can not be changed by the currently
   authenticated UPN, and depending on the implementation and other
   "VCAR" components; might not be able to be changed by any UPN using
   CAP, and never when the CUA gets a "DECREED:TRUE" VCAR.

   When a user attempts to modify or override a decreed "VCAR" component
   rules an error will be returned indicating that the user has
   insufficient authorization to perform the operation. The reply to the
   CUA MUST BE the same as if a non-decreed VCAR caused the failure.

   The CAP protocol does not define the semantics used to initially
   create a decreed VCAR. This administrative task is outside the scope
   of the CAP protocol.

   For example; an implementation or a CS administrator may wish to
   define a VCAR that will always allow the calendar owners to have full
   access to their own calendars.

   Decreed "VCAR" components MUST BE readable by the calendar owner in
   standard "VCAR" component format.

4.3 CAP Session Identity

   A [BEEP] session has an associated set of authentication credentials,
   from which is derived a UPN. This UPN is the identity of the CAP
   session, and is used to determine access rights for the session.

   The CUA may change the identity of a CAP session by calling the
   "IDENTIFY" command. The CS only permits the operation if the
   session's authentication credentials are good for the requested
   identity. The method of checking this permission is implementation
   dependent, but may be thought of as a mapping from authentication
   credentials to UPNs. The "IDENTIFY" command allows a single set of
   authentication credentials to choose from multiple identities, and
   allows multiple sets of authentication credentials to assume the same
   identity.

   For anonymous access the identity of the session is "@". A UPN with a
   null Username and null Realm is anonymous. A UPN with a null
   Username, but non-null Realm, such as "@foo.com" may be used to mean
   any identity from that Realm, which is useful to grant access rights
   to all users in a given Realm. A UPN with a non-null Username and
   null Realm, such as "bob@" could be a security risk and MUST NOT be
   used.

   As the UPN includes Realm information it may be used to govern
   calendar store access rights across Realms. However, governing access
   rights across Realms is only useful if login access is available.
   This could be done through a trusted server relationship or a
   temporary account. Note that trusted server relationships are outside
   the scope of [CAP].

   The "IDENTIFY" command also provides for a weak group implementation.
   By allowing multiple sets of authentication credentials belonging to
   different users to identify as the same UPN, that UPN essentially
   identifies a group of people, and may be used for group calendar
   ownership, or the granting of access rights to a group.

5. CAP URL and Calendar Address

   The CAP URL scheme is used to designate calendar stores and calendars
   accessible using the CAP protocol.

   The CAP URL scheme conform to the generic URL syntax, defined in RFC
   2396, and follows the Guidelines for URL Schemes, set forth in RFC
   2718.

   A CAP URL begins with the protocol prefix "cap" and is defined by the
   following grammar.

   capurl   = "cap://" csid [ "/" relcalid ]
   csid     = hostport   ; As defined in Section 3.2.2 of RFC 2396
   relcalid = *uric      ; As defined in Section 2 of RFC 2396

   A 'relcalid' is an identifier that uniquely identifies a calendar on
   a particular calendar store. There is no implied structure in a
   Relative CALID (relcalid). It may refer to the calendar of a user or
   of a resource such as a conference room. It MUST BE unique within the
   calendar store.

   Examples:

   cap://cal.example.com
   cap://cal.example.com/Company/Holidays
   cap://cal.example.com/abcd1234Usr

   A 'relcalid' is permitted and is resolved according to the rules
   defined in Section 5 of RFC 2396.

   Examples of valid relative CAP URLs:

   opqaueXzz123String
   UserName/Personal

   A Calendar addresses can be described as qualified or relative CAP
   URLs.

   For a user currently authenticated to the CS on cal.example.com,
   these two example calendar addresses refer to the same calendar:

   cap://cal.example.com/abcd1234USR
   abcd1234USR

6. New Value Types

   The following sections contains new components, properties,
   parameters, and value definitions.

   The purpose of these is to extend the iCalendar objects in a
   compatible way so that existing iCalendar "VERSION" property "2.0"
   value parsers can still parse the objects without modification.

6.1 Property Value Data Types

6.1.1 CAL-QUERY Value Type

   Subject: Registration of text/calendar MIME value type CAL-QUERY

   Value Name: CAL-QUERY

   Value Type Purpose: This value type is used to identify values and
   contains query statements targeted at locating those values.

   This is based on [SQL92] and [SQLCOM].

   1.  For the purpose of a query, all components should be handled as
       tables, and the properties of those components, should be handled
       as columns.

   2.  All VAGENDAs and CSs look like tables for the purpose of a QUERY.
       And all of their properties look like columns in those tables.

   3.  You CAN NOT do any cross component-type joins. And that means you
       can ONLY have one component, OR one "VAGENDA" component OR one
       "VCALSTORE" component in the "FROM" clause.

   4.  Everything in the "SELECT" clause and "WHERE" clauses in MUST BE
       from the same component type, or "VAGENDA" component OR
       "VCALSTORE" component in the "FROM" clause.

   5.  When multiple "QUERY" properties are supplied in a single
       "VQUERY" component, the results returned are the same as the
       results returned for multiple "VQUERY" components having each a
       single "QUERY" property.

   6.  The '.' is used to separate the table name (component) and column
       name (property or component) when selecting a property that is
       contained inside of a component that is targeted in the TARGET
       property.

   7.  A contained component without a '.' is not the same as
       "component-name.*". If given as "component-name" (no dot) the
       encapsulating BEGIN/END statement will be supplied for
       "component-name".:

   In this example the '.' is used to separate the "TRIGGER" property
   from its contained component (VALARM). Which is contained in any
   "VEVENT" component in the selected "TARGET" property value (a
   relcalid). All "TRIGGER" properties in any "VEVENT" component in
   relcalid would be returned.

   TARGET:relcalid
   QUERY:SELECT VALARM.TRIGGER FROM VEVENT

   SELECT VALARM FROM VEVENT WHERE UID = "123"

   This returns one BEGIN/END "VALARM" component for each
   "VALARM" component in the matching "VEVENT" component.
   As there is no '.' (dot) in the VALARM after the SELECT above:

   BEGIN:VALARM
   TRIGGER;RELATED=END:PT5M
   REPEAT:4
   ...
   END:VALARM
   BEGIN:VALARM
   TRIGGER;RELATED=START:PT5M
   DURATION:PT10M
   ...
   END:VALARM
   ...
   ...

   If provided as "component-name.*", then only the properties and any
   contained components will be returned:

   SELECT VALARM.* FROM VEVENT WHERE UID = "123"

   Will return all of the properties in each "VALARM" component
   in the matching "VEVENT" component:

   TRIGGER;RELATED=END:PT5M
   REPEAT:4
   ...
   TRIGGER;RELATED=START:PT5M
   DURATION:PT10M
   ...
   ...

       (a) SELECT <a-property-name> FROM VEVENT

       (b) SELECT VALARM FROM VEVENT

       (c) SELECT VALARM.* FROM VEVENT

       (d) SELECT * FROM VEVENT

       (e) SELECT * FROM VEVENT WHERE
            VALARM.TRIGGER < '20020201T000000Z'
            AND VALARM.TRIGGER > '20020101T000000Z'

   Note:
       (a) Selects all instances of <a-property-name>
        from all "VEVENT" components.

       (b) and (c) Select all "VALARM" components from all
        "VEVENT" components. (b) would return then in
        BEGIN/END VALARM tags. (c) would return all
        of the properties without BEGIN/END VALARM tags.

       (d) Selects every property and every component
        that is in any "VEVENT" component, with each "VEVENT"
           component wrapped in a BEGIN/END VALARM tags.

       (e) Selects all properties and all contained
        components in all "VEVENT" components that have a "VALARM"
        component with a "TRIGGER" property value between
        the provided dates and times, with each "VEVENT"
           component wrapped in a BEGIN/END VALARM tags.

   NOT VALID:

       (f) SELECT VEVENT.VALARM.TRIGGER FROM VEVENT

       (g) SELECT DTSTART,UID FROM VEVENT WHERE
         VTODO.SUMMERY = "Fix typo in CAP"
   Note: (f) Is NOT valid because it contains
        two '.' characters in the "SELECT" clause.

       (g) Is NOT valid because it mixes VEVENT
        and VTODO properties in the same VQUERY.

   Formal Definition: The value type is defined by the following
   notation:

     cal-query  = "SELECT"   SP   cap-val  SP
               "FROM"     SP   comp-name SP
               "WHERE"    SP   cap-expr

             / "SELECT" SP cap-cols SP
               "FROM"   SP comp-name

     cap-val    = cap-cols / param
             / ( cap-val "," cap-val )

                ; NOTE: there is NO space around the "," on
                ; the next line
     cap-cols   = cap-col / ( cap-cols "," cap-col)
               / "*"

                  ; A 'cap-col' is:
                  ;
                  ; Any property name ('cap-prop') found in the component
               ; named in the 'comp-name' used in the "FROM" clause.
               ;
               ;   SELECT ORGANIZER FROM VEVENT ...
               ;
               ; OR
               ;
               ; A component name ('comp-name') of an existing component
                  ; contained inside of the 'comp-name' used in the "FROM"
                  ; clause.
               ;
               ;   SELECT VALARM FROM VEVENT ...
               ;
               ; OR
               ;
               ; A component name ('comp-name') of an existing
                  ; component contained inside of the 'comp-name' used
                  ; in the "FROM" clause followed by a property
                  ; name ('cap-prop') to be selected from that component.

                  ; (comp-name "." cap-prop)
               ;
               ;   SELECT VALARM.TRIGGER FROM VEVENT ...

     cap-col    = comp-name
                / comp-name "." cap-prop
                / cap-prop

     comp-name  = "VEVENT"  / "VTODO"     / "VJOURNAL" / "VFREEBUSY"
                / "VALARM"  / "DAYLIGHT"  / "STANDARD" / "VAGENDA"
                / "VCAR"    / "VCALSTORE" / "VQUERY"   / "VTIMEZONE"
                / "VRIGHT"  / x-comp    / iana-comp

     cap-prop   = ; A property that may be in the 'cap-comp' named
                  ; in the "SELECT" clause.

     cap-expr   = "(" cap-expr ")"
             / cap-term

     cap-term   = cap-expr SP cap-logical SP cap-expr
             / cap-factor

     cap-logical= "AND" / "OR"

     cap-factor = cap-colval SP cap-oper SP col-value
             / cap-colval SP "LIKE" SP col-value
             / cap-colval SP "NOT LIKE" SP col-value
             / cap-colval SP "IS NULL"
             / cap-colval SP "IS NOT NULL"
             / col-value SP "IN" cap-colval"
             / col-value SP "NOT IN" cap-colval"
             / "STATE()" "=" ( "BOOKED"
                              / "UNPROCESSED"
                              / "DELETED"
                                 / iana-state
                                 / x-state )

    iana-state  = ; Any state registered by IANA directly or
                  ; included in an RFC that may be applied to
                  ; the component and within the rules published.

     x-state    = ; Any experimental state that starts with
                  ; "x-" or "X-".

     cap-colval = cap-col /  param

     param      = "PARAM(" cap-col "," cap-param ")"
     cap-param  = ; Any parameter that may be contained in the cap-col
                  ; in the supplied PARAM() function

     col-value  = col-literal
             / "SELF()"
             / "CAL-OWNERS()"
             / "CAL-OWNERS(" cal-address ")"
             / "CURRENT-TARGET()"

     cal-address = ; A CALID as define by CAP

     col-literal = "'" literal-data "'"

    literal-data = ; Any data that matches the value type of the
                ; column that is being compared. That is you can
                ; not compare PRIORITY to "some string" because
                ; PRIORITY has a value type of integer. If it is
                ; not preceded by the LIKE element, any '%' and '_'
                ; characters in the literal data are not treated as
                ; wildcard characters and do not have to be backslash
                ; escaped.
                ;
                ; OR
                ;
                ; If the literal-data is preceded by the LIKE
                ; element it may also contain the '%' and '_'
                ; wildcard characters. And if the literal data
                ; that is comparing contains any '%' or '_'
                ; characters, they MUST BE backslash escaped as
                ; described in the notes below in order for them not
                ; to be treated as wildcard characters.
                   ;
                   ; And if the literal data contains any characters
                   ; that would have to be backslash escaped if
                   ; a property or parameter value then they must
                   ; be backslash escaped in the literal-data.
                   ; PLUS the quote character (') must be backslash
                   ; escaped. Example:
                   ;
                   ; ... WHERE SUBJECT = 'It\'s time to ski'
                   ;

     cap-oper    = "="
              / "!="
              / "<"
              / ">"
              / "<="
              / ">="
     SP          = ; A single white space ASCII character
                ; (value in HEX %x20).

     x-comp      = ; As defined in [iCAL] section 4.6

     iana-comp   = ; As defined in [iCAL] section 4.6

6.1.1.1 [NOT] CAL-OWNERS()

   This function returns the list of "OWNER" properties for the named
   calendar when used in the "SELECT" clause.

   If called as 'CAL-OWNERS()', it is equivalent to the comma separated
   list of all of the owners of the calendar that match the provided
   "TARGET" property value. If the target is a "VCALSTORE", it returns
   the "CALMASTER" property.

   If called as 'CAL-OWNERS(cal-address)', then it is the equivalent to
   the comma separated list of owners for the named calendar id. If
   'cal-address' is a CS, it returns the "CALMASTER" property.

   If used in the "WHERE" clause it then returns true if the currently
   authenticated UPN is an owner of the currently selected object
   matched in the provided "TARGET" property. Used in a CAL-QUERY
   "WHERE" clause and in the UPN-FILTER.

6.1.1.2 CURRENT-TARGET()

   Is equivalent to the value of the "TARGET" property in the current
   command. Used in a CAL-QUERY "WHERE" clause.

6.1.1.3 PARAM()

   Used in a CAL-QUERY. Returns or tests for the value of the named
   parameter from the named property.

6.1.1.3.1 PARAM() in SELECT

   When used in a "SELECT" clause, it returns the entire property and
   all of that properties parameters (the result is not limited to the
   supplied parameter). If the property does not contain the named
   parameter, then the property is not returned (It could however be
   returned as a result of another "SELECT" clause value.) If multiple
   properties of the supplied name have the named parameter, all
   properties with that named parameter are returned. If multiple
   PARAM() clauses in a single "SELECT" CLAUSE match the same property,
   then the single matching property is returned only once.

   Also note that many parameters have default values defined in [iCAL]
   that must be treated as existing with their default value in the
   properties as defined in [iCAL} even when not explicitly present. So
   for example if a query were performed with PARAM(ATTENDEE,ROLE) then
   ALL "ATTENDEE" properties would match because even when they do not
   explicitly contain the "ROLE" parameter, it has a default value and
   therefore must match.

   So when PARAM() is used in a "SELECT" clause, then it is more
   accurate to say that it means return the property if it contains the
   named parameter explicitly in the property or simply because the
   parameter has a default for that property.

6.1.1.3.2 PARAM() in WHERE

   When used in the "WHERE" clause, a match is true when the parameter
   value matches the compare clause according to the supplied WHERE
   values. If multiple named properties contain the named parameter,
   then each parameter value is compared in turn to the condition and if
   any match, then the results would be true for that condition the same
   as if only one had existed. Each matching properties or components
   are returned only once.

   As a parameter may be multivalued then the comparison might need to
   be done with an "IN" or "NOT IN" comparator.

   Given the following query:

     ATTENDEE;PARTSTAT=ACCEPTED:cap://host.com/joe

     SELECT VEVENT FROM VAGENDA
      WHERE PARAM(ATTENDEE,PARTSTAT) = 'ACCEPTED'

   Then all "VEVENT" components that contain one or more "ATTENDEE"
   properties that have a "PARTSTAT" parameter with a "ACCEPTED" value
   would be returned. And each uniquely matching VEVENT would only be
   returned once no matter how many "ATTENDEE" properties had matching
   roles in each unique "VEVENT" component.

   Also note that many parameters have default values defined in [iCAL].
   So if the following query were performed on the "ATTENDEE" property
   in the above example:

     SELECT VEVENT FROM VAGENDA
      WHERE PARAM(ATTENDEE,ROLE) = 'REQ-PARTICIPANT'
   It would return the "ATTENDEE" property exampled above because the
   default value for the "ROLE" parameter is "REQ-PARTICIPANT".

6.1.1.4 SELF()

   Used in a CAL-QUERY "WHERE" clause. Returns the UPN of the currently
   authenticated UPN or their current UPN as a result of an IDENTIFY
   command.

6.1.1.5 STATE()

   Returns one of three values, "BOOKED", "UNPROCESSED", or "DELETED"
   depending on the state of the object. Where "DELETED" is a component
   in the marked for delete state. Components that have been removed
   from the store are never returned.

   If not specified in a query then both "BOOKED" and "UNPROCESSED" data
   is returned. Each unique "METHOD" property must be in a separate MIME
   object per the [iCAL] section 3.2 restriction.

6.1.1.6 Use of single quote

   All literal values are surrounded by single quotes ('), not double
   quotes ("), and not without any quotes. If the value contains quotes
   or any other ESCAPED-CHAR, they MUST BE backslash escaped as
   described in section 4.3.11 "Text" of [iCAL]. Any "LIKE" clause
   wildcard characters that are part of any literal data that is
   preceded by a "LIKE" clause or "NOT LIKE" clause and is not intended
   to mean wildcard search MUST BE escaped as described in note (7)
   below.

6.1.1.7 Comparing DATE and DATE-TIME values

   When comparing "DATE-TIME" values to "DATE" values and when comparing
   "DATE" values to "DATE-TIME" values, the result will be true if the
   "DATE" value is on the same day as the "DATE-TIME" value. And they
   are compared in UTC no matter what time zone the data may actual have
   been stored in.

   Local time event as descibed in section 4.2.19 of [iCAL] must be
   considered to be in the CUA default timezone that was supplied by the
   CUA in the "CAPABILITY" exchange.

   VALUE-1             VALUE-2            Compare Results

   20020304            20020304T123456    TRUE
   (in UTC-3)          (in UTC-3)
   20020304            20020304T003456    FALSE
   (in UTC)            (in UTC-4)

   20020304T003456Z    20020205T003456    FALSE
   (in UTC-0)          (in UTC-7)

   When comparing "DATE" values and "DATE-TIME" values with the "LIKE"
   clause the comparison will be done as if the value is a [iCAL] DATE
   or DATE-TIME string value.

   LIKE '2002%' will match anything in the year 2002.

   LIKE '200201%' will match anything in January 2002.

   LIKE '%T000000' will match anything at midnight.

   LIKE '____01__T%' will match anything for any year or
              time that is in January.
              (Four '_', '01', two '_' 'T%').

   Using a "LIKE" clause value of "%00%, would return any value that
   contained two consecutive zeros.

   All comparisons will be done in UTC.

6.1.1.8 DTEND and DURATION

   The "DTEND" property value is not included in the time occupied by
   the component. That is a "DTEND" property value of 20030614T12000
   includes all of the time up to but not including noon on that day.

   The "DURATION" property value end time is also not inclusive. So an
   object with a "DTSTART" property value of 20030514T110000 and a
   "DURATION" property value of "1H" does not include noon on that day.

   When a "QUERY" property value contains a "DTEND" value, then the CS
   MUST also evaluate any existing "DURATION" property value and
   determine if it has an effective end time that matches the "QUERY"
   property supplied "DTEND" value or any range of values supplied by
   the "QUERY" property.

   When a "QUERY" property contains a "DURATION" value, then the CS MUST
   also evaluate any existing "DTEND" property values and determine if
   they have an effective duration that matches the "QUERY" property
   value supplied "DURATION" value or any range of values supplied by
   the "QUERY" property.

6.1.1.9 [NOT] LIKE

   The pattern matching characters are the '%' that matches zero or more
   characters, and '_' that matches exactly one character (where
   character does not always mean octet).

   "LIKE" clause pattern matches always cover the entire string. To
   match a pattern anywhere within a string, the pattern must start and
   end with a percent sign.

   To match a '%' or '_' in the data and not have it interpreted as a
   wildcard character, they MUST BE backslash escaped. That is to search
   for a '%' or '_' in the string:

     LIKE '%\%%'    Matches any string with a '%' in it.
     LIKE '%\_%'    Matches any string with a '_' in it.

   Strings compared using the "LIKE" clause MUST BE performed using case
   in-sensitive comparisons when the locale allows. (Example: in
   US-ASCII the compare assumes 'a' = 'A').

   If the "LIKE" clause is preceded by 'NOT' then there is a match when
   the string compare fails.

   Some property values (such as the 'recur' value type), contain commas
   and are not multi valued. The CS must understand the objects being
   compared and understand how to determine how any multi valued or
   multi instances properties or parameter values are separated, quoted,
   and backslash escaped and perform the comparisons as if each value
   existed by itself and not quoted or backslash escaped when comparing
   using the LIKE element.

   See related examples in Section 6.1.1.11

6.1.1.10 Empty vs. NULL

   When used in a CAL-QUERY value, "NULL" means that the property or
   parameter is not present in the object. Paramaters that are not
   provided and have a default value in the property are considered to
   exist with their default value and will not be "NULL".

   If the property exists but has no value then "NULL" MUST NOT match.
   If the parameter exists but has no value then "NULL" MUST NOT match.
   If the parameter not present and has a default value then "NULL" MUST
   NOT match.

   If the property (or parameter) exists, but has no value then it
   matches the empty string '' (quote quote).

6.1.1.11 [NOT] IN

   This is similar to the "LIKE" clause, except it does value matching
   and not string comparison matches.

   Some iCalendar objects can be multi instance and multi valued. The
   "IN" clause will return a match if the literal value supplied as part
   of the "IN" clause is contained in the value of any instance of the
   named property or parameter, or is in any of the multiple values in
   the named property or parameter. Unlike the "LIKE" clause, the '%'
   and '_' matching characters are not used with the "IN" clause and
   have no special meaning.

          BEGIN:A-COMPONENT
   a       property:value1,value2        One property, two values.
   b       property:"value1,value2"      One property, one value.
   c       property:parameter=1,2:x           One parameter, two values.
   d       property:parameter="1,2",3:y       One parameter, one value.
   e       property:parameter=",":z           One parameter, one value.
   f       property:x,y,z                One property, three values
          END:A-COMPONENT

          'value1' IN property          would match (a) only.
          'value1,value2' IN property   would match (b) only.
          'value%'  IN property         would NOT match any.
          ',' IN property               would NOT match any.
          '%,%' IN property             would NOT match any.
          'x' IN property               would match (f) and (c).
          '2' IN parameter              would match (c) only.
          '1,2' IN parameter            would match (d) only.
          ',' IN parameter              would match (e) only.
          '%,%' IN parameter            would NOT match any.

          property  LIKE 'value1%'      would match (a) and (b).
          property  LIKE 'value%'       would match (a) and (b).
          property  LIKE 'x'            would match (f) and (c).
          parameter LIKE '1%'           would match (c) and (d).
          parameter LIKE '%2%'          would match (c) and (d).
          parameter LIKE ','            would match (e) only.

   Some property values (such as the "RECUR" value type), contain commas
   and are not multi valued. The CS must understand the objects being
   compared and understand how to determine how any multi valued or
   multi instances properties or parameter values are separated, quoted,
   and backslash escaped and perform the comparisons as if each value
   existed by itself and not quoted or backslash escaped when comparing
   using the IN element.

   If the "IN" clause is preceded by 'NOT' then there is a match when
   the value does not exist in the property or parameter value.

6.1.1.12 DATE-TIME and TIME values in a WHERE clause

   All "DATE-TIME" and "TIME" literal values supplied in a "WHERE"
   clause MUST BE terminated with 'Z'. That means that the CUA MUST
   supply the values in UTC.

   Valid:

   WHERE alarm.TRIGGER < '20020201T000000Z'
    AND alarm.TRIGGER > '20020101T000000Z'

   Not valid and it is a syntax error and the CS MUST reject the QUERY.

   WHERE alarm.TRIGGER < '20020201T000000'
   AND alarm.TRIGGER > '20020101T000000'

6.1.1.13 Multiple contained components

   If a query references a component and a component or property
   contained in the component, any clauses referring to the contained
   component or property must be evaluated on all of the contained
   components or properties.  If any of the contained components or
   properties match the query, and the conditions on the containing
   component are also true, the component matches the query.

   For example, in the query below, if a BOOKED VEVENT contains multiple
   VALARMs, and the VALARM.TRIGGER clause is true for any of the VALARMs
   in the VEVENT, then the UID, SUMMARY, and DESCRIPTION of this VEVENT
   would be included in the QUERY results.

   BEGIN:VQUERY
   EXPAND:TRUE
   QUERY:SELECT UID,SUMMARY,DESCRIPTION FROM VEVENT
   WHERE VALARM.TRIGGER >= '20000101T030405Z'
   AND VALARM.TRIGGER <= '20001231T235959Z'
   AND STATE() = 'BOOKED'
   END:VQUERY

6.1.1.14 Example, Query by UID

   The following example would match the entire content of a "VEVENT" or
   "VTODO" component with the "UID" property equal to "uid123" and not
   expand any multiple instances of the component.  If the CUA does not
   know  if "uid123" was a "VEVENT", "VTODO", "VJOURNAL", or any other
   component, then all components that the CUA supports MUST BE supplied
   in a QUERY property. This example assumes the CUA is only interested
   in "VTODO" and "VEVENT" components.

   If the results were empty it could also mean that "uid123" was a
   property in a component other than a VTODO or VEVENT.

   BEGIN:VQUERY
   QUERY:SELECT * FROM VTODO WHERE UID = 'uid123'
   QUERY:SELECT * FROM VEVENT WHERE UID = 'uid123'
   END:VQUERY

6.1.1.15 Query by Date-Time range

   This query selects the entire content of every booked "VEVENT"
   component that has an instance greater than or equal to July 1st,
   2000 00:00:00 UTC and less than or equal to July 30st, 2000 23:59:59
   UTC. This includes single instance "VEVENT" components that do no
   explicitly contain any recurence properties or "RECURRENCE-ID"
   properties. This works only for CSs that have the "RECUR-EXPAND"
   property value set to "TRUE" in the "GET-CAPABILITY" exchange.

   BEGIN:VQUERY
   EXPAND:TRUE
   QUERY:SELECT * FROM VEVENT
   WHERE RECURRENCE-ID >= '20000701T000000Z'
   AND RECURRENCE-ID <= '20000730T235959Z'
   AND STATE() = 'BOOKED'
   END:VQUERY

6.1.1.16 Query for all Unprocessed Entries

   The following example selects the entire contents of all non-booked
   "VTODO" and "VEVENT" components in the "UNPROCESSED" state. The
   default for the "EXPAND" property is FALSE, so the recurrence rules
   will not be expanded.

   BEGIN:VQUERY
   QUERYID:Fetch VEVENT and VTODO iTIP components
   QUERY:SELECT * FROM VEVENT WHERE STATE() = 'UNPROCESSED'
   QUERY:SELECT * FROM VTODO WHERE STATE() = 'UNPROCESSED'
   END:VQUERY

   The following example fetches all "VEVENT" and "VTODO" components in
   the "BOOKED" state.

   BEGIN:VQUERY
   QUERYID:Fetch All Booked VEVENT and VTODO components
   QUERY:SELECT * FROM VEVENT WHERE STATE() = 'BOOKED'
   QUERY:SELECT * FROM VTODO WHERE STATE() = 'BOOKED'
   END:VQUERY

   The following fetches the "UID" property for all "VEVENT" and "VTODO"
   components that have been marked for delete.

   BEGIN:VQUERY
   QUERYID:Fetch UIDs of marked for delete VEVENTs and VTODOs
   QUERY:SELECT UID FROM VEVENT WHERE STATE() = 'DELETE'
   QUERY:SELECT UID FROM VTODO WHERE STATE() = 'DELETE'
   END:VQUERY

6.1.1.17 Query with Subset of Properties by Date/Time

   In this example only the named properties will be selected and all
   booked and non-booked components will be selected that have a
   "DTSTART" value from February 1st to February 10th 2000 (in UTC).

   BEGIN:VQUERY
   QUERY:SELECT UID,DTSTART,DESCRIPTION,SUMMARY FROM VEVENT
   WHERE DTSTART >= '20000201T000000Z'
   AND DTSTART <= '20000210T235959Z'
   END:VQUERY

6.1.1.18 Query with Components and Alarms In A Range

   This example fetches all booked "VEVENT" components with an alarm
   that triggers within the specified time range. In this case only the
   "UID", "SUMMARY", and "DESCRIPTION" properties will be selected for
   all booked "VEVENTS" components that have an alarm between the two
   date-times supplied.

   BEGIN:VQUERY
   EXPAND:TRUE
   QUERY:SELECT UID,SUMMARY,DESCRIPTION FROM VEVENT
   WHERE VALARM.TRIGGER >= '20000101T030405Z'
   AND VALARM.TRIGGER <= '20001231T235959Z'
   AND STATE() = 'BOOKED'
   END:VQUERY

6.1.2 UPN Value Type

   Value Name: UPN

   Purpose: This value type is used to identify values that contain user
   principal name of CU or group of CU.

   Formal Definition: The value type is defined by the following
   notation:

   upn        = "@"
        / [ dot-atom-text ] "@" dot-atom-text

          ; dot-atom-text is defined in RFC 2822

   Description: This data type is an identifier that denotes a CU or a
   group of CU. A UPN is a RFC 2822 compliant email address, with
   exceptions listed below, and in most cases it is deliverable to the
   CU. In some cases it is identical to the CU's well known email
   address.  A CU's UPN MUST never be an e-mail address that is
   deliverable to a different person. And there is no requirement that a
   person's UPN MUST BE their e-mail address. A UPN is formatted as a
   user name followed by "@" followed by a Realm in the form of a valid,
   and unique, DNS domain name. The user name MUST BE unique within the
   Realm. In  it's simplest form it looks like "user@example.com".

   In certain cases a UPN will not be RFC 2822 compliant. When anonymous
   authentication is used, or anonymous authorization is being defined,
   the special UPN "@" will be used. When authentication MUST BE used,
   but unique identity MUST BE obscured, a UPN of the form
   @DNS-domain-name may be used. For example, "@example.com".

   Example:

   The following is a UPN for a CU:

   jdoe@example.com

   The following is a example of a UPN that could be for a group of CU:

   staff@example.com

   The following is a UPN for an anonymous CU belonging to a specific
   realm or when used as a UPN-FILTER it specifies that it applies to
   all UPNs in a specific realm:

   @example.com

   The following is a UPN for an anonymous CU:

   @

6.1.3 UPN-FILTER Value

   Value Name: UPN-FILTER

   Purpose: This value type is used to identify values that contain a
   user principal name filter.

   Formal Definition: The value type is defined by the following
   notation:

             ; NOTE: "CAL-OWNERS(cal-address)"
             ;       and "NOT CAL-OWNERS(cal-address)"
             ;       are both NOT allowed below.
             ;
   upn-filter    = "CAL-OWNERS()" /

             "NOT CAL-OWNERS()" /
             "*" /
             [ "*" / dot-atom-text ] "@" ( "*" / dot-atom-text )

            ; dot-atom-text is defined in RFC 2822

   Description: The value is used to match user principal names (UPNs).
   For "CAL-OWNERS()" and "NOT CAL-OWNERS()", see Section 8.24.

   *           Matches all UPNs.

   @           Matches the UPN of anonymous CUs
               belonging to the null realm

   @*          Matches the UPN of anonymous CUs
               belonging to any non-null realm

   @realm      Matches the UPN of anonymous CUs
               belonging to the specified realm.

   *@*         Matches the UPN of non-anonymous CUs
               belonging to any non-null realm

   *@realm     Matches the UPN of non-anonymous CUs
               belonging to the specified realm

   user@realm  Matches the UPN of the specified CU
               belonging to the specified realm

   user@*      Not allowed.

   user@       Not allowed.

   Example: The following are examples of this value type:

   DENY:NON CAL-OWNERS()
   DENY:@hackers.example.com
   DENY:*@hackers.example.com
   GRANT:sam@example.com

7. New Parameters

7.1 ACTION Parameter

   Parameter Name: ACTION

   Purpose: This parameter indicates the action to be taken when a
   timeout occurs.

   Value Type: TEXT

   Conformance: This property can be specified in the "CMD" property.

   When present in a "CMD" property the "ACTION" parameter specifies the
   action to be taken when the command timeout expires.

   Formal Definition: The parameter is defined by the following
   notation:

   action-param     = ";" "ACTION" "=" ( "ASK" / "ABORT" )
                    ; If 'action-param' is supplied then
                    ; 'latency-param' MUST BE supplied.

   Example: The following is an example of this parameter:

   CMD;LATENCY=10;ACTION=ASK:CREATE

7.2 ENABLE Parameter

   Parameter Name: ENABLE

   Purpose: This parameter indicates whether or not the property should
   be ignored. Example if a "TRIGGER" property in a "VALARM" component
   should be ignored.

   Value Type: BOOLEAN

   Conformance: This property can be specified in the "TRIGGER"
   properties.

   Description: When a non owner sends an [iTIP] "REQUEST" to a calendar
   that object might contain a "VALARM" component. The owner may wish to
   have local control over their own CUA and when or how alarms are
   triggered.

   A CUA may add the "ENABLE" parameter to any "TRIGGER" property before
   booking the component. If the "ENABLE" parameter is set to "FALSE",
   then the alarm will be ignored by the CUA. If set to "TRUE", or if
   the "ENABLE" property is not in the "TRIGGER" property, the alarm is
   enabled. This parameter may not be known by pre-CAP implementations
   and should not be an issue as it conforms to an 'ianaparam' as
   defined in [iCAL].

   Formal Definition: The property is defined by the following notation:

   enable-param       = "ENABLE" "=" boolean

   Example: The following is an example of this property for a "VAGENDA"
   component:

   TRIGGER;ENABLE=FALSE;RELATED=END:PT5M

7.3 ID Parameter

   Parameter Name: ID

   Purpose: When used in a "CMD" component provides a unique identifier.

   Value Type: TEXT

   Conformance: This parameter can be specified in the "CMD" property.

   Description: If there is more than one command sent then the "ID"
   parameter is used to uniquely identify the command.

   A CUA may add the "ID" parameter to any "CMD" property before sending
   the command. There must not be more than one outstanding command
   tagged with the same "ID" parameter value.

   Formal Definition: The property is defined by the following notation:

   id-param         = ";" "ID" "=" unique-id
                    ; The text value supplied is a unique value
                    ; shared between the CUA and CS to uniquely
                    ; identify the instance of command in the
                    ; the current CUA session. The value has
                    ; no meaning to other CUAs or other sessions.

   unique-id        = ; text

   text          = ; As defined in [iCAL].

   Example: The following is an example of this parameter component:

   CMD;UD=some-unique-value:CREATE

7.4 LATENCY Parameter

   Parameter Name: LATENCY

   Purpose: This parameter indicates time in seconds for when a timeout
   occurs.

   Value Type: TEXT

   Conformance: This property can be specified in the "CMD" property.

   When present in a "CMD" property the "LATENCY" parameter specifies
   the time in sections when the command timeout expires.

   Formal Definition: The parameter is defined by the following
   notation:

   latency-param    = ";" "LATENCY" "=" latency-sec
                    ; The value supplied in the time in seconds.
                    ; If 'latency-param' is supplied then
                    ; 'action-param' MUST BE supplied.

   latency-sec      = posint1

   ; Default is zero (0) meaning no timeout.

   Example: The following is an example of this parameter:

   CMD;LATENCY=10;ACTION=ASK:CREATE

7.5 LOCAL Parameter

   Parameter Name: LOCAL

   Purpose: Indicates if the named component should be exported to any
   non-organizer calendar.

   Value Type: BOOLEAN

   Conformance: This parameter can be specified in the "SEQUENCE"
   properties in a "VALARM" component.

   Description: When a non owner sends an [iTIP] "REQUEST" to a calendar
   that object might contain a "VALARM" component. The owner may wish to
   have local control over their own CUA and when or how alarms are
   triggered.

   A CUA may add the "LOCAL" parameter to the "SEQUENCE" property before
   booking the component. If the "LOCAL" parameter is set to "TRUE",
   then the alarm MUST NOT be forwarded to any other calender. If set to
   "FALSE", or if the "LOCAL" parameter is not in the "SEQUENCE"
   property, the alarm is global.

   Formal Definition: The property is defined by the following notation:

   local-param        = "LOCAL" "=" boolean

   Example: The following is an example of this parameter:

   SEQUENCE;LOCAL=TRUE:4

7.6 LOCALIZE Parameter

   Parameter Name: LOCALIZE

   Purpose: If provided the "LOCALIZE" parameter specifies the desired
   language for error and warning messages.

   Value Type: TEXT
   Conformance: This parameter can be specified in the "CMD" properties.

   When the "LOCALIZE" parameter is supplied then its value MUST BE one
   of the values listed in the initial [BEEP] greeting 'localize'
   attribute.

   A CUA may add the "LOCALIZE" parameter to the "CMD" property to
   specify the language of any error or warning messages.

   Formal Definition: The property is defined by the following notation:

   localize-param   = ";" "LOCALIZE" "=" beep-localize

   beep-localize    = text ; As defined in [BEEP]
                    ; The value supplied MUST BE one value from the initial
                    ; [BEEP] greeting 'localize' attribute specifying
                    ; the locale to use for error messages during
                    ; this instance of the command sent.

   Example: The following is an example of this parameter:

   CMD;LOCALIZE=fr_CA:CREATE

7.7 OPTIONS Parameter

   Parameter Name: OPTIONS

   Purpose: If provided the "OPTIONS" parameter specifies some "CMD"
   property specific options.

   Value Type: TEXT

   Conformance: This parameter can be specified in the "CMD" properties.

   A CUA adds the "OPTIONS" parameter to the "CMD" property when the
   command needs extra values.

   Formal Definition: The property is defined by the following notation:

   option-param     = ";" "OPTIONS" "=" cmd-specific

   cmd-specific     = ; The value supplied is dependent on the
                      ; CMD value. See the specific CMDs for the
                      ; correct values to use for each CMD.

   Example: The following is an example of this parameter:

   CMD;OPTIONS=10:GENERATE-UID

8. New Properties

8.1 ALLOW-CONFLICT Property

   Property Name: ALLOW-CONFLICT

   Purpose: This property indicates whether or not the calendar and CS
   supports component conflicts. That is, whether or not any of the
   components in the calendar can overlap.

   Value Type: BOOLEAN

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: This property can be specified in "VAGENDA" and
   "VCALSTORE" component.

   Description: This property is used to indicate whether components may
   conflict. That is, if their expanded instances may share the same
   time or overlap the same time periods. If it has a value of TRUE,
   then conflicts are allowed. If FALSE, the no two components may
   conflict.

   If FALSE in the "VCALSTORE" component, then all "VAGENDA" component
   "ALLOW-CONFLICT" property values MUST BE false in the CS.

   Formal Definition: The property is defined by the following notation:

   allow-conflict     = "ALLOW-CONFLICT" other-params ":" boolean CRLF

   Example: The following is an example of this property for a "VAGENDA"
   component:

   ALLOW-CONFLICT:FALSE

8.2 ATT-COUNTER Property

   Property Name: ATT-COUNTER

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: This property MUST be specified in an iCalendar object
   that specifies counter proposal to a group scheduled calendar entity.
   When storing a "METHOD" property with the "COUNTER" method, there
   needs to be a way to remember who sent the COUNTER. The ATT-COUNTER
   property MUST BE added to all "COUNTER" [iTIP] components by the CUA
   before storing in a CS.

   Description: This property is used to identify the CAL-ADDRESS of the
   entity that sent the "COUNTER" [iTIP] object.

   Formal Definition: The property is defined by the following notation:

   attcounter   = "ATT-COUNTER" other-params ":" cal-address CRLF

   Examples:

   ATT-COUNTER:cap:example.com/Doug
   ATT-COUNTER:mailto:Doug@Example.com

8.3 CALID Property

   Property Name: CALID

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: This property can be specified in the "VAGENDA"
   component.

   Description: This property is used to specify a fully qualified
   CALID.

   Formal Definition: The property is defined by the following notation:

   CALID   = "CALID" other-params ":" relcalid CRLF

   Example:

   CALID:cap://cal.example.com/sdfifgty4321

8.4 CALMASTER Property

   Property Name: CALMASTER

   Purpose: The property specifies an e-mail address of a person
   responsible for the calendar store.

   Value Type: URI

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: The property can be specified in a "VCALSTORE"
   component.

   Description: The parameter value SHOULD BE a MAILTO URI as defined in
   [URL]. It MUST BE a contact URI such as a MAILTO URI and not a home
   page or file URI that describes how to contact the calmasters.

   Formal Definition: The property is defined by the following notation:

   calmaster = "CALMASTER" other-params ":" uri CRLF

   uri = ; IANA registered uri as defined in [iCAL]

   Example: The following is an example of this property:

   CALMASTER:mailto:administrator@example.com

8.5 CAP-VERSION Property

   Property Name: CAP-VERSION

   Purpose: This property specifies the version of CAP supported.

   Value Type: TEXT

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: This property is specified in the "VREPLY" component
   that is sent in response to a "GET-CAPABILITY" command.

   Description: This specifies the version of CAP that the endpoint
   supports. The list is a comma separated list of RFC numbers
   supported. The list MUST contain at least XXXX (NOTE 'XXXX' WILL BE
   REPLACED WITH THE RFC NUMBER OF THIS DOCUMENT).

   Formal Definition: The property is defined by the following notation:

   cap-version   = "CAP-VERSION" other-params ":" text CRLF

   Example: The following are examples of this property:

   CAP-VERSION:XXXX

8.6 CARID Property

   Property Name: CARID

   Purpose: This property specifies the identifier for an access right
   component.

   Value Type: TEXT

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: This property MUST BE specified once in a "VCAR"
   component.

   Description: This property is used in the "VCAR" component to specify
   an identifier. A "CARID" property value is unique per container.

   Formal Definition: The property is defined by the following notation:

   carid      = "CARID" other-params ":" text CRLF

   Example: The following are examples of this property:

   CARID:xyzzy-007
   CARID:User Rights

8.7 CAR-LEVEL Property

   Property Name: CAR-LEVEL
   Purpose: The property specifies the level of VCAR supported.

   Value Type: TEXT

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: The property can be specified in a "VREPLY" component
   that is sent in response to a "GET-CAPABILITY" command.

   Description: The value is one from a list of "CAR-NONE", "CAR-MIN",
   or "CAR-FULL-1". If "CAR-FULL-1" is supplied then "CAR-MIN" is also
   available. A "CAR-MIN" implementation only supported the
   "DEFAULT-VCARS" property values listed in the "VCALSTORE" component
   and a "CAR-MIN" implementation does not support the creation or
   modification of "VCAR" components from the CUA.

   Formal Definition: The property is defined by the following notation:

   car-level        = "CAR-LEVEL" ":" other-params : car-level-values

   car-level-values = ( "CAR-NONE" / "CAR-MIN" / "CAR-FULL-1"
                        / other-levels )

   other-levels     = ; Any name published in an RFC for a "CAR-LEVEL"
                      ; property value.

   Example: The following is an example of this property:

   CAR-LEVEL:CAR-FULL-1

8.8 COMPONENTS Property

   Property Name: COMPONENTS

   Purpose: The property specifies a the list of components supported by
   the endpoint.

   Value Type: TEXT

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: The property can be specified in a "VREPLY" component in
   response to a "GET-CAPABILITY" command.

   Description: A comma separated list of components supported by the
   endpoint. If not in the list sent from the endpoint then they are not
   supported by that endpoint. Sending an unsupported component results
   in unpredictable results. This includes any components inside of
   other components (VALARM for example). The recommended list is
   "VCALSTORE,VCALENDAR,VREPLY,VAGENDA,
   VEVENT,VALARM,VTIMEZONE,VJOURNAL,VTODO,VALARM
   DAYLIGHT,STANDARD,VCAR,VRIGHT,VQUERY"

   Formal Definition: The property is defined by the following notation:

   components     = "COMPONENTS" other-params ":" comp-list CRLF

                  ; All of these MUST BE supplied only once.
                  ;
   comp-list-req  = "VCALSTORE" "," "VCALENDAR" "," "VTIMEZONE" ","
                    "VREPLY"    "," "VAGENDA"   "," "STANDARD"  ","
                    "DAYLIGHT"

                  ; At least one MUST BE supplied. The same value
                  ; MUST NOT occur more than once.
                  ;
   comp-list-min  = ( "," "VEVENT") / ( "," "VTODO") / ( "," "VJOURNAL" )

                  ; The same value MUST NOT occur
                  ; more than once. If "VCAR" is supplied then
                  ' "VRIGHT" must be supplied.
                  ;
   comp-list-opt  = ( "," "VFREEBUSY" ) / ( "," "VALARM" )
                    / ( "," "VCAR" )    / ( "," "VRIGHT" )
                    / ( "," "VQUERY")   / ( "," x-comp )
                    / ( "," iana-comp )

   comp-list        = comp-list-req 1*3comp-list-min *(comp-list-opt)

   Example: The following is an example of this property:

   COMPONENTS:VCALSTORE,VCALENDAR,VREPLY,VAGENDA,
    VEVENT,VALARM,VTIMEZONE,VJOURNAL,VTODO,
    DAYLIGHT,STANDARD,VFREEBUSY,VCAR,VRIGHT,VQUERY

8.9 CSID Property

   Property Name: CSID

   Purpose: The property specifies a the globally unique identifier for
   the calendar store.

   Value Type: URI

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: The property can be specified in a "VCALSTORE"
   component.

   Description: The identifier MUST BE globally unique. Each CS needs
   its own unique identifier. The "CSID" property is the official unique
   identifier for the CS. If the [BEEP] 'serverName' attribute was
   supplied in the [BEEP] 'start' message, then the CSID will be mapped
   to the virtual host name supplied and the host name part of the CSID
   MUST BE the same as the 'serverName' value. This allows one CS
   implementation to service multiple virtual hosts. CS's are not
   required to support virtual hosting. If a CS does not support virtual
   hosting then it must ignore the [BEEP] 'serverName' attribute.

   Formal Definition: The property is defined by the following notation:

   csid = "CSID" other-params ":" capurl CRLF

   Example: The following is an example of this property:

   CSID:cap://calendar.example.com

8.10 DECREED Property

   Property Name: DECREED

   Purpose: This property specifies if an access right calendar
   component is decreed or not.

   Value Type: BOOLEAN

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: This property MAY be specified once in a "VCAR"
   component.

   Description: This property is used in the "VCAR" component to specify
   whether the component is decreed or not. If the "DECREED" property
   value is "true" then the CUA will be unable to change the contents of
   the "VCAR" component and any attempt will fail with an error.

   Formal Definition: The property is defined by the following notation:

   decreed      = "DECREED" other-params ":" boolean CRLF

   Example: The following is an example of this property:

   DECREED:TRUE

8.11 DEFAULT-CHARSET Property

   Property Name: DEFAULT-CHARSET

   Purpose: This property indicates the default charset.

   Value Type: TEXT

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: This property can be specified in "VAGENDA" and
   "VCALSTORE" calendar component.

   Description: In a "VAGENDA" component this property is used to
   indicate the charset of calendar. If not specified, the default is
   the first value in the "VCALSTORE" components "DEFAULT-CHARSET"
   property value list. The value MUST BE an IANA registered character
   set as defined in [CHARREG].

   In a "VCALSTORE" component it is a comma separated list of charsets
   supported by the CS. The first entry is the default entry for all
   newly created "VAGENDA" components. The "UTF-8" value MUST BE in the
   "VCALSTORE" component "DEFAULT-CHARSET" property list. All compliant
   CAP implementations (CS and CUA) MUST support at least the "UTF-8"
   charset.

   If a charset name contains a comma (,), then that comma must be
   backslashed escaped in the value.

   Formal Definition: The property is defined by the following notation:

   default-charset     = "DEFAULT-CHARSET" other-params ":" text
                         *( "," text) CRLF

   Example: The following is an example of this property for a "VAGENDA"
   component:

   DEFAULT-CHARSET:Shift_JIS,UTF-8

8.12 DEFAULT-LOCALE Property

   Property Name: DEFAULT-LOCALE

   Purpose: This property specifies the default language for text
   values.

   Value Type: TEXT

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: This property can be specified in "VAGENDA" and
   "VCALSTORE" components.

   Description: In a "VAGENDA" component, the "DEFAULT-LOCALE" property
   is used to indicate the locale of the calendar. The full locale
   SHOULD be used. The default and minimum locale is POSIX (aka the 'C'
   locale).

   In a "VCALSTORE" component it is a comma separated list of locales
   supported by the CS. The first value in the list is the default for
   all newly created VAGENDAs. "POSIX" MUST BE in the list.

   Formal Definition: The property is defined by the following notation:

   default-locale     = "DEFAULT-LOCALE" other-params ":" language
                         *( "," language) CRLF

   language = Text identifying a locale, as defined in [CHARPOL]

   Example: The following is an example of this property:

   DEFAULT-LOCALE:en-US.iso-8859-1,POSIX

8.13 DEFAULT-TZID Property

   Property Name: DEFAULT-TZID

   Purpose: This property specifies the text value that specifies the
   time zones.

   Value Type: TEXT

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: This property may be specified once in a "VAGENDA" and
   "VCALSTORE" components.

   Description: A multi valued property that lists the known time zones.
   The first is the default. Where "TZID" property values are the same
   as the "TZID" property as defined in [iCAL].

   If in a "VCALSTORE" component it is a comma separated list of TZIDs
   known to the CS. The entry is used as the default TZID list for all
   newly created calendars. The list MUST contain at least "UTC". A
   "VCALSTORE" components MUST have one "VTIMEZONE" component contained
   in it for each value in the "DEFAULT-TZID" property value.

   If in a "VAGENDA" component it is a comma separated list of "TZID"
   property values naming the time zones known to the calendar. The
   first time zone in the list is the default and is used as the
   localtime for objects that contain a date or date-time value without
   a time zone. All "VAGENDA" components MUST have one "VTIMEZONE"
   component contained for each value in the "DEFAULT-TZID" property
   value.

   If a "TZID" property value contains a comma (,), the comma must be
   backslash escaped.

   Formal Definition: This property is defined by the following
   notation:

   default-tzid       = "DEFAULT-TZID" other-params
                        ":" [tzidprefix] text
                        *("," [tzidprefix] text) CRLF

   Example: The following is an example of this property:

   DEFAULT-TZID:US/Mountain,UTC

8.14 DEFAULT-VCARS Property

   Property Name: DEFAULT-VCARS

   Purpose: This property is used to specify the "CARID" property ids of
   the default "VCAR" components for newly created "VAGENDA" components.

   Value Type: TEXT

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: This property MUST BE specified in "VCALSTORE" calendar
   component and MUST at least specify the following values:
   "READBUSYTIMEINFO", "REQUESTONLY", "UPDATEPARTSTATUS", and
   "DEFAULTOWNER".

   Description: This property is used in the "VCALSTORE" component to
   specify the "CARID" value of the "VCAR" components that MUST BE
   copied into now "VAGENDA" components at creation time by the CS. All
   "DEFAULT-VCAR" values must have "VCARS" components stored in the
   "VCALSTORE".

   Formal Definition: The property is defined by the following notation:

   def-vcars      = "DEFAULT-VCARS" other-params ":" text
                    *( "," text ) CRLF

   Example: The following is an example of this property:

   DEFAULT-VCARS:READBUSYTIMEINFO,REQUESTONLY,
    UPDATEPARTSTATUS,DEFAULTOWNER

8.15 DENY Property

   Property Name: DENY

   Purpose: This property identifies the UPN(s) being denied access in
   the "VRIGHT" component.

   Value Type: UPN-FILTER

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: This property can be specified in "VRIGHT" components.

   Description: This property is used in the "VRIGHT" component to
   define the CU or UG being denied access.

   Formal Definition: The property is defined by the following notation:

   deny       = "DENY" other-params ":" upn-filter CRLF

   Example: The following are examples of this property:

   DENY:*

   DENY:bob@example.com

8.16 EXPAND property

   Property Name: EXPAND

   Purpose: This property is to notify the CS if it should or should not
   expand any component with recurrence rules into multiple instances in
   a query reply.

   Value Type: BOOLEAN

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: This property can be specified in "VQUERY" components.

   Description: If a CUA wishes to see all of the instances of a
   recurring component the CUA sets EXPAND=TRUE in the "VQUERY"
   component. If not specified, the default is FALSE. Note that if the
   CS has its "RECUR-EXPAND" CS property value set to false then the
   "EXPAND" property will be ignored and the result will be as if the
   "EXPAND" value was set to false. The results will be bounded by any
   date range or other limits in the query.

   Formal Definition: The property is defined by the following notation:

   expand     = "EXPAND" other-params ":" ("TRUE" / "FALSE") CRLF

   Example: The following are examples of this property:

   EXPAND:FALSE
   EXPAND:TRUE

8.17 GRANT Property

   Property Name: GRANT

   Purpose: This property identifies the UPN(s) being granted access in
   the "VRIGHT" component.

   Value Type: UPN-FILTER

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: This property can be specified in "VRIGHT" calendar
   components.

   Description: This property is used in the "VRIGHT" component to
   specify the CU or UG being granted access.

   Formal Definition: The property is defined by the following notation:

   grant     = "GRANT" other-params ":" upn-filter CRLF
   Example: The following are examples of this property:

   GRANT:*

   GRANT:bob@example.com

8.18 ITIP-VERSION Property

   Property Name: ITIP-VERSION

   Purpose: This property specifies the version of ITIP supported.

   Value Type: TEXT

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: This property is specified in the "VREPLY" component
   that is sent in response to a "GET-CAPABILITY" command.

   Description: This specifies the version of ITIP that the endpoint
   supports. The list is a comma separated list of RFC numbers
   supported. The list MUST contain at least 2446 to mean [iTIP]

   Formal Definition: The property is defined by the following notation:

   itip-version   = "ITIP-VERSION" other-params ":" text CRLF

   Example: The following are examples of this property:

   ITIP-VERSION:2446

8.19 MAX-COMP-SIZE Property

   Property Name: MAX-COMP-SIZE

   Purpose: This property specifies the largest size of any object
   accepted.

   Value Type: TEXT
   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: This property is specified in the "VREPLY" component
   that is sent in response to a "GET-CAPABILITY" command.

   Description: A positive integer value that specifies the size of the
   largest iCalendar object that can be accepted in octets.  Objects
   larger than this will be rejected. A value of zero (0) means no
   limit. This is also the maximum value of any [BEEP] payload that will
   be accepted or sent.

   Formal Definition: The property is defined by the following notation:

   max-comp-size   = "MAX-COMP-SIZE" other-params ":" posint0 CRLF

   Example: The following are examples of this property:

   MAX-COMP-SIZE:1024

8.20 MAXDATE Property

   Property Name: MAXDATE

   Purpose: This property specifies the date/time in the future beyond
   which the CS or CUA cannot represent.

   Value Type: DATE-TIME

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: The property can be specified in the "VCALSTORE"
   component.

   Description: The date and time MUST BE a UTC value and end with 'Z'.

   Formal Definition: The property is defined by the following notation:

   maxdate    = "MAXDATE" other-params ":" date-time CRLF
   Example: The following is an example of this property:

   MAXDATE:20990101T000000Z

8.21 MINDATE Property

   Property Name: MINDATE

   Purpose: This property specifies the date/time in the past prior to
   which the server cannot represent.

   Value Type: DATE-TIME

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: The property can be specified in the "VCALSTORE"
   component.

   Description: The date and time MUST BE a UTC value and end with 'Z'.

   Formal Definition: The property is defined by the following notation:

   mindate    = "MINDATE" other-params ":" date-time CRLF

   Example: The following is an example of this property:

   MINDATE:19710101T000000Z

8.22 MULTIPART Property

   Property Name: MULTIPART

   Purpose: This property provides a comma separated list of supported
   MIME multipart types supported by the sender.

   Value Type: TEXT

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: This property is specified in the "VREPLY" component
   that is sent in response to a "GET-CAPABILITY" command.

   Description: This property is used in the in the "GET-CAPABILITY"
   command reply to indicated the MIME multipart types supported. A CS
   and CUA SHOULD support all registered MIME multipart types.

   Formal Definition: The property is defined by the following notation:

   mname = "MULTIPART" other-params ":" text *( "," text) CRLF

   Example: The following is an example of this property:

   MULTIPART:related,alternate,mixed

8.23 NAME Property

   Property Name: NAME

   Purpose: This property provides a localizable display name for a
   component.

   Value Type: TEXT

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: This property can be specified in a component.

   Description: This property is used in the in component to specify a
   localizable display name. If more than one "NAME" properties are in a
   component, then they MUST have unique "LANG" parameters. If the
   "LANG" parameter is not supplied, then it defaults to the "VAGENDA"
   components "DEFAULT-LOCALE" first value as the default. If the
   component is a "VAGENDA" then the default value is the "VAGENDA"s
   components "DEFAULT-LOCALE" first value as the default. A "VCALSTORE"
   components "DEFAULT-LOCALE" first value is the default if the
   component is stored at the "VCALSTORE" level.

   Formal Definition: The property is defined by the following notation:

   name = "NAME" nameparam ":" text CRLF
   nameparam = other-params [ ";" languageparam ] other-params

   languageparam = ; As defined in [iCAL].

   Example: The following is an example of this property:

   NAME:Restrict Guests From Creating VALARMs On VEVENTs

8.24 OWNER Property

   Property Name: OWNER

   Purpose: The property specifies an owner of the component.

   Value Type: UPN

   Property Parameters: Non-standard, alternate text representation and
   language property parameters can be specified on this property.

   Conformance: The property MUST BE specified at in a "VAGENDA"
   component.

   Description: A multi-instanced property indicating the calendar
   owner.

   Formal Definition: The property is defined by the following notation:

   owner = "OWNER" other-params ":" upn CRLF

   Example: The following is an example of this property:

   OWNER:jsmith@example.com
   OWNER:jdough@example.com

8.25 PERMISSION Property

   Property Name: PERMISSION

   Purpose: This property defines a permission that is granted or denied
   in a "VRIGHT" component.

   Value Type: TEXT

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: This property can be specified in "VRIGHT" components.

   Description: This property is used in the "VRIGHT" component to
   define a permission that is granted or denied.

   Formal Definition: The property is defined by the following notation:

   perm      = "PERMISSION" other-params ":" permvalue CRLF

   permvalue = ( "SEARCH" / "CREATE" / "DELETE"
               / "MODIFY" / "MOVE" / all
               / iana-cmd / x-cmd )

   all         = "*"

   iana-cmd    = ; Any command registered by IANA directly or
                 ; included in an RFC that may be applied as
                 ; a command.

   x-cmd       = ; Any experimental command that starts with
                 ; "x-" or "X-".

   Example: The following is an example of this property:

   PERMISSION:SEARCH

8.26 QUERY property

   Property Name: QUERY

   Purpose: Specifies the query for the component.

   Value Type: CAL-QUERY

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: This property can be specified in "VQUERY" components.

   Description: A "QUERY" is used to specify the "CAL-QUERY" (Section
   6.1.1 for the query.

   Formal Definition: The property is defined by the following notation:

   query      = "QUERY" other-params ":" cal-query CRLF

   Example: The following is an example of this property:

   QUERY:SELECT * FROM VEVENT

8.27 QUERYID property

   Property Name: QUERYID

   Purpose: Specifies a unique ID for a query in the targeted container.

   Value Type: TEXT

   Property Parameters: Non-standard property parameters are specified
   on this property.

   Conformance: This property can be specified in "VQUERY" components.

   Description: A "QUERYID" property is used to specify the unique id
   for a query. A "QUERYID" property value is unique per container.

   Formal Definition: The property is defined by the following notation:

   queryid      = "QUERYID" other-params ":" text CRLF

   Example: The following are examples of this property:

   QUERYID:Any Text String
   QUERYID:fetchUnProcessed

8.28 REQUEST-STATUS property

   This description is a revision of the "REQUEST-STATUS" property for
   [iCAL] objects with a "VCALENDAR" component "VERSION" property that
   includes a value of "2.0" or newer.  The 'statdesc' is optional and
   the 'extdata' may be included when 'statdesc' is not provided.

   rstatus  = "REQUEST-STATUS" rstatparam ":"
              statcode ";" [ statdesc ] ";" [ extdata ]

   rstatparam  = other-params [";" languageparam] other-params

   statcode  = 1*DIGIT *("." 1*DIGIT)
            ;Hierarchical, numeric return status code

   statdesc  = text
            ;An optional textual status description, content is
            ;decided by the implementer. May be empty.

    extdata  = text
            ; Textual exception data. For example, the offending
            ; property name and value or complete property line.

   Example: The following are some possible examples of this property.
   The COMMA and SEMICOLON separator characters in the property value
   are BACKSLASH character escaped because they appear in a text value.

   REQUEST-STATUS:2.0;Success

   REQUEST-STATUS:3.1;Invalid property value;DTSTART:96-Apr-01

   REQUEST-STATUS:2.8; Success\, repeating VEVENT ignored. Scheduled
   as a single VEVENT.;RRULE:FREQ=WEEKLY;INTERVAL=2

   REQUEST-STATUS:4.1;Time conflict. Date/time is busy.

   REQUEST-STATUS:3.7;Invalid calendar user;ATTENDEE:
   MAILTO:jsmith@example.com

   REQUEST-STATUS:3.7;;ATTENDEE:MAILTO:jsmith@example.com

   REQUEST-STATUS:10.4;Help! That really shouldn't have happened.

8.29 QUERY-LEVEL Property

   Property Name: QUERY-LEVEL

   Purpose: This property specifies the level of query supported.

   Value Type: TEXT

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: The property can be specified in the "VREPLY" component
   in response to a "GET-CAPABILITY" command.

   Description: Indicates level of query support. CAL-QL-NONE is for
   CS's that allow ITIP methods only to be deposited and nothing else.

   Formal Definition: The property is defined by the following notation:

   query-level = "QUERY-LEVEL" other-params
                 ":" ( "CAL-QL-1" / "CAL-QL-NONE") CRLF

   Example: The following is an example of this property:

   QUERY-LEVEL:CAL-QL-1

8.30 RECUR-ACCEPTED Property

   Property Name: RECUR-ACCEPTED

   Purpose: This property specifies if the endpoint supports recurring
   instances.

   Value Type: BOOLEAN

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: The property can be specified in the "VREPLY" component
   in response to a "GET-CAPABILITY" command.

   Description: Indicates if recurrence rules are supported. If FALSE
   then the endpoint can not process any kind of recurring rules.

   Formal Definition: The property is defined by the following notation:

   recur-accepted = "RECUR-ACCEPTED" other-params ":" boolean CRLF

   Example: The following is an example of this property:

   RECUR-ACCEPTED:TRUE
   RECUR-ACCEPTED:FALSE

8.31 RECUR-LIMIT Property

   Property Name: RECUR-LIMIT

   Purpose: This property specifies the maximum number of instances the
   endpoint will expand instances into at query or storage time.

   Value Type: INTEGER

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: The property can be specified in the "VREPLY" component
   in response to a "GET-CAPABILITY" command.

   Description: For implementations that have the "STORES-EXPANDED"
   value set to TRUE, then this value specifies the maximum number of
   instances that will be stored and fetched. For all implementations
   this is the maximum number of instances that will be returned when
   the "EXPAND" parameter is specified as TRUE and the results contain a
   infinite or large number of recurring instances.

   Formal Definition: The property is defined by the following notation:

   recur-limit = "RECUR-LIMIT" other-params ":" posint1 CRLF

   Example: The following is an example of this property:

   RECUR-LIMIT:1000

8.32 RECUR-EXPAND Property

   Property Name: RECUR-EXPAND

   Purpose: This property specifies if the endpoint can expand
   recurrences into multiple objects.

   Value Type: BOOLEAN

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: The property can be specified in the "VREPLY" component
   in response to a "GET-CAPABILITY" command.

   Description: If TRUE then the endpoint can expand an object into
   multiple instances as defined by its recurrence rules when the
   "EXPAND" property is supplied. If FALSE then the endpoint ignores the
   "EXPAND" property.

   Formal Definition: The property is defined by the following notation:

   recur-expand = "RECUR-EXPAND" other-params ":" boolean CRLF

   Example: The following is an example of this property:

   RECUR-EXPAND:TRUE
   RECUR-EXPAND:FALSE

8.33 RESTRICTION Property

   Property Name: RESTRICTION

   Purpose: This property defines restrictions on the result value of
   new or existing components.

   Value Type: CAL-QUERY

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: This property can be specified in "VRIGHT" components,
   but only when the "PERMISSION" property is set to "CREATE", "MODIFY",
   or "*" property value.

   Description: This property is used in the "VRIGHT" component to
   define restrictions on the components that can be written (i.e., by
   using the "CREATE" or "MOVE" commands) as well as on the values that
   may take existent calendar store properties, calendar properties,
   components, and  properties (i.e., by using the "MODIFY" command).
   Accepted values MUST match any specified "RESTRICTION" property
   values.

   Formal Definition: The property is defined by the following notation:

   restrict      = "RESTRICTION" other-params ":" cal-query CRLF

   Example: The following are examples of this property:

   RESTRICTION:SELECT * FROM VCALENDAR WHERE METHOD = 'REQUEST'

   RESTRICTION:SELECT * FROM VEVENT WHERE
   SELF() IN ORGANIZER

   RESTRICTION:SELECT * FROM VEVENT WHERE 'BUSINESS' IN
   CATEGORIES

8.34 SCOPE Property

   Property Name: SCOPE

   Purpose: This property identifies the objects in the CS to which the
   access rights applies.

   Value Type: CAL-QUERY

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: This property can be specified in "VRIGHT" components.

   Description: This property is used in the "VRIGHT" component to
   define the set of objects subject to the access right being defined.

   Formal Definition: The property is defined by the following notation:

   scope      = "SCOPE" other-params ":" cal-query CRLF

   Example: The following is an example of this property:

   SCOPE:SELECT DTSTART,DTEND FROM VEVENT WHERE CLASS = 'PUBLIC'

8.35 STORES-EXPANDED Property

   Property Name: STORES-EXPANDED

   Purpose: This property specifies if the sending endpoint expands
   recurrence rules prior to storing them into the CS.

   Value Type: BOOLEAN

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: This property can be specified in a "VREPLY" component
   in response to a "GET-CAPABILITY" command.

   Description: If the value is TRUE then the endpoint expands
   recurrence rules and then stores the results into the CS. If this is
   TRUE then the "RECUR-LIMIT" property is significant because an
   infinitely recurring appointment will be stored no more than
   "RECUR-LIMIT" property values into the CS and all other instances
   will be lost.

   Formal Definition: The property is specified by the following
   notation:

   stores-expanded   = "STORES-EXPANDED" other-params ":" boolean CRLF

   The following is an example of this property:

   STORES-EXPANDED:TRUE
   STORES-EXPANDED:FALSE

8.36 TARGET Property

   Property Name: TARGET

   Purpose: This property defines the container that the command that is
   issued will act upon. Its value is a capurl as defined in Section 5.

   Value Type: URI

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: This property can be specified in a command component.

   Description: This property value is used to specify the container
   that the command will effect. When used in a command, the command
   will be performed on the container which has a capurl matching the
   value.

   Formal Definition: The property is specified by the following
   notation:

   target   = "TARGET" other-params ":" ( capurl / relcalid ) CRLF

   The following is an example of this property:

   TARGET:cap://mycal.example.com
   TARGET:SomeRelCalid

8.37 TRANSP Property

   Property Name: TRANSP

   Purpose: This property defines whether an component is transparent or
   not to busy time searches. This is a modification to [iCAL] "TRANSP"
   property in that it adds some values.

   Value Type: TEXT

   Property Parameters: Non-standard property parameters can be
   specified on this property.

   Conformance: This property can be specified in a component.

   Description: Time Transparency is the characteristic of an object
   that determines whether it appears to consume time on a calendar.
   Objects that consume actual time for the individual or resource
   associated with the calendar SHOULD be recorded as "OPAQUE", allowing
   them to be detected by free-busy time searches. Other objects, which
   do not take up the individual's (or resource's) time SHOULD be
   recorded as "TRANSPARENT", making them invisible to free-busy time
   searches.

   Formal Definition: The property is specified by the following
   notation:

   transp   = "TRANSP" other-params ":" transvalue CRLF

   transvalue
            = "OPAQUE" ;Blocks or opaque on busy time searches.
            / "TRANSPARENT"    ;Transparent on busy time searches.

            / "TRANSPARENT-NOCONFLICT" ; Transparent on busy time
            ; searches and no other OPAQUE or OPAQUE-NOCONFLICT objects
            ; can overlap it.

            / "OPAQUE-NOCONFLICT"  ; Opaque on busy time
            ; searches and no other OPAQUE or OPAQUE-NOCONFLICT objects
            ; can overlap it.
            ;
            ;Default value is OPAQUE

   The following is an example of this property for an object that is
   opaque or blocks on free/busy time searches plus no other object can
   overlap it:

   TRANSP:OPAQUE-NOCONFLICT

9. New Components

9.1 VAGENDA Component

   Component Name: VAGENDA

   Purpose: Provide a grouping of properties that defines an agenda.

   Formal Definition: There are two formats of the "VAGENDA" component.
   (1) When it is being created, and (2) how it exists in the
   "VCALSTORE" component.

   A "VAGENDA" component in a "VCALSTORE" component is defined by the
   following notes and ABNF notation:

   CALSCALE -  The value MUST BE from the "VCALSTORE" "CALSCALE"
      property list. The default is the first entry in the VCALSTORE
      CALSCALE list.

   CREATED -  The timestamp of the calendar's create date. This is a
      READ ONLY property in a "VAGENDA".

   LAST-MODIFIED - The timestamp of any change to the "VAGENDA"
      properties or when any component was last created, modified, or
      deleted.

   agenda      = "BEGIN" ":" "VAGENDA" CRLF
                 agendaprop
                 *(icalobject)     ; as defined in [iCAL]
                 "END" ":" "VAGENDA" CRLF

   agendaprop  = *(
                 ; The following MUST occur exactly once.
                 ;
                   allow-conflict / relcalid / calscale / created
                 / default-charset / default-locale
                 / default-tzid / last-mod /

                 ; The following MUST occur at least once.
                 ; and the value MUST NOT be empty.

                 / owner

                 ; The following are optional,
                 ; and MAY occur more than once.

                 / name / related-to / other-props / x-comp
               )

   When creating a VAGENDA, use the following notation:

   agendac     = "BEGIN" ":" "VAGENDA" CRLF
                 agendacprop
                 *(icalobject)     ; as defined in [iCAL]
                 "END" ":" "VAGENDA" CRLF

   agendacprop  = *(
                  ; The following MUST occur exactly once.
                  ;
                    allow-conflict / relcalid / calscale
                  / default-charset / default-locale
                  / default-tzid /

                  ; The following MUST occur at least once.
                  ; and the value MUST NOT be empty.
                  ;
                  / owner

                  ; The following are optional,
                  ; and MAY occur more than once.
                  ;
                  / name / related-to / other-props / x-comp
                 )

   To fetch all of the properties from the targeted "VAGENDA" component.
   This does not fetch any components:

   SELECT * FROM VAGENDA

   To fetch all of the properties from the targeted VAGENDA and all of
   the contained components, use the special '*.*' value:

   SELECT *.* FROM VAGENDA

9.2 VCALSTORE Component

   Component Name: VCALSTORE

   Purpose: Provide a grouping of properties that defines a calendar
   store.

   Formal Definition: A "VCALSTORE" component is defined by the
   following table and ABNF notation. The creation of a "VCALSTORE"
   component is an administrative task and not part of the CAP protocol.

   The following are notes to some of the properties in the "VCALSTORE"
   component.

   CALSCALE -  A comma separated list of CALSCALEs supported by this CS.
      All "VAGENDA" component calendar CALSCALE properties MUST BE from
      this list. This list MUST contain at least "GREGORIAN". The
      default for newly created "VAGENDA" components is the first entry.

   RELATED-TO -  This is a multiple instance property. There must be a
      "RELATED-TO" property MUST for each of the "VAGENDA" components
      contained in the "VCALSTORE" component each with the "RELTYPE"
      parameter value set to "CHILD". Other "RELATED-TO" properties may
      be included.

   CREATED -  The timestamp of the CS creation time. This is a READ ONLY
      property.

   CSID -  The CSID of this calendar store. MUST NOT be empty. How this
      property is set in the VCALSTORE is an administrative or
      implementation specific issue and is not covered in CAP. This is a
      READ ONLY property. A suggested value is the fully qualified host
      name or a fully qualified virtual host name supported by the
      system.

   LAST-MODIFIED -  The timestamp when the Properties of the "VCALSTORE"
      component were last updated or calendars were created or deleted.
      This is a READ ONLY PROPERTY.

   calstorec     = "BEGIN" ":" "VCALSTORE" CRLF
             calstoreprop
                *(vagendac)
             "END" ":" "VCALSTORE" CRLF

   calstoreprop  = *(
                     ; the following MUST occur exactly once
                       allow-conflict / calscale / calmaster
                     / created / csid / default-charset
                     / default-locale / default-vcars
                     / default-tzid / last-mod / maxdate / mindate

                     ; the following are optional,
                     ; and MAY occur more than once

                     / name / related-to / other-props / x-comp
                    )

   last-mod     = ; As defined in [iCAL].

   To fetch all of the properties from the targeted VCALSTORE and not
   fetch the calendars that it contains:

   SELECT * FROM VCALSTORE

   To fetch all of the properties from the targeted "VCALSTORE"
   component and all of the contained calendars and all of those
   calendars contained properties and components, use the special '*.*'
   value:

   SELECT *.* FROM VCALSTORE

9.3 VCAR Component

   Component Name: VCAR

   Purpose: Provide a grouping of calendar access rights.

   Formal Definition: A "VCAR" component is defined by the following
   notation:

   carc    =  "BEGIN" ":" "VCAR" CRLF
              carprop 1*rightc
              "END" ":" "VCAR" CRLF

   carprop = 1*(
           ; 'carid' is REQUIRED,
           ; but MUST NOT occur more than once

            carid /

           ; the following are OPTIONAL,
           ; and MAY occur more than once

            name / decreed / other-props
           )

   Description: A "VCAR" component is a grouping of properties, and
   "VRIGHT" components, that represents access rights granted or denied
   to UPNs.

   The "CARID" property specifies the local identifier for the "VCAR"
   component.  The "NAME" property specifies a localizable display name.

   Example: In the following example, the UPN "foo@example.com" is given
   search access to the "DTSTART" and "DTEND" VEVENT properties.  No
   other access is specified:

   BEGIN:VCAR
   CARID:View Start and End Times
   NAME:View Start and End Times
   BEGIN:VRIGHT
   GRANT:foo@example.com
   PERMISSION:SEARCH
   SCOPE:SELECT DTSTART,DTEND FROM VEVENT
   END:VRIGHT
   END:VCAR

   In this example, all UPNs are given search access to "DTSTART" and
   "DTEND" properties of VEVENT components. "All CUs and UGs" are
   specified by the UPN value "*".  Note that this enumerated UPN value
   is not in quotes:

   BEGIN:VCAR
   CARID:ViewStartEnd2
   NAME:View Start and End Times 2
   BEGIN:VRIGHT
   GRANT:*
   PERMISSION:SEARCH
   SCOPE:SELECT DTSTART,DTEND FROM VEVENT
   END:VRIGHT
   END:VCAR

   In these examples, full calendar access rights are given to the
   CAL-OWNERS(), and a hypothetical administrator is given access rights
   to specify calendar access rights.  If no other rights are specified,
   only these two UPNs can specify calendar access rights:

   BEGIN:VCAR
   CARID:some-id-3
   NAME:Only OWNER or ADMIN Settable VCARs
   BEGIN:VRIGHT
   GRANT:CAL-OWNERS()
   PERMISSION:*
   SCOPE:SELECT * FROM VAGENDA
   END:VRIGHT
   BEGIN:VRIGHT
   GRANT:cal-admin@example.com
   PERMISSION:*
   SCOPE:SELECT * FROM VCAR
   RESTRICTION:SELECT * FROM VCAR
   END:VRIGHT
   END:VCAR

   In this example, rights to write, search, modify or delete calendar
   access rights are denied to all UPNs.  This example would disable
   providing different access rights to the calendar store or calendar.
   This calendar access right should be specified with great care, as it
   removes the ability to change calendar access; even for the owner or
   administrator. It could be used by small devices that do not support
   the changing of any VCAR:

   BEGIN:VCAR
   CARID:VeryRestrictiveVCAR-2
   NAME:No CAR At All
   BEGIN:VRIGHT
   DENY:*
   PERMISSION:*
   SCOPE:SELECT * FROM VCAR
   END:VRIGHT
   END:VCAR

9.4 VRIGHT Component

   Component Name: "VRIGHT"

   Purpose: Provide a grouping of properties that describe an access
   right (granted or denied).

   Formal Definition: A "VRIGHT" component is defined by the following
   notation:

   rightc    = "BEGIN" ":" "VRIGHT" CRLF
               rightprop
               "END" ":" "VRIGHT" CRLF

   rightprop = 2*(

             ; either 'grant' or 'deny' MUST
             ; occur at least once
             ; and MAY occur more than once

              grant / deny /

             ; 'permission' MUST occur at least once
             ; and MAY occur more than once

              permission /

             ; the following are optional,
             ; and MAY occur more than once

              scope / restriction / other-props

          )

   Description: A "VRIGHT" component is a grouping of calendar access
   right properties.

   The "GRANT" property specifies the UPN that is being granted access.
   The "DENY" property specifies the UPN is being denied access. The
   "PERMISSION" property specifies the actual permission being set. The
   "SCOPE" property identifies the calendar store properties, calendar
   properties, components, or properties to which the access right
   applies.  The "RESTRICTION" property specifies restriction on the
   value that may take calendar store properties, calendar properties,
   calendar components, and properties after a "CREATE" or "MODIFY"
   command. Values MUST match all the instances of the "RESTRICTION"
   property to be valid.

9.5 VREPLY Component

   Component Name: "VREPLY"

   Purpose: Provide a grouping of arbitrary properties and components
   that are the data set result from an issued command.

   Formal Definition: A "VREPLY" component is defined by the following
   notation:

   replyc           =  "BEGIN" ":" "VREPLY" CRLF
                       any-prop-or-comp
                       "END" ":" "VREPLY" CRLF

   any-prop-or-comp = ; Zero or more iana or experimental
                      ; properties and components, in any order.

   Description: Provide a grouping of arbitrary properties and
   components that are the data set result from an issued command.

   A query can return a predictable set of arbitrary properties and
   components. This component is used by query and other commands to
   return data that does not fit into any other component. It may
   contain any valid property or component, even if they are not
   registered.

9.6 VQUERY Component

   Component Name: VQUERY

   Purpose: A component describes a set of objects to be acted upon.

   Formal Definition: A "VQUERY" component is defined by the following
   notation:

   queryc    =  "BEGIN" ":" "VQUERY" CRLF
                queryprop
                "END" ":" "VCAR" CRLF

   queryprop = 1*(

             ; 'queryid' is OPTIONAL but MUST NOT occur
             ; more than once. If the "TARGET" property
             ; is supplied then the "QUERYID" property
             ; MUST BE supplied.
             ;
              queryid / target

             ; 'expand' is OPTIONAL but MUST NOT occur
             ; more than once.

              expand

             ; the following are OPTIONAL, and MAY occur
             ; more than once
             ;
             / name / other-props

             ; the following MUST occur at least once if
             ; queryid is not supplied.
             ;
             / query

           )

   Description: A "VQUERY" contains properties that describe which
   properties and components the CS is requested to act upon.

   The "QUERYID" property specifies the local identifier for a "VQUERY"
   component.

   For a search, if the "TARGET" property is supplied in a "VQUERY"
   component, then the CS is to search for the query in the CALID
   supplied by the "TARGET" property value.

   For a create the "TARGET" property MUST NOT be supplied as the
   destination container is already supplied in the "TARGET" property of
   the "VCALENDAR" component.

   For examples, see Section 6.1.1.

10. Commands and Responses

   CAP commands and responses are described in this section.

10.1 CAP Commands (CMD)

   All commands are send using the CMD property.

   Property Name: CMD

   Purpose: The property defines the command to be sent.

   Value Type: TEXT

   Property Parameters: Non-standard, id, localize, latency, action or
   options.

   Conformance: This property is the method used to specify the commands
   to a CS and can exist in any object sent to the CS.

   Description: All of the commands to the CS are supplied in this
   property. The "OPTIONS" parameter is overloaded and its meaning is
   dependent on the CMD value supplied.

   Formal Definition: The property is defined by the following notation:

   cmd              = "CMD" (
                    / abort-cmd
                    / continue-cmd
                    / create-cmd
                    / delete-cmd
                    / generate-uid-cmd
                    / get-capability-cmd
                    / identify-cmd
                    / modify-cmd
                    / move-cmd
                    / reply-cmd
                    / search-cmd
                    / set-locale-cmd
                    / iana-cmd
                    / x-cmd
                     ) CRLF

   option-value     = paramtext ; As defined in [iCAL]

   Calendaring commands allow a CUA to directly manipulate a calendar.

   Calendar access rights can be granted or denied for any commands.

10.1.1 Bounded Latency

   A CAP command can have an associated maximum latency time by
   specifying the "LATENCY" parameter.  If the command is unable to be
   completed in the specified amount of time (as specified by the
   "LATENCY" parameter value with an "ACTION" parameter set to the "ASK"
   value), then a "TIMEOUT" command MUST BE sent on the same channel" to
   which there MUST BE a an "ABORT" or a "CONTINUE" command reply. If
   the CUA initiated the original command, then the CS would issue the
   "TIMEOUT" command and the CUA would then have to issue an "ABORT" or
   "CONTINUE" command. If the CS initiated the original command then the
   CUA would have to issue the "TIMEOUT" and the CS would send the
   "ABORT" or "CONTINUE".

   Upon receiving an "ABORT" command, the command must then be
   terminated. Only the "ABORT", "TIMEOUT", "REPLY, and "CONTINUE"
   commands can not be aborted. The "ABORT", "TIMEOUT", and "REPLY"
   commands MUST NOT have latency set.

   Upon receiving a "CONTINUE" command the work continues as if it had
   not been delayed or stopped. Note that a new latency time MAY BE
   included in a "CONTINUE" command indicating to continue the original
   command until the "LATENCY" parameter value expires or the results of
   the original command can be returned.

   Both the "LATENCY" parameter and the "ACTION" parameter MUST BE
   supplied to any "CMD" property, or nether can be added to the "CMD"
   property. The "LATENCY" parameter MUST BE set to the maximum latency
   time in seconds.  The "ACTION" parameter accepts the following
   values: "ASK" and "ABORT" parameters.

   If the maximum latency time is exceeded and the "ACTION" parameter is
   set to the "ASK" value, then "TIMEOUT" command MUST BE sent.
   Otherwise if the "ACTION" parameter is set to the "ABORT" value then
   the command MUST BE terminated and return a REQUEST-STATUS code of
   2.0.3 for the original command.

   If a CS can both start sending the reply to a command and guarantee
   that all of the results can be sent from a command (short of
   something like network or power failure) prior to the "LATENCY"
   timeout value then the "LATENCY" time has not expired.

   Example:

   In this example the initiator asks for the listeners capabilities.

   I: Content-Type: text/calendar
   I:
   I: BEGIN:VCALENDAR
   I: VERSION:2.0
   I: PRODID:The CUA's PRODID
   I: CMD;ID=xyz12346;LATENCY=3;ACTION=ask:GET-CAPABILITY
   I: END:VCALENDAR

   # After 3 seconds

   L: Content-Type: text/calendar
   L:
   L: BEGIN:VCALENDAR
   L: PRODID:-//someone's prodid
   L: VERSION:2.0
   L: CMD;ID=xyz12346:TIMEOUT
   L: END:VCALENDAR

   In order to continue and give the CS more time then the CUA would
   issue a "CONTINUE" command:

   I: Content-Type: text/calendar
   I:
   I: BEGIN:VCALENDAR
   I: VERSION:2.0
   I: PRODID:-//someone's prodid
   I: CMD;ID=xyz12346;LATENCY=3;ACTION=ask:CONTINUE
   I: END:VCALENDAR

   L: Content-Type: text/calendar
   L:
   L: BEGIN:VCALENDAR
   L: VERSION:2.0
   L: PRODID:-//someone's prodid
   L: CMD;ID=xyz12346:REPLY
   L: BEGIN:VREPLY
   L: REQUEST-STATUS:2.0.3;Continued for 3 more seconds
   L: END:VREPLY
   L: END:VCALENDAR

   Above the "2.0.3" status is returend because it is not an error, it
   is a progress status sent in reply to the "CONTINUE" command.

   To abort the command and not wait any further then issue an "ABORT"
   command:

   I: Content-Type: text/calendar
   I:
   I: BEGIN:VCALENDAR
   I: VERSION:2.0
   I: PRODID:-//someone's prodid
   I: CMD;ID=xyz12346:ABORT
   I: END:VCALENDAR

   # Which would result in a 2.0.3 reply.

   L: Content-Type: text/calendar
   L:
   L: BEGIN:VCALENDAR
   L: VERSION:2.0
   L: PRODID:-//someone's prodid
   L: CMD;ID=xyz12346:REPLY
   L: BEGIN:VREPLY
   L: REQUEST-STATUS:2.0.3;Aborted As Requested.
   L: END:VREPLY
   L: END:VCALENDAR

   If the "ACTION" value had been set to "ABORT", then the listiner
   would send a "7.0" error on timeout in the reply to the command that
   initiated the command that timed out.

10.2 ABORT Command

   CMD: ABORT

   Purpose: The "ABORT" command is sent to request that the named or
   only in process command be aborted. Latency MUST not be supplied with
   the "ABORT" command.

   Formal Definition: An "ABORT" command is defined by the following
   notation:

    abort-cmd   = abortparam ":" "ABORT"

   abortparam   = *(

             ; the following are optional,
             ; but MUST NOT occur more than once

               id-param
             / localize-param
             ; the following is optional,
             ; and MAY occur more than once

             / other-params

             )

   The REPLY of any "ABORT" command is:

   abort-reply  = "BEGIN" ":" "VCALENDAR" CRLF
                calprops
                abort-vreply
               "END" ":" "VCALENDAR" CRLF

   abort-vreply  = "BEGIN" ":" "VREPLY" CRLF
                 request-status
                 other-props
                "END" ":" "VREPLY" CRLF

10.3 CONTINUE Command

   CMD: CONTINUE

   Purpose: The "CONTINUE" command is only sent after a "TIMEOUT"
   command has been received to inform the other end of the session to
   resume working on a command.

   Formal Definition: A "CONTINUE" command is defined by the following
   notation:

   continue-cmd   = continueparam ":" "CONTINUE"

   continueparam   = *(

                   ; the following are optional,
                   ; but MUST NOT occur more than once

                     id-param
                   / localize-param
                   / latency-param

                   ; the following MUST occur exactly once and only
                   ; when the latency-param has been supplied and
                   ; MUST NOT be supplied if the latency-param is
                   ; not supplied.

                   / action-param

                   ; the following are optional,
                   ; and MAY occur more than once

                   / other-params
                   )

   The REPLY of any "CONTINUE" command is:

   continue-reply   = "BEGIN" ":" "VCALENDAR" CRLF
                      calprops
                      continue-vreply
                      "END" ":" "VCALENDAR" CRLF

   continue-vreply  = "BEGIN" ":" "VREPLY" CRLF
                      request-status
                      other-props
                      "END" ":" "VREPLY" CRLF

10.4 CREATE Command

   CMD: CREATE

   Purpose:  The "CREATE" command is used to create one or more
   iCalendar objects in the store in the "BOOKED" or "UNPROCESSED"
   state.

   A CUA MAY send a "CREATE" command to a CS. The "CREATE" command MUST
   BE implemented by all CSs.

   The CS MUST NOT send a "CREATE" command to any CUA.

   Formal Definition: A "CREATE" command is defined by the following
   notation and the hierarchy restrictions as defined in Section 3.2:

   create-cmd     = createparam ":" "CREATE"

   createparam    = *(

                  ; the following are optional,
                  ; but MUST NOT occur more than once
                    id-param
                  / localize-param
                  / latency-param

                  ; the following MUST occur exactly once and only
                  ; when the latency-param has been supplied and
                  ; MUST NOT be supplied if the latency-param is
                  ; not supplied.

                  / action-param

                  ; the following is optional,
                  ; and MAY occur more than once

                  / other-params
                 )

   Response:

   One iCalendar object per TARGET property MUST BE returned.

   The REPLY of any "CREATE" command is:

   Restriction Table for the iCalendar section of a reply that contains
   an iCalendar object is any valid [iTIP] response plus any from this
   ABNF:

   create-reply   = "BEGIN" ":" "VCALENDAR" CRLF
                     creply-props
                     1*(create-vreply)
                     "END" ":" "VCALENDAR" CRLF

   create-vreply  = "BEGIN" ":" "VREPLY" CRLF
                    created-id
                    request-status
                    other-props
                    "END" ":" "VREPLY" CRLF

                  ; Where the id is appropriate for the
                  ; type of object created:
                  ;
                  ; VAGENDA = relcalid
                  ; VALARM = sequence
                  ; VCAR = carid
                  ; VEVENT, VFREEBUSY, VJOURNAL, VTODO = uid
                  ; VQUERY = queryid
                  ; VTIMEZONE = tzid
                  ; x-component = x-id
                  ;
   created-id    = ( relcalid / carid / uid / queryid /
                     tzid / sequence / x-id)

   x-id          = ; An ID for an x-component.

   creply-props  = 4*(
                  ; These are REQUIRED and MUST NOT occur
                  ; more than once.
                  ;
                    prodid /version / target / reply-cmd

                  ; These are optional, and may occur more
                  ; than once.
                  ;
                    other-props

   For a "CREATE" command the "TARGET" property specifies the containers
   where the components will be created.

   If the iCalendar object being created does not have a "METHOD"
   property, then is not an [iTIP] object, then its state will be
   "BOOKED". Use the "DELETE" command to set the state of an object to
   the "DELETED" state (tagged for deletion). A CUA can not use the
   "CREATE" command to create an object in the "DELETED" state.

   If the intention is to book an [iTIP] object then the "METHOD"
   property MUST NOT BE supplied. Otherwise any [iTIP] object MUST have
   a valid [iTIP] "METHOD" property value and it is a scheduling request
   being deposited into the CS and will have its state set to
   "UNPROCESSED" state.

   ABNF for a "CREATE" object is:

   create-object = "BEGIN" ":" "VCALENDAR" CRLF
                 ; If 'calprops' contain the "METHOD" property
                 ; then this 'create-object' component MUST
                 ; conform to [iTIP] restrictions.
                 ;
                 ; calprops MUST include 'create-cmd'
                 ;
                   calprops
                   other-props
                   1*(create-comp)
                   "END" ":" "VCALENDAR" CRLF

                 ; NOTE: The 'VCALSTORE' component is not included in
                 ; 'create-comp' as it is out of scope for CAP to create
                 ; a new CS.
                 ;
    create-comp =  agendac / carc / queryc
                  / timezonec / freebusyc
                  / eventc / todoc / journalc
                  / iana-comp / x-component

   In the following example two new top level "VAGENDA" components are
   created. Note that the "CSID" value  of the server is cal.example.com
   which is  where the new "VAGENDA" components are going to be created.

   C: Content-Type: text/calendar
   C:
   C: BEGIN:VCALENDAR
   C: PRODID:-//someone's prodid
   C: VERSION:2.0
   C: CMD;ID=creation01:CREATE
   C: TARGET:cal.example.com
   C: BEGIN:VAGENDA                 <- data for 1st new calendar
   C: CALID:relcalz1
   C: NAME;LANGUAGE=en_US:Bill's Soccer Team
   C: OWNER:bill
   C: CALMASTER:mailto:bill@example.com
   C: TZID:US/Pacific
   C: END:VAGENDA
   C: BEGIN:VAGENDA                 <- data for 2nd new calendar
   C: CALID:relcalz2
   C: NAME;LANGUAGE=EN-us:Mary's personal calendar
   C: OWNER:mary
   C: CALMASTER:mailto:mary@example.com
   C: TZID:US/Pacific
   C: END:VAGENDA
   C: END:VCALENDAR

   S: Content-Type: text/calendar
   S:
   S: BEGIN:VCALENDAR
   S: VERSION:2.0
   S: PRODID:-//someone's prodid
   S: CMD;ID=creation01:REPLY
   S: TARGET:cal.example.com
   S: BEGIN:VREPLY                    <- Reply for 1st calendar create
   S: CALID:relcalz1
   S: REQUEST-STATUS:2.0
   S: END:REPLY
   S: BEGIN:VREPLY                    <- Reply for 2nd calendar create
   S: CALID:relcalz2
   S: REQUEST-STATUS:2.0
   S: END:VREPLY
   S: END:VCALENDAR

   To create a new component in multiple containers simply name all of
   the containers in the "TARGET" in the create command. Here a new
   "VEVENT" component is created in two TARGET components. In this
   example, the "VEVENT" component is one new [iTIP] "REQUEST" to be
   stored in two calendars. The results would be iCalendar objects that
   conform to the [iTIP] replies as defined in [iTIP].

   This example shows two [iTIP] "VEVENT" components being created in
   each of the two supplied "TARGET" properties and as it contains the
   "METHOD" property they will be stored in the "UNPROCESSED" state:

   C: Content-Type: text/calendar
   C:
   C: BEGIN:VCALENDAR
   C: VERSION:2.0
   C: PRODID:-//someone's prodid
   C: CMD;ID=creation02:CREATE
   C: METHOD:REQUEST
   C: TARGET:relcalz1
   C: TARGET:relcalz2
   C: BEGIN:VEVENT
   C: DTSTART:20030307T180000Z
   C: UID:FirstInThisExample-1
   C: DTEND:20030307T190000Z
   C: SUMMARY:Important Meeting
   C: END:VEVENT
   C: BEGIN:VEVENT
   C: DTSTART:20040307T180000Z
   C: UID:SecondInThisExample-2
   C: DTEND:20040307T190000Z
   C: SUMMARY:Important Meeting
   C: END:VEVENT
   C: END:VCALENDAR

   The CS sends the "VREPLY" commands in separate MIME objects, one per
   supplied "TARGET" property value.

   S: Content-Type: text/calendar
   S:
   S: BEGIN:VCALENDAR
   S: VERSION:2.0
   S: PRODID:-//someone's prodid
   S: CMD;ID=creation02:REPLY
   S: TARGET:relcalz1    <- 1st TARGET listed.
   S: BEGIN:REPLY        <- Reply for 1st VEVENT create in 1st TARGET.
   S: UID:FirstInThisExample-1
   S: REQUEST-STATUS:2.0
   S: END:VREPLY
   S: BEGIN:REPLY        <- Reply for 2nd VEVENT crate in 1st TARGET.
   S: UID:SecondInThisExample-2
   S: REQUEST-STATUS:2.0
   S: END:VREPLY
   S: END:VCALENDAR

   And the second reply for the 2nd TARGET:

   S: Content-Type: text/calendar
   S:
   S: BEGIN:VCALENDAR
   S: VERSION:2.0
   S: PRODID:-//someone's prodid
   S: CMD;ID=creation02:REPLY
   S: TARGET:relcalz2    <- 2nd TARGET listed
   S: BEGIN:REPLY        <- Reply for 1st VEVENT create in 2nd TARGET.
   S: UID:FirstInThisExample-1
   S: REQUEST-STATUS:2.0
   S: END:VREPLY
   S: BEGIN:REPLY        <- Reply for 2nd VEVENT crate in 2nd TARGET.
   S: UID:SecondInThisExample-2
   S: REQUEST-STATUS:2.0
   S: END:VREPLY
   S: END:VCALENDAR

10.5 DELETE Command

   CMD: DELETE

   Purpose: The "DELETE" command physically removes the QUERY result
   from the store or marks it for deletion.

   A CUA MAY send a "DELETE" command to a CS. The "DELETE" command MUST
   BE implemented by all CSs.

   The CS MUST NOT send a "DELETE" command to any CUA.

   Formal Definition: A "DELETE" command is defined by the following
   notation:

   delete-cmd   = deleteparam ":" "DELETE"

   deleteparam  = *(

                ; the following are optional,
                ; but MUST NOT occur more than once
                ;
                 id-param
                / localize-param
                / latency-param
                / option-param "MARK"

                ; The following MUST occur exactly once and only
                ; when the latency-param has been supplied and
                ; MUST NOT be supplied if the latency-param is
                ; not supplied.
                ;
                / action-param

                ; the following is optional,
                ; and MAY occur more than once
                ;
                / other-params
               )

   The "DELETE" command is used to delete calendars or components. The
   included "VQUERY" component(s) specifies the container(s) to delete.

   If a component is to be marked for delete and not physically removed,
   then include the "OPTIONS" parameter with its value set to the "MARK"
   value in order to alter its state to "DELETED".

   When components are deleted, only the top most component
   "REQUEST-STATUS" properties are returned. No "REQUEST-STATUS"
   properties are returned for components inside of the selected
   components. There MUST BE one "VREPLY" component returned for each
   object that is deleted or marked for delete. Note that if no "VREPLY"
   components are returned then nothing matched and nothing was deleted.

   Restriction Table for the "REPLY" command for any "DELETE" command.

   delete-reply   = "BEGIN" ":" "VCALENDAR" CRLF
                    calprops   ; MUST include 'reply-cmd'
                    *(delete-vreply)
                    "END" ":" "VCALENDAR" CRLF

   delete-vreply  = "BEGIN" ":" "VREPLY" CRLF
                    deleted-id
                    request-status
                    "END" ":" "VREPLY" CRLF

                   ; Where the id is appropriate for the
                   ; type of object deleted:
                   ;
                   ; VAGENDA = relcalid
                   ; VCAR = carid
                   ; VEVENT, VFREEBUSY, VJOURNAL, VTODO = uid
                   ; VQUERY = queryid
                   ; ALARM = sequence
                   ; VTIMEZONE = tzid
                   ; x-component = x-id
                   ; An instance = uid recurid
                   ;
   deleted-id    = ( relcalid / carid / uid / uid recurid
                  / queryid / tzid / sequence / x-id )

   Example to delete a "VEVENT" component with "UID" value of
   'abcd12345' from the calendar "relcald-22" from the current CS:

   C: Content-Type: text/calendar
   C:
   C: BEGIN:VCALENDAR
   C: TARGET:relcalid-22
   C: CMD;ID:"random but unique per CUA":DELETE
   C: BEGIN:VQUERY
   C: QUERY:SELECT VEVENT FROM VAGENDA WHERE UID = 'abcd12345'
   C: END:VQUERY
   C: END:VCALENDAR

   S: BEGIN:VCALENAR
   S: TARGET:relcalid-22
   S: CMD;ID:"random but unique per CUA":REPLY
   S: BEGIN:VREPLY
   S: UID:abcd12345
   S: REQUEST-STATUS:3.0
   S: END:VREPLY
   S: END:VCALENDAR

   One or more iCalendar objects will be returned that contain a
   "REQUEST-STATUS" properties for the deleted components. There could
   have been more than one component deleted. Any booked and any number
   of unprocessed [iTIP] scheduling components that matched the QUERY
   value in the above example. Each unique "METHOD" property value that
   was deleted from the store MUST BE in a separate iCalendar object.
   This is because only one "METHOD" property is allowed in a single
   "VCALENDAR" BEGIN/END block.

10.6 GENERATE-UID Command

   CMD: GENERATE-UID

   Purpose: The "GENERATE-UID" command returns one or more unique
   identifiers which MUST BE globally unique.

   The "GENERATE-UID" command MAY BE sent to any CS. The "GENERATE-UID"
   command MUST BE implemented by all CSs.

   The "GENERATE-UID" command MUST NOT be sent to a CUA.

   Formal Definition: A "GENERATE-UID" command is defined by the
   following notation:

   generate-uid-cmd   = genuidparam ":" "GENERATE-UID"

   genuidparam     = *(

                   ; The following are optional,
                   ; but MUST NOT occur more than once.

                     id-param
                   / localize-param
                   / latency-param

                   ; The following MUST occur exactly once and only
                   ; when the latency-param has been supplied and
                   ; MUST NOT be supplied if the latency-param is
                   ; not supplied.

                   / action-param
                   ; The following is optional,
                   ; and MAY occur more than once.

                   / other-params

                   ; The following MUST BE supplied exactly once.
                   ; The value specifies the number of UIDs to
                   ; be returned.

                   / option-param posint1

                 )

   Response:

   gen-reply   = "BEGIN" ":" "VCALENDAR" CRLF
                 calprops              ; Which MUST include 'reply-cmd'
                 1*(gen-vreply)
                 "END" ":" "VCALENDAR" CRLF

   gen-vreply  = "BEGIN" ":" "VREPLY" CRLF
                 1*(uid)
                 request-status
                 "END" ":" "VREPLY" CRLF

   Example:

   C: BEGIN:VCALENDAR
   C: VERSION:2.0
   C: PRODID:-//someone's prodid
   C: CMD;ID=unique-per-cua-124;OPTIONS=5:GENERATE-UID
   C: END:VCALENDAR

   S: Content-Type: text/calendar
   S:
   S: BEGIN:VCALENDAR
   S: VERSION:2.0
   S: PRODID:-//someone's prodid
   S: CMD;ID=unique-per-cua-124:REPLY
   S: BEGIN:VREPLY
   S: UID:20011121T120000Z-12340@cal.example.com
   S: UID:20011121T120000Z-12341@cal.example.com
   S: UID:20011121T120000Z-12342@cal.example.com
   S: UID:20011121T120000Z-12343@cal.example.com
   S: UID:20011121T120000Z-12344@cal.example.com
   S: REQUEST-STATUS:2.0
   S: END:VREPLY
   S: END:VCALENDAR

10.7 GET-CAPABILITY Command

   CMD: GET-CAPABILITY

   Purpose: The "GET-CAPABILITY" command returns the capabilities of the
   other end point of the session.

   A CUA MUST send a "GET-CAPABILITY" command to a CS after the initial
   connection. A CS MUST send a "GET-CAPABILITY" command to a CUA after
   the initial connection. The "GET-CAPABILITY" command and reply MUST
   BE implemented by all CSs and CUAs.

   Formal Definition: A "GET-CAPABILITY" command is defined by the
   following notation:

   get-capability-cmd   = capibiltyparam ":" "GET-CAPABILITY"

   capibiltyparam     = *(

                      ; the following are optional,
                      ; but MUST NOT occur more than once
                      ;
                       id-param / localize-param / latency-param

                      ; the following MUST occur exactly once and only
                      ; when the latency-param has been supplied and
                      ; MUST NOT be supplied if the latency-param is
                      ; not supplied.
                      ;
                      / action-param

                      ; the following is optional,
                      ; and MAY occur more than once
                      ;
                      / other-params
                      )

   Response:

   The "GET-CAPABILITY" command returns information about the Calendar
   other end of the session given the current state of the connection.
   The values returned may differ depending on current user identify and
   the security level of the connection.

   Client implementations SHOULD NOT require any capability element
   beyond those defined in this specification or future RFC publications
   , and MAY ignore any nonstandard, experimental capability elements.
   The "GET-CAPABILITY" reply may return  different results depending on
   the UPN and if the UPN is authenticated.

   When sending a reply to a "GET-CAPABILITY" command, all of these MUST
   BE supplied. The following properties are returned in response to a
   "GET-CAPABILITY" command:

   cap-vreply     = "BEGIN" ":" "VCALENDAR" CRLF
                   ; The following properties may be in any order.
                   ;
                    prodid
                    version
                    reply-cmd
                    other-props
                    "BEGIN" ":" "VREPLY" CRLF
                    ; The following properties may be in any order.
                    ;
                    cap-version
                    car-level
                    components
                    stores-expanded
                    maxdate
                    mindate
                    itip-version
                    max-comp-size
                    multipart
                    query-level
                    recur-accepted
                    recur-expand
                    recur-limit
                    other-props
                    "END" ":" "VREPLY" CRLF
                   "END" ":" "VCALENDAR" CRLF

      Example:

      I: Content-Type: text/calendar
      I:
      I: BEGIN:VCALENDAR
      I: VERSION:2.0
      I: PRODID:-//someone's prodid
      I: CMD;ID=unique-per-cua-125:GET-CAPABILITY
      I: END:VCALENDAR

      L: Content-Type: text/calendar
      L:
      L: BEGIN:VCALENDAR
      L: VERSION:2.0
      L: PRODID:-//someone's prodid
      L: CMD;ID=unique-per-cua-125:REPLY
      L: BEGIN:VREPLY
      L: CAP-VERSION:1.0
      L: PRODID:The CS prodid
      L: QUERY-LEVEL:CAL-QL-1
      L: CAR-LEVEL:CAR-FULL-1
      L: MAXDATE:99991231T235959Z
      L: MINDATE:00000101T000000Z
      L: MAX-COMPONENT-SIZE:0
      L: COMPONENTS:VCALENDAR,VTODO,VJOURNAL,VEVENT,VCAR,
      L:  VALARM,VFREEBUSY,VTIMEZONE,STANDARD,DAYLIGHT,VREPLY
      L: ITIP-VERSION:2446
      L: RECUR-ACCEPTED:TRUE
      L: RECUR-EXPAND:TRUE
      L: RECUR-LIMIT:0
      L: STORES-EXPANDED:FALSE
      L: X-INET-PRIVATE-COMMANDS:1.0
      L: END:VREPLY
      L: END:VCALENDAR

10.8 IDENTIFY Command

   CMD: IDENTIFY

   Purpose: The "IDENTIFY" command allows the CUA to set a new identity
   to be used for calendar access.

   A CUA MAY send an "IDENTIFY" command to a CS. The "IDENTIFY" command
   MUST BE implemented by all CSs. A CS implementation MAY reject all
   "IDENTIFY" commands.

   The CS MUST NOT send a "IDENTIFY" command to any CUA.

   Formal Definition: A "IDENTIFY" command is defined by the following
   notation:

        identify-cmd    = identifyparam ":" "IDENTIFY"

        identifyparam   = *(

                        ; the following are optional,
                        ; but MUST NOT occur more than once

                          id-param
                        / localize-param
                        / latency-param

                        ; the following MUST occur exactly once and only
                        ; when the latency-param has been supplied and
                        ; MUST NOT be supplied if the latency-param is
                        ; not supplied.

                        / action-param

                        ; the following is optional,
                        ; and MAY occur more than once

                        / other-params

                        ; The value is the UPN of the requested
                        ; identity. If option is  not supplied it is
                        ; a request to return to the original authenticated
                        ; identity.

                        / option-param upn

                        )

         Response:

            A "REQUEST-STATUS" property wrapped in a "VREPLY" component with only one of the following
            request-status codes:

                  2.0 Successful.

                  6.4 Identity not permitted. VCAR restriction.

   The CS determines through an internal mechanism if the credentials
   supplied at authentication permit the operation as the selected
   identity. If they do, the session assumes the new identity, otherwise
   a security error is returned.

   Example:

      C: Content-Type: text/calendar
      C:
      C: BEGIN:VCALENDAR
      C: VERSION:2.0
      C: PRODID:-//someone's prodid
      C: CMD;ID=unique-per-cua-999;OPTIONS=newUserId:IDENTIFY
      C: END:VCALENDAR

      S: Content-Type: text/calendar
      S:
      S: BEGIN:VCALENDAR
      S: VERSION:2.0
      S: PRODID:-//someone's prodid
      S: BEGIN:VREPLY
      S: REQUEST-STATUS:2.0;Request Approved
      S: END:VREPLY
      S: END:VCALENDAR

      Or if denied:

      S: Content-Type: text/calendar
      S:
      S: BEGIN:VCALENDAR
      S: PRODID:-//someone's prodid
      S: VERSION:2.0
      S: BEGIN:VREPLY
      S: REQUEST-STATUS:6.4;Request Denied
      S: END:VREPLY
      S: END:VCALENDAR

      And for the CUA to return to its original authenticated identity
      the OPTIONS parameter is omitted:

      C: Content-Type: text/calendar
      C:
      C: BEGIN:VCALENDAR
      C: VERSION:2.0
      C: PRODID:-//someone's prodid
      C: CMD;ID=unique-per-cua-995:IDENTIFY
      C: END:VCALENDAR

   The CS may accept (2.0) or deny (6.4) the request to return to the
   original identity.

   If a CS considers the "IDENTIFY" command an attempt to violate
   security, the CS MAY terminate the [BEEP] session without any further
   notice to the CUA after sending the "REQUEST-STATUS" 6.4 reply.

10.9 MODIFY Command

   CMD: MODIFY

   Purpose: The "MODIFY" command is used to modify existing components.

   A CUA MAY send a "MODIFY" command to a CS. The "MODIFY" command MUST
   BE implemented by all CSs.

   The CS MUST NOT send a "MODIFY" command to any CUA.

   Formal Definition: A "MODIFY" command is defined by the following
   notation:

           modify-cmd   = modifyparam ":" "MODIFY"

          modifyparam   = *(

                        ; the following are optional,
                        ; but MUST NOT occur more than once

                          id-param
                        / localize-param
                        / latency-param

                        ; the following MUST occur exactly once and only
                        ; when the latency-param has been supplied and
                        ; MUST NOT be supplied if the latency-param is
                        ; not supplied.

                        / action-param

                        ; the following is optional,
                        ; and MAY occur more than once

                        / other-params

                        )

   The "MODIFY" command is used to modify existing components.  The
   TARGET property specifies the calendars where the components exist
   that are going to be modified.

   The format of the request is three components inside of "VCALENDAR"
   component:

           BEGIN:VCALENDAR
           ...
           BEGIN:VQUERY
           ...
           END:VQUERY
           BEGIN:XXX
           ...old-values...
           END:XXX
           BEGIN:XXX
           ...new-values...
           END:XXX
           END:VCALENDAR

   The "VQUERY" component selects the components that are to be
   modified.

   Where "XXX" above is a named component type (VEVENT, VTODO, ...).
   Both the old and new components MUST BE of the same type.

   The old-values is a component and the contents of that component are
   going to change and may contain information that helps uniquely
   identify the original component (SEQUENCE in the example below). If
   the CS can not find a component that matches the QUERY and does not
   have at least all of the OLD-VALUES, then a 6.1 error is returned.

   The new-values is a component of the same type as old-values and
   new-values contains the new data for each selected component. Any
   data that is in old-values and not in new-values is deleted from the
   selected component. Any values in new-values that was not in
   old-values is added to the component.

   In this example the "VEVENT" component with a "UID" property value of
   'unique-58' has; the "LOCATION" property and "LAST-MODIFIED" property
   changed, the "VALARM" component with the "SEQUENCE" property with a
   value of "3" has its "TRIGGER" property disabled, the "X-LOCAL"
   property is removed from the "VEVENT" component, and a "COMMENT"
   property is added.

   Because "SEQUENCE" property is used to locate the "VALARM" component
   in this example,  both the old-values and the new-values contain the
   "SEQUENCE" property with a value of "3" and if the "SEQUENCE"
   property were to be left out of new-values, it would have been
   deleted.

     Example:

     C: Content-Type: text/calendar
     C:
     C: BEGIN:VCALENDAR
     C: VERSION:2.0
     C: PRODID:-//someone's prodid
     C: TARGET:my-cal
     C: CMD:ID=unique-mod:MODIFY
     C: BEGIN:VQUERY                   <- Query to select data set.
     C: QUERY:SELECT * FROM VEVENT WHERE UID = 'unique-58'
     C: END:VQUERY
     C: BEGIN:VEVENT                   <- Start of old data.
     C: LOCATION:building 3
     C: LAST-MODIFIED:20020101T123456Z
     C: X-LOCAL:some private stuff
     C: BEGIN:VALARM
     C: SEQUENCE:3
     C: TRIGGER;RELATED=END:PT5M
     C: END:VALARM
     C: END:VEVENT                     <- End of old data.
     C: BEGIN:VEVENT                   <- Start of new data.
     C: LOCATION:building 4
     C: LAST-MODIFIED:20020202T010203Z
     C: COMMENT:Ignore global trigger.
     C: BEGIN:VALARM
     C: SEQUENCE:3
     C: TRIGGER;ENABLE=FALSE:RELATED=END:PT5M
     C: END:VALARM
     C: END:VEVENT                     <- End of new data.
     C: END:VCALENDAR

   The "X-LOCAL" property was not supplied in the new-values, so it was
   deleted. The "LOCATION" property value was altered, as was the
   "LAST-MODIFIED" value. The "VALARM" component with a "SEQUENCE"
   property value of "3" had its "TRIGGER" property disabled, and the
   "SEQUENCE" property value did not change so it was not effected. The
   "COMMENT" property was added.

   When it comes to inline ATTACHMENTs, the CUA only needs to uniquely
   identify the contents of the ATTACHMENT value in the old-values in
   order to delete them. When the CS compares the attachment data it is
   compared in its binary form. The ATTACHMENT value supplied by the CUA
   MUST BE valid encoded information.

   For example, to delete the same huge inline attachment from every
   VEVENT in 'my-cal' that has an "ATTACH" property value with the
   old-values:

           BEGIN:VCALENDAR
           VERSION:2.0
           PRODID:-//someone's prodid
           TARGET:my-cal
           CMD:MODIFY
           BEGIN:VQUERY
           QUERY:SELECT ATTACH FROM VEVENT
           END:VQUERY
           BEGIN:VEVENT
           ATTACH;FMTTYPE=image/basic;ENCODING=BASE64;VALUE=BINARY:
            MIICajCCAdOgAwIBAgICBEUwDQYJKoZIhvcNAQEEBQAwdzELMAkGA1U
            EBhMCVVMxLDAqBgNVBAoTI05ldHNjYXBlIENvbW11bmljYXRpb25zIE
            ...< remainder of attachment data NOT supplied >....
           END:VEVENT
           BEGIN:VEVENT
           END:VEVENT
           END:VCALENDAR

   Above the new-values is empty, so everything in the old-values is
   deleted.

   Furthermore, the following additional restrictions apply:

   1.  One can not change the "UID" property of a component.

   2.  If a contained component is changed inside of a selected
       component, and that contained component has multiple instances,
       then old-values MUST contain information that uniquely identifies
       the instance or instances that are changing. It is valid to
       change more than one. As all contained components that match
       old-values will be modified. In the first modify example above,
       if "SEQUENCE" properties were to be deleted from both the
       old-values and new-values, then all "TRIGGER" properties that
       matched the old-values in all "VALARM" components in the selected
       "VEVENT" components would be disabled.

   3.  The result of the modify MUST BE a valid iCalendar object.

   Response:

   A "VCALENDAR" component is returned with one ore more
   "REQUEST-STATUS" property values.

   If any error occurred:

      No component will be changed at all. That is, it will appear just
      as it was prior to the modify and the CAP server SHOULD return a
      "REQUEST-STATUS" property for each error that occurred.

      There MUST BE at least one error reported.

   If multiple components are selected, then what uniquely identified
   the component MUST BE returned (UID, QUERYID, ...) if the component
   contains a unique identifier. If not, sufficient information to
   uniquely identify the modified components MUST BE returned in the
   reply.

      S: Content-Type: text/calendar
      S:
      S: BEGIN:VCALENDAR
      S: TARGET:relcalid
      S: CMD;ID=delete#1:REPLY
      S: BEGIN:VREPLY
      S: BEGIN:VEVENT
      S: UID:123
      S: REQUEST-STATUS:2.0
      S: END:VEVENT
      S: END:VREPLY
      S: END:VCALENDAR

10.10 MOVE Command

   CMD: MOVE

   Purpose: The "MOVE" command is used to move components within the CS.

   A CUA MAY send a "MOVE" command to a CS. The "MOVE" command MUST BE
   implemented by all CSs.

   The CS MUST NOT send a "MOVE" command to any CUA.

   Formal Definition: A "MOVE" command is defined by the following
   notation:

             move-cmd   = moveparam ":" "MOVE"

            moveparam   = *(

                        ; the following are optional,
                        ; but MUST NOT occur more than once
                          id-param
                        / localize-param
                        / latency-param

                        ; the following MUST occur exactly once and only
                        ; when the latency-param has been supplied and
                        ; MUST NOT be supplied if the latency-param is
                        ; not supplied.

                        / action-param

                        ; the following is optional,
                        ; and MAY occur more than once

                        / other-params

                        )

      Response:
              The REQUEST-STATUS in a VCALENDAR object.

   The content of each "result" is subject to the result restriction
   table defined below.

   The access control on the "VAGENDA" component after it has been moved
   to its new location in the calstore MUST BE at least as secure as it
   was prior to the move. If the CS is not able to ensure the same level
   of security, a permission denied "REQUEST-STATUS" property value MUST
   BE returned and the "MOVE" command not performed.

   The "TARGET" property value specifies the new location, and the
   "VQUERY" component specifies the old location.

   Restriction Table for the "REPLY" command of any "MOVE" command.

           move-reply  = "BEGIN" ":" "VCALENDAR" CRLF
                          calprops
                          1*(move-vreply)
                         "END" ":" "VCALENDAR" CRLF

          move-vreply  = "BEGIN" ":" "VREPLY" CRLF
                          move-id
                           request-status
                         "END" ":" "VREPLY" CRLF
                         ; Where the id is appropriate for the
                         ; type of object moved:
                         ;
                         ; VAGENDA = relcalid
                         ; VCAR = carid
                         ; VEVENT, VFREEBUSY, VJOURNAL, VTODO = uid
                         ; VQUERY = queryid
                         ; ALARM = sequence
                         ; An instance = uid recurid
                         ; x-component = x-id
                         ;
           move-id    =  ( relcalid / carid / uid / uid recurid
                          / queryid / tzid / sequence / x-id)

   Example: moving the VAGENDA Nellis to Area-51

       C: Content-Type: text/calendar
       C:
       C: BEGIN:VCALENDAR
       C: VERSION:2.0
       C: PRODID:-//someone's prodid
       C: CMD:MOVE
       C: TARGET:Area-51
       C: BEGIN:VQUERY
       C: QUERY: SELECT * FROM VAGENDA WHERE CALID='Nellis'
       C: END:VQUERY
       C: END:VCALENDAR

       S: Content-Type: text/calendar
       S:
       S: BEGIN:VCALENDAR
       S: VERSION:2.0
       S: PRODID:-//someone's prodid
       S: TARGET:Area-51
       S: BEGIN:VREPLY
       S: CALID:Nellis
       S: REQUEST-STATUS: 2.0
       S: END:VREPLY
       S: END:VCALENDAR

10.11 REPLY Response to a Command

   CMD: REPLY
   Purpose: The "REPLY" value to the "CMD" property is used to return
   the results of all other commands to the CUA.

   A CUA MUST send a "REPLY" command to a CS for any command a CS MAY
   send to the CUA. The "REPLY" command MUST BE implemented by all CUAs
   that support getting the "GET-CAPABILITY" command.

   A CS MUST send a "REPLY" command to a CUA for any command a CUA MAY
   send to the CS.  The "REPLY" command MUST BE implemented by all CSs.

   Formal Definition: A "REPLY" command is defined by the following
   notation:

           reply-cmd    = replyparam ":" "REPLY"

          replyparam   = *(

                     ; The 'id' parameter value MUST BE exactly the
                        ; same as the value sent in the original
                        ; CMD property. If the original CMD did
                        ; not have an 'id' parameter, then the 'id'
                        ; MUST NOT be supplied in the REPLY.

                        id-param

                        ; the following is optional,
                        ; and MAY occur more than once

                        / other-params

                        )

10.12 SEARCH Command

   CMD: SEARCH

   Purpose: The "SEARCH" command is used to return selected components
   to the CUA.

   A CUA MAY send a "SEARCH" command to a CS. The "SEARCH" command MUST
   BE implemented by all CSs.

   The CS MUST NOT send a "SEARCH" command to any CUA.

   Formal Definition: A "SEARCH" command is defined by the following
   notation:

           search-cmd   = searchparam ":" "SEARCH"

          searchparam   = *(

                        ; the following are optional,
                        ; but MUST NOT occur more than once

                          id-param
                        / localize-param
                        / latency-param

                        ; the following MUST occur exactly once and only
                        ; when the latency-param has been supplied and
                        ; MUST NOT be supplied if the latency-param is
                        ; not supplied.

                        / action-param

                        ; the following is optional,
                        ; and MAY occur more than once

                        / other-params

                        )

   The format of the request is the search command (search-cmd) followed
   by one or more (query) "VQUERY" components

   Response:

   The data in each result set contains one or more iCalendar components
   composed of all the selected results enclosed in a single "VREPLY"
   component per "QUERY".

   Only "REQUEST-STATUS" property and the properties mentioned in the
   "SELECT" clause of the QUERY are included in the components. Each
   "VCALENDAR" component is tagged with the "TARGET" property.

   Searching for objects

   In the example below objects on March 10,1999 between 080000Z and
   190000Z are read. In this case only 4 properties for each objects are
   returned. Two calendars are specified. Only booked (vs scheduled)
   entries are to be returned (this example only selected VEVENT
   objects):

      C: Content-Type: text/calendar
      C:
      C: BEGIN:VCALENDAR
      C: VERSION:2.0
      C: PRODID:-//someone's prodid
      C: CMD:SEARCH
      C: TARGET:relcal2
      C: TARGET:relcal3
      C: BEGIN:VQUERY
      C: QUERY:SELECT DTSTART,DTEND,SUMMARY,UID
      C:  FROM VEVENT
      C:  WHERE DTEND >= '19990310T080000Z'
      C:  AND DTSTART <= '19990310T190000Z'
      C:  AND STATE() = 'BOOKED'
      C: END:VQUERY
      C: END:VCALENDAR

   The return values are subject to VCAR filtering. That is, if the
   request contains properties to which the UPN does not have access,
   those properties will not appear in the return values. If the UPN has
   access to at least one property of the component, but has been denied
   access to all properties called out in the request, the response will
   contain a single "REQUEST-STATUS" property indicating the error.

   Here the request was successful, however one of the "VEVENT"
   components contents were not accessible (4.1).

      S: Content-Type: text/calendar
      S:
      S: BEGIN:VCALENDAR
      S: TARGET:relcalid
      S: CMD:REPLY
      S: VERSION:2.0
      S: PRODID:-//someone's prodid
      S: BEGIN:VREPLY
      S: BEGIN:VEVENT
      S: REQUEST-STATUS:4.1
      S: END:VEVENT
      S: BEGIN:VEVENT
      S: REQUEST-STATUS:2.0
      S: UID:123
      S: DTEND:19990310T080000Z
      S: DSTART:19990310T190000Z
      S: SUMMARY: Big meeting
      S: END:VEVENT
      S: END:VREPLY
      S: END:VCALENDAR

   If the UPN has no access to any components at all, the response will
   simply be an empty data set.  The response looks the same if there
   the particular components did not exist.

      S: Content-Type: text/calendar
      S:
      S: BEGIN:VCALENDAR
      S: VERSION:2.0
      S: PRODID:-//someone's prodid
      S: CMD:REPLY
      S: TARGET:ralcalid
      S: BEGIN:VREPLY
      S: REQUEST-STATUS:2.0
      S: END:VREPLY
      S: END:VCALENDAR

   If there are multiple targets, each iCalendar reply is contained
   within its own iCalendar object.

10.12.1 Searching for VFREEBUSY

   If a CS sets the "RECUR-EXPAND" property to "TRUE" and contains the
   "VFREEBUSY" component in the "COMPONENTS" value in a reply to the
   "GET-CAPABILITY" command, then it is the CS's responsibility and not
   the CUA's responsibility to provide the correct "VFREEBUSY"
   information for a calendar.

   If a CUA issues a "CREATE" "VFREEBUSY", such a CS MUST return success
   and not store the "VFREEBUSY" component as the results would never be
   used.

   Such a CS MUST dynamically create the results of a search for
   "VFREEBUSY" components at search time when searching for STATE() =
   'BOOKED' items.

   If a CUA searches for "VFREEBUSY" components with STATE() =
   'UNPROCESSED', such a CS MUST return a "VREPLY" with no components.

   If a CUA searches for "VFREEBUSY" components without specifying the
   STATE, such a CS MUST return the same result as if STATE()='BOOKED'
   had been specified.

   For CSs that set the "CAPABILITY" "RECUR-EXPAND" property to "FALSE"
   and have the "VFREEBUSY" component in the "COMPONENTS" value in the
   "CAPABILITY" reply, a CUA MAY store the "VFREEBUSY" information on
   the CS. These CSs then MUST return a "VFREEBUSY" component calculated
   from the stored components. If no "VFREEBUSY" information is
   available for the "TARGET" calendar, then a "VFREEBUSY" with no
   blocked out time will be returned with a success code. A CUA sets the
   "VFREEBUSY" time on a those calendars by creating a "VFREEBUSY"
   component without a "METHOD" creating a "BOOKED" entry.

   If a CS does not set the "VFREEBUSY" value in the "COMPONENTS"
   "CAPABILITY" value, the CS does not support the "VFREEBUSY" component
   and all creation and searching for a "VFREEBUSY" component MUST fail.
   Examples of calendars that may be in this category are public event
   calendars that will never require scheduling with other UPNs.

10.13 SET-LOCALE Command

   CMD: SET-LOCALE

   Purpose: The "SET-LOCALE" command is used to select the locale that
   will be used in error codes used in the "REQUEST-STATUS" property.

   A CUA MAY send a "SET-LOCALE" command to a CS. The SET-LOCALE command
   MUST BE implemented by all CSs.

   The CS MUST NOT send a "SET-LOCALE" command to any CUA.

   Formal Definition: A "SET-LOCALE" command is defined by the following
   notation:

           setlocale-cmd   = setlocaleparam ":" "SET-LOCALE"

          setlocaleparam   = *(

                           ; the following are optional,
                           ; but MUST NOT occur more than once

                             id-param
                           / localize-param
                           / latency-param
                           / setlocale-option

                           ; the following MUST occur exactly once and only
                           ; when the latency-param has been supplied and
                           ; MUST NOT be supplied if the latency-param is
                           ; not supplied.

                           / action-param

                           ; the following is optional,
                           ; and MAY occur more than once

                           / other-params

         setlocal-option   = option-param newlocale

               newlocale   = ; Any locale supplied in the initial [BEEP]
                             ; "greeting" "localize" parameter and
                             ; and any charset supported by the CS
                             ; and listed in the DEFAULT-CHARSET property
                             ; of the VCALSTORE.

                           )

   Examples:

         CMD:OPTIONS=en_US.UTF-8:SET-LOCALE
         CMD:OPTIONS=th_TH.ISO8859-11:SET-LOCALE
         CMD:OPTIONS=es_MX.ISO8859-1:SET-LOCALE

   Restriction Table for the "REPLY" command of any "SET-LOCALE"
   command.

           setlocale-reply  = "BEGIN" ":" "VCALENDAR" CRLF
                              calprops
                              1*(setlocale-vreply)
                             "END" ":" "VCALENDAR" CRLF

          setlocale-vreply  = "BEGIN" ":" "VREPLY" CRLF
                              request-status
                              "END" ":" "VREPLY" CRLF

10.14 TIMEOUT Command

   CMD: TIMEOUT
   Purpose: The "TIMEOUT" command is only sent after a command has been
   sent with a latency value set. When received it means the command
   could not be completed in the time allowed.

   Formal Definition: A "TIMEOUT" command is defined by the following
   notation:

         timeout-cmd   = timeoutparam ":" "TIMEOUT"

        timeoutparam   = *(

                        ; the following are optional,
                        ; but MUST NOT occur more than once

                          id-param
                        / localize-param

                        / other-params

                        )

10.15 Response Codes

   Numeric response codes are returned using the "REQUEST-STATUS"
   property.

   The format of these codes is described in [iCAL], and extend in
   [iTIP] and [iMIP]. The following describes new codes added to this
   set and how existing codes apply to CAP.

   At the application layer response codes are returned as the value of
   a "REQUEST-STATUS" property. The value type of this property is
   modified from that defined in [iCAL], in order to make the
   accompanying "REQUEST-STATUS" property text optional.

       Code              Description
       --------------------------------------------------------------
       2.0               Success. The parameters vary with the
                         operation and are specified.

       2.0.3             In response to the client issuing an
                         "abort" reply, this reply code indicates
                         that any command currently underway was
                         successfully aborted.

       3.1.4             Capability not supported.

       4.1               Calendar store access denied.

       6.1               Container not found.

       6.2               Attempt to create or modify an object
                         such that it would overlap another object
                         in either of the following two circumstances:

                         (a) One of the objects has a TRANSP
                         property set to OPAQUE-NOCONFLICT or
                         TRANSPARENT-NOCONFLICT.

                         (b) The calendar's ALLOW-CONFLICT
                         property is set to FALSE.

       6.3               Bad args.

       6.4               Permission denied - VCAR restriction.
                         A VCAR exists and the CS will not perform
                         the operation.

       7.0               A timeout has occurred. The server was
                         unable to complete the operation in the
                         requested time.

       8.0               A failure has occurred in the CS
                         that prevents the operation from
                         succeeding.

       8.1               A query was performed and the query is
                         too complex for the CS. The operation
                         was not performed.

       8.2               Used to signal that an iCalendar object has
                         exceeded the server's size limit

       8.3               A DATETIME value was too far in the future
                         represented on this Calendar.

       8.4               A DATETIME value was too far in the past
                         to be represented on this Calendar.

       8.5               An attempt was made to create a new
                         object but the unique UID specified is
                         already in use.

       9.0               An unrecognized command was received.
                         Or an unsupported command was received.

       10.4              The operation has not been performed
                         because it would cause the resources
                         (memory, disk, CPU, etc) to exceed the
                         allocated quota.

        --------------------------------------------------------------

11. Object Registration

   This section provides the process for registration of new or modified
   properties, parameters, commands, or other modifications, additions,
   or deletions to objects.

11.1 Registration of New and Modified Entities

   New objects are registered by the publication of an IETF Request for
   Comment (RFC). Changes to a objects are registered by the publication
   of a revision to the RFC in a new RFC.

11.2 Post the item definition

   The object description MUST BE posted to the new object discussion
   list: ietf-calendar@imc.org.

11.3 Allow a comment period

   Discussion on a new object MUST BE allowed to take place on the list
   for a minimum of two weeks. Consensus MUST BE reached on the object
   before proceeding to the next step.

11.4 Release a new RFC

   The new object will be submitted for publication as any other
   internet draft requesting RFC status.

12. BEEP and CAP

12.1 BEEP Profile Registration

   Beep replies will be one to one (1:1 MSG/RPY) if possible and one to
   many (1:many MSG/ANS) when the TARGET "TARGET" property value changes. No
   more than one "TARGET" property value per reply.

   Profile Identification: specify a URI [10] [URI] that authoritatively
   identifies this profile.

   http://iana.org/beep/cap/1.0

   Message Exchanged during Channel Creation:

   CUAs SHOULD supply the BEEP "localize" attributes in the BEEP
   "greeting" messages.

   CSs SHOULD supply the BEEP "localize" attributes in the BEEP
   "greeting" messages.

   CUAs SHOULD supply the BEEP "serverName" attribute at channel
   creation time to the CS so that if the CS is performing virtual
   hosting the CS can determine the intended virtual host. CSs that do
   not support virtual hosting may ignore the BEEP "serverName"
   attribute.

   Messages starting one-to-one exchanges:

   The initial message after authentication each direction MUST BE
   single "text/calendar" object containing a CAP "CAPABILITY" CMD and
   must not be part of a MIME multipart message.

   After the initial message then a BEEP "MSG" may contain one or more
   MIME objects at least one of which MUST be "text/calendar" and each
   "text/calendar" MIME object MUST contain a CAP "CMD" property.

   Multiple iCal objects may be sent in a single BEEP message by either
   representing them as separate MIME text/calendar parts contained
   within a MIME multipart/mixed part or by simple concatenation within
   a single text/calendar MIME object.

   In either case, all iCal objects transmitted together must have the
   same TARGET property.

   The sending of multipart MIME entities over BEEP is not permitted for
   CAP unless the other endpoint has indicated its ability to accept
   them via the appropriate CAPABILITY.

   Messages in positive replies:

   After the initial message then a BEEP "RPY" may contain one or more
   MIME objects at least one of which MUST be "text/calendar" and each
   "text/calendar" MIME object MUST contain a CAP "CMD" property. All
   "text/calendar" MIME objects in a single BEEP "RPY" messages MUST
   have the same "TARGET" property value.

   Multiple iCal objects may be sent in a single BEEP message by either
   representing them as separate MIME text/calendar parts contained
   within a MIME multipart/mixed part or by simple concatenation within
   a single text/calendar MIME object.

   In either case, all iCal objects transmitted together must have the
   same TARGET property.

   The sending of multipart MIME entities over BEEP is not permitted for
   CAP unless the other endpoint has indicated its ability to accept
   them via the appropriate CAPABILITY.

   Messages in negative replies:

   Any valid "text/calendar" MIME object that contains CAP
   "REQUEST-STATUS" property and a CAP "CMD" property with a property
   value of "REPLY". And where the CS has determined the requested
   operation to be a fatal error. And when the CS has performed NO
   operation that effected the contents of any part of the CS or any
   calendar controlled by the CS.

   Messages in one-to-many exchanges:

   After the initial message then a BEEP "MSG" may contain one or more
   MIME objects at least one of which MUST be "text/calendar" and each
   "text/calendar" MIME object MUST contain a CAP "CMD" property.

   The BEEP "MSG" messages can only contain MIME "multipart" MIME
   objects if the other endpoint has received a CAP "CAPABILITY"
   indicating the other endpoint supports multipart MIME objects. This
   does not prevent the endpoint from sending multiple [iCAL]
   'icalobject' objects in a single BEEP "MSG" so long as all of them
   have the same "TARGET" property value.

   Multiple iCal objects may be sent in a single BEEP message by either
   representing them as separate MIME text/calendar parts contained
   within a MIME multipart/mixed part or by simple concatenation within
   a single text/calendar MIME object.

   In either case, all iCal objects transmitted together must have the
   same TARGET property.

   The sending of multipart MIME entities over BEEP is not permitted for
   CAP unless the other endpoint has indicated its ability to accept
   them via the appropriate CAPABILITY.

   Message Syntax:

   They are CAP "text/calendar" MIME objects as specified in this memo.
   (Remember this text will be part of CAP).

   Message Semantics:

   As defined in this memo. (Remember this will be part of CAP).

12.2 BEEP Exchange Styles

   [BEEP] defines three styles of message exchange:

   MSG/ANS,ANS,...,NUL -  For one to many exchanges.

   MSG/RPY -  For one to one exchanges.

   MSG/ERR -  For requests the cannot be processed due to an error.

   A CAP request targeted at more than one containers, MAY use a one-
   to-many exchange, with a distinct answer associated with each target.
   CAP request targeted at a single container MAY use a one-to-one
   exchange or a one-to-many exchange.  "MSG/ERR" MAY only be used when
   an error condition prevents the execution of the request on all the
   targeted calendars.

12.3 BEEP connection details

   All CAP communications must be done securelsecurely. So the initial
   greeting includes the TLS profile.

          L: <wait for incoming connection>

          I: <open connection>

          L: RPY 0 0 . 0 110
          L: Content-Type: application/beep+xml
          L:
          L: <greeting>
          L:    <profile uri='http://iana.org/beep/TLS' />
          L: </greeting>
          L: END

          I: RPY 0 0 . 0 52
          I: Content-Type: application/beep+xml
          I:
          I: <greeting/>
          I: END

   At this point the connection is secure. The TLS profile 'resets' the
   connection, so it resends the greetings. And advertise the CAP
   profiles supported. And reply with the profile selected (only one
   profile exists at this time):

          L: <wait for incoming connection>

          I: <open connection>

          L: RPY 0 0 . 0 110
          L: Content-Type: application/beep+xml
          L:
          L: <greeting>
          L:    <profile uri='http://iana.org/beep/cap/1.0'/>
          L: </greeting>
          L: END

          I: RPY 0 0 . 0 110
          I: Content-Type: application/beep+xml
          I:
          I: <greeting>
          I:    <profile uri='http://iana.org/beep/cap/1.0'/>
          I: </greeting>
          I: END

   Then each channel must be authenticated before work can start. Now
   starting a channel involves authentication. Any SASL profile may be
   included such as these:

          <profile uri='http://iana.org/beep/SASL/OTP'/>
          <profile uri='http://iana.org/beep/SASL/DIGEST-MD5'/>
          <profile uri='http://iana.org/beep/SASL/ANONYMOUS'/>

   Example of anonymous channel:

          C: <start number='1'>
          C:    <profile uri='http://iana.org/beep/SASL/ANONYMOUS'/>
          C: </start>

          S: RPY 0 1 . 221 87
          S: Content-Type: application/beep+xml
          S:
          S:

          S: END

   Example of DIGEST-MD5 channel:

          C: <start number='1'>
          C:    <profile uri='http://iana.org/beep/SASL/DIGEST-MD5'/>
          C: </start>

          S: RPY 0 1 . 221 87
          S: Content-Type: application/beep+xml
          S:
          S:

          S: END

   Piggybacking the "CAPABILITY" command. The "CAPABILITY" reply may be
   included during channel start (see RFC3080, section 2.3.1.2) as BEEP
   allows for the start command to include the initial data transfer.
   This reduces the number of round trips to initiate a CAP session.

13. IANA Considerations

   This memo defines IANA registered extensions to the attributes
   defined by iCalendar, as defined in [iCAL], and [iTIP].

   IANA registration proposals for iCalendar and [iTIP] are to be mailed
   to the registration agent for the "text/calendar" [MIME]
   content-type, <MAILTO: ietf-calendar@imc.org> using the format
   defined in section 7 of [iCAL].

   If the IESG approves this memo for publication, then the IANA
   registers the profile specified in Section 12.1, and selects an
   IANA-specific URI, e.g., http://iana.org/beep/cap/1.0.

14. Security Considerations

   Access rights should be granted cautiously. Without careful planning
   it is possible to open up access to a greater degree than desired.

   The "IDENTIFY" command should be carefully implemented.

   In addition, since CAP is a profile of [BEEP], consult [BEEP]'s
   Section 9 for a discussion of BEEP-specific security issues.

   There are risks of allowing anonymous UPNs to deposit REQUEST and
   REFRESH objects. (calendar spam and deninal of service for example)
   So implementations should consider methods to restrict anonymous
   requests to within acceptable usages.

   CS implementations might consider automatically creating VCARs that
   allow CAP ATTENDEEs in booked objects to deposit REFRESH and REPLY
   objects for those UIDs if they otherwise do not have access rather
   then opening up world access. And they may consider also allowing
   COUNTER objects for those ATTENDEEs.

   When an object is booked by a CUA the CS reply may wish to include
   warning messages to the CUA for ATTENDEEs that have CAP urls that do
   not have local UPNs as those ATTENDEES may be unable to REPLY or
   REFRESH. Some CSs may wish this to be an error.

   Although service provisioning is a policy matter, at a minimum, all
   implementations must provide the following tuning profiles:

      for authentication: http://iana.org/beep/SASL/DIGEST-MD5

      for confidentiality: http://iana.org/beep/TLS (using the
      TLS_RSA_WITH_3DES_EDE_CBC_SHA cipher)

      for both: http://iana.org/beep/TLS (using the
      TLS_RSA_WITH_3DES_EDE_CBC_SHA cipher supporting client-side
      certificates)

URIs

   [1]  <http://www.imc.org/html.charters/calsch-charter.html>

Authors' Addresses

   Doug Royer
   INET-Consulting.com
   1795 W. Broadway #266
   Idaho Falls, ID  83402
   US

   Phone: +1-866-594-8574
   Fax:   +1-866-594-8574
   EMail: Doug@Royer.com
   URI:   http://INET-Consulting.com

   George Babics
   Oracle
   2000 Peel Street
   Montreal, Quebec  H3A 2W5
   CA

   Phone: +1-514-733-8500 x4201
   Fax:   +1-514-733-8878
   EMail: George.Babics@Oracle.com

   Paul Hill
   Massachusetts Institute of Technology
   W92-172
   77 Massachusetts Avenue
   Cambridge, MA  02139
   US

   Phone: +1-617-253-0124
   Fax:   +1-617-258-8736
   EMail: phb@mit.edu
   Steve Mansour
   AOL/Netscape
   466 Ellis Road
   Mountain View, CA  94043
   US

   Phone: +1-650-937-3351
   EMail: sman@netscape.com

Appendix A. Acknowledgments

   The following have individuals were major contributors in the
   drafting and discussion of this memo:

   Harald Alvestrand, Christopher Apple, G. Barnes, ArentJan Banck,
   Martijn van Beers, Mario Bonin, memo and are greatly appreciated:

   Alan Davies, Andrea Campi, Darryl Champagne, Damon
   Chaplin, Karen Chu, Shannon Clark, Andre Courtemanche, Dave Crocker,
   Alan Davies, Andrew Davison, Mark Davidson, Anil
   Srivastava, ArentJan Banck, Arnaud Quillaud, Benjamin Sonntag,
   Bernard Desruisseaux,
   Frank Dawson, Pat Egen, Greg FitzPatrick, illes Fortin, Ned Freed,
   Gary Frederick, Jagan Garimella, Graham Gilmore, Micah Gorrell,
   Lawrence Greenfield, Bertrand Guiheneuf, Olivier Gutknecht, Mike
   Hixson, Jeff Hodges, Paul Hoffman, Scott Hollenbeck, Alex Hoppman, Bob Mahoney, Bob Morgan,
   Bruce Kahn, Lata Kannan, suchet singh khalsa, Chris Dudding, Chris Olds, Christopher Apple, Cortlandt
   Winters, Craig Johnson, Cyrus Daboo, Damon Chaplin, Dan Hickman, Dan
   Kohn, Patrice
   Lapierre, Jonathan Lennox, Lisa Lippert, Robert Lusardi, Dan Winship, Darryl Champagne, David Madeo,
   Bob Mahoney, Murata Makoto, Gary McGath, Libby Miller, Steve Miller,
   Bob Morgan, C. Thewlis, David Nicol,
   David Nusbaum, Pete O'Leary, Mark Paterson,
   Ralph Patterson, David West, Derik Stenerson, Eric R. Plamondon, Robert Ransdell, Frank
   Dawson, Frank Nitsch, Gary Frederick, Gary McGath, Gilles Fortin,
   Graham Gilmore, Greg Barnes, Greg FitzPatrick, Harald Alvestrand,
   Harrie Hazewinkel, Helge Hess, Jagan Garimella, Jay Parker, Jim Ray,
   Marshall Rose, JP Rosevear, Paul Sharpe, Richard Shusterman, Tony
   Small,
   Jim Smith, Joerg Reichelt, John Berthels, John Smith, Benjamin Sonntag, John Stracke, Preston
   Stephenson, Alexander Taler,
   Jonathan Lennox, JP Rosevear, Karen Chu, Katie Capps Parlante, Kees
   Cook, Ken Crawford, Ki Wong, Lars Eggert, Lata Kannan, Lawrence
   Greenfield, Libby Miller, Lisa Dusseault, Lyndon Nerenberg, Mark
   Davidson, Mark Paterson, Mark Smith, Mark Swanson, Mark Tearle,
   Marshall Rose, Martijn van Beers, Martin Jackson, Matthias Laabs, Max
   Froumentin, Micah Gorrell, Michael Fair, Mike Higginbottom, Mike
   Hixson, Murata Makoto, Natalia Syracuse, Nathaniel Borenstein, Ned
   Freed, Olivier Gutknecht, Patrice Lapierre, Patrice Scattolin, Paul
   Hoffman, Paul Sharpe, Payod Deshpande, Pekka Pessi, Peter Thompson,
   Preston Stephenson, Prometeo Sandino Roman Corral, Ralph Patterson,
   Robert Lusardi, Robert Ransdell, Rob Siemborski, Satyanarayana
   Vempati, Satya Vempati, Scott Hollenbeck, Seamus Garvey, Shannon
   Clark, Shriram Vishwanathan, Steve Coya, Steve Mansour, Steve Miller,
   Steve Vinter, Mark Wahl,
   Dan Winship Stuart Guthrie, Suchet Singh Khalsa, Ted Hardie, Tim
   Hare, Timo Sirainen, Vicky Oliver, Yael Shaham-Gafni

Appendix B. Bibliography

   [BEEP]    Rose, M., "The Block Extensible Exchange Protocol Core",
             ftp://ftp.isi.edu/in-notes/rfc3080.txt
             ftp://ftp.isi.edu/in-notes/rfc3081.txt

   [BEEPGUIDE] Rose, M., "BEEP, The Definitive Guide", ISBN 0-596-00244-0,
             O'Reilly & Associates, Inc.

   [CHARREG] Freed, N., Postel, J., "IANA Charset Registration Procedures",
             RFC 2278, January 1998,
             ftp://ftp.isi.edu/in-notes/rfc2278.txt

   [CHARPOL] Alvestrand, H., "IETF Policy on Character Sets and Languages",
             RFC 2277, January 1998,
             ftp://ftp.isi.edu/in-notes/rfc2277.txt

   [GUIDE]   Mahoney, B., Babics, G., Taler, A. "Guide to Internet
             Calendaring", RFC 3283, June 2002,
             ftp://ftp.isi.edu/in-notes/rfc3283.txt

   [iCAL]    Dawson, F. and Stenerson, D., "Internet Calendaring and
             Scheduling Core Object Specification (iCalendar)", RFC 2445,
             November 1998 ftp://ftp.isi.edu/in-notes/rfc2445.txt

   [iTIP]    Silverberg, S., Mansour, S., Dawson, F. and Hopson, R.,
             "iCalendar Transport-Independent Interoperability Protocol
             (iTIP) Events, BusyTime, To-dos and Journal Entries",
             RFC 2446, November 1998 ftp://ftp.isi.edu/in-notes/rfc2446.txt

   [iMIP]    Dawson, F., Mansour, S. and Silverberg, "iCalendar
             Message-Based Interoperability Protocol (iMIP)", RFC 2447,
             November 1998 ftp://ftp.isi.edu/in-notes/rfc2447.txt

   [MIME]    Borenstein, N. and Freed, N., "Multipurpose Internet Mail
             Extensions (MIME) Part One: Format of Internet Message Bodies",
             RFC 2045, November 1996
             ftp://ftp.isi.edu/in-notes/rfc2045.txt

   [RFCWORDS] Bradner, S., "Key words for use in RFCs to Indicate
             ftp://ftp.isi.edu/in-notes/rfc2119.txt
   [SASL]    Myers, J., "Simple Authentication and Security Layer (SASL)",
             RFC 2222, October 1997
             ftp://ftp.isi.edu/in-notes/rfc2222.txt

   [SQL92]   "Database Language SQL", ANSI/ISO/IEC 9075: 1992,
             aka ANSI X3.135-1992, aka FiPS PUB 127-2

   [SQLCOM]  ANSI/ISO/IEC 9075:1992/TC-1-1995, Technical corrigendum 1
             to ISO/IEC 9075: 1992, also adopted as Amendment 1 to
             ANSI X3.135.1992

   [URLGUIDE] Masinter, L., Alvestrand, H., Zigmond, D., Petke, R.,
              "Guidelines for new URL Schemes", RFC 2718, November 1999,
              ftp://ftp.isi.edu/in-notes/rfc2718.txt

   [URI]     Berners-Lee, T., Fielding, R. and Masinter, L., "Uniform Resource
             Identifiers (URI): Generic Syntax", RFC 2396, August 1998
             ftp://ftp.isi.edu/in-notes/rfc2396.txt

   [URL]     Berners-Lee, T, Masinter, L. and McCahil, M., "Uniform
             Resource Locators (URL)", RFC 1738, December 1994
             ftp://ftp.isi.edu/in-notes/rfc1738.txt

   [X509CRL]  Housley, R., Ford, W., Polk, W., Solo, D. "Internet X.509
              Public Key Infrastructure, Certificate and CRL Profile",
              RFC 2459, January 1999,
              ftp://ftp.isi.edu/in-notes/rfc2459.txt

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Acknowledgment

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