Network Working Group                   Steve Mansour/Netscape
          Internet Draft                                      Doug                                         S. Mansour
Internet-Draft                                         Netscape, iPlanet
Expires: January 18, 2002                                       D. Royer
          <draft-ietf-calsch-cap-04.txt>           George Babics/Steltor
                                                           Paul Hill/MIT

                                                               G. Babics
                                                                 Steltor
                                                                 P. Hill
                                              Massachusetts Institute of
                                                              Technology
                                                           July 20, 2001

                     Calendar Access Protocol (CAP)
                        draft-ietf-calsch-cap-05

Status of this Memo

   This memo 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
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          Distribution of this document is unlimited.

   This Internet-Draft will expire on January 18, 2002.

Copyright Statement Notice

   Copyright (C) The Internet Society 2000. (2001).  All Rights Reserved.

Abstract

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

   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
   http://www.imc.org/ietf-calendarand at the IETF web site at http://www.ietf.org/html.charters/calsch-
          charter.html.
   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.

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

Table Of of Contents
          1 Introduction.............................................4

   1.        Introduction . . . . . . . . . . . . . . . . . . . . .    5
   1.1       Formatting Conventions...............................4 Conventions . . . . . . . . . . . . . . . .    5
   1.2       Related Documents....................................5 Documents  . . . . . . . . . . . . . . . . . .    6
   1.3  Definitions..........................................5
          2       Definitions  . . . . . . . . . . . . . . . . . . . . .    6
   2.        CAP Design..............................................12 Design . . . . . . . . . . . . . . . . . . . . . .   13
   2.1       System Model........................................12 Model . . . . . . . . . . . . . . . . . . . . .   13
   2.1.1     Firewalls and Fanout . . . . . . . . . . . . . . . . .   14
   2.2       Calendar Store Object Model.........................13 Model  . . . . . . . . . . . . .   15
   2.3       Protocol Model......................................15 Model . . . . . . . . . . . . . . . . . . . .   16
   2.4       Security Model......................................16 Model . . . . . . . . . . . . . . . . . . . .   17
   2.4.1     Authentication, Credentials, and Identity........17 Identity  . . . . . .   18
   2.4.2     Calendar User and UPNs...........................18 UPNs . . . . . . . . . . . . . . . .   19
   2.4.2.1   UPNs and Certificates  . . . . . . . . . . . . . . . .   19
   2.4.2.2   Anonymous Users and Authentication . . . . . . . . . .   20
   2.4.2.3   Required Security Mechanisms . . . . . . . . . . . . .   21
   2.4.2.4   TLS Ciphersuites . . . . . . . . . . . . . . . . . . .   21
   2.4.3     User Groups......................................21 Groups  . . . . . . . . . . . . . . . . . . . . .   22
   2.4.4     Access Rights - Summary..........................22 Summary  . . . . . . . . . . . . . . .   23
   2.4.4.1   VCalendar Access Right (VCAR)  . . . . . . . . . . . .   24
   2.4.4.2   Decreed VCARs  . . . . . . . . . . . . . . . . . . . .   24
   2.4.5 Inheritance......................................23     Inheritance  . . . . . . . . . . . . . . . . . . . . .   25
   2.4.6     CAP Session Identity.............................24 Identity . . . . . . . . . . . . . . . . .   25
   2.5  Roles...............................................25       Roles  . . . . . . . . . . . . . . . . . . . . . . . .   26
   2.6       Calendar Addresses..................................25
           2.7  Extensions to iCalendar.............................26
           2.8  Relationship of RFC 2446 (ITIP) to CAP..............27
          3 State Diagram...........................................29
          4 Protocol Framework......................................30 Addresses . . . . . . . . . . . . . . . . . .   26
   2.7       Extensions to iCalendar  . . . . . . . . . . . . . . .   27
   2.8       Relationship of RFC 2446 (ITIP) to CAP . . . . . . . .   28
   3.        State Diagram  . . . . . . . . . . . . . . . . . . . .   30
   4.        Protocol Framework . . . . . . . . . . . . . . . . . .   32
   4.1       CAP Application Layer...............................30 Layer  . . . . . . . . . . . . . . . .   32
   4.2       CAP Transfer Protocol...............................31 Protocol  . . . . . . . . . . . . . . . .   32
   4.3       Pipelining of Commands..............................32 Commands  . . . . . . . . . . . . . . . . .   33
   4.4       Auto-logout Timer...................................32 Timer  . . . . . . . . . . . . . . . . . .   33
   4.5       Bounded Latency.....................................32 Latency  . . . . . . . . . . . . . . . . . . .   33
   4.6       Data Elements.......................................32
          5 Elements  . . . . . . . . . . . . . . . . . . . .   34
   5.        Formal Command Syntax...................................32 Syntax  . . . . . . . . . . . . . . . .   35
   5.1       Searching and Filtering.............................32 Filtering  . . . . . . . . . . . . . . .   35
   5.1.1     Grammar For Search Mechanism.....................33
            5.1.2 SQL-MIN notes....................................34
            5.1.3 SQL-92 notes.....................................35
            5.1.4 Example, Query by UID............................35
            5.1.5 Query by Mechanism . . . . . . . . . . . . .   35
   5.1.2     SQL-MIN notes  . . . . . . . . . . . . . . . . . . . .   36
   5.1.3     SQL-92 notes . . . . . . . . . . . . . . . . . . . . .   37
   5.1.4     Example, Query by UID  . . . . . . . . . . . . . . . .   37
   5.1.5     Query by Date-Time range.........................35 range . . . . . . . . . . . . . . .   38
   5.1.6     Query for all Non-Booked Entries.................36 Entries . . . . . . . . . . .   38
   5.1.7     Query with Subset of Properties by Date/Time.....36 Date/Time . . . . .   38
   5.1.8     Components With Alarms In A Range................36
          6 Range  . . . . . . . . . .   39
   6.        Access Rights...........................................37 Rights  . . . . . . . . . . . . . . . . . . . .   40
   6.1       VCAR Inheritance....................................37 Inheritance . . . . . . . . . . . . . . . . . . .   40
   6.2       Access Control and NOCONFLICT.......................37
          7 NOCONFLICT  . . . . . . . . . . . .   40
   7.        Commands and Responses..................................38 Responses . . . . . . . . . . . . . . . .   41
   7.1       Transfer Protocol Commands..........................38 Commands . . . . . . . . . . . . . .   41
   7.1.1     Initial Connection...............................38 Connection . . . . . . . . . . . . . . . . . .   41
   7.1.2     ABORT Command....................................39
            7.1.3 AUTHENTICATE Command.............................39
            7.1.4 CALIDEXPAND Command..............................43
            7.1.5 CAPABILITY Command...............................45
            7.1.6 CONTINUE Command.................................47

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

            7.1.7 DISCONNECT Command...............................48
            7.1.8 SENDDATA Command.................................49
           7.2  Application Protocol Commands.......................52 Command  . . . . . . . . . . . . . . . . . . . .   42
   7.1.3     AUTHENTICATE Command . . . . . . . . . . . . . . . . .   42
   7.1.3.1   AUTHENTICATE ANONYMOUS . . . . . . . . . . . . . . . .   45
   7.1.4     CALIDEXPAND Command  . . . . . . . . . . . . . . . . .   46
   7.1.5     CAPABILITY Command . . . . . . . . . . . . . . . . . .   48
   7.1.6     CONTINUE Command . . . . . . . . . . . . . . . . . . .   50
   7.1.7     DISCONNECT Command . . . . . . . . . . . . . . . . . .   51
   7.1.8     IDENTIFY Command . . . . . . . . . . . . . . . . . . .   52
   7.1.9     SENDDATA Command . . . . . . . . . . . . . . . . . . .   52
   7.1.10    STARTTLS Command . . . . . . . . . . . . . . . . . . .   53
   7.1.11    UPNEXPAND Method . . . . . . . . . . . . . . . . . . .   53
   7.1.12    NOOP Command . . . . . . . . . . . . . . . . . . . . .   55
   7.2       Application Protocol Commands  . . . . . . . . . . . .   55
   7.2.1     Calendaring Commands.............................52 Commands . . . . . . . . . . . . . . . . .   55
   7.2.1.1   Restriction Tables . . . . . . . . . . . . . . . . . .   56
   7.2.1.2   CREATE Method  . . . . . . . . . . . . . . . . . . . .   56
   7.2.1.2.1 Creating New Calendars . . . . . . . . . . . . . . . .   64
   7.2.1.2.2 Creating a new VQUERY  . . . . . . . . . . . . . . . .   66
   7.2.1.3   DELETE Method  . . . . . . . . . . . . . . . . . . . .   67
   7.2.1.4   GENERATEUID Method . . . . . . . . . . . . . . . . . .   71
   7.2.1.5   MODIFY Method  . . . . . . . . . . . . . . . . . . . .   71
   7.2.1.6   MOVE Method  . . . . . . . . . . . . . . . . . . . . .   80
   7.2.1.7   READ Method  . . . . . . . . . . . . . . . . . . . . .   83
   7.2.1.7.1 Query With A Stored Query  . . . . . . . . . . . . . .   90
   7.2.2     Scheduling Commands..............................84 Commands  . . . . . . . . . . . . . . . . .   91
   7.2.2.1   Reading Scheduling Components  . . . . . . . . . . . .   92
   7.2.2.2   PUBLISH  . . . . . . . . . . . . . . . . . . . . . . .   93
   7.2.2.3   REQUEST  . . . . . . . . . . . . . . . . . . . . . . .   94
   7.2.2.4   REPLY  . . . . . . . . . . . . . . . . . . . . . . . .   94
   7.2.2.5   ADD  . . . . . . . . . . . . . . . . . . . . . . . . .   95
   7.2.2.6   CANCEL . . . . . . . . . . . . . . . . . . . . . . . .   95
   7.2.2.7   REFRESH  . . . . . . . . . . . . . . . . . . . . . . .   95
   7.2.2.8   COUNTER  . . . . . . . . . . . . . . . . . . . . . . .   96
   7.2.2.9   DECLINECOUNTER . . . . . . . . . . . . . . . . . . . .   96
   7.2.3     iTIP Examples....................................89
          8 Examples  . . . . . . . . . . . . . . . . . . . .   96
   7.2.3.1   Sending and Receiving an iTIP request  . . . . . . . .   96
   7.2.3.2   Handling an iTIP refresh . . . . . . . . . . . . . . .   99
   7.2.3.3   Sending and accepting an iTIP counter  . . . . . . . .  100
   7.2.3.4   Declining an iTIP counter  . . . . . . . . . . . . . .  102
   8.        Response Codes..........................................96
          9 Examples................................................98
           9.1 Codes . . . . . . . . . . . . . . . . . . . .  104
   8.1       Examples . . . . . . . . . . . . . . . . . . . . . . .  106
   8.1.1     Authentication Examples.............................98
            9.1.1 Examples  . . . . . . . . . . . . . . .  106
   8.1.1.1   Login Using Kerberos V4..........................98
            9.1.2 V4  . . . . . . . . . . . . . . .  106
   8.1.1.2   Error Scenarios..................................99
           9.2 Scenarios  . . . . . . . . . . . . . . . . . . .  106
   8.2       Read Examples  . . . . . . . . . . . . . . . . . . . .  106
   8.2.1     Read Examples......................................100
            9.2.1 From A Single Calendar  . . . . . . . . . . . . .  106
   8.2.2     Read From Multiple Calendars....................101
            9.2.2 Timeouts........................................102
            9.2.3 Calendars . . . . . . . . . . . . .  107
   8.2.3     Timeouts . . . . . . . . . . . . . . . . . . . . . . .  109
   8.2.4     Using Parent and Children Properties............103
            9.2.4 Properties . . . . . . . . .  110
   8.2.5     Query VEVENT.DTSTART and VALARM.DTSTART.........103
          10 VALARM.DTSTART  . . . . . . .  110
   9.        Implementation Issues................................103
          11  Properties...........................................104
           11.1 Issues  . . . . . . . . . . . . . . . .  111
   10.       Properties . . . . . . . . . . . . . . . . . . . . . .  112
   10.1      Calendar Store Properties........................104
           11.2 Properties  . . . . . . . . . . . . . .  112
   10.2      Calendar Properties..............................105
          12 Properties  . . . . . . . . . . . . . . . . .  113
   11.       Security Considerations..............................107
          13 Considerations  . . . . . . . . . . . . . . .  116
   12.       CAP Item Registration................................107
           13.1 Registration  . . . . . . . . . . . . . . . .  117
   12.1      Registration of New and Modified CAP Entities....107
           13.2 Entities  . . . .  117
   12.2      Registration of New Entities.....................107
            13.2.1 Entities . . . . . . . . . . . . .  117
   12.2.1    Define the Item...............................108
            13.2.2 Item  . . . . . . . . . . . . . . . . . . .  117
   12.2.2    Post the item definition......................109
            13.2.3 definition . . . . . . . . . . . . . . .  118
   12.2.3    Allow a comment period........................109
            13.2.4 period . . . . . . . . . . . . . . . .  118
   12.2.4    Submit the proposal for approval..............109
           13.3 approval . . . . . . . . . . .  118
   12.3      Property Change Control..........................109
          14 Control  . . . . . . . . . . . . . . .  119
   13.       IANA Considerations..................................110
          15  Acknowledgments......................................110
          16  Bibliography.........................................111
          17  Author's Address.....................................112
          18 Considerations  . . . . . . . . . . . . . . . . .  120
             Authors' Addresses . . . . . . . . . . . . . . . . . .  120
   A.        Acknowledegements  . . . . . . . . . . . . . . . . . .  122
   B.        Bibliography . . . . . . . . . . . . . . . . . . . . .  123
             Full Copyright Statement.............................112

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

          1 Statement . . . . . . . . . . . . . . .  124

1. Introduction

   This document specifies how a Calendar User Agent (CUA) interacts
   with a Calendar Store (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.

   This protocol is based on request/response form of data units, sent
   from a client CUA to a calendar server.  The protocol data units
   leverage the standard iCalendar format [iCAL] for conveying CS
   related information.

1.1 Formatting Conventions

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY" and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].

   Calendaring and scheduling roles are referred to in quoted- strings
   of text with the first character of each word in upper case.  For
   example, "Organizer" refers to a role of a "Calendar User" (CU)
   within the protocol defined by this memo.  Calendar components
   defined by [iCAL] are referred to with capitalized, quoted-strings of
   text.  All calendar components start with the letter "V".  For
   example, "VEVENT" refers to the event calendar component, "VTODO"
   refers to the to-do calendar component and "VJOURNAL" refers to the
   daily journal calendar component.  Calendar access methods defined by
   this memo, as well as scheduling methods defined by [iTIP], are
   referred to with capitalized, quoted-strings of text.  For example,
   "CREATE" refers to the method for creating a calendar component on a
   calendar, "READ" refers to the method for reading calendar
   components.

   Properties defined by this memo are referred to with capitalized,
   quoted-strings of text, followed by the word "property".  For
   example, "ATTENDEE" property refers to the iCalendar property used to
   convey the calendar address of a "Calendar User".  Property
   parameters defined by this memo are referred to with lower case,
   quoted-strings of text, followed by the word "parameter".  For
   example, "value" parameter refers to the iCalendar property parameter
   used to override the default data type for a property value.
   Enumerated values defined by this memo are referred to with
   capitalized text, either alone or followed by the word "value".

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

   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 implementations.  The related documents
   are:

   [iMIP] (RFC2447) which specifies an Internet email binding for
   [iTIP].

   [IMPL] (draft/rfc...) which is a guide to implementers and describes
   the elements of a calendaring system, how they interact with each
   other, how they interact with end users, and how the standards and
   protocols are used.

   This memo does not attempt to repeat the specification of concepts or
   definitions from these other memos.  Where possible, references are
   made to the memo that provides for the specification of these
   concepts or definitions.

1.3 Definitions

   Authentication ID (AuthID)

      A tuple of username, realm, and authentication method, used by the
      Calendar Service internally to identify a successfully
      authenticated CAP session.

   Booked

      A entry in a calendar has one of two conceptual states.  It is
      scheduled or it is booked.  A scheduled entry has been stored in
      the calendar store but has not been acted on by a calendar user or
      calendar user agent.  A booked appointment is an entry that has
      had its state changed from one of the [iTIP] scheduling methods to
      a CAP method of CREATE by a calendar user

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001 or calendar user agent
      which resulted in decision to keep the entry in the calendar
      store.

   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 other calendar properties or
      calendar components.In addition, a calendar might be
      hierarchically related to other sub-calendars.  A calendar is
      identified by its unique calendar identifier.  The [iCAL] defines
      calendar properties, calendar components and component properties
      that make up the content of a calendar.

   Calendar Access Protocol (CAP)

      The standard Internet protocol that permits a Calendar User Agent
      to access and manipulate a calendar residing on a Calendar Store.

   Calendar Access Rights (CAR)

      The mechanism for specifying the CAP operations ("ACTIONS") that a
      particular calendar user ("UPN") are granted or denied permission
      to perform on a given calendar item ("OBJECT").  The calendar
      access rights are specified with the "VCAR" calendar components
      within a CS and calendar.

   Calendar Collection

      A collection of Calendars, Resource Calendars, and/or other
      Calendar Collections.  These collections are expanded by the CS
      and may reside either locally or in an external database or
      directory.  The calendars in the collection may be fixed or
      dynamic over time.

   Calendar Component

      An item within a calendar.  Some types of calendar components
      include events, to-dos, journals, alarms, time zones and freebusy
      data.  A calendar component consists of component properties and
      possibly other

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001 sub-components.  For example, an event may contain
      an alarm component.

   Calendar Component Properties

      An attribute of a particular calendar component.  Some calendar
      component properties are applicable to different types of calendar
      components.  For example, DTSTART is applicable to VEVENT, VTODO,
      VJOURNAL calendar components.  Other calendar components are
      applicable only to an individual type of calendar component.  For
      example, TZURL is only applicable to VTIMEZONE calendar
      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.

   Calendar Policy

      A CAP operational restriction on the access or manipulation of a
      calendar.  For example, "events MUST be scheduled in unit
      intervals of one hour".

   Calendar Properties

      An attribute of a calendar.  The attribute applies to the
      calendar, as a whole.  For example, CALSCALE specifies the
      calendar scale (e.g., GREGORIAN) for the whole calendar.

   Calendar Service

      An implementation of a Calendar Store that manages one or more
      calendars.

   Calendar Store (CS)

      The data and service model definition for a Calendar Service.

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

   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].

   Calendar Store Components

      Components maintained in a CS specify a grouping of calendar
      store-wide information.  Calendar store components can be accessed
      using CAP.

   Calendar Store Properties

      Properties maintained in a Calendar Store calendar store-wide
      information.  Calendar store properties can be accessed using CAP.

   Calendar User (CU)

      An entity (often biological) that uses a calendaring system.

   Calendar User Agent (CUA)

      The CUA is the client application that a CU or UG utilizes to
      access and manipulate a calendar.

   Calendaring and Scheduling System

      The computer sub-system that provides the services for accessing,
      manipulating calendars and scheduling calendar components.

   CAP Session

      An open communication channel between a CAP CUA and a CAP CS.

   Connected Mode

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

      A mobile computing mode where the CUA is directly connected to the
      CS.

   Delegate

      Is a calendar user (sometimes called the delegatee) who has been
      assigned participation in a scheduled calendar component (e.g.,
      VEVENT) by one of the attendees in the scheduled calendar
      component (sometimes called the delegator).  An example of a
      delegate is a team member told to go to a particular meeting.

   Designate

      Is a calendar user who is authorized to act on behalf of another
      calendar user.  An example of a designate is an assistant.

   Disconnected Mode

      A mobile computing mode where a CUA can be disconnected from a CS.
      When the CUA is disconnected, it is in the disconnected mode.

   Fan Out

      The calendaring and scheduling process by which a calendar
      operation on one calendar is also performed on every other
      calendar specified in the operation.  This may include the
      calendar associated with TARGET calendar property.

   Hierarchical Calendars

      A CS feature where a calendar have a hierarchical relationship
      with another calendar in the CS.  The top-most calendar in the
      hierarchical relationship has the CS as its parent.  There may be
      multiple top- most calendars in a given CS.  Within a given
      hierarchical relationship, all sub-calendars have a calendar with
      a "parent" topographical relationship.  In addition, sub-calendars
      may have a relationship

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001 with another calendar that has a "child"
      topographical relationship.  In addition, a calendar may have a
      relationship such that one or more calendars have a "sibling"
      topographical relationship with the calendar.  The hierarchical
      calendar feature is not a storage relationship of the calendars
      within the CS.  Instead it is a feature that relates access
      control rights to calendar content between different calendars in
      the CS.  The hierarchical relationship of a calendar is specified
      in the "PARENT" and "CHILDREN" calendar properties.

   High Bandwidth Connection

      A communications connection supporting high transfer rates;
      transfer rates commonly found within a LAN.

   Local Store

      A CS which is on the same platform as the CUA.

   Low Bandwidth Connection

      A communications connection supporting slow transfer rates;
      transfer rates commonly found in remote access technology.

   Overlapped Booking

      A policy which indicates whether or not OPAQUE events can overlap
      one another.  When the policy is applied to a calendar it
      indicates whether or not the time span of any OPAQUE
                  events entry (VEVENT,
      VTODO, ...) in the calendar can overlap. overlap the time span of any other
      entry in the same calendar.  When applied to an individual event, entry,
      it indicates whether or not it
                  can be overlapped by any other OPAQUE event. entry's time span can
      overlap that individual entry.

   Owner

      One or more CUs or UGs that have "OWNER" calendar access rights
      for a calendar.  The owner is specified in the "OWNER" calendar
      property and in the "OWNER" calendar store property.

   Qualified Calendar Identifier (Qualified CalID)

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

      A CalID where both the <scheme> and <csid> 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.  (eg: 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
      is unique within a calendar store.  It is recommended to be
      globally unique.  A Relative CalID consists of the portion of the
      "scheme part" of a Qualified CalID following the Calendar Store
      Identifier.  This is the same as the "URL path" of the "Common
      Internet Scheme Syntax" portion of a URL, as defined by [URL].

   Remote Store

      A CS which is not on the same platform as the CUA.

   Resource Calendar (RC)

      A non-human Calendar, associated with an organizational resource.
      There is no syntactic difference between an RC and a Calendar.

   Session Identity

      A UPN associated with a CAP session.  A session gains an identity
      after successful authentication.  The identity is used in
      combination with CAR to determine access to data in the CS.

   Sub-calendars

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

      Calendars that have a "child" hierarchical relationship with
      another calendar, its "parent".

   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.

   User Name

      A name which denotes a Calendar User within a realm.  This is part
      of a UPN.

   User Principal Name (UPN)

      An identifier that denotes a unique CU.  A UPN is an RFC 822
      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 to email address
      mapping MUST never be  deliverable to a different person. person as there
      is not requirement that they are the same.   It consists of  a
      realm  in the form of a valid,  and unique, DNS domain  name and a
      unique username.  In  it's simplest form it  looks like
      "user@example.com".

      In certain cases a UPN will not be RFC 822 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".  Usage of these special cases is further discussed
      in the authentication and authorization sections of this document.

          2

2. CAP Design

2.1 System Model

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

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

   CAP is used by a "Calendar User Agent" (CUA) to send commands to and
   receive responses from a "Calendar Service" (CS).  The CUA prepares a
   [MIME] encapsulated iCalendar object containing a command, sends it
   to the CS, and receives a [MIME] encapsulated iCalendar object as a
   response.  There are two distinct protocols in operation to
   accomplish this exchange.  The Transfer Protocol is used to move
   these encapsulations between a CUA and a CS.  The Application
   Protocol defines the content and semantics of the iCalendar objects
   sent between the CUA and the CS.  This document defines both the
   Transfer Protocol and the Application Protocol.

   In the diagram below, a user uses CUA1 to communicate with CS1 using
   CAP.  The CUA must authenticate the Calendar User (CU) so that access
   to calendars on CS1 can be controlled.  The CUA can then view,
   create, edit, and delete calendars, calendar properties, and calendar
   components subject to the access rights.

   CAP servers support fanout.  Fanout allows a CUA to communicate with
   a single CS to perform scheduling operations with calendars on
   multiple CSs.  That is, a CU can book or schedule events (or to-dos)
   on or read events (or to-dos) from calendars on other calendar
   stores.  To accomplish this, a CAP server takes on these roles:

      * CS1 MAY play the role of a CUA and use CAP to access CS2;

      * CS1 MUST be able play the role of a CUA and use [iMIP] to
      interoperate with other CUAs.

   	    +-----+          +-----+
   	    |     |   CAP    |     |   CAP
     CUA1------| CS1 |----------| CS2 |--------- CUA2
   	    |     |          |     |           A
   	    |     |          |     |           |
   	    |     |          |     |           |
                    +-----+          +-----+
   	    +-----+          +-----+           |
   	      |        IMIP                    |
   	      +--------------------------------+

   Note that the fanout feature in CAP is a convenience to the CUA.  It
   is perfectly valid for the CUA to assume the responsibility for
   fanout if it wishes.  That is, [iMIP] messages could also be sent
   from CUA1 to CUA2.

   CAP does not specify any trust model between CS1 and CS2.
   Implementations may require a trust model to exist in order to
   accomplish scheduling between CS1 and CS2.

2.1.1 Firewalls and Fanout

               - - - ------INTERNET---------------------- - -  -
                  |        |
                     +----------------+      +----------------------+
                     | Site Public CS |<---->| Other Site Public CS |
                     |    (CS-P)      |      |      (CS-P2)         |
                     +----------------+      +----------------------+
                  ^        ^
                  |        .
                  v        .
                     +----------------+      .
                     | Site Firewall  |   - - - ---Other  LAN----  -
                     +----------------+
                  |
                - -  ---------------LAN---------------------------- - - -
                  |          |        |
                 +--------------+  +--------------+     +- -  - - - -  - - +
                 | Department-1 |  | Department-2 |     |      . . .       |
                 |    CS-1      |  |    CS-2      |     |        IMIP      CS-n        |
                      +--------------------------------+

          Note
                 +--------------+  +--------------+     +- -  - - - -  - - +

   One example of a site site policy  could be that all entries in
   department calendars that  were marked PUBLIC, were visible on the
   internet to any users that was granted access to CS-P.

   With fanout feature in CAP is a convenience place, CS-P would authenticate the  internet user and
   decide in  an implementation specific way,  which user CS (CS-1, CS-
   2, CS-n) the  TARGET calendar  physically existed.  Then using
   fanout,  CS- P  sends the request subject to VCARs or immutable
   VCARS from CS-P  to the
          CUA. It is perfectly valid for users  CS and back to the CUA through CS-P.
   CS-P could be a smart proxy.

   And there  is no reason that the target calendar need to assume exist under
   the
          responsibility for fanout if it wishes. That is, [iMIP]
          messages firewall (CS-P2), only that the CSs can authenticate with each
   other.  In this way all users in a domain  could also appear to  be sent at
   calendar.site.com, hiding  all CS-1 through CS-n from CUA1 the internet.
   And also hiding that fact  that CS-P2 may be a separate domain
   controlled by the  same site administrators as CS-P (which  in turn
   could do fanout to CUA2. its LAN).

2.2 Calendar Store Object Model

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

   The conceptual model for a calendar store is shown below.  The
   calendar store contains calendars, VTIMEZONEs, VCARs, and calendar
   store properties.

   Calendars contain VEVENTs, VTODOs, VJOURNALs, VALARMs, VCARs, and
   calendar properties.  Calendars may also contain other calendars.

     Calendar Store
       |
       +-- VCARs
       +-- Properties
       +-- VCARs
            +-- VTIMEZONEs
       +-- VCALENDARs
   	  |
   	  +--VEVENTs
   	       +--VALARMs
   	  +--VTODOs
   	       +--VALARMs
   	  +--VJOURNALs
   	  +--VCARs
   	  +--Properties
   	  +--VTIMEZONEs
   	  +--VSCHEDULE
   	  +--VQUERY
   	  +--Calendar
   	       |
   	       +--VEVENTs
   		    +--VALARMs
   	       +--VTODOs
   		    +--VALARMs
   	       +--VJOURNALs
                       +--VALARMs
   	       +--VCARs
   	       +--Properties
   	       +--VTIMEZONEs
   	       +--VSCHEDULE
   	       +--VQUERY
   	       +--Calendar
   		    |
   		   ...

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

   In this model, VSCHEDULE is a queue of scheduling messages that have
   not yet been applied to the calendar.  Items in VSCHEDULE are
   discussed in more detail below.

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

2.3 Protocol Model

   A generic transfer-layer, Calendar Server Transfer Protocol (CSTP),
   is used to move data objects between a CUA and the CS.  CSTP commands
   are listed below and their usage and semantics are defined in section
   7.1 of this document.

              CSTP Commands
              -----------------------------------------------------------
              Command         Description
              -----------------------------------------------------------
              ABORT           Stop a command. Perhaps because its latency
                              time has been exceeded.
              AUTHENTICATE    Authenticate a UPN.
              CONTINUE        Continue the execution of a command whose
                              Latency time has been exceeded.
              IDENTIFY        Set a new identity for calendar access.
              DISCONNECT      Terminate a connection with the server.
              SENDDATA        Send a data object [MIME] encapsulated
                              iCalendar.
              STARTTLS        Negotiate transport level security using
                              [TLS].
              NOOP            Do nothing operation.
              -----------------------------------------------------------

   Application-level commands are used to manipulate data on the
   calendar store.  They are listed below and discussed in detail in
   section 7.2.

              CAP Calendaring Commands
          -----------------------------------------------------------
              ----------------------------------------------------------
              Command         Description
          -----------------------------------------------------------
              ----------------------------------------------------------
              CREATE          Create a new calendar or component.
              DELETE          Delete a calendar or component.
              GENERATEUID     Generate one or more unique ids.
              MODIFY          Change a calendar or component.
              MOVE            Move a calendar.
              READ            Read a calendar properties or components.
          -----------------------------------------------------------
              ----------------------------------------------------------

              CAP Scheduling Commands
              (As defined in [iTIP])
              -----------------------------------------------------------
              Command        Description
              -----------------------------------------------------------

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
              PUBLISH        Publish a calendar entry to one or more
                             calendars.
              REQUEST        Schedule a calendar entry with one or more
                             calendars.
              REPLY          Response to a scheduling request.
              ADD            Add one or more instances to an existing
                             calendar entry.
              CANCEL         Cancel one or more instances to an existing
                             calendar entry.
              REFRESH        A request for the latest version of a
                             calendar entry.
              COUNTER        A request for a change(a counter-proposal)to change (a counter-proposal)
                             to a calendar entry.
              DECLINECOUNTER Decline a counter proposal.
              -----------------------------------------------------------

2.4 Security Model

   Authentication to the CS will be performed using [SASL].

   As noted in the CAP system model section, a variety of connectivity
   scenarios are possible.  This complicates the security model
   considerably, and a thorough familiarity with the concepts is
   required to ensure interoperability.

   Basic threats to a Calendaring and Scheduling System include:

      (1) Unauthorized access to data via data-fetching operations,

      (2) Unauthorized access to reusable client authentication
      information by monitoring others' access,

      (3) Unauthorized access to data by monitoring others' access,

      (4) Unauthorized modification of data,

      (5) Unauthorized or excessive use of resources (denial of
      service), and

      (6) Spoofing of CS: Tricking a client into believing that
      information came     from the CS when in fact it did not, either
      by modifying data in transit or misdirecting the client's
      connection.

   Threats (1), (4), (5) and (6) are due to hostile clients.  Threats
   (2), and (3) are due to hostile agents on the path between client and
   server, or posing as a server.

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

   CAP can be protected with the following security mechanisms:

      (1) Client authentication by means of the SASL mechanism set,
      possibly backed by the TLS credentials exchange mechanism,

      (2) Client authorization by means of access control based on the
      requestor's authenticated identity,

      (3) Data integrity protection by means of the TLS protocol or data
      integrity SASL mechanisms,

      (4) Protection against snooping by means of the TLS protocol or
      data encrypting SASL mechanisms,

      (5) Resource limitation by means of administrative limits on
      service controls, and

      (6) Server authentication by means of the TLS protocol or SASL
      mechanism.

   Imposition of access controls (authorizations) is done by means of
   VCARs, an overview is provided in the section 2.4.4 <fwd ref>, ref> and a
   detailed syntax is provided in section 6 <fwd ref>. ref> Authentication is
   explained in detail in section 2.4.1 <fwd ref>. ref>

2.4.1 Authentication, Credentials, and Identity

   Generically, authentication credentials are the evidence supplied by
   one party to another, asserting the identity of the supplying party
   (e.g.  a user) who is attempting to establish an association with the
   other party (typically a server).  Authentication is the process of
   generating, transmitting, and verifying these credentials and thus
   the identity they assert.  An authentication identity is the name
   presented in a credential.

   There are many forms of authentication credentials.  The form used
   depends upon the particular authentication mechanism negotiated by
   the parties.  For example: X.509 certificates, Kerberos tickets,
   simple identity and password pairs.  Note that an authentication
   mechanism may constrain the form of authentication identities used
   with it.

   SASL only provides a protocol to negotiate a mutually acceptable
   authentication mechanism.  SASL itself does not constrain or dictate
   the form of the authentication identities used to perform the
   authentication.

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

2.4.2 Calendar User and UPNs

   A Calendar User(CU) is an entity that can be authenticated.  It is
   represented in CAP as a UPN.  A UPN is the owner of a calendar and
   the subject 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 control policy, requiring a server-specific mapping
   to be done.  The method by which a server composes and validates an
   authorization identity from the authentication credentials supplied
   by a client is implementation-specific.

   For Calendaring and Scheduling Systems that are integrated with a
   directory system, the CS MUST support the ability to configure which
   schema attribute stores the UPN.  The CS MAY allow one or more
   attributes to be searched for the UPN.

2.4.2.1 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 subjectAlt-
      Name extension (e.g., a key bound only to an email address or
      URI), then the subject name MUST

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001 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 822 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 RFC 2459]) 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" property said (e.g.) "ATTENDEE;CN=Joe
   Random User:juser@example.com" then the email address should be
   checked against the UPN, and the CN should also be checked.  This is
   so the "ATTENDEE" property couldn't be munged to something misleading
   like "ATTENDEE;CN=Joe Rictus User:juser@example.com" and have it pass
   validation.  This validation will also defeat other attempts at
   confusion.

2.4.2.2 Anonymous Users and Authentication

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

   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.

   CAP implementations MUST support anonymous authentication, as defined
   in section <fwd ref 7.1.3>. 7.1.3>

   CAP implementations MAY support anonymous authentication with TLS, as
   defined in section <fwd ref 7.1.3.2>. 7.1.3.2>

2.4.2.3 Required Security Mechanisms

   The following implementation conformance requirements are in place:

      (1) For a read-only, public CS, anonymous authentication,
      described in section <fwd ref 7.1.3.1>, 7.1.3.1> can be used.

      (2) Implementations providing password-based authenticated access
      MUST support authentication using Digest, as described in section
      <fwd ref>. ref&gt  [ed note: this section has not yet been defined.
      Paul can you please look into it?];  This provides client
      authentication with protection against passive eavesdropping
      attacks, but does not provide protection against active
      intermediary attacks.

      (3) For a CS needing session protection and authentication, the
      Start TLS extended operation, and either the simple authentication
      choice or the SASL EXTERNAL mechanism, are to be used together.
      Implementations SHOULD support authentication with a password as
      described in section <fwd
          ref>, ref> and SHOULD support authentication
      with a certificate as described in section <fwd ref>. ref>  Together,
      these can provide integrity and disclosure protection of
      transmitted data, and authentication of client and server,
      including protection against active intermediary attacks.

2.4.2.4 TLS Ciphersuites

   The following ciphersuites defined in [RFC 2246] MUST NOT be used for
   confidentiality protection of passwords or data:

      TLS_NULL_WITH_NULL_NULL

      TLS_RSA_WITH_NULL_MD5

      TLS_RSA_WITH_NULL_SHA

   The following ciphersuites defined in [RFC 2246] can be cracked
   easily (less than a week of CPU time on a standard CPU in 1997).  The
   client and server SHOULD carefully consider the

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001 value of the password
   or data being protected before using these ciphersuites:

      TLS_RSA_EXPORT_WITH_RC4_40_MD5

      TLS_RSA_EXPORT_WITH_RC2_CBC_40_MD5

      TLS_RSA_EXPORT_WITH_DES40_CBC_SHA
      TLS_DH_DSS_EXPORT_WITH_DES40_CBC_SHA

      TLS_DH_RSA_EXPORT_WITH_DES40_CBC_SHA

      TLS_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA

      TLS_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA

      TLS_DH_anon_EXPORT_WITH_RC4_40_MD5

      TLS_DH_anon_EXPORT_WITH_DES40_CBC_SHA

   The following ciphersuites are vulnerable to man-in-the-middle
   attacks, and SHOULD NOT be used to protect passwords or sensitive
   data, unless the network configuration is such that the danger of a
   man-in-the-middle attack is tolerable:

      TLS_DH_anon_EXPORT_WITH_RC4_40_MD5

      TLS_DH_anon_WITH_RC4_128_MD5

      TLS_DH_anon_EXPORT_WITH_DES40_CBC_SHA

      TLS_DH_anon_WITH_DES_CBC_SHA

      TLS_DH_anon_WITH_3DES_EDE_CBC_SHA

   A client or server that supports TLS MUST support at least:

      TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA

2.4.3 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 MUST accept a CUA
   request for UG expansion, although the CS may be configured to
   restrict some responses.  The CS MAY expand a UG (including nested
   UGs) to obtain a list of unique CUs.  Duplicate UPNs are filtered
   during expansion.  Incomplete expansion should be treated as a
   failure.

   Groups may be in a directory service with its own ACL model and CAP
   should use the directory service to expand a UPN subject to the
   directory service access control model for the authenticated entity.

   The CS SHOULD should not preserve UG expansions across operations.  A UG may
   reference a static list of members, or it may represent a dynamic
   list.  Each operation SHOULD generate its own

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001 expansion in order to
   recognize changes to UG membership.  However, during fan out to other
   CSs, the originating CS SHOULD expand all UGs so that the target CS
   receives only a list of unique CUs.  This is to prevent confusion
   when two CSs do not share the same UG database or directory.

   CAP does not define commands or methods for managing UGs.

   Small UG:

      The Three Stooges.  There is only and always three at any one
      time.

   Large UG:

      The MIT graduating class of 1999.  This is a static list.

   Dynamic UG:

      The IETF membership which is a large and changing list of members.

   Nested UG:

      The National Football League, made up of the AFC and NFC, which
      are   made up of 3 divisions each...

2.4.4 Access Rights - Summary

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

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

   All rights MUST be denied unless specifically granted; individual
   VCARs MUST be specifically granted to an authenticated CU.

   The access for a particular UPN is the union of all grants for that
   UPN minus the union of its denies.

2.4.4.1 VCalendar Access Right (VCAR)

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

   Access rights within CAP are specified with the "VCAR" calendar
   component, "RIGHTS" value type and the "GRANT", "DENY" and "CARID"
   component properties.

   Properties within an iCalendar object are unordered.  This also is
   the case for the "GRANT", "DENY" and "CARID" properties.  Likewise,
   there is no implied ordering required for components of a "RIGHTS"
   value type other than that specified by the ABNF.  [EDITOR'S NOTE,
   this requires a lot of review.  We think that this paragraph may be
   incorrect.  ]

   For details on the VCAR syntax please see section <forward ref>

2.4.4.2 Decreed VCARs

   A CS MAY choose to implement and allow persistent immutable VCARs,
   that are configured by the CS Administrator, which apply to all
   calendars on the server.

   When a user attempts to modify a decreed VCAR an error will be
   returned, indicating that the user has insufficient authorization to
   perform the operation.

   The CAP protocol does not define the semantics used to initially
   create a decreed VCAR.  This administrative task is out side 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.  The GRANT property allows the OWNERs
   all (OBJECT=*) access to their own calendar objects.  The DENY
   property disallows anyone (UPN=*) from being able to delete or modify
   this VCAR.

                BEGIN:VCAR
                CARID:Users Default Access
                GRANT:UPN=OWNER;OBJECT=*;OBJECT=OBJECT=METHOD;VALUE=*
                DENY:UPN=*;OBJECT=VCAR;OBJECT=CARID;
                 VALUE="Users Default Access"
                 ;OBJECT=METHOD,VALUE=DELETE,MODIFY
                END:VCAR

   Decreed VCARs MUST be readable by the calendar owner in standard VCAR
   format.

2.4.5 Inheritance

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

   Calendars inherit VCARs from their parent calendar.  Calendars whose
   parent is the Calendar Store inherit VCARs from the Calendar Store.

   VCARs specified in a calendar or a sub-calendar override all
   inherited VCARs.

2.4.6 CAP Session Identity

   A CAP 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 Calendar Service 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.  A UPN with a null username, but non-null 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 non-null username and null realm, such as
   "bob@" could be a security risk and MUST NOT be used.

   Since 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.

   The "IDENTIFY" command 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.

   Examples:

      Small UG:

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

         The Three Stooges.  There will always be three, it will not
         change.

      Large UG:

         The MIT graduating class of 1999.  This is a static list.

      Dynamic UG:

         The IETF membership, which is a large and changing list of
         members.

      Nested UG:

         The National Football League, made up of the AFC and NFC, which
         are made up of 3 divisions each.

2.5 Roles

   CAP defines methods for managing [iCAL] objects on a Calendar Store
   and exchanging [iCAL] objects for the purposes of group calendaring
   and scheduling between "Calendar Users" (CUs) or "User Groups" (UGs).
   There are two distinct roles taken on by CUs in CAP.  The CU who
   creates an initial event or to-do and invites other CUs or UGs as
   attendees takes on the role of "Organizer".  The CUs or UGs asked to
   participate in the group event or to-do take on the role of
   "Attendee".  Note that "role" is also a descriptive parameter to the
   "ATTENDEE" property.  Its use is to convey descriptive context to an
   "Attendee" such as "chair", "REQ-PARTICIPANT" or "NON- PARTICIPANT"
   and has nothing to do with the scheduling workflow.

2.6 Calendar Addresses

   Calendar addresses are URIs that are modeled after URLs [URL].  CAP
   uses the following forms of URI.

      [[<scheme>]://<csid>[:<port>]/]<relativeCALID>

   where:

      <scheme> is "cap", the protocol described in this memo.

      <csid> is the Calendar Store ID.  It is the network address of the
      computer on which the CAP server is running.

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

      <port> is optional.  Its default value is 5229.  The port must be
      present in the URL if the CAP server does not listen on this
      default port of 5229.

      <relativeCALID> is an identifier that uniquely identifies the
      calendar on a particular calendar store.  There is no implied
      structure in a Relative CALID.  It is an arbitrary string of
      printable 7 bit ASCII characters.  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.  It is recommended that the
      Relative CALID be globally unique.

   If the <scheme> and <csid> are present the calendar address is said
   to be "qualified".  Senders are required to supply the
   <relativeCALID> portion of the address.  A qualified calendar address
   is required when the <csid> of the target calendar address differs
   from that of the CAP server receiving the command.

   Examples of CAP URIs:

       cap://calendar.example.com/user1
       ://calendar.example.com/user1
       user1
       cap://calendar.example.com/conferenceRoomA
       cap://calendar.example.com/89798-098-zytytasd

   For a user currently authenticated to a CAP server on
   calendar.example.com, the first three addresses refer to the same
   calendar.

2.7 Extensions to iCalendar

   In mapping the CAP command set, query feature, and access rights onto
   the iCalendar format, several extended iCalendar methods and
   components are defined by this memo.

               *

      The search function is specified with the new iCalendar QUERY
      method.  The QUERY method makes use of a new component, called
      VQUERY, that contains the search filter.  The component consists
      of a set of new properties: EXPAND, MAXSIZE, MAXRESULTS, MAXRESULTSSIZE, QUERY and
      QUERYNAME, that define the search filter.  Note that QUERY simply
      is the filter that is used by the CS to select the data used in
      METHOD:READ, METHOD:CREATE,

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001 METHOD:MODIFY, METHOD:DELETE, any
      other METHOD that is defined to use a QUERY filter.
               *

      Access control is specified the the new iCalendar VCAR component.
               *

      The iCalendar METHOD property format has been updated with new
      values.
               *

      A new iCalendar component, VCOMMAND, has been added.  VCOMMANDs
      are needed to specify CAP commands.
               *

      VCAP is a new container for data that is transmitted as part of a
      VCOMMAND

      TARGET is a new property within the VCOMMAND component.  It
      indicates  the calendars to which the command applies
               *

      CMDID is a Command ID that is used in a VCOMMAND to uniquely
      identify  a command.  Responses to a VCOMMAND will contain the
      same CMDID.

2.8 Relationship of RFC 2446 (ITIP) to CAP

   [iTIP] describes scheduling methods which result in indirect
   manipulation of calendar components.  CAP methods provide direct
   manipulation of calendar components.  In the CAP calendar store
   model, scheduling messages are conceptually kept separate from other
   calendar components.  This is modeled with the VSCHEDULE queue.  Note
   that this is a conceptual model, the actual storage details are left
   to implementations.  The model is shown pictorially as follows:

   +-----------------VCALENDAR-------------------+
   |                                             |
   |  +-----------+  +-------VSCHEDULE---------+ |
   |  | VEVENTs   |  | PUBLISH messages        | |
   |  | VTODOs    |  | REQUEST messages        | |
   |  | VJOURNALs |  | REPLY messages          | |
   |  |           |  | ADD messages            | |
   |  |           |  | CANCEL messages         | |
   |  |           |  | REFRESH messages        | |
   |  |           |  | COUNTER messages        | |
   |  |           |  | DECLINECOUNTER messages | |
   |  +-----------+  +-------------------------+ |
   +---------------------------------------------+

   The METHOD is saved along with components.  Scheduled components
   become booked components when the METHOD changes from an ITIP method
   to the CAP storage method CREATE.  For example, a component whose
   METHOD is "REQUEST" is scheduled.  The component becomes booked when
   the METHOD is changed to "CREATED".

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

   Several scheduled entries can be in the CS for the same UID.  They
   are consolidated when booked.  Or they are removed from the CS.

   For example, if you were on vacation, you could have a REQUEST to
   attend a meeting and several updates to that meeting.  Your CUA would
   have to READ them out of 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 entry or MODIFY an existing entry.  Followed
   by a DELETE of all of these now old scheduling requests in the CS.
   See [iTIP] for details on resolving multiple [iTIP] scheduling
   entries.

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

          3

3. State Diagram

   This section describes the states of the transport connection between
   a CUA and a CS.  The state diagram is shown below.  State names are
   shown with first letter capitalized.  Commands used to switch between
   states are shown next to an arrow connecting the states.  The
   commands are listed in all capital letters.  A condition that causes
   a state to change is shown in lower case letters.

    STARTTLS /
    CAPABILITY
   +-------+
   |       |                       +---------------+
   |   +-----------+ AUTHENTICATE  |               |
   +-->| Connected |-------------->| Authenticated |
       +-----------+               |               |
         |                         +---------------+
         |                                |
         |                                |     +-----+
         |                                V     |     |STARTTLS /
         |                         +---------------+  |IDENTIFY
         |                         |               |<-+
         |                         |   Identified  |<-----+
         |                +--------|               |      |
         |                |        +---------------+      |
         |                |                |       command|
         V                |DISCONNECT      |     completes|
       +--------------+   |                |              |
       | Disconnected |<--+                |              |
       +--------------+                    |SENDDATA      | ABORT
              A                            |              |
              |                            V              |
              |    DISCONNECT      +---------------+      |
              +--------------------|    Receive    |------+
                                   |               |<--+
                                   +---------------+   |
                                                  |    |
                                                  +----+
                                                 CONTINUE

   The connection begins the Connected state when a CUA connects to a
   CAP server.  The capabilities of the CS are reported in the response
   from the CS.  From this state, the CUA can issue the DISCONNECT
   command to terminate the connection, the CAPABILITY, STARTTLS, or
   AUTHENTICATE commands.  One use of the CAPABILITY command at this
   stage is to determine the supported

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001 authentication mechanisms
   supported by the server.  Once the STARTTLS command has been
   successfully executed from either the Connected or Authenticated
   state, it must not be executed again.

   If an AUTHENTICATE command is successful, the connection enters the
   Authenticated state and then immediately goes to the IDENTIFIED
   state.  While in the Identified state, allow the CALIDEXPAND and UPNEXPAND commands.
   commands can be executed.  From here the CUA can issue the CAPABILITY
   command.  The capabilities offered by the server
          offers in the Authenticated
   state may be different than those in the Connected state to allow for
   the users user's realm to be used to grant or deny features.  The CUA can
   also use the IDENTIFY command to change the identity of the user
   subject to access control.  The connection remains in the Authenticated Identified
   state after the CAPABILITY command completes.  The CUA can issue the
   DISCONNECT command to terminate the connection.  The SENDDATA command
   can be used to send a request to read, write, modify, or delete data
   on the server.

   After the SENDDATA command has been issued the connection enters the
   Receive state while the CUA awaits and reads a server reply.
   Normally, the server handles the command, sends a reply which is read
   by the CUA and the connection returns to the Authenticated state.
   The CUA may have issued the SENDATA command with a maximum latency
   time.  This informs the server that the CUA expects a response within
   the maximum latency time, even if the command was not completed.
   When the server is unable to complete the command in the maximum
   latency time, it issues an appropriate reply code and waits for the
   CUA to tell it how to proceed.  If the CUA issues a CONTINUE command
   the server continues processing the command and the connection
   remains in the Receive state.  If the CUA issues the ABORT command
   the server need not process the command any further and the
   connection returns to the Authenticated Identified state.  The DISCONNECT command
   can also be issued from the Receive state.

          4

4. Protocol Framework

4.1 CAP Application Layer

   The CAP application layer is used for the manipulation of the
   calendar store.  Commands and responses are transmitted between the
   CUA and CS inside "VCALENDAR" component "VCAP" wrappers.  Commands are specified as the
   value of a "METHOD" property, and responses are specified as the
   value of a "REQUEST-STATUS" property.

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001  An optional "CMDID" may be
   used to uniquely identify commands.

4.2 CAP Transfer Protocol

   The CAP transfer protocol defines the format of data transmitted
   between a CUA and the CS.

   CAP transfer protocol commands are transmitted using the underlying
   transport.  The transport used is a TCP/IP socket connection between
   the CUA and the CS.  The default port that the CS listens for
   connections on is port 5229.

   Messages sent between the CUA and CS are formatted as a command
   followed by any associated data:

   <command> [<command data>]

          Response Format

   Server responses consist of a response code and any parameters:

     <transfer-level response-code> [response-args] [; debug-text ]
     <CRLF>.<CRLF>
     [<application-data>]
     <CRLF>.<CRLF>

   The response-args are defined in Section 8.  The debug-text is
          human-readable human-
   readable information for protocol debugging and is optional and is
   only used to aid developers writing CSs and CUAs.  The debug-text
   MUST not be depended on by CUAs in normal interactions with a CS.

   The optional application-data begins on the next line.

   The response is terminated with the second <CRLF> "." <CRLF>
   sequence.  Any <CRLF> "." sequences which appear in the transmitted
   data must be quoted by placing an additional "." between the <CRLF>
   and the ".".  For example, the following sequences of characters in
   the application data:

     .
     ..2
     ...3

   are quoted as follows:

     ..
     ...2
     ....3

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

4.3 Pipelining of Commands

   If the CS returns a PIPELINE  number greater then one  (1) as a
   result of a CAPABILITY  command  then the CUA can send up to PIPELINE
          VCOMMANDS
   VCAP (each with a  unique CMDID/VCOMMAND) without waiting for the CS
   to reply.

   It is unspecified what happens of the CUA exceedes the CS limit.

4.4 Auto-logout Timer

   If a server has an inactivity auto-logout timer, that timer MUST be
   of at least 15 minutes duration if there is no value of
   AUTOLOGOUTTIME returned in the CS CAPABILITY reply.  The receipt of
   ANY command from the client during that interval MAY reset the auto-logout auto-
   logout timer, subject to CS administrators policy.  A CUA may be
   discouraged from attempts to do useless things only to keep the
   connection alive.

   A CS MAY have different AUTOLOGOUTTIME values depending on the UPN or
   the realm of the UPN.

   When a timeout occurs, the server drops the connection to the CUA.

4.5 Bounded Latency

   CAP is designed so that the CUA can either obtain an immediate
   response from a request or discover within a specified amount of time
   that the request could not be completed in the requested amount of
   time.  When the CUA initiates a command that the server cannot
   complete within the specified latency time, the server returns an
   appropriate response code.  The CUA then issues either a CONTINUE or
   ABORT command.  The ABORT command immediately terminates the command
   in progress identified by CMDID and the connection returns to the
   Authenticated state.  The CONTINUE command instructs the server to
   continue processing the command identified by the CMDID.

4.6 Data Elements

   The data elements for CAP are [MIME] encapsulated iCalendar objects.

          5

5. Formal Command Syntax

5.1 Searching and Filtering

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

   This section describes CAPs CAP's selecting and filtering entities within
   a calendar store.  It is based on the Standard Query Language (SQL)
   defined in [SQL].

5.1.1 Grammar For Search Mechanism

    search     = "BEGIN:VQUERY" CRLF
                 [expand] [maxresults] [maxsize] querycomp
                 "END:VQUERY" CRLF

    expand     = "EXPAND" ":" ( "TRUE" / "FALSE")
               # the default is EXPAND:FALSE

    comp-name  = "VEVENT" / "VTODO" / "VJOURNAL"
               / "VTIMEZONE" / "VALARM" / "VFREEBUSY"
               / "VCAR" / iana-name / x-name

    maxresults = "MAXRESULTS" ":" integer

    maxsize    = "MAXSIZE" ":" integer

    querycomp  = ( query ) / ( queryname query ) / queryname

    queryname  = "QUERYNAME:" text

    query      = "QUERY:" ( query-min / query-92 )
    #
    # NOTE: query-min MUST be implemented in CSs.
    #
    #   query-92 is ONLY used if CAPABILITY returns SQL-92
    #   as the QUERYLEVEL value or if QUERYLEVEL is not
    #    specified.
    #

    query-min      = capselect-min capfrom-min capwhere-min

    capselect-min  = "SELECT" capmin-cols "FROM" capmin-comps
                     "WHERE" capmin-cmp

    capmin-col     = # Any property name found in any of the
                     components.

    capmin-cols    = ( capmin-col / capmin-col ","
                     capmin-cols )
    capmin-comps   = ( comp-name / comp-name ","
                     compmin-comps )

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

    capmin-cmp     = ( colname cmpmin-oper colvalue
                   / colname cmpmin-oper colvalue
                     capmin-logical capmin-cmp )

    colname        = ( # Any valid component property name.
                   / "*" )

    cmpmin-oper    = ( " = "  / " != " / " < " / " > " / " <= "
                   / " >= " )

    capmin-logical = ( " AND " / " OR " )

    query-92       = capselect-92 capfrom-92 capwhere-92
                     caporderby-92

    capselect-92   = # Any valid [SQL] string that goes into
                     a SELECT clause.

    capfrom-92     = # Like capmin-comps except embedded spaces
                     # are allowed between commas - per [SQL].

    capwhere-92    = # Any valid [SQL] string that goes into a
                     # WHERE clause.

    caporderby-92  = # Any valid [SQL] string that goes into a
                     # ORDERBY clause.

5.1.2 SQL-MIN notes

      (1) No inlined spaces are allowed if not in the grammar above.

      (2) Note that cmpmin-oper and capmin-logical elements are
      surrounded by exactly one space.

     Use 'VEVENT,VTODO', not 'VEVENT, VTODO'
     Use 'DTSTART <= 20000605T131313Z', not
         'DTSTART<=  20000605T131313Z'.
     Use ' AND ' and ' OR ', not 'AND' and not 'OR'.

      (3) There is no ORDERBY.  Sorting will take place in the order the
      columns are supplied in the command.

      (4) The CS MUST sort at least the first column.The CS MAY sort
      additional columns.

      (5) If EXPAND=FALSE and if colname is "*" sorting will be by the
      DTSTART  value ascending.

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001  If EXPAND=TRUE and if colname is "*"
      sorting will be by the RECURRENCE-ID value ascending.

      If colname is "*" and capmin-coms is VALARM only then sorting will
      be by TRIGGER time in GMT ascending.

      (6) SQL-MIN MUST be implemented.

5.1.3 SQL-92 notes

   (1) Although this memo specifies that any [SQL] query can be used,
   some of the [SQL] grammar is optional and therefore is considered
   optional in CSs advertising an SQL-92 implementation with CAPABILITY.

   (2) A CS implementation MAY implement SQL-92.  If a CS does not
   implement SQL-92 then it MUST advertise SQL-MIN in the capability
   reply.

5.1.4 Example, Query by UID

   This example would select the entire contents of uid123 and not
   expand any multiple instances of the component.  If the CUA does not
   know if 'uid123' was a VEVENT, VTODO, VJOURNAL, or other component,
   then all components that the CUA supports MUST be supplied on the
   QUERY property.  This example assumes the CUA only supports VTODO and
   VEVENT.

   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 VEVENT,VTODO WHERE UID = 'uid123'
               END:VQUERY

   This example would select the entire contents of uid123 and would
   expand any instances of the component after applying any recurrence
   rules.  This query could select multiple instances of components each
   with the same UID.  Each instance would have a unique RECURRENCE-ID
   of the expanded component.

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

5.1.5 Query by Date-Time range

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

   This query selects the entire contents of every booked VEVENT that
   has an instance less than or equal to July 31st, 2000 23:59:59 Z and
   greater than or equal to July 1st, 2000 00:00:00 Z

               BEGIN:VQUERY
               EXPAND:TRUE
               QUERY:SELECT * FROM VEVENT
                 WHERE RECURRENCE-ID >= '20000801T000000Z'
                 AND RECURRENCE-ID <= '20000831T235959Z'
                 AND METHOD = 'CREATE'
               END:VQUERY

5.1.6 Query for all Non-Booked Entries

   This example selects the entire contents of all scheduling
          (non-booked) (non-
   booked) VEVENTS in the CS.  The default for EXPAND is FALSE, so the
   recurrence rules will not be expanded.

               BEGIN:VQUERY
               QUERY:SELECT * FROM VEVENT,VTODO WHERE METHOD != 'CREATE'
               END:VQUERY

   The following example fetches the UIDs of all non-booked VEVENTs and
   VTODOs.

               BEGIN:VQUERY
               QUERY:SELECT UID FROM VEVENT,VTODO WHERE METHOD != 'CREATE'
               END:VQUERY

5.1.7 Query with Subset of Properties by Date/Time

   This MUST implement is similar to the one above, except only the
   named properties will be selected and all booked and non- booked
   components will be selected that have a DTSTART from Feb 1st to Feb
   10th.

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

5.1.8 Components With Alarms In A Range

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

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

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

          6

6. Access Rights

   Access rights within CAP are specified with the "VCAR" calendar
   component, "RIGHTS" value type and the "GRANT", "DENY" and "CARID"
   component properties.

   Individual calendar access rights MUST be specifically granted to an
   authenticated calendar user (i.e., UPN); all rights are denied unless
   specifically granted.

   Properties within a VCAR must be evaluated in the order provided.

6.1 VCAR Inheritance

   Calendar access rights specified in a calendar store are inherited as
   default calendar access rights for any calendar in the parent
   calendar store.  Likewise, any calendar access rights specified in a
   root calendar are inherited as default calendar access rights for any
   sub- calendar to the root calendar.  By implication, calendar access
   rights specified in a sub-calendar are inherited as default calendar
   access rights for any calendars that are hierarchically below the
   sub- calendar.

   Calendar access rights specified in a calendar override any default
   calendar access rights.  Calendar access rights specified within a
   sub-calendar override any default calendar access rights.

6.2 Access Control and NOCONFLICT

   The TRANSP property can take on values (TRANSPARENT- NOCONFLICT,
   OPAQUE-NOCONFLICT) that prohibit other events from overlapping it.
   This setting overrides access While access control may allow a UPN to
   store an event on a particular calendar.  , the CONFLICTS Calendar or
   component setting may prevent it, returning an error code "6.3"

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

          7

7. Commands and Responses

   CAP commands and responses are described in this section.

   Command arguments, identified by "Arguments:" in the command
   descriptions below, are described by function, not by syntax.  The
   precise syntax of command arguments is described in the Formal Syntax
   section.

   Some commands cause specific server data to be returned; these are
   identified by "Data:" in the command descriptions below.  See the
   response descriptions in the Responses section for information on
   these responses, and the Formal Syntax section for the precise syntax
   of these responses.

   The "Result:" in the command description refers to the possible
   status responses to a command, and any special interpretation of
   these status responses.

   Commands have the general form:

                     <command> [arguments...]

   where <command> is a command listed in the table above.  A command
   MAY have arguments.  Arguments are defined in the detailed command
   definitions below.

   Responses to commands have the following general form:

                     responseCode [sep transportDescr sep
                     [applicationDescr]]
                     CRLF "." CRLF

   In the examples below, lines preceded with "S:" refer to the sender
   and lines preceded with "R:" refer to the receiver.  Lines in which
   the first non-whitespace character is a "#" are editorial comments
   and are not part of the protocol.

7.1 Transfer Protocol Commands

7.1.1 Initial Connection

   Arguments:  none

   Data:       none

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

   Result:     2.0  - success.  8.1  - server too busy
   Upon session startup, the server sends a response of 2.0 to indicate
   that it is ready to receive commands.  A response of 8.1 indicates
   that the server is too busy to accept the connection.  In addition,
   the general capabilities of the CS are reported in the response from
   the CS.  These capabilities may be different than those reported in
   the authenticated state.

7.1.2 ABORT Command

   Arguments:  [CMDID]

   Data:       none

   Result:     2.0 - success 2.2 - no command is in progress

   The ABORT command is issued by the CUA to stop a command.  A common
   usage could be to ABORT a command whose latency time has been
   exceeded.  When the latency time is specified on the SENDATA command,
   the CS must issue a reply to the CUA within the specified time.  It
   may be a reply code indicating that the CS has not yet processed the
   request.  The CUA must then tell the server whether to continue or
   abort.

   The CUA can issue the ABORT command at any time after the SENDATA
   command has been completed but before receiving a reply.

   If CMDID is supplied then the command identified by CMDID is aborted.

   If CMDID is not supplied then the fist command that is still pending
   is aborted.

7.1.3 AUTHENTICATE Command

   Arguments:  <SASL mechanism name> [<initial data>]

   Data:       continuation data may be requested

   Result:

      2.0 - Authenticate completed, now in authenticated

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001 state.

      6.0 -  Failed authentication.  6.1 -  Authorization identity
      refused.

      6.2 -  Sender aborted authentication, authentication exchange
      cancelled.

      6.3 -  Unsupported Authentication Mechanism.

      6.4 -  Temporary failure (back end authentication server down).

      6.5 -  Authentication exchange cancelled.

      6.6 -  Authentication mechanism too weak.

      6.7 -  Encryption required.

      6.8 -  Pass phrase expired.  The pass phrase was correct but
      expired.  The user will have to contact a pass phrase change
      server prior to authenticating.

      6.9 -  The user is valid but the server does not have an entry in
      the authentication database for the requested mechanism (e.g.,
      DIGEST- MD5).  If the user successfully authenticates using a
      plain text password, then the back end back end entry will be
      updated.  Note that if the client chooses to fall back to plain
      text password authentication it should enable an encryption layer
      or get user-con- firmation that a one-time transition is ac-
      ceptable.

      6.10 -  User account disabled.  The user will have to contact the
      system administrator to  get  the account re-enabled.

      9.1 -  Unexpected command.

   The capabilities of the CS in the authenticated state are reported in
   the response from the CS.  These may be different than the
   capabilities in the Connected, but unauthenticated state.

   The AUTHENTICATE command is used by the CUA to identify the user to
   the CS.  CAP supports a number of authentication methods, the SASL
   specification for authentication is the preferred method.

   If STARTTLS is negotiated prior to the AUTHENTICATE command, the
   client MUST discard all information about the CS capabilities fetched
   prior to the TLS negotiation.  In particular, the value of supported
   SASL Mechanisms MAY be different after TLS has been negotiated.

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

   If a SASL security layer is negotiated, the client MUST discard all
   information about the CS capabilities fetched prior to SASL.  In
   particular, if the client is configured to support multiple SASL
   mechanisms, it SHOULD fetch supported SASL Mechanisms both before and
   after the SASL security layer is negotiated and verify that the value
   has not changed after the SASL security layer was negotiated.  This
   detects active attacks which remove supported SASL mechanisms from
   the supported SASL Mechanisms list.

   <initial data> is an optional parameter which can be used for
   mechanisms which require an initial response from the CUA.

   The AUTHENTICATE command is followed by an authentication protocol
   exchange, in the form of a series of CS challenges and CUA responses,
   per the relevant RFC that describes the specific SASL mechanism being
   used.

   Cancelling the authentication process during its negotiation is
   implementation specific and not within scope of the CAP
   specification.

   If a security layer was negotiated it comes into effect for the CS
   starting with the first octet transmitted after the CRLF which
   follows the 2.0 reply code, and for the CUA starting with the first
   octet after the CRLF of its last response in the authentication
   exchange.  Encrypted data is transmitted as described in SASL.

   The service name specified by this protocol's profile of SASL is
   "cap".  [EDITORS NOTE: this must be registered with IANA, has anyone
   done this yet?]

   The result of the AUTHENTICATE command includes data indicating the
   identity which has been assigned to the session, derived from the
   supplied authentication credentials, and/or authorization identifier.
   A CAP session does not have an identity until the CUA has issued the
   "AUTHENTICATE" command.

   The CUA may not issue the "AUTHENTICATE" command multiple times, even
   if the first attempt was aborted.  If a CUA attempts to do this the
   CS must terminate the session.

   Here is an example of a successful authentication:

                C: AUTHENTICATE KERBEROS_V4
                S: AmFYig==

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
                C: BAcAQU5EUkVXLkNNVS5FRFUAOCAsho84kLN3/IJmrMG+25a4DT
                S: or//EoAADZI=
                C: DiAF5A4gA+oOIALuBkAAmw==
                S: 2.0
                S: .
                S: Content-Type:text/calendar; method=REQUEST;
                S:  charset=US-ASCII
                S: Content-Transfer-Encoding: 7bit
                S:
                S: BEGIN:VCAP
                S: PRODID:-//ACME/CAPserver//EN
                S: VERSION:2.1
                S: IDENTITY=bill@example.com
                S: CAPVERSION=1.0
                S: ITIPVERSION=1.0
                S: AUTH=KERBEROS_V4
                S: AUTH=DIGEST_MD5
                S: CAR=CAR-FULL-1
                S: MINDATE=19700101T000000Z
                S: MAXDATE=20370201T000000Z
                S: END:VCAP
                S: .

   This example shows a failed authentication:

                C: AUTHENTICATE KERBEROS_V4

                S: AmFYig==
                C: BAcAQU5EUkVXLkNNVS5FRFUAOCAsho84kLN3/IJmrMG+25a4DT
                S: .
                S: 6.0
                S: .
                S: .

7.1.3.1 AUTHENTICATE ANONYMOUS

   RFC-2245 defines the Anonymous SASL mechanism.  This RFC states that
   "the mechanism consists of a single message from the client to the
   server.  The client sends optional trace information in the form of a
   human readable string.  The trace information should take one of
   three forms: an Internet email address, an opaque string which does
   not contain the '@' character and can be interpreted by the system
   administrator of the client's domain, or nothing.  For privacy
   reasons, an Internet email address should only be used with
   permission from the user."

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

   RFC-2245 goes on to state, "A client which uses the user's correct
   email address as trace information without explicit permission may
   violate that user's privacy." Information about who accesses an
   anonymous CS on a sensitive subject (e.g., AA meeting times and
   locations) has strong privacy needs.  "Clients should not send the
   email address without explicit permission of the user and should
   offer the option of supplying no trace token -- thus only exposing
   the source IP address and time."

   Example of CUA using the Capability command followed by an anonymous
   authentication:

                C: CAPABILITY
                S: 2.0
                S:CAPVERSION=1.0
                S:AUTH=KERBEROS_V4
                S:AUTH=DIGEST_MD5
                S:AUTH=ANONYMOUS
                S:.
                C:AUTHENTICATE ANONYMOUS
                S:+
                C:c21yaGM=
                S:2.0

   Subsequent to the initial Anonymous Authentication with a CS, a CUA
   will have to provide a UPN for some CAP operations.  For anonymous
   access the UPN that MUST be used by the CUA is "@", a UPN with a null
   username and null realm.  The user's normal UPN MUST not be used for
   the subsequent CAP operations.

   Note that the CS implementation may have internal audit logs that use
   the user's asserted UPN as trace information.  However, this UPN will
   not appear on the wire after the initial SASL anonymous
   authentication.

   Use of the "@" UPN and wild-carding of UPNs within VCARs are covered
   in

   Section <forward ref>.

7.1.4 CALIDEXPAND Command

   Arguments:  CalID

   Data:       no specific data for this command

   Result:     2.0 Successful, and requested data follows

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

      2.1 Permission Denied

      2.2 Requested CSID not found

      2.3 Result exceeds MAXEXPANDLIST

      2.4 Misc.  EXPAND error

   Return the members of the argument CalID.  Successful result yields
   one or more Calendars and/or Resource Calendars.  More than one C or
   RC returned implies that the CalID was a CC.

          Example:

   If the number of items exceeds MAXCALIDEXPAND, then up to
   MAXCALIDEXPAND items are returned along with result  2.3.

   If the result is 2.4, then as many of the items as possible will be
   returned.  It is possible that no items will  be returned.  The 2.4
   response may  have optional text describing the problem.  Any  such
   text MUST  be in the language and charset that is defined by the
   calendar store properties LANGUAGE and CHARSET.  If calendar store
   CHARSET is  not set, but the LANGUAGE property is set, then  the
   error message will be in LANGUAGE in the UTF-8 charset.  If calendar
   store LANGUAGE property is not set, then  the CS MUST NOT return any
   text with  the results.

   Examples:

   Example #1: Request lookup of CSID which is a Calendar Collection

                C: CALIDEXPAND cap://cal.example.com/calid14
                S: 2.0
                S: cap://cal.example.com/calid14
                S: cap://cal.example.com/calid2
                S: cap://cal.example.com/calid5
                S: cap://cal.example.com/calid66
                S: .

   Example #2: Request lookup a CSID which is a Resource Calendar

                C: CALIDEXPAND cap://cal.example.com/conf5
                S: 2.0
                S: cap://cal.example.com/conf5
                S: cap://cal.example.com/conf5
                S: .

   Example #3: Request CSID which exceeds MAXCALIDEXPANDLIST

                C: CALIDEXPAND cap://cal.example.com/calid76
                S: 2.0 2.3 Expansion resulted in too much data
                S: cap://cal.example.com/calid76
                S: cap://cal.example.com/calid3
                S: cap://cal.example.com/calid12
                S: cap://cal.example.com/calid21
                S: cap://cal.example.com/calid33
                S: 2.3 Expansion resulted in too much data
             S: .

   Example #4: CS loses contact with directory server during CALIDEXPAND

             C: CALIDEXPAND cap://cal.example.com/calid76
             S: 2.0

                C: CALIDEXPAND cap://cal.example.com/calid76
                S: cap://cal.example.com/calid3
             S: cap://cal.example.com/calid5
             S: 2.4 Lost contact with directory server
                S: cap://cal.example.com/calid76
                S: cap://cal.example.com/calid3
                S: cap://cal.example.com/calid5
                S: .

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

7.1.5 CAPABILITY Command

   Arguments:  none

   Data:       none

   Result:     capabilities as described below

   The CAPABILITY command returns information about the CAP server given
   the current state of the connection with the client.  The values
   returned may differ depending on whether the connection is in the
   Connected or the Authenticated state.  The return values may also be
   different for a secure versus a non-secure connection.

   Client implementations SHOULD NOT require any capability name beyond
   those defined in this specification, and MAY ignore any non-standard,
   experimental capability names.  Non-standard experimental capability
   names MUST be prefixed with the text "X-".  The prefix SHOULD also
   include a short character vendor identifier For example, "X-FOO-BARCAPABILITY", "X-FOO-
   BARCAPABILITY", for the non- standard "BARCAPABILITY" capability of
   the implementor "FOO".  This command may return different results in
   the Connected state versus the Authenticated state.  It may also
   return different results depending on the UPN.

             Capability   Occurs     Description
             -------------------------------------------------------
             AUTH         1+         The authentication mechanisms
                                     supported. Implementations MUST
                                     implement at least

             AUTOLOGOUTTIME
                          0 or 1     An integer value that specifies
                                     the default idle time in seconds
                                     the CS will wait before
                                     disconnecting an idle CUA.If the
                                     CS is busy the CS may adjust down
                                     the auto-logout timer.  If not
                                     specified, the value is 15 minutes
                                     (900 seconds). A value of zero (0)
                                     indicates unlimited connect time
                                     is allowed.

             CAPVERSION   1          Revision of CAP, MUST include at
                                     least "1.0". Comma separated
                                     values.

             ITIPVERSION  0 or 1     Revision of ITIP, MAY be present.
                                     If present, it MUST include at
                                     least "1.0"
             CAR          0 or 1     Indicates level of CAR support.
                                     CAR-MIN or CAR-FULL-1. If not
                                     specified the default is
                                     CAR-FULL-1.  Implementations
                                     MUST implement CAR-MIN.
                                     Implementations MAY implement
                                     CAR-FULL-1.

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

             QUERYLEVEL   0 or 1     Indicates level of SQL support.
                                     SQL-MIN or SQL-92. If not
                                     specified the default is SQL-92.
                                     Implementations MUST implement
                                     SQL-MIN.  Implementations MAY
                                     implement SQL-92.

             MAXICALOBJECTSIZE
                          0 or 1     An integer value that specifies
                                     The largest ICAL object the server
                                     will accept in bytes. Objects
                                     larger than this will be rejected.
                                     A value of zero (0) indicates
                                     unlimited. The default is zero (0)
                                     if not specified.

             MAXDATE      0 or 1     The datetime value in GMT beyond
                                     which the server cannot accept. If
                                     not specified the default is
                                     99991231T235959Z.

             MAXCALIDEXPANDLIST
                          0 or 1     An integer value that specifies
                                     the maximum number of CalIDs that
                                     can be returned by the CALIDEXPAND
                                     Command. A value of zero (0)
                                     indicates unlimited which is the
                                     default if not specified.

             MAXUPNEXPANDLIST
                          0 or 1     An integer value that specifies
                                     the maximum number of UPNs that
                                     can be returned by the UPNEXPAND
                                     Command. A value of zero (0)
                                     indicates unlimited which is the
                                     default if not specified.

             MINDATE      0 or 1     The datetime value prior to which
                                     the server cannot accept. If not
                                     specified the default is
                                     00000101T000000Z.

             PIPELINE     0 or 1     An integer value that specifies
                                     the maximum number of commands a
                                     CUA may send without the CUA
                                     waiting for a reply from the CS.
                                     If not specified, the default
                                     value is one (1). A value of zero
                                     (0)indicates unlimited.

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

          AUTOLOGOUTTIME
                       0 or 1     An integer value that specifies
                                  the default idle time in seconds
                                  the CS will wait before
                                  disconnecting an idle CUA.If the
                                  CS is busy the CS may adjust down
                                  the auto-logout timer.  If not
                                  specified, the value is 15 minutes
                                  (900 seconds). A value of zero (0)
                                  indicates unlimited connect time
                                  is allowed.

   Example:

               C: CAPABILTIY
               S: 2.0
               S: .
               S: CAPVERSION=1.0
               S: ITIPVERSION=1.0
               S: AUTH=KERBEROS_V4
               S: AUTH=DIGEST_MD5
               S: .

7.1.6 CONTINUE Command

   Arguments: latency time in seconds (optional)

   Data:    none

   Result:   results from the command in progress 2.0.2 - reply pending.

   The CONTINUE command is issued by the client in response to a SENDATA
   timeout.  When a timeout value is specified on the SENDDATA command,
   the server must issue a reply to the client within the specified
   time.  If the latency time has elapsed prior to the server completing
   the command it returns a timeout response code.  If the client wants
   the server to continue processing the command it responds with the
   CONTINUE command.

   If latencyTime is present, it must be a positive integer that
   specifies the maximum number of seconds the client will wait for the
   next response.  If it is omitted, the receiver waits an indefinite
   period of time for the response.

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

   In this example, the client requests a response from the server every
   10 seconds.

               C: SENDDATA:10
               C: Content-Type:text/calendar; method=READ; component=VEVENT
               C:
               C: BEGIN:VCAP
               # etc
               C: END:VCAP
               C: .
               # after 10 seconds...
               S: .
               S: 2.0.2
               S: .
               S: .
               C: CONTINUE:10
               S: 2.0
               S: .
               S: Content-type:text/calendar;
               S:   Method=RESPONSE;Component=VDATA;   Method=RESPONSE;Component=VCAP;
               S: Optinfo=VERSION:2.1
               S:
               S: BEGIN:VCAP

               S: VERSION:2.1
               S: CALID:cap://cal.example.com/relcal2
               # etc.
               S: END:VCAP
               S: .

7.1.7 DISCONNECT Command

   Arguments: none

   Data:

   Result:   2.0

   The DISCONNECT command is used by a client to terminate a connection.
   It always succeeds.

   The CUA MUST wait for the CS 2.0 reply to ensure that TCP/IP (which
   knows nothing about CAP) can be sure the connection should go away.
   This avoids the CS connection being stuck in TCP-WAIT state.

   Example:

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

               C: DISCONNECT
               # [ed. [EDITORS NOTE: Note: should the client now wait for a response from
             the
               server
               #  before disconnecting? ]
               S: 2.0
               S: .
               S: .
               S: <drops connection>
               C: <drops connection>

          7.1.8.

7.1.8 IDENTIFY Command

   Arguments: Identity to assume

   Data:      None

   Result:    2.0 .4 Identity not permitted

   The "IDENTIFY" command allows the CUA to select a new identity to be
   used for calendar access.  This command may only be called in the
   Identified State.

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

          7.1.8

7.1.9 SENDDATA Command

   Arguments: [latencyTime]

   Data:      a [MIME] encapsulated iCalendar object

   Result:    2.0.1 - Server will now accept input until <CRLF>.<CRLF>
   is encountered.

   The SENDDATA command is used to send calendar requests and commands
   to the server.  After a response code of 2.0.1 is issued the CUA
   sends a [MIME] encapsulated iCalendar object to the server.  The end
   of this [MIME] data is signaled by the special sequence <CRLF>.<CRLF>
   .

          7.1.10.

7.1.10 STARTTLS Command

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

   Arguments: None

   Data:      None

   Result:    2.0 5  TLS not supported

   The "STARTTLS" command is issued by the CUA to indicate to the CS
   that it wishes to negotiate transport level security using [TLS].  If
   the CS does not support TLS it returns status code 6.5.  If the CS
   supports TLS it issues an initial response of 2.0.12 indicating that
   the CUA should proceed with TLS negotiation.  Once the TLS
   negotiation is complete the server returns the response code 2.0.

   After issuing the "STARTTLS" command the CUA issues the
   "AUTHENTICATE" command.  The SASL external mechanism may be used if
   the CUA wishes to use the authentication id which was used in the TLS
   negotiation.

   The CUA MUST NOT issue a "STARTTLS" if it has already issued an
   "AUTHENTICATE" or "STARTTLS" command in this session.  If a CUA does
   this the CS must terminate the session.

   The following examples illustrate the use of the "STARTTLS" command:

   Unsupported TLS:

               C: STARTTLS
               S: 6.5

   Supported TLS:

               C: STARTTLS
               S: 2.0.12
                <tls negotiation>
               S: 2.0

               S: .
               S: .

          7.1.8.1

7.1.11 UPNEXPAND Method

   Arguments: UPN

   Data:      no specific data for this command

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
   Result:    2.0 - success 2.1 Permission Denied 2.2 Requested UPN not
   found 2.3 Result exceeds MAXUPNEXPANDLIST 2.4 Misc.  UPNEXPAND error

   Return the members of the argument UPN.  Successful result yields one
   or more CalIDs.  More than one CalID returned implies that the UPN was a UG. UPN
   was a UG.

   If the number of items exceeds MAXUPNEXPANDLIST,  then up to
   MAXUPNEXPANDLIST items are returned along with result  2.3.

   If the result is 2.4, then as many of the items as possible will be
   returned.  It is possible that no items will  be returned.  The 2.4
   response may  have optional text describing the problem.  Any  such
   text MUST  be in the language and charset that is defined by the
   calendar store properties LANGUAGE and CHARSET.

   If calendar store CHARSET is  not set, but the LANGUAGE property is
   set, then  the error message will be in LANGUAGE in the UTF-8
   charset.  If calendar store LANGUAGE property is not set, then  the
   CS MUST NOT return any text with  the results.

   Example #1: Request lookup of a UPN which is a CU

               C: UPNEXPAND upn@example.com
               S: 2.0
               S: upn@example.com
               S: cap://cal.example.com/calid3
               S: .

   Example #2: Request lookup of UPN which is a UG

               C: UPNEXPAND group@example.com
               S: 2.0
               S: group@example.com
               S: cap://cal.example.com/calid3
               S: cap://cal.example.com/calid6
               S: cap://cal.example.com/calid1342
               S: .

   Example #3: Request lookup exceeds MAXUPNEXPANDLIST

               C: UPNEXPAND group@example.com
               S: 2.0 2.3 Lookup resulted in too much data
               S: group@example.com
               S: cap://cal.example.com/calid3
               S: cap://cal.example.com/calid12
               S: cap://cal.example.com/calid21
               S: cap://cal.example.com/calid33
               S: 2.3 Lookup resulted in too much data
            S: .

   Example #4: CS loses contact with directory server during UPNEXPAND

               C: UPNEXPAND group@example.com
               S: 2.0 group@example.com
               S: cap://cal.example.com/calid3
            S: cap://cal.example.com/calid5

            S: 2.4 Lost contact with directory server
               S: cap://cal.example.com/calid3
               S: cap://cal.example.com/calid5
               S: .

7.1.12 NOOP Command

   Arguments: none

   Data:      none

   Result:    2.0 - success

   This method does nothing.  It can be sent to the server periodically
   to request that the CS not time out the session.

   [EDITORS NOTE: should an unauthenticated and unidentified client be
   able to issue this command?]

   [EDITORS NOTE: need to add NOOP in the state diagram?]

   Example:

             C: NOOP

             S: 2.0
             S: .

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

7.2 Application Protocol Commands

7.2.1 Calendaring Commands

   The following methods provide a set of calendaring commands in CAP.
   Calendaring commands (or methods) allow a CU to directly manipulate a
   calendar.

   Calendar access rights can be granted for the more generalized access
   provided by the calendar commands.

7.2.1.1 Restriction Tables

   Commands are sent to CAP servers encapsulated in iCalendar objects.
   The reply to these commands are also encapsulated in iCalendar
   objects.  The restriction tables listed in the commands below
   describe the composition of the iCalendar data for these commands and
   replies.

   The Presence column uses the following values to assert whether a
   property is required, is optional and the number of times it may
   appear in the iCalendar object.  A Comment may be provided to further
   clarify the presence criteria.

   The table below defines the values for the Presence column.

             Presence Value  Description
             --------------------------------------------------------------
             1         One instance MUST be present
             1+        At least one instance MUST be present
             0         Instances of this property Must NOT be present
             0+        Multiple instances MAY be present
             0 or 1    Up to 1 instance of this property MAY be present
             --------------------------------------------------------------

   While the tables list every component and property, their purpose is
   not to define the meaning of the component or property.

   There will be a REQUEST-STATUS for each VCALENDAR and component
   created, modified, deleted, or requested.  The number of REQUEST-STATUS REQUEST-
   STATUS values returned MUST be equal to the number of TARGETS times
   the number of objects in the command.  The responses MUST be ordered
   first by TARGET then by the order of the objects as supplied in the
   command.

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

7.2.1.2 CREATE Method

   Arguments: none

   Data:    no specific data for this command

   Result:

      2.0 - successfully created the component or calendar

      6.0 - Permission denied

      6.1 - Container(s) not found
      6.2 - Calendar or component already exists

      6.3 - Bad args

   The CREATE method is used to create a new iCalendar object of type
   objtype.  The property TARGET specifies the container(s) for the
   create.  The type of object wrapped inside of the VCALENDAR/CREATE
   object is the object type(s) being created.  When creating a new
   calendar at the top level, the CSID is specified.  Otherwise the
   container will be a CalID.

   Restriction table

             Component/Property     Presence Comment
             -------------------    -------- -----------------------------
             VCAP                   1+       The CUA can send up
                                             PIPELINE commands
                                             without processing a
                                             response

             . VERSION              1        MUST be 2.0
             . [IANA-PROP]          0+       any IANA registered
                                             property

             . VCOMMAND             1        MUST at least one container
                                             (VCALENDAR, VCAR, VQUERY,
                                             VEVENT, VTODO, VJOURNAL)
             . . CMDID              0 or 1   If CMDID is not supplied,
                                             then there must not be
                                             pending replies to previous
                                             command.

             . . [IANA-PROP]        0+       any IANA registered
                                             property
             . . METHOD             1        MUST be CREATE.
             . . TARGET             1+       MUST be the CSID or CALID

             . . VCALENDAR          0+

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
             . . . CALMASTER        0 or 1
             . . . NAME             0 or 1
             . . . OWNER            1+
             . . . RELCALID         1
             . . . TZID             0 or 1
             . . . [IANA-PROP]      0+       any IANA registered
                                             property

             . . VCAR               0+
             . . . CARID            0 or 1
             . . . DENY             0+       Note, there must be at
                                             least one GRANT or DENY
                                             within the VCAR.
             . . . GRANT            0+       Note, there must be at
                                             least one GRANT or DENY
                                             within the VCAR.
             . . . [IANA-PROP]      0+       any IANA registered
                                             property

             . . VQUERY             0+
             . . . EXPAND           0 or 1
             . . . MAXRESULTS       0 or 1
             . . . MAXSIZE          0 or 1
             . . . QUERYNAME        1
             . . . QUERY            1
             . . . [IANA-PROP]      0+       any IANA registered
                                             property

             . . VEVENT             0+
             . . . ATTENDEE         0+
             . . . SEQUENCE         0 or 1   MUST be present if value is
                                             greater than 0,
                                             MAY be present if 0
             . . . SUMMARY          1        Can be null
             . . . UID              1

             . . . ATTACH           0+
             . . . CATEGORIES       0 or 1
             . . . CLASS            0 or 1
             . . . COMMENT          0 or 1
             . . . CONTACT          0+
             . . . CREATED          0 or 1
             . . . DESCRIPTION      0 or 1   Can be null
             . . . DTEND            0 or 1   if present DURATION MUST
                                             NOT be present
             . . . DTSTAMP          1
             . . . DTSTART          1
             . . . DURATION         0 or 1   if present DTEND MUST NOT
                                             be present

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
             . . . EXDATE           0+
             . . . EXRULE           0+
             . . . GEO              0 or 1
             . . . LAST-MODIFIED    0 or 1
             . . . LOCATION         0 or 1
             . . . METHOD           1        <<placeholder. it may move
                                             to meta-info>>
             . . . ORGANIZER        1
             . . . PRIORITY         0 or 1
             . . . RDATE            0+
             . . . RECURRENCE-ID    0 or 1   only if referring to an
                                             instance of a recurring
                                             calendar component.
                                             Otherwise it MUST NOT be
                                             present.
             . . . RELATED-TO       0+
             . . . REQUEST-STATUS   0+
             . . . RESOURCES        0 or 1   This property MAY contain a
                                             list of values
             . . . RRULE            0+
             . . . STATUS           0 or 1
             . . . TRANSP           0 or 1
             . . . URL              0 or 1
             . . . X-PROPERTY       0+
             . . . [IANA-PROP]      0+       any IANA registered
                                             property

             . . . VALARM           0+
             . . . . ACTION         1
             . . . . ALARMID        0 or 1   MUST be 1 if multiple
                                             VALARMs are present in
                                             same component.
             . . . . ATTACH         0+
             . . . . DESCRIPTION    0 or 1
             . . . . DURATION       0 or 1  if present REPEAT MUST be
                                            present
             . . . . REPEAT         0 or 1  if present DURATION MUST be
                                            present
             . . . . SUMMARY        0 or 1
             . . . . TRIGGER        1
             . . . . X-PROPERTY     0+
             . . . . [IANA-PROP]    0+      any IANA registered property

             . . VTODO              0+
             . . . ATTENDEE         0+
             . . . SEQUENCE         0 or 1  MUST be present if value is
                                            greater than 0, MAY be
                                            present if 0

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
             . . . SUMMARY          1       Can be null.
             . . . UID              1

             . . . ATTACH           0+
             . . . CATEGORIES       0 or 1  This property may contain a
                                            list of values
             . . . CLASS            0 or 1
             . . . COMMENT          0 or 1
             . . . CONTACT          0+
             . . . CREATED          0 or 1
             . . . DESCRIPTION      0 or 1  Can be null
             . . . DTSTAMP          1
             . . . DTSTART          1
             . . . DUE              0 or 1  If present DURATION MUST NOT
                                            be present
             . . . DURATION         0 or 1  If present DUE MUST NOT be
                                            present
             . . . EXDATE           0+
             . . . EXRULE           0+
             . . . GEO              0 or 1
             . . . LAST-MODIFIED    0 or 1
             . . . LOCATION         0 or 1
             . . . METHOD           1       <<placeholder. it may move
                                            to meta-info>>
             . . . ORGANIZER        1
             . . . PRIORITY         1
             . . . PERCENT-COMPLETE 0 or 1
             . . . RDATE            0+
             . . . RECURRENCE-ID    0 or 1  MUST only if referring to an
                                            instance of a recurring
                                            calendar component.
                                            Otherwise it MUST NOT be
                                            present.
             . . . RELATED-TO       0+
             . . . REQUEST-STATUS   0
             . . . RESOURCES        0 or 1  This property may contain a
                                            list of values
             . . . RRULE            0+
             . . . STATUS           0 or 1  MAY be one of COMPLETED,
                                            NEEDS-ACTION,
                                            IN-PROCESS, CANCELLED
             . . . URL              0 or 1

             . . . X-PROPERTY       0+
             . . . [IANA-PROP]      0+      any IANA registered property

             . . . VALARM           0+
             . . . . ACTION         1
             . . . . ALARMID        0 or 1  MUST be 1 if multiple

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
                                            VALARMs are present in
                                            same component.
             . . . . ATTACH         0+
             . . . . DESCRIPTION    0 or 1
             . . . . DURATION       0 or 1  if present REPEAT MUST be
                                            present
             . . . . REPEAT         0 or 1  if present DURATION MUST be
                                            present
             . . . . SUMMARY        0 or 1
             . . . . TRIGGER        1
             . . . . X-PROPERTY     0+
             . . . . [IANA-PROP]    0+      any IANA registered property

             . . VJOURNAL           0+
             . . . ATTENDEE         0
             . . . DESCRIPTION      1    Can be null.
             . . . DTSTAMP          1
             . . . DTSTART          1
             . . . ORGANIZER        1
             . . . UID              1

             . . . ATTACH           0+
             . . . CATEGORIES       0 or 1 This property MAY contain a list
             of values
             . . . CLASS            0 or 1
             . . . COMMENT          0 or 1
             . . . CONTACT          0+
             . . . CREATED          0 or 1
             . . . EXDATE           0+
             . . . EXRULE           0+
             . . . LAST-MODIFIED    0 or 1
             . . . METHOD           1        <<placeholder. it may move
                                             to meta-info>>
             . . . RDATE            0+
             . . . RECURRENCE-ID    0 or 1   MUST only if referring to
                                             an instance of a recurring
                                             calendar component.
                                             Otherwise it MUST NOT be
                                             present.
             . . . RELATED-TO       0+
             . . . RRULE            0+
             . . . SEQUENCE         0 or 1   MUST be present if
                                             non-zero. MAY be
                                             present if zero.
             . . . STATUS           0 or 1
             . . . SUMMARY          0 or 1   Can be null
             . . . URL              0 or 1
             . . . X-PROPERTY       0+

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
             . . . [IANA-PROP]      0+       any IANA registered
                                             property

             . . VFREEBUSY          0
             . . VTIMEZONE          0+       MUST be present if any
                                             date/time refers to a
                                             timezone
             . . . DAYLIGHT         0+       MUST be one or more of
                                             either STANDARD or
                                             DAYLIGHT
             . . . . . COMMENT      0 or 1
             . . . . . DTSTART      1
             . . . . . RDATE        0+       if present RRULE MUST NOT
                                             be present
             . . . . . RRULE        0+       if present RDATE MUST NOT
                                             be present
             . . . . . TZNAME       0 or 1
             . . . . . TZOFFSET     1
             . . . . . TZOFFSETFROM 1
             . . . . . TZOFFSETTO   1
             . . . . . X-PROPERTY   0+
             . . . . . [IANA-PROP]  0+       any IANA registered
                                             property
             . . . LAST-MODIFIED    0 or 1
             . . . STANDARD         0+
             . . . . . COMMENT      0 or 1
             . . . . . DTSTART      1
             . . . . . RDATE        0+       if present RRULE MUST NOT
                                             be present
             . . . . . RRULE        0+       if present RDATE MUST NOT
                                             be present
             . . . . . TZNAME       0 or 1
             . . . . . TZOFFSETFROM 1
             . . . . . TZOFFSETTO   1
             . . . . . X-PROPERTY   0+
             . . . . . [IANA-PROP]  0+       any IANA registered property
             . . . TZID             1
             . . . TZURL            0 or 1
             . . . X-PROPERTY       0+
             . . . [IANA-PROP]      0+       any IANA registered property

   Server Restriction Table for the CREATE command

             Component/Property  Presence Comment
             ------------------- -------- -------------------------------

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

             VCAP                   1+
             . VCALENDAR            1+
             . . TARGET             1

             . . VERSION            1        MUST be 2.0
             . . CMDID              0 or 1   MUST be returned if the
                                             request contained
                                             a CMDID
             . . REQUEST-STATUS     0        if not creating a calendar
                                    1+       if creating a calendar

             . . . VCAR             0+
             . . . . REQUEST-STATUS   1+
             . . . . *              0        No other VCAR properties
                                             are present
             .
             . . . VCOMMAND         0

             . . . VEVENT           0+
             . . . . REQUEST-STATUS    1+
             . . . . *              0        No other VEVENT properties
                                             are present
             . . . . VALARM         0        if VEVENT was successfully
                                             saved
                                    1+       if there were errors saving
                                             alarms
             . . . . . REQUEST-STATUS  1+

             . . . VFREEBUSY        0+
             . . . . REQUEST-STATUS    1+
             . . . . *              0        No other VFREEBUSY
                                             properties are present

             . . . VJOURNAL         0+
             . . . . REQUEST-STATUS    1+
             . . . . *              0        No other VJOURNAL
                                             properties are present

             . . . VQUERY           0+
             . . . . REQUEST-STATUS    1+
             . . . . *              0        No other VQUERY properties
                                             are present

             . . . VTODO            0+
             . . . . REQUEST-STATUS    1+
             . . . . *              0        No other VTODO properties
                                             are present

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

             . . . . VALARM         0        if VTODO was successfully
                                             saved
                                    1+       if there were errors saving
                                             alarms
             . . . . . REQUEST-STATUS   1+

7.2.1.2.1 Creating New Calendars

   Example to create two new calendars different containers.  In the
   following example, the client is in the Authenticated state with CS
   cal.example.com.

               C: SENDDATA
               C: CONTENT-TYPE: text/calendar; method=CREATE;
               C:   component=VCOMMAND
               C: Content-Transfer-Encoding:7bit
               C:
               C: BEGIN:VCAP
               C: VERSION:2.1
               C: BEGIN:VCOMMAND
               C: METHOD:CREATE
               C: TARGET:cap://cal.example.com/
               C: TARGET:relcal4
               C: BEGIN:VCALENDAR
               C: RELCALID:relcalz1
               C: NAME:CHARSET=us-ascii;LANGUAGE=EN-us:Bill's Soccer Team
               C: OWNER:bill
               C: CALMASTER:mailto:bill@example.com
               C: TZID:US_PST
               C: BEGIN:VCAR
               C: CARID:12345
               C: GRANT:UPN=bill;ACTION=*;OBJECT=*
               C: END:VCAR
               C: END:VCALENDAR
               C: BEGIN:VCALENDAR
               C: RELCALID:relcalz2
               C: NAME:CHARSET=us-ascii;LANGUAGE=EN-us:Mary's personal
               C:   calendar
               C: OWNER:mary
               C: CALMASTER:mailto:mary@example.com
               C: TZID:US_PST
               C: BEGIN:VCAR
               C: CARID:12346
               C: GRANT:UPN=mary;ACTION=*;OBJECT=*
               C: END:VCAR
               C: END:VCALENDAR
               C: END:VCOMMAND
               C: END:VCAP

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
               C: .
               S: 2.0
               S: Content-Type:text/calendar; method=RESPONSE;
               S:   OPTINFO="CMDID:abcde"
               #  This 2.0 is the transport reply status and ends with a
               #  CRLF.CRLF (below)
               S: BEGIN:VCAP
               S: METHOD:RESPONSE
               S: TARGET:cap://cal.example.com/
               S: REQUEST-STATUS:2.0
               S: END:VCAP
               S: BEGIN:VCAP
               S: METHOD:RESPONSE
               S: REQUEST-STATUS:2.0
               S: END:VCAP
               S: .

   Example to create a new component.

               C: SENDDATA
               C: Content-Type:text/calendar; method=CREATE;
               C:   charset=US-ASCII
               C: Content-Transfer-Encoding:7bit
               C:
               C: BEGIN:VCAP
               C: VERSION:2.1
               C: CMDID:abcde
               C: BEGIN:VCOMMAND
               C: METHOD:CREATE
               C: TARGET:cap://cal.example.com/relcal1
               C: TARGET:relcal2
               C: BEGIN:VEVENT BEGIN:VEVENT

               C: DTSTART:99990307T180000Z
               C: UID:abcd12345
               C: DTEND:99990307T190000Z
               C: SUMMARY:Important Meeting
               C: END:VEVENT
               C: END:VCOMMAND
               C: END:VCAP
               C: .
               S: 2.0
               S: Content-Type:text/calendar; method=RESPONSE;
               S:   OPTINFO="CMDID:abcde"
               S:
               S: BEGIN:VCAP
               S: VERSION:2.1
               S: CMDID:abcde
               S: METHOD:RESPONSE
               S: BEGIN:VEVENT
               S: TARGET::cap://cal.example.com/relcal1
               S: REQUEST-STATUS:2.9
               S: END:VEVENT
               S: BEGIN:VEVENT
               S: REQUEST-STATUS:2.9
               S: REQUEST-STATUS:2.10
               S: END:VEVENT
               S: END:VCAP
               S: .

   The response contains the calendar (CALID) and UID of the component
   so that the CUA can match up the TARGET from multiple objects created
   on multiple calendards (TARGETs).

7.2.1.2.2 Creating a new VQUERY

   This  example  creates  a stored VQUERY  that selects all unprocessed
   scheduling entries.  QUERYNAME must not exist in the  TARGET
   calendar.

      C: SENDDATA
      C: Content-Type:text/calendar; method=CREATE; charset=US-ASCII
      C: Content-Transfer-Encoding:7bit
      C:
      C: BEGIN:VCAP
      C: VERSION:2.1
      C: CMDID:abcde-2
      C: METHOD:CREATE
      C: TARGET:cap://cal.example.com/relcal1
      C: BEGIN:VQUERY
      C: DTSTART:99990307T180000Z BEGIN:VQUERY
      C: UID:abcd12345 QUERYNAME:GetAlliTIPinQueue
      C: DTEND:99990307T190000Z QUERY:SELECT UID FROM VEVENT,VTODO WHERE METHOD != 'CREATE'
      C: SUMMARY:Important Meeting END:VQUERY
      C: END:VEVENT
      C: END:VCOMMAND
            C: END:VCAP
      C: .
      S: 2.0
      S: Content-Type:text/calendar; method=RESPONSE;
            S: OPTINFO="CMDID:abcde"
      S:
      S: BEGIN:VCAP
      S: VERSION:2.1
            S: CMDID:abcde

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001 CMDID:abcde-2
      S: METHOD:RESPONSE
      S: BEGIN:VEVENT
            S: TARGET::cap://cal.example.com/relcal1
      S: REQUEST-STATUS:2.9
            S: END:VEVENT
            S: BEGIN:VEVENT
            S: REQUEST-STATUS:2.9 BEGIN:VQUERY
      S: REQUEST-STATUS:2.10 REQUEST-STATUS:2.0;
      S: END:VEVENT END:VQUERY
      S: END:VCAP
      S: .

          The response contains the calendar (CALID) and UID of the
          component so that the CUA

   [EDITORS NOTE  - can match up the TARGET from
          multiple objects created on multiple calendards (TARGETs). return QUERYNAME already exists error]

7.2.1.3 DELETE Method

   Arguments: none

   Data:    no specific data for this command

   Result:

      2.0 - successfully deleted the component or calendar

      Permission

      Calendar or component not found

      Bad args

      Container(s) not found

   The DELETE method is used to delete a calendar or component.  The
   TARGET properties specify the container(s) for the delete.  When
   deleting a calendar at the top level, the CSID is specified.
   Otherwise the   container will be a CalID.

   Restriction Table

             Component/Property    Presence Comment
             -------------------   -------- ---------------------------
             VCAP                  1+       The CUA can send up
                                            PIPELINE commands
                                            without processing a
                                            response

              VERSION              1        MUST be 2.0

              VCOMMAND             1
               CMDID               0 or 1   If CMDID is not supplied,
                                            then there must
                                            not be pending replies to

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
                                            previous command.
               METHOD              1        MUST be DELETE.
               TARGET              1+       MUST be a the CSID or CALID

               VQUERY              0+
                EXPAND             0    ?
                MAXRESULTS         0 or 1   Limit the solution set to
                                            no more than this many
                                            entries.

                MAXSIZE            0    ?
                QUERYNAME          1        Name by which this query is
                                            referenced
                QUERY              1        The query

   Server Restriction Table for the DELETE command

             Component/Property  Presence Comment
             ------------------- -------- -----------------------------

             VCAP                1+
             TARGET              1

             VERSION             1        MUST be 2.0

             CMDID               0 or 1   MUST be returned if the
                                          request contained a CMDID

             VCALENDAR                    Only if VCALENDARs were
                                          deleted
               REQUEST-STATUS    1
               *                 1+       No other VALARM properties
                                          are present

             VALARM              0+       Only if VALARM components
                                          were deleted
               REQUEST-STATUS    1
               *                 0        No other VALARM properties
                                          are present

             VCAR                0+       Only if VCAR components were
                                          deleted
               REQUEST-STATUS    1
               *                 0        No other VCAR properties are
                                          present

             VEVENT              0+       Only if VEVENT components
                                          were deleted
               REQUEST-STATUS    1+

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

               *                 0        No other VEVENT properties
                                          are present

             VFREEBUSY           0
               REQUEST-STATUS    1+
               *                 0        No other VFREEBUSY properties
                                          are present
             VJOURNAL            0+       Only if VJOURNAL components
                                          were deleted
               REQUEST-STATUS    1+
               *                 0        No other VJOURNAL properties
                                          are present

             VQUERY              0+       Only if VQUERY components
                                          were deleted
               REQUEST-STATUS    1+
               *                 0        No other VQUERY properties
                                          are present

             VTIMEZONE           0+       Only if VTIMEZONE components
                                          were deleted
               REQUEST-STATUS    1+
               *                 0        No other VQUERY properties
                                          are present

             VTODO               0+       Only if VTODO components were
                                          deleted
               REQUEST-STATUS    1+
               *                 0        No other VTODO properties are
                                          present

             ----------------------------------------------------------

          [Editors note:

   [EDITORS NOTE: Issues:

      - Currently CAP requires that the server return a response status.
      However, if there are multiple components deleted, should the UID
      also be returned?

      - VQUERY EXPAND and MAXSIZE parameters do not seem to apply to
      deletion?

      - Can one use DELETE to remove all VALARMs and VTIMEZONEs that
      match a certain search criteria and that belong to all components,
      event though VALARMs and VTIMEZONEs never exist as independent
      components? Or should one use MODIFY? If they can

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001 be deleted, do
      we return the REQUEST-STATUS of their deletion in a VEVENT or
      separately?

      - In the example in CAP where a calendar is deleted all the server
      returns is 2.0, nothing else?

      - We should not be able to delete any VFREEBUSY components?
      - Can we delete multiple calendars?

      - Currently one can not delete a VCALENDAR and some other
      component in the same DELETE command.  This seems OK.  Anyone see
      any need to be able to do this?

      - Should the MAXRESULTS property of VQUERY apply to deletion? We
      can use it to delete only the first n components that match.  ]

   Example to delete a VEVENT with UID 'abcd12345':

               C: SENDDATA
               C: Content-Type:text/calendar; method=DELETE;
             component=VCOMMAND
               C: Content-Transfer-Encoding:7bit
               C:

             C: BEGIN:VCAP
               C: BEGIN:VCOMMAND
               C: METHOD:DELETE
               C: TARGET:cap://cal.foo.com/bill
               C: BEGIN:VQUERY
               C: QUERY:SELECT UID FROM VEVENT WHERE UID = 'abcd12345'
               C: END:VQUERY
               C: END:VCOMMAND
               C: END:VCAP
               C: .
               S: 2.0
               S: Content-Type:text/calendar; method=DELETE;
               S:  component=VCOMMAND
               S:
               S: BEGIN:VCAP
               S: METHOD:RESPONSE
               S: BEGIN:VEVENT
               S: REQUEST-STATUS:2.0
               S: END:VEVENT
               S: END:VCAP
               S: .

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

          And an example to delete the 'MrBill' calendar:
               C: SENDDATA
               C: Content-Type:text/calendar; method=DELETE;
               C:  component=VCOMMAND
               C: Content-Transfer-Encoding:7bit
               C:
               C: BEGIN:VCAP
               C: BEGIN:VCOMMAND
               C: METHOD:DELETE
               C: TARGET:cap://cal.foo.com/MrBill
               C: END:VCOMMAND
               C: END:VCAP
               C: .
               S: 2.0
               S: .

7.2.1.4 GENERATEUID Method

   Arguments: Number of UIDs to generate.

   Data:      new uids

   Result:    2.0

   GENERATEUID returns one or more new unique identifier which MUST be
   unique on the server's calendar store.  It is recommended that the
   return value be a globally unique id.

   Example:

   C: GENERATEUID 2
   S: 2.0
   S: abcde1234567-asdf-lkhh
   S: abcde1234567-asdf-3455
   S: .

   [EDITORS NOTE: this example needs work.  It's not packaged right]

7.2.1.5 MODIFY Method

   Arguments: none

   Data:     no specific data for this command

   Result:

      2.0 - successfully modified the component or calendar

      Permission

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

      Calendar or component not found

      Bad args

      Container(s) not found

   The MODIFY method is used to change an existing calendar or
   component.  TARGET specify the container(s) of the modification.

   When modifying a calendar at the top level, the CSID is specified.
   Otherwise the container will be a CalID.

   The format of the request is two or three containers inside of a
   VCOMMAND container:

               BEGIN:VCOMMAND
               [VQUERY]
               OLD-VALUES
               NEW-VALUES
               END:VCOMMAND

   If a VQUERY is present, then only objects matching the query results
   are modified.

   Restriction Table

             Component/Property     Presence Comment
             -------------------    -------- ---------------------------
             VCAP                   1+       The CUA can send up
                                             PIPELINE commands
                                             without processing a
                                             response

             . VERSION              1        MUST be 2.0
             . [IANA-PROP]          0+       any IANA registered
                                             property

             . VCOMMAND             1        MUST have at least one
                                             container (VCALENDAR,
                                             VCAR, VQUERY, VEVENT,
                                             VTODO, VJOURNAL)
             . . CMDID                0 or 1 If CMDID is not supplied,
                                             then there must
                                             not be pending replies to
                                             previous command.
             . . [IANA-PROP]        0+       any IANA registered
                                             property
             . . METHOD             1        MUST be MODIFY
             . . TARGET             1+       MUST be the CALID

             . . VCALENDAR          0+

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
             . . . CALMASTER        0 or 1
             . . . NAME             0 or 1
             . . . OWNER            1+
             . . . RELCALID         1
             . . . TZID             0 or 1
             . . . [IANA-PROP]      0+       any IANA registered
                                             property

             . . VCAR               0+
             . . . CARID            0 or 1
             . . . DENY             0+       Note, there must be at
                                             least one GRANT or DENY
                                             within the VCAR.
             . . . GRANT            0+       Note, there must be at
                                             least one GRANT or DENY
                                             within the VCAR.
             . . . [IANA-PROP]      0+       any IANA registered
                                             property

             . . VQUERY             0+
             . . . EXPAND           0 or 1
             . . . MAXRESULTS       0 or 1
             . . . MAXSIZE          0 or 1
             . . . QUERYNAME        1
             . . . QUERY            1
             . . . [IANA-PROP]      0+       any IANA registered
                                             property

             . . VEVENT             0+
             . . . ATTENDEE         0+
             . . . SEQUENCE         0 or 1   MUST be present if value is
                                             greater than 0,
                                             MAY be present if 0
             . . . SUMMARY          1        Can be null
             . . . UID              1

             . . . ATTACH           0+
             . . . CATEGORIES       0 or 1
             . . . CLASS            0 or 1
             . . . COMMENT          0 or 1
             . . . CONTACT          0+
             . . . CREATED          0 or 1
             . . . DESCRIPTION      0 or 1   Can be null
             . . . DTEND            0 or 1   if present DURATION MUST
                                             NOT be present
             . . . DTSTAMP          1
             . . . DTSTART          1
             . . . DURATION         0 or 1   if present DTEND MUST NOT
                                             be present

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
             . . . EXDATE           0+
             . . . EXRULE           0+
             . . . GEO              0 or 1
             . . . LAST-MODIFIED    0 or 1
             . . . LOCATION         0 or 1
             . . . METHOD           1         <<placeholder. it may move
                                                to meta-info>>
             . . . ORGANIZER        1
             . . . PRIORITY         0 or 1
             . . . RDATE            0+
             . . . RECURRENCE-ID    0 or 1   only if referring to an
                                             instance of a recurring
                                             calendar component.
                                             Otherwise it MUST NOT be
                                             present.
             . . . RELATED-TO       0+
             . . . REQUEST-STATUS   0+
             . . . RESOURCES        0 or 1   This property MAY contain a
                                             list of values
             . . . RRULE            0+
             . . . STATUS           0 or 1
             . . . TRANSP           0 or 1
             . . . URL              0 or 1
             . . . X-PROPERTY       0+
             . . . [IANA-PROP]      0+       any IANA registered
                                             property

             . . . VALARM           0+
             . . . . ACTION         1
             . . . . ALARMID        0 or 1   MUST be 1 if multiple
                                             VALARMs are present in same
                                             component.
             . . . . ATTACH         0+
             . . . . DESCRIPTION    0 or 1
             . . . . DURATION       0 or 1   if present REPEAT MUST be
                                             present
             . . . . REPEAT         0 or 1   if present DURATION MUST be
                                             present
             . . . . SUMMARY        0 or 1
             . . . . TRIGGER        1
             . . . . X-PROPERTY     0+
             . . . . [IANA-PROP]    0+       any IANA registered
                                             property

             . . VTODO              0+
             . . . ATTENDEE         0+
             . . . SEQUENCE         0 or 1   MUST be present if value is
                                             greater than 0, MAY be

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
                                             present if 0
             . . . SUMMARY          1        Can be null.
             . . . UID              1
             . . . ATTACH           0+
             . . . CATEGORIES       0 or 1   This property may contain a
                                             list of values
             . . . CLASS            0 or 1
             . . . COMMENT          0 or 1
             . . . CONTACT          0+
             . . . CREATED          0 or 1
             . . . DESCRIPTION      0 or 1   Can be null
             . . . DTSTAMP          1
             . . . DTSTART          1
             . . . DUE              0 or 1   If present DURATION MUST
                                             NOT be present
             . . . DURATION         0 or 1   If present DUE MUST NOT be
                                             present
             . . . EXDATE           0+
             . . . EXRULE           0+
             . . . GEO              0 or 1
             . . . LAST-MODIFIED    0 or 1
             . . . LOCATION         0 or 1
             . . . METHOD           1        <<placeholder. it may move
                                             to meta-info>>
             . . . ORGANIZER        1
             . . . PRIORITY         1
             . . . PERCENT-COMPLETE 0 or 1
             . . . RDATE            0+
             . . . RECURRENCE-ID    0 or 1   MUST only if referring to
                                             an instance of a recurring
                                             calendar component.
                                             Otherwise it MUST NOT
                                             be present.
             . . . RELATED-TO       0+
             . . . REQUEST-STATUS   0
             . . . RESOURCES        0 or 1   This property may contain a
                                             list of values
             . . . RRULE            0+
             . . . STATUS           0 or 1   MAY be one of COMPLETED,
                                             NEEDS-ACTION,
                                             IN-PROCESS, CANCELLED
             . . . URL              0 or 1

             . . . X-PROPERTY       0+
             . . . [IANA-PROP]      0+       any IANA registered
                                             property

             . . . VALARM           0+

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
             . . . . ACTION         1
             . . . . ALARMID        0 or 1   MUST be 1 if multiple
                                             VALARMs are present in
                                             same component.
             . . . . ATTACH         0+
             . . . . DESCRIPTION    0 or 1
             . . . . DURATION       0 or 1   if present REPEAT MUST be
                                             present
             . . . . REPEAT         0 or 1   if present DURATION MUST be
                                             present
             . . . . SUMMARY        0 or 1
             . . . . TRIGGER        1
             . . . . X-PROPERTY     0+
             . . . . [IANA-PROP]    0+       any IANA registered
                                             property

             . . VJOURNAL           0+
             . . . ATTENDEE         0
             . . . DESCRIPTION      1        Can be null.
             . . . DTSTAMP          1
             . . . DTSTART          1
             . . . ORGANIZER        1
             . . . UID              1

             . . . ATTACH           0+
             . . . CATEGORIES       0 or 1   This property MAY contain a
                                             list of values
             . . . CLASS            0 or 1
             . . . COMMENT          0 or 1
             . . . CONTACT          0+
             . . . CREATED          0 or 1
             . . . EXDATE           0+
             . . . EXRULE           0+
             . . . LAST-MODIFIED    0 or 1
             . . . METHOD           1        <<placeholder. it may move
                                             to meta-info>>
             . . . RDATE            0+
             . . . RECURRENCE-ID    0 or 1   MUST only if referring to

                                             an instance of a recurring
                                             calendar component.
                                             Otherwise it MUST NOT be
                                             present.
             . . . RELATED-TO       0+
             . . . RRULE            0+
             . . . SEQUENCE         0 or 1   MUST be present if non-
                                             zero. MAY be
             . . . . .                       present if zero.

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

             . . . STATUS           0 or 1
             . . . SUMMARY          0 or 1   Can be null
             . . . URL              0 or 1
             . . . X-PROPERTY       0+
             . . . [IANA-PROP]      0+       any IANA registered
                                             property

             . . VFREEBUSY          0

             . . VTIMEZONE          0+       MUST be present if any
                                             date/time refers
                                             to a timezone
             . . . DAYLIGHT         0+       MUST be one or more of
                                             either STANDARD
                                             or DAYLIGHT
             . . . . . COMMENT      0 or 1
             . . . . . DTSTART      1
             . . . . . RDATE        0+       if present RRULE MUST NOT
                                             be present
             . . . . . RRULE        0+       if present RDATE MUST NOT
                                             be present
             . . . . . TZNAME       0 or 1
             . . . . . TZOFFSET     1
             . . . . . TZOFFSETFROM 1
             . . . . . TZOFFSETTO   1
             . . . . . X-PROPERTY   0+
             . . . . . [IANA-PROP]  0+       any IANA registered
                                             property
             . . . LAST-MODIFIED    0 or 1
             . . . STANDARD         0+
             . . . . . COMMENT      0 or 1
             . . . . . DTSTART      1
             . . . . . RDATE        0+       if present RRULE MUST NOT
                                             be present
             . . . . . RRULE        0+       if present RDATE MUST NOT
                                             be present
             . . . . . TZNAME       0 or 1
             . . . . . TZOFFSETFROM 1
             . . . . . TZOFFSETTO   1
             . . . . . X-PROPERTY   0+
             . . . . . [IANA-PROP]  0+       any IANA registered
                                             property
             . . . TZID             1
             . . . TZURL            0 or 1
             . . . X-PROPERTY       0+
             . . . [IANA-PROP]      0+       any IANA registered
                                             property

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
   Server Restriction Table for the MODIFY command

             Component/Property    Presence   Comment
             --------------------- --------   --------------------------

             VCAP                  1+
             . VCALENDAR           1+
             . . TARGET            1

             . . VERSION           1        MUST be 2.0

             . . CMDID             0 or 1   MUST be returned if the
                                            request contained a CMDID
             . . REQUEST-STATUS    0        if not creating a calendar
                                   1+       if creating a calendar

             . . . VCAR            0+
             . . . . REQUEST-STATUS    1+
             . . . . *             0        No other VCAR properties are
                                            present
             .
             . . . VCOMMAND        0

             . . . VEVENT         0+
             . . . . REQUEST-STATUS    1+
             . . . . *            0         No other VEVENT properties
                                            are present
             . . . . VALARM       0         if VEVENT was successfully
                                            saved
                                  1+        if there were errors saving
                                            alarms
             . . . . . REQUEST-STATUS   1+

             . . . VFREEBUSY       0+
             . . . . REQUEST-STATUS    1+
             . . . . *             0        No other VFREEBUSY
                                            properties are
                                            present

             . . . VJOURNAL        0+
             . . . . REQUEST-STATUS    1+
             . . . . *             0        No other VJOURNAL properties
                                            are present

             . . . VQUERY          0+
             . . . . REQUEST-STATUS    1+

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
             . . . . *             0        No other VQUERY properties
                                            are present

             . . . VTODO           0+
             . . . . REQUEST-STATUS    1+
             . . . . *             0        No other VTODO properties
                                            are present
             . . . . VALARM        0        if VTODO was successfully
                                            saved
                                   1+       if there were errors saving
                                            alarms
             . . . . . REQUEST-STATUS   1+

          [EditorĖs notes:

   [EDITORS NOTES: Issues: freebusy - a cap server should dynamically
   calculate freebusy information we recommend that you cannot create,
   modify, or delete  freebusy composers ]

   In the example below, the start and end time of the event with UID
   abcd12345 is changed and the LOCATION property is removed.

               C: SENDDATA
               C: Content-type:text/calendar; Method=MODIFY;
               C:  Component=VCOMMAND
               C:
               C: BEGIN:VCAP
               C: VERSION:2.1
               C: BEGIN:VCOMMAND
               C: METHOD:MODIFY
               C: TARGET:relcal2
               C: BEGIN:VCOMMAND
               C: BEGIN:VQUERY
               C: QUERY:SELECT UID FROM VEVENT WHERE UID = 'abcd12345'
               C: END:VQUERY
               C: BEGIN:VEVENT
               C: DTSTART:19990421T160000Z
               C: DTEND:19990421T163000Z
               C: LOCATION:Joe's Diner
               C: END:VCOMMAND
               C: END:VEVENT

               C: BEGIN:VEVENT
               C: DTSTART:19990421T160000Z
               C: DTEND:19990421T163000Z
               C: END:VEVENT
               C: END:VCOMMAND
               C: END:VCAP
               C: .

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

               S: 2.0 cap://cal.example.com/relcal2

   And in this example, all instances of "Building 6" are replaced by
   "New office lobby" in VEVENTs:

               C: SENDDATA
               C: Content-type:text/calendar; Method=MODIFY;
               C:  Component=VCOMMAND
               C:
               C: BEGIN:VCAP
               C: VERSION:2.1
               C: BEGIN:VCOMMAND
               C: METHOD:MODIFY
               C: TARGET:relcal2
               C: BEGIN:VCOMMAND
               C: BEGIN:VEVENT
               C: LOCATION:Building 6
               C: END:VEVENT
               C: BEGIN:VEVENT
               C: LOCATION:New office lobby
               C: END:VEVENT
               C: END:VCOMMAND
               C: END:VCOMMAND
               C: END:VCAP
               C: .
               S: 2.0 cap://cal.example.com/relcal2

7.2.1.6 MOVE Method

   Arguments: ContainerId

   Data:      data as described below

   Result:

      2.0 - success

      2.2 - will attempt operation on the remote CAP server

      Permission

      Calendar already exists

      Bad args

      Parent Calendar(s) not found
   The format of the command is:

             BEGIN:VCALENDAR
             METHOD:MOVE
             ...
             TARGET:target-name
             BEGIN:VCOMMAND
             BEGIN:VCALENDAR
             PARENT:<old-parent>
             END:VCALENDAR
             BEGIN:VCALENDAR
             PARENT:<new-parent>
             END:VCALENDAR
             END:VCOMMAND
             END:VCALENDAR

   This  looks similar to a MODIFY command.  Except the CS MUST ensure
   that VCARs are still valid after the move.  And the CS MUST update
   the CHILDREN list in the  new and  old parent containers.

   This method is used to move a calendar within the CS's hierarchy of
   calendars.

   Restriction Table

             Component/Property     Presence  Comment
             -------------------    -------- ---------------------
             VCAP                   1+       The CUA can send up

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
                                             PIPELINE commands without
                                             processing a response

             . VERSION              1        MUST be 2.0

             . VCOMMAND             1        MUST have at least one
                                             VCALENDAR

             . . CMDID              0 or 1   If CMDID is not supplied,
                                             then there must not be
                                             pending replies to
                                             previous command.

             . . [IANA-PROP]        0+       any IANA registered
                                             property

             . . METHOD             1        MUST be MOVE.
             . . TARGET             1        MUST be a the CSID or
                                             CALID
             . . VCALENDAR          1+
             . . . CALMASTER        0
             . . . NAME             0
             . . . OWNER            0
             . . . RELCALID         1
             . . . TZID             0
             . . . [IANA-PROP]      0+       any IANA registered
                                             property

   Server Restriction Table for the MOVE command

             Component/Property  Presence Comment
             ------------------- -------- -----------------------------

             VCAP                1+

             . VCALENDAR         1+

             . . TARGET          1
             . . VERSION         1        MUST be 2.0

             . . CMDID           0 or 1   MUST be returned if the
                                          request contained
                                          a CMDID
             . . REQUEST-STATUS  1+

             ---------------------------------------------------------

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

          [Editors note:

   [EDITORS NOTE: Issues:

      1) Should one be able to move a calendar owned by person X into a
      calendar owned by person Y.  (Can these such rights be specified
      in VCARs?)

      2) Should we also be able to move components from one calendar to
      another? What if the calendars are owned by different users? (With
      components one can do a copy, then delete the original.)

      3) There was very little information about MOVE in CAP.  Why was
      it added? Was there some major need for it?

      4) Can one move multiple calendars into one calendar?
          ]

          7.2.1.7   NOOP Method

          Arguments: none

          Data:      none

          Result:    2.0 - success

          This method does nothing. It can be sent to the server
          periodically calendar?]

   An example of moving  a calendar from  Nellis to request that the CS not time out the session.

          7.2.1.8 Area-51

       C: SENDDATA
       C: Content-type:text/calendar; Method=MODIFY; Component=VCOMMAND
       C:
       C: BEGIN:VCAP
       C: VERSION:2.1
       C: METHOD:MOVE
       C: TARGET:Nellis
       C: BEGIN:VCOMMAND
       C: BEGIN:VCALENDAR
       C: PARENT:Department-33
       C: END:VCALENDAR
       C: BEGIN:CALENDAR
       C: PARENT:Area-51
       C: END:VCALENDAR
       C: END:VCOMMAND
       C: END:VCAP
       C: .
       S: 2.0
       S: Content-Type:text/calendar; method=RESPONSE
       S:
       S: BEGIN:VCAP
       S: METHOD:RESPONSE
       S: TARGET:relcal2
       S: BEGIN:VCALENDAR
       S: REQUEST-STATUS:2.0;
       S: END:VCALENDAR
       S: END:VCAP
       S: .

7.2.1.7 READ Method

   Arguments: ContainerId

   Data:      data as described below

   Result:

      2.0 - - successful and the requested data follows

      2.2 - will attempt read on the remote CAP server

      Permission

      Bad args

   Restriction Table

             Component/Property     Presence Comment
             -------------------    -------- ---------------------------
             VCAP                   1+       The CUA can send
                                             PIPELINE commands
                                             without processing a
                                             response

             . VERSION              1        MUST be 2.0
             . [IANA-PROP]          0+       any IANA registered
                                             property

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

             . VCOMMAND             1        MUST have at least one
                                             container (VCALENDAR,
                                             VCAR, VQUERY, VEVENT,
                                             VTODO, VJOURNAL)
             . . CMDID              0 or 1   If CMDID is not supplied,
                                             then there must not be pending
                                             replies to previous command.
             . . [IANA-PROP]        0+       any IANA registered
                                             property
             . . METHOD             1        MUST be READ
             . . TARGET             1+       MUST be the CALID

             . . VCALENDAR          0+
             . . . CALMASTER        0 or 1
             . . . NAME             0 or 1
             . . . OWNER            1+
             . . . RELCALID         1
             . . . TZID             0 or 1
             . . . [IANA-PROP]      0+       any IANA registered
                                             property

             . . VCAR               0

             . . VQUERY             1
             . . . EXPAND           0 or 1
             . . . MAXRESULTS       0 or 1
             . . . MAXSIZE          0 or 1
             . . . QUERYNAME        1
             . . . QUERY            1
             . . . [IANA-PROP]      0+       any IANA registered
                                             property

             . . VEVENT             0
             . . VTODO              0
             . . VJOURNAL           0
             . . VFREEBUSY          0

             . . VTIMEZONE          0+       MUST be present if any
                                             date/time refers
                                             to a timezone
             . . . DAYLIGHT         0+       MUST be one or more of
                                             either STANDARD
                                             or DAYLIGHT
             . . . . . COMMENT      0 or 1
             . . . . . DTSTART      1
             . . . . . RDATE        0+       if present RRULE MUST NOT
                                             be present
             . . . . . RRULE        0+       if present RDATE MUST NOT

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

                                             be present
             . . . . . TZNAME       0 or 1
             . . . . . TZOFFSET     1
             . . . . . TZOFFSETFROM 1
             . . . . . TZOFFSETTO   1
             . . . . . X-PROPERTY   0+
             . . . . . [IANA-PROP]  0+       any IANA registered
                                             property
             . . . LAST-MODIFIED    0 or 1
             . . . STANDARD         0+
             . . . . . COMMENT      0 or 1
             . . . . . DTSTART      1
             . . . . . RDATE        0+       if present RRULE MUST NOT
                                             be present
             . . . . . RRULE        0+       if present RDATE MUST NOT
                                             be present
             . . . . . TZNAME       0 or 1
             . . . . . TZOFFSETFROM 1
             . . . . . TZOFFSETTO   1
             . . . . . X-PROPERTY   0+
             . . . . . [IANA-PROP]  0+       any IANA registered
                                             property
             . . . TZID             1
             . . . TZURL            0 or 1
             . . . X-PROPERTY       0+
             . . . [IANA-PROP]      0+       any IANA registered
                                             property

   Server Restriction Table for the READ command

             Component/Property    Presence Comment
             --------------------- -------- --------------------------

             VCAP                    1+
             . VCALENDAR             1+
             . . TARGET              1
             . . VERSION             1      MUST be 2.0

             . . CMDID               0 or 1 MUST be returned if the
                                            request contained a CMDID
             . . REQUEST-STATUS      0      if not creating a calendar
                                     1+     if creating a calendar

             . . . VCAR              0+
             . . . . REQUEST-STATUS  1+
             . . . . *               0      No other VCAR properties are

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

                                            present
             .
             . . . VCOMMAND          0

             . . . VEVENT            0+
             . . . . REQUEST-STATUS  1+
             . . . . *               0      No other VEVENT properties
                                            are present
             . . . . VALARM          0      if VEVENT was successfully
                                            saved
                                     1+     if there were errors saving
                                            alarms
             . . . . . REQUEST-STATUS 1+

             . . . VFREEBUSY         0+
             . . . . REQUEST-STATUS  1+
             . . . . *               0      No other VFREEBUSY
                                            properties are
                                            present

             . . . VJOURNAL          0+
             . . . . REQUEST-STATUS  1+
             . . . . *               0      No other VJOURNAL properties
                                            are present

             . . . VQUERY            0+
             . . . . REQUEST-STATUS  1+
             . . . . *               0      No other VQUERY properties
                                            are present

             . . . VTODO             0+
             . . . . REQUEST-STATUS  1+
             . . . . *               0      No other VTODO properties
                                            are present
             . . . . VALARM          0      if VTODO was successfully
                                            saved
                                     1+     if there were errors saving
                                            alarms
             . . . . . REQUEST-STATUS 1+

   Read Events

   In the example below events on March 10,1999 between 080000Z and
   190000Z are read.  In this case only 4 properties for each event are
   returned.  Two calendars are specified.  Only booked (vs scheduled)
   entries are to be returned.  The first returns

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001 two VEVENTS that match
   in that TARGET, the second result returns only one VEVENT for the
   second TARGET.

               C: SENDDATA
               C: Content-type:text/calendar; Method=READ; Component=VQUERY
               C:
               C: BEGIN:VCAP
               C: VERSION:2.1
               C: BEGIN:VCOMMAND
               C: METHOD:READ
               C: CMDID:xyz12345
               C: TARGET:relcal2
               C: TARGET:cap://bobo.ex.com/relcal3
               C: BEGIN:VQUERY
               C: QUERY:SELECT DTSTART,DTEND,SUMMARY,UID
                   FROM VEVENT
                   WHERE DTEND >= '19990310T080000Z'
                   AND DTSTART <= '19990310T190000Z'
                   AND METHOD = 'CREATE'
               C: END:VQUERY
               C: END:VCOMMAND
               C: END:VCAP
               C: .
               S: 2.0 cap://cal.example.com/relcal2
               S: Content-type:text/calendar; Method=RESPONSE;
                   Optinfo=VERSION:2.1
               S: Content-Transfer-Encoding: 7bit
               S:
               S: BEGIN:VCAP
               S: VERSION:2.1
               S: METHOD:RESPONSE
               S: BEGIN:VEVENT

               S: DTSTART:19990310T090000Z
               S: DTEND:19990310T100000Z
               S: UID:abcxyz12345
               S: SUMMARY:Meet with  Sir Elton
               S: END:VEVENT
               S: BEGIN:VEVENT
               S: DTSTART:19990310T130000Z
               S: DTEND:19990310T133000Z
               S: UID:abcxyz8999
               S: SUMMARY:Meet with  brave brave Sir Robin
               S: END:VEVENT
               S: END:VCAP
               S: .
               S: 2.0 cap://bobo.ex.com/relcal3
               S: Content-type:text/calendar; Method=RESPONSE;
               S:    Component=VDATA;    Optinfo=VERSION:2.1

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
               S: Content-Transfer-Encoding: 7bit
               S:
               S: BEGIN:VCAP
               S: VERSION:2.1
               S: METHOD:RESPONSE
               S: BEGIN:VDATA
            S: BEGIN:VEVENT
               S: DTSTART:19990310T140000Z
               S: DTEND:19990310T150000Z
               S: UID:123456asdf
               S: SUMMARY:Summer Budget
               S: END:VEVENT
               S: END:VDATA
            S: END:VCAP
               S: .

   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 events, 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.  That
   is, the VEVENT components will be the following:

   [EDITORS NOTE: Should the one(s) that the UPN has access to - be
   returned?]

               S: 2.0 cap://bobo.ex.com/sally
               S: Content-type:text/calendar;
          Method=RESPONSE;Component=VDATA;
             Method=RESPONSE;
               S:    Optinfo=VERSION:2.1
               S: Content-Transfer-Encoding: 7bit
               S:
               S: BEGIN:VCAP
               S: VERSION:2.1
               S: BEGIN:VDATA
            S: BEGIN:VEVENT
               S: REQUEST-STATUS:3.8
               S: END:VEVENT
               S: END:VDATA
            S: END:VCAP
               S: .

   If the UPN has no access to any events at all, the response will
   simply be an empty data set.  The response looks the same

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001 if there
   are particular events to which the requester has been denied access.

               S: 2.0 cap://bobo.ex.com/sally
               S: Content-type:text/calendar; Method=RESPONSE;
               S:  Component=VDATA;
            S: Optinfo=VERSION:2.1
               S: Content-Transfer-Encoding: 7bit
               S:
               S: BEGIN:VCAP
               S: VERSION:2.1
               S: BEGIN:VDATA
            S: END:VDATA
            S: END:VCAP
               S: .

   Find alarms within a range of time for booked (METHOD = CREATE)
   VEVENTs.

               C: SENDDATA
               C: Content-type:text/calendar; Method=READ; Component=VQUERY
               C:
               C: BEGIN:VCAP
               C: VERSION:2.1
               C: BEGIN:VCOMMAND
               C: METHOD:READ
               C: CMDID:xyz12345
               C: TARGET:relcal2
               C: TARGET:cap://bobo.ex.com/relcal3
               C: BEGIN:VQUERY
               C: QUERY:SELECT DTSTART,DTEND,SUMMARY,UID, VALARM.*
                   FROM VEVENT,VTODO
                   WHERE VALARM.TRIGGER >= '19990310T080000Z'
                   AND VALARM.TRIGGER <= '19990310T190000Z'
                   AND METHOD = 'CREATE'
               C: END:VQUERY
               C: END:VCOMMAND
               C: END:VCAP
               C: .
               S: 2.0 cap://bobo.ex.com/relcal3
               S: Content-type:text/calendar; Method=RESPONSE;
               S: Optinfo=VERSION:2.1
               S: Content-Transfer-Encoding: 7bit
               S:
               S: BEGIN:VCAP
               S: VERSION:2.1
               S: METHOD:RESPONSE
               S: CMDID:xyz12345
               S: TARGET:cap://bobo.ex.com/relcal3

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
               S: BEGIN:VEVENT
               S: DTSTART:19990310T130000Z
               S: DTEND:19990310T133000Z

               S: UID:abcxyz8999
               S: SUMMARY:Meet with brave brave Sir Robin
               S: BEGIN:VALARM
               S: TRIGGER:19990310T132500Z
               S: SUMMARY:Almost time..
               S: ACTION:DISPLAY
               S: END:VALARM
               S: END:VEVENT
               S: END:VCAP
               S: .
               S: 2.0 cap://bobo.ex.com/relcal2
               S: Content-type:text/calendar; Method=RESPONSE;
               S: Optinfo=VERSION:2.1
               S: Content-Transfer-Encoding: 7bit
               S:
               S: BEGIN:VCAP
               S: VERSION:2.1
               S: METHOD:RESPONSE
               S: CMDID:xyz12345
               S: TARGET:cap://bobo.ex.com/relcal2
               S: BEGIN:VEVENT
               S: REQUEST-STATUS:2.0
               S: END:VEVENT
               S: END:VCAP
               S: .

7.2.1.7.1 Query With A Stored Query

   This  will run a stored VQUERY and return the  results  of the
   VQUERY.

              BEGIN:VQUERY
              QUERYNAME:StoredVQuery-1
              END:VQUERY

   This  will fetch all calendar  store properties.  This  MUST NOT
   return  any VCALENDARs.

                BEGIN:VCAP
                VERSION:2.1
                METHOD:READ
                CMDID:-2ir-
                TARGET:cap://bobo.ex.com
                BEGIN:VQUERY
                QUERY:SELECT  * FROM CALSTORE
                END:VQUERY
                END:VCAP

   This  will fetch all calendar  properties.  This MUST NOT return any
   components.

                BEGIN:VCAP
                VERSION:2.1
                METHOD:READ
                CMDID:-2ir-
                TARGET:cap://bobo.ex.com/relcal4
                BEGIN:VQUERY
                QUERY:SELECT  * FROM VCALENDAR
                END:VQUERY
                END:VCAP

   This  will fetch all stored VQUERYs.

                BEGIN:VCAP
                VERSION:2.1
                METHOD:READ
                CMDID:didmc
                TARGET:cap://bobo.ex.com/relcal4
                BEGIN:VQUERY
                QUERY:SELECT  * FROM VQUERY
                END:VQUERY
                END:VCAP

7.2.2 Scheduling Commands

   The following provide a set of scheduling commands (or methods) in
   CAP.  Scheduling commands allow a CU to indirectly manipulate a
   calendar by asking another CU to perform an operation on their
   calendar.  For example, CU-A can request CU- B to add a meeting to
   their calendar; in effect inviting CU-B to the meeting.

   Calendar access rights can be granted for scheduling commands without
   granting rights for more generalized access with the calendar
   commands.

   [EDITORS NOTE: This section needs to be completed by adding the
   restriction tables for each of these iTIP methods.  The basis for the
   text is to be taken from [iTIP].]

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

7.2.2.1 Reading Scheduling Components

   A CU might be invited to a meeting.  If the CU had been invited by
   CAP, the entry in the CU calendar will be scheduled, but not booked.
   So a CUA will need to look for scheduled entries in the calendar and
   present them to the CU or automaticly decide if the invitation is to
   be accepted or processed.

   Example:

   The little league coach places the teams entire schedule into your
   calendar.  Lets say that every game and practice is on a Friday night
   and your calendar now has this iTIP scheduling data:

               BEGIN:VCAP
               VERSION:2.0
               METHOD:PUBLISH
               BEGIN:VEVENT
               DTSTAMP;TZID=US/Pacific:20000229T180000
               DTSTART;TZID=US/Pacific:20000303T180000
               ORGANIZER:coach@little.league.com
               SUMMARY: Schedule of games and practice
               UID:1-coach@little.league.com
               SEQUENCE:0
               DESCRIPTION:Please have your child at the field
                and ready to play by 6pm.
               RRULE:FREQ=WEEKLY;COUNT=10
               END:VEVENT
               END:VCAP

   At this point the above VEVENT is not booked in your calendar, It is
   simply scheduled.  A CUA would fetch this and all other scheduled
   VEVENTs from your calendar with:

               C: SENDDATA
               C: Content-type:text/calendar; Method=READ; Component=VQUERY
               C:
               C: BEGIN:VCAP
               C: VERSION:2.1
               C: BEGIN:VCOMMAND
               C: METHOD:READ
               C: CMDID:xyz12345
               C: TARGET:relcal2
               C: BEGIN:VQUERY
               C: QUERY:SELECT * WHERE FROM VEVENT METHOD != 'CREATE'
               C: END:VQUERY
               C: END:VCOMMAND
               C: END:VCAP

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
               C: .

   The the CUA and CU could determine which scheduling items were to
   remain on the calendar.  Each scheduling component could be deleted
   or updated with METHOD:MODIFY to change the METHOD from PUBLISH,
   REQUEST, REPLY, ADD, CANCEL, REFRESH, COUNTER, or DECLINE-COUNTER to
   what the CU and CUA had decided.

   In some cases the CUA could automaticly do the work and inform the
   CU.  An example of this is CANCEL.  If configured to process
   METHOD:CANCEL it could METHOD:DELETE the component an inform the CU
   that the booked component had been canceled.

   The CUA MUST process the scheduled components in the order sent.
   Some optimization could be done by the CUA.  One example is if a
   PUBLISH and later a CANCEL for the same component with the same
   SEQUENCE number were scheduled, but not booked.  The CUA might never
   inform the CU and treat it as if the PUBLISH had never been received
   by doing a METHOD:DELETE on both entries.

   It is important to note that scheduled components do not show up in
   busy time as BUSY.  Only when they are booked does the TRANSP:OPAQUE
   property take effect.  A CS implementation MAY mark the time as
   TENTATIVE.  This is an implementation and administrative choice.

7.2.2.2 PUBLISH

   Arguments:

   Data:      data as described below

   Result:

      2.0 - success

      2.2 - will attempt operation on the remote CAP server

      Permission

      Calendar already exists

      Bad args

      Parent Calendar(s) not found

          This method is used to move a calendar within the CS's
          hierarchy of calendars.

   If the CU wishes to keep the  published entry.  A METHOD:MODIFY
   changing the entries METHOD from PUBLISH to CREATE would be done,
   booking the entry.  Or METHOD:DELETE if the CU did not wish this
   scheduled item to exist in their calendar.

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

7.2.2.3 REQUEST

   Arguments:

   Data:      data as described below

   Result:

      2.0 - success

      2.2 - will attempt operation on the remote CAP server

      Permission

      Calendar already exists

      Bad args

      Parent Calendar(s) not found

   This as described in [iTIP] and would be modified just like PUBLISH
   above.

7.2.2.4 REPLY

   Arguments:

   Data:      data as described below

   Result:

      2.0 - success

      2.2 - will attempt operation on the remote CAP server

      Permission

      Calendar already exists

      Bad args

      Parent Calendar(s) not found

7.2.2.5 ADD

   Arguments:

   Data:      data as described below

   Result:

      2.0 - success

      2.2 - will attempt operation on the remote CAP server

      Permission

      Calendar already exists

      Bad args

      Parent Calendar(s) not found

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

7.2.2.6 CANCEL

   Arguments:

   Data:      data as described below

   Result:    2.0 - success
                       2.2 - will attempt operation on the remote CAP
                             server
                       Permission
                       Calendar already exists
                       Bad args
                       Parent Calendar(s) not found

7.2.2.7 REFRESH

   Arguments:

   Data:      data as described below

   Result:    2.0 - success
                       2.2 - will attempt operation on

   This  as described in  [iTIP] and would be modified just like PUBLISH
   above.  The CS MAY automaticly send out REFRESH replies via iMIP or
   CAP if able, then METHOD:DELETE the REFRESH.  But only if there are
   no other pending scheduled entries for this calendar that may  effect
   what REFRESH would send back.  If  the CS is not able to reply to the
   REFRESH request then  it is left in the scheduling queue until the
   CUA and CU  processes the queue.  At the remote CAP
                             server
                       Permission
                       Calendar already exists
                       Bad args
                       Parent Calendar(s) not found point where there  are no
   outstanding scheduled command that  would effect the reply results,
   the CS may then  automaticly send  the reply to the REFRESH request.

7.2.2.8 COUNTER

   Arguments:

   Data:      data as described below

   Result:    2.0 - success
                       2.2 - will attempt operation on the remote CAP
                             server
                       Permission
                       Calendar already exists
                       Bad args
                       Parent Calendar(s) not found

7.2.2.9 DECLINECOUNTER

   Arguments:

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

   Data:      data as described below

   Result:    2.0 - success
                       2.2 - will attempt operation on the remote CAP
                             server
                       Permission
                       Calendar already exists
                       Bad args
                       Parent Calendar(s) not found

7.2.3 iTIP Examples

   The following examples describe scenarios for the handling of
   incoming iTIP data.  An appropriate sort-order for the handling of
   incoming iTIP is by UID, Recurrence-id, sequence, dtstamp.  This
   processing may be optimized, for instance, REFRESHs could be
   processed last.

   As an update to [iTIP], data with the "COUNTER" method should be
   processed even if the Sequence number is stale.

7.2.3.1 Sending and Receiving an iTIP request

   In this example A invites B and C to a meeting, B accepts the meeting
   and C rejects it.  The calendars for A, B and C are relcal1, relcal2
   and relcal3 respectively, and are all on the same server,
   "cal.foo.com".  A lot of these described actions are performed by the
   CUAs and not the users themselves, the CUAs are called A-c, B-c and
   C-c respectively.

   A wishes to create a meeting with B and C, so A-c uses CAP to send
   the following iTIP request to relcal2 and relcal3, while logged in to
   "cal.foo.com".

               BEGIN:VCAP
               VERSION:2.1

               CMDID:xhj-dd
               BEGIN:VCOMMAND
               METHOD:REQUEST
               TARGET:cap://cal.foo.com/relcal2
               TARGET:relcal3
               BEGIN:VEVENT
               UID:abcd12345
               DTSTART:19990307T180000Z
               DTEND:19990307T190000Z
               ORGANIZER:cap://cal.foo.com/relcal1

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
               ATTENDEE;RSVP=TRUE;PARTSTAT=NEEDS-
             ACTION:cap://cal.foo.com/relcal2
               ATTENDEE;RSVP=TRUE;PARTSTAT=NEEDS-
             ACTION:cap://cal.foo.com/relcal3
               SUMMARY:Important Meeting
               END:VEVENT
               END:VCOMMAND
               END:VCAP

   An incoming event (indicated by the value of the "METHOD" property)
   then appears in relcal2 and relcal3, with the following data:

               BEGIN:VEVENT
               METHOD:REQUEST
               UID:abcd12345
               DTSTART:19990307T180000Z
               DTEND:19990307T190000Z
               ORGANIZER:cap://cal.foo.com/relcal1
               ATTENDEE;RSVP=TRUE;PARTSTAT=NEEDS-ACTION:cap://cal.foo.c
                om/relcal2
               ATTENDEE;RSVP=TRUE;PARTSTAT=NEEDS-ACTION:cap://cal.foo.c
                om/relcal3
               SUMMARY:Important Meeting
               END:VEVENT

   B-c and C-c must search for such incoming events, they do so using
   the following CAP search:

               BEGIN:VCAP
               VERSION:2.1
               BEGIN:VCOMMAND
               METHOD:READ
               CMDID:xhr-de
               TARGET:relcal2
               # or TARGET:relcal3
               BEGIN:VCOMMAND
               BEGIN:VQUERY
               QUERY:SELECT * FROM VEVENT WHERE METHOD = 'REQUEST';
               END:VQUERY
               END:VCOMMAND
               END:VCOMMAND
               END:VCAP

   In response to this search they get the above event.  B-c and C-c
   must then crack open the VEVENT, find the UID and determine if there
   is already an event on their calendar with that UID.  To do this they
   use the following search:

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

               BEGIN:VCAP
               VERSION:2.1
               BEGIN:VCOMMAND
               METHOD:READ
               CMDID:xhr-df
               TARGET:relcal2

               BEGIN:VCOMMAND
               BEGIN:VQUERY
               QUERY:SELECT * FROM VEVENT WHERE UID = 'abcd12345' AND
                METHOD = 'CREATE'
               END:VQUERY
               END:VCOMMAND
               END:VCOMMAND
               END:VCAP

   We assume that the event is not already in their relcal2 or relcal3.

   B-c prompts B who decides to accept the meeting request, and B-c
   creates a copy of the event in relcal2, with the "PARTSTAT" parameter
   set to ACCEPTED.  B-c also sends this copy to the Organizer at
   relcal1 as an iTIP REPLY, preserving the CMDID:

               BEGIN:VCAP
               VERSION:2.1
               CMDID:xhj-dd
               METHOD:REPLY
               TARGET:cap://cal.foo.com/relcal1
               BEGIN:VEVENT
               UID:abcd12345
               DTSTART:19990307T180000Z
               DTEND:19990307T190000Z
               ORGANIZER:cap://cal.foo.com/relcal1
               ATTENDEE;PARTSTAT=ACCEPTED:cap://cal.foo.com/relcal2
               SUMMARY:Important Meeting
               END:VEVENT
               END:VCAP

   C, on the other hand, decides to decline the meeting, and C-c sends a
   reply to the Organizer to that effect, as follows:

            BEGIN:VCALENDAR

               BEGIN:VCAP
               VERSION:2.1
               CMDID:xhj-dd
               METHOD:REPLY
               TARGET:cap://cal.foo.com/relcal1
               BEGIN:VEVENT

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
               UID:abcd12345
               DTSTART:19990307T180000Z
               DTEND:19990307T190000Z
               ORGANIZER:cap://cal.foo.com/relcal1
               ATTENDEE;PARTSTAT=DECLINED:cap://cal.foo.com/relcal3
               SUMMARY:Important Meeting
               END:VEVENT
            END:VCALENDAR
               END:VCAP

   It is preferable that C-c store the event in relcal3 even though it
   has been declined.  Storing the event in relcal3 allows subsequent
   iTIP messages to be interpreted correctly.  The "PARTSTAT" parameter
   indicates that the event was refused.

   After receiving the replies from relcal2 and relcal3, A-c updates the
   version of the event in relcal1 to indicate the new participation
   status:

               BEGIN:VEVENT
               METHOD:REQUEST
               UID:abcd12345
               DTSTART:19990307T180000Z
               DTEND:19990307T190000Z
               ORGANIZER:cap://cal.foo.com/relcal1
               ATTENDEE;PARTSTAT=ACCEPTED:cap://cal.foo.com/relcal2
               ATTENDEE;PARTSTAT=DECLINED:cap://cal.foo.com/relcal3
               SUMMARY:Important Meeting
               END:VEVENT

   A-c then sends a new iTIP request to relcal2 only, indicating the
   updated information.

7.2.3.2 Handling an iTIP refresh

   A little bit later, C is thinking about accepting the event in the
   previous example, but first wants to check the current state of the
   event.  To find the current state C-c uses the iTIP "REFRESH" method,
   sending the following to relcal1:

            BEGIN:VCALENDAR

               BEGIN:VCAP
               VERSION:2.1
               CMDID:xud-pn
               METHOD:REFRESH
               TARGET:cap://cal.foo.com/relcal1
               BEGIN:VEVENT
               UID:abcd12345
               ORGANIZER:cap://cal.foo.com/relcal1
               ATTENDEE:cap://cal.foo.com/relcal3

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
               DTSTAMP:19990306T202333Z
               END:VEVENT
            END:VCALENDAR
               END:VCAP

   A-c finds the refresh as an incoming iTIP, and searches for the
   corresponding event.  Having found the event (with no changes since
   the last example) A-c then verifies that relcal3 is in fact an
   Attendee of the event and is thus allowed to request a refresh.  (In
   the case of a published event things are more complicated.) A-c
   packages the event up as an iTIP request and sends it to relcal3:

            BEGIN:VCALENDAR

               BEGIN:VCAP
               VERSION:2.1
               CMDID: xud-pn
               METHOD:REQUEST
               TARGET:cap://cal.foo.com/relcal3
               BEGIN:VEVENT
               UID:abcd12345
               DTSTART:19990307T180000Z
               DTEND:19990307T190000Z
               ORGANIZER:cap://cal.foo.com/relcal1
               ATTENDEE;PARTSTAT=ACCEPTED:cap://cal.foo.com/relcal2
               ATTENDEE;PARTSTAT=DECLINED:cap://cal.foo.com/relcal3
               SUMMARY:Important Meeting
               SEQUENCE:0
               DTSTAMP:19990306T204333Z
               END:VEVENT
            END:VCALENDAR
               END:VCAP

7.2.3.3 Sending and accepting an iTIP counter

   Having received the latest copy of the event C wishes to propose a
   venue for the event, using an iTIP COUNTER.  To do this C-c sends the
   following to relcal1:

               BEGIN:VCAP
               VERSION:2.1
               CMDID:zzykjjk
               METHOD:COUNTER
               TARGET:cap://cal.foo.com/relcal1
               BEGIN:VEVENT
               UID:abcd12345
               DTSTART:19990307T180000Z
               DTEND:19990307T190000Z
               ORGANIZER:cap://cal.foo.com/relcal1

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
               ATTENDEE;PARTSTAT=DECLINED:cap://cal.foo.com/relcal3
               SUMMARY:Important Meeting
               LOCATION:La Belle Province
               COMMENT:My favorite restaurant, I'll definitely go if it's
             there.
               END:VEVENT
               END:VCAP

   Having sent the information to relcal1, C-c shouldn't store the new
   details in relcal3.  If C-c updated the version in relcal3 and
   relcal1 did not reply to the counter, then relcal3 would have
   incorrect information.  Instead C-c preserves the correct information
   and waits for a response from relcal1.  A CUA implementation may wish
   to preserve this information itself, externally to the CS.

   In order to receive an iTIP counter A-c follows the same search as
   for other iTIP data, first find the incoming message, next find any
   matching events in the calendar store.

   Having found the matching event, A reviews the proposed changes and
   decides to accept the COUNTER.  To do this, A-c modifies the version
   in relcal1 (bumping the sequence number) to:

               BEGIN:VEVENT
               METHOD:CREATE
               UID:abcd12345
               DTSTART:19990307T180000Z
               DTEND:19990307T190000Z
               ORGANIZER:cap://cal.foo.com/relcal1
               ATTENDEE;PARTSTAT=ACCEPTED:cap://cal.foo.com/relcal2

               ATTENDEE;PARTSTAT=DECLINED:cap://cal.foo.com/relcal3
               SUMMARY:Important Meeting
               LOCATION:La Belle Province
               SEQUENCE:1
               END:VEVENT

   A-c then sends the updated version as a request to both relcal2 and
   relcal3:

               BEGIN:VCAP
               VERSION:2.1
               CMDID:xup-po
               METHOD:REQUEST
               TARGET:cap://cal.foo.com/relcal2
               TARGET:cap://cal.foo.com/relcal3
               BEGIN:VEVENT

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
               UID:abcd12345
               DTSTART:19990307T180000Z
               DTEND:19990307T190000Z
               ORGANIZER:cap://cal.foo.com/relcal1
               ATTENDEE;RSVP=TRUE;PARTSTAT=NEEDS-
             ACTION:cap://cal.foo.com/relcal2
               ATTENDEE;RSVP=TRUE;PARTSTAT=NEEDS-
             ACTION:cap://cal.foo.com/relcal3
               SUMMARY:Important Meeting
               LOCATION:La Belle Province
               SEQUENCE:1
               DTSTAMP:19990307T054339Z
               END:VEVENT
               END:VCAP

7.2.3.4 Declining an iTIP counter

   B does not like the new location and also counters the event, B-c
   sends the following iTIP:

               BEGIN:VCAP
               VERSION:2.1
               CMDID:xim-ef
               METHOD:COUNTER
               TARGET:cap://cal.foo.com/relcal1
               BEGIN:VEVENT
               UID:abcd12345
               DTSTART:19990307T180000Z
               DTEND:19990307T190000Z
               ORGANIZER:cap://cal.foo.com/relcal1
               ATTENDEE:cap://cal.foo.com/relcal2
               SUMMARY:Important Meeting
               LOCATION:Au Coin Dor=E9
               END:VEVENT
               END:VCAP

   However, C does not accept the counter, and C-c replies with a
   decline counter:

               BEGIN:VCAP
               VERSION:2.1
               CMDID:xim-ef
               METHOD:DECLINE-COUNTER
               TARGET:cap://cal.foo.com/relcal2
               BEGIN:VEVENT
               DTSTAMP:19990307T093245Z
               UID:abcd12345
               ORGANIZER:cap://cal.foo.com/relcal1

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
               SEQUENCE:1
               END:VEVENT
               END:VCAP

          Fortunately B-c kept

   CUA-b MUST keep the original  information when sending the counter,
   and there is no problem when no information is returned in the
   DECLINE-COUNTER.

          8

8. Response Codes

   Numeric response codes are returned at both the transfer and
   application layer.  The same set of codes is used in both cases.

   [EDITORS NOTE: Do we want to use the same set of codes?]

   The format of these codes is described in [iCAL], and extend in
   [iTIP] and [iMIP].  The following describes new codes added to this
   set.

   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], to make the accompanying text
   optional.

             Code  Params      Description
             --------------------------------------------------------------
             2.0  [CMDID] varies
                               Success, The parameters vary with the
                               operation and are specified.

             2.0.1  [CMDID]    Success, send data, terminate  with
                            <CRLF>.<CRLF>
                               >CRLF>.>CRLF>

             2.0.2  [CMDID]    A reply is pending. It could not be com-
                               pleted in the specified amount of time.
                               The server awaits a CONTINUE or ABORT
                               command. If can optionally be followed
                               by a CMDID. If the SENDDATA object con-
                               tained a CMDID, then the CS MUST append
                               the CMDID to the 2.0.2 reply for that
                               object.

             2.0.3  [CMDID]    In response to the client issuing an
                               ABORT command, this reply code indicates
                               that any command currently underway was
                               successfully aborted. If can optionally
                               be followed by a CMDID. If the SENDDATA

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
                               object contained a CMDID, then the CS
                               MUST append the CMDID to the 2.0.2 reply
                               for that object.

             2.0.6  [CMDID]    An operation is being attempted on a
                               re-mote server. This response indicates
                               that the server has not yet been con-
                               tacted but an attempt will be made to
                               contact it after the command has been
                               sent.

             3.1.4  [CMDID]    Capability not supported.

             4.1   [CMDID]     Calendar store access denied.

             6. 1  [CMDID]     Authenticate failure: unsupported au-
                               thentication mechanism, credentials re-
                               jected.

             6.2   [CMDID]     Sender aborted authentication, authenti-
                               cation exchange cancelled.

             6.3   [CMDID]     Attempt to create or modify an event
                               such that it would overlap another event
                               in either of the following two circum-
                               stances:

                               (a) One of the events has a TRANSP
                               property set to OPAQUE-NOCONFLICT or
                               TRANSPARENT-NOCONFLICT.

                               (b) The calendar's ALLOW-CONFLICT
                               property is set to NO.

             6.XXX  [CMDID]    [EDITORS NOTE: More are in this memo -
                               add here TODO]

             7.0  [CMDID]      A timeout has occurred. The server was
                               unable to complete the operation in the
                               requested time.

             8.0  [CMDID]      A failure has occurred in the Receiver
                               that prevents the operation from
                               succeeding.

             8.1  [CMDID]      Sent when a session cannot be
                               established because the CAP Server is too
                               busy.

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

             8.2  [CMDID]      Used to signal that an ICAL object has
                               exceeded the server's size limit

             8.3  [CMDID]      A DATETIME value was too large to be
                               represented on this Calendar.

             8.4  [CMDID]      A DATETIME value was too far in the past
                               to be represented on this Calendar.

             8.5  [CMDID]      An attempt was made to create a new
                               object but the unique id specified is
                               already in use.

             9.0  [CMDID]      An unrecognized command was received.

             10.1  <old-address> <new- address> [CMDID]
                               Accompanied by an alternate address. The
                               RECIPIENT specified should be contacted at
                               the given alternate address. The
                               referral address MUST follow the reply
                               code.

             10.2              The server is shutting down.

             10.4              The operation has not be performed
                            because it would cause the resources
                            (memory, disk,CPU, etc) to exceed the
                            allocated quota.

          10.5  [CMDID]     The ITIP message has been queued too too
                            long. Delivery has been aborted.
          --------------------------------------------------------------

          9  Examples

          For all the examples in this section, the authenticated user
          is  user@example.com.

          9.1 Authentication Examples

          9.1.1  Login Using Kerberos V4

            Use Kerberos V4 to authenticate as bill@example.com to the
          CAP server on
            cal.example.com.

            C: <connect to cal.example.com on port ...>
            S: 2.0

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

            S: .
            C: CAPABILTY
            S: CAPVERSION=1.0
            S: ITIPVERSION=1.0
            S: AUTH=KERBEROS_V4
            S: AUTH=DIGEST_MD5
            S: .
            C: AUTHENTICATE KERBEROS_V4
            S: AmFYig==
            C: BAcAQU5EUkVXLkNNVS5FRFUAOCAsho84kLN3/IJmrMG+25a4DT
            S: or//EoAADZI=
            C: DiAF5A4gA+oOIALuBkAAmw==
            S: 2.0
            S: IDENTITY=bill@example.com
            S: CAPVERSION=1.0

            S: ITIPVERSION=1.0
            S: AUTH=KERBEROS_V4
            S: AUTH=DIGEST_MD5
            S: CAR=CAR-FULL-1
            S: MINDATE=19700101T000000Z
            S: MAXDATE=20380118T191407Z
            S: .

          9.1.2  Error Scenarios

          Use of SASL Authorization Identity is not supported. Use
                               because it would cause the
          IDENTITY command instead. If you attempt resources
                               (memory, disk,CPU, etc) to use exceed the
          Authorization Identity, an error status will be returned.

            C: AUTHENTICATE KERBEROS_V4
            S: AmFYig==
            C: BAcAQU5EUkVXLkNNVS5FRFUAOCAsho84kLN3/IJmrMG+25a4DT
            S: or//EoAADZI=
            C: DiAF5A4gA+oOIALuBkAAmw==
            S: 6.1
            S: .

          Sender aborted authentication:

            C: AUTHENTICATE KERBEROS_V4
            S: AmFYig==
            C: .
            S: 6.2
            S: .

          Unsupported mechanism:

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

            C: AUTHENTICATE Experimental_Auth
            S: 6.3
            S: .

          9.2
                               allocated quota.

             10.5  [CMDID]     The ITIP message has been queued too too
                               long. Delivery has been aborted.
             --------------------------------------------------------------

8.1 Examples

8.1.1 Authentication Examples

8.1.1.1 Login Using Kerberos V4

8.1.1.2 Error Scenarios

8.2 Read Examples

          10.2.1.

8.2.1 Read From A Single Calendar

   In this example bill@example.com reads a day's worth of events from
   cap://cal.example.com/opaqueid99.

               C: SENDDATA
               C: Content-type:text/calendar; Method=READ; Component=VQUERY
               C:
               C: BEGIN:VCAP
               C: VERSION:2.1
               C: BEGIN:VCOMMAND
               C: METHOD:READ
               C: CMDID:xyz12345
               C: TARGET:cap://cal.example.com/opaqueid99
               C: BEGIN:VQUERY
               C: QUERY:SELECT DTSTART,DTEND,SUMMARY, UID FROM VEVENT
                 WHERE DTEND >= '19990714T080000Z'
                 AND DTSTART <= '19990715T080000Z'
               C: END:VQUERY
               C: END:VCOMMAND
               C: END:VCAP
               C: .
               # this response code means that the transport successfully
               # delivered the data.
               S: 2.0 ; got the request OK ; really
               S: .
               S: Content-type:text/calendar; Method=RESPONSE;
               S:  Optinfo=VERSION:2.1
               S: Content-Transfer-Encoding: 7bit
               S:
               S: BEGIN:VCAP
               S: VERSION:2.1
               S: METHOD:RESPONSE
               S: TARGET:cap://cal.example.com/opaqueid99
               S: CMDID:xyz12345
               S: REQUEST-STATUS:2.0
               S: BEGIN:VEVENT
               S: DTSTART:19990714T200000Z
               S: DTEND:19990714T210000Z

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
               S: UID:000444888929922
               S: SUMMARY:Blah bla
               S: END:VEVENT
               S: BEGIN:VEVENT
               S: UID:0034848098038888989443
               S: SUMMARY:meeting
               S: DTEND:19990714T233000Z
               S: DTSTART:19990714T223000Z
               S: END:VEVENT
               S: END:VCAP
               S: .

          9.2.1

8.2.2 Read From Multiple Calendars

   In this example bill@example.com reads a day's worth of events from
   cap://cal.example.com/opaqueid101 and
   cap://cal.example.com/opaqueid103

               C: SENDDATA
               C: Content-type:text/calendar; Method=READ; Component=VQUERY
               C:

               C: BEGIN:VCAP
               C: VERSION:2.1
               C: BEGIN:VCOMMAND
               C: METHOD:READ
               C: CMDID:xyz12346
               C: TARGET:cap://cal.example.com/opaqueid101
               C: TARGET:opaqueid103
               C: BEGIN:VQUERY
               C: VSCOPE:VEVENT

               C: QUERY:SELECT DTSTART,DTEND,SUMMARY,UID FROM VEVENT
               C: WHERE DTEND >= 19990714T080000Z AND
               C:   DTSTART <= 19990715T080000Z
               C: END:VQUERY
               C: END:VCOMMAND
               C: END:VCAP
               C: .
               S: 2.0
               S: .
               S: Content-Type:multipart/mixed;
               S:  boundary="--FEE3790DC7E35189CA67"
               S:
               S: ----FEE3790DC7E35189CA67
               S: Content-type:text/calendar; Method=RESPONSE;
               S: Optinfo=VERSION:2.1
               S: Content-Transfer-Encoding: 7bit

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
               S:
               S: BEGIN:VCAP
               S: VERSION:2.1
               S: METHOD:RESPONSE
               S: TARGET:cap://cal.example.com/opaqueid103
               S: CMDID:xyz12346
               S: REQUEST-STATUS:2.0
               S: BEGIN:VEVENT
               S: UID:0034848098038888989443
               S: SUMMARY:meeting
               S: DTEND:19990714T233000Z
               S: DTSTART:19990714T223000Z
               S: END:VEVENT
               S: END:VCAP
               S:
               S: ----FEE3790DC7E35189CA67CE2C
               S: Content-type:text/calendar; Method=RESPONSE;
               S: Optinfo=VERSION:2.1
               S: Content-Transfer-Encoding: 7bit
               S:
               S: BEGIN:VCAP
               S: VERSION:2.1
               S: METHOD:RESPONSE
               S: TARGET:cap://cal.example.com/opaqueid101
               S: CMDID:xyz12346
               S: REQUEST-STATUS:4.1 ; access denied
               S: END:VCAP
               S:
               S: ----FEE3790DC7E35189CA67CE2C
               S: .

          9.2.2

8.2.3 Timeouts

   In this example bill@example.com attempts to read a calendar but the
   latency time he supplies is not sufficient for the server to complete
   the command.

               C: SENDDATA 3
               C: Content-type:text/calendar; Method=READ; Component=VQUERY
               C:
               C: BEGIN:VCAP
               C: VERSION:2.1
               C: BEGIN:VCOMMAND
               C: METHOD:READ
               C: CMDID:xyz12346
               C: TARGET:cap://cal.example.com/opaqueid101

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
               C: TARGET:opaqueid103
               C: BEGIN:VQUERY
               C: QUERY:SELECT DTSTART,DTEND,SUMMARY,UID FROM VEVENT
               C:   WHERE DTEND >= '19990714T080000Z' AND
               C:   DTSTART <= '19990715T080000Z'
               C: END:VQUERY
               C: END:VCOMMAND
               C: END:VCALENDAR
               C: .
               S: 7.0 ; xyz12346
               S: .
               S: .

   If Bill wants to continue and give the server more time he would
   issue a CONTINUE command:

               C: CONTINUE 10 ; xyz12346

   If Bill wants to abort the command and not wait any further he would
   issue an ABORT command:

               C: ABORT ; xyz12346
               S: 2.0
               S: .
               S: .

          9.2.3

8.2.4 Using Parent and Children Properties

          9.2.4

8.2.5 Query VEVENT.DTSTART and VALARM.DTSTART

          10

9. Implementation Issues

   1.  What are the minimum component properties set required to create
   a new VEVENT, VTODO and VJOURNAL?.  PROPOSAL: DTSTART, SUMMARY and
   UID.

   [EDITORS NOTE (dr): They MUST be the same as for iTIP]

   2.  What is the state of all undefined properties? PROPOSAL: Not
   defined.  So a query will not return them, if they are selected.

   [EDITORS NOTE (dr): Many have default values, a CS may return the
   default values?]

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

          11

10. Properties

   [EDITORS NOTE: These extensions/changes to iCalendar need to be
   reformatted to conform to the IANA registration process defined in
   section 7 of [iCAL].]

          11.1

10.1 Calendar Store Properties

   The following are properties of the calendar store.

             Name           Read  Value     Description
                            Only  Type
             --------------------------------------------------------------
             CALMASTER      N     URI       The email address for a
                                            Responsible person. MUST be a
                                            mailto URL.

             CSID           Y     URI       The CSID of this calendar
                                            store. If not specified, it is
                                            the same as the hostname or
                                            virtual host name.

             DEFAULT_VCARS  N     TEXT      A multivalued property
                                            Containing the default VCARs
                                            for newly created top level
                                            calendars. Each entry is a
                                            CARID It MUST include at a
                                            minimum
                                            READBUSYTIMEINFO,REQUESTONLY,
                                            UPDATEPARTSTATUS, and
                                            DEFAULTOWNER.

             MAXDATE        Y     DATE-TIME The date/time in the future
                                            beyond which the server cannot
                                            represent. If not specified,
                                            then 99991231T235959 will be
                                            assumed.

             MINDATE        Y     DATE-TIME The date/time in the past prior
                                            To which the server cannot
                                            represent. If not specified,
                                            then 00000101T000000 will be
                                            assumed.

             CURRENT_DATETIME  Y  DATE-TIME Current server time. This is
                                            returned as a local time and
                                            TZID.

             RECUR_ACCEPTED  Y    BOOLEAN   Boolean value will be set to

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
                                            TRUE if the server will accept
                                            recurrence rules. It will be
                                            set to FALSE if the server will
                                            not accept recurrence rules. If
                                            not specified a CUA MUST assume
                                            TRUE.

             RECUR_EXPAND   Y     BOOLEAN   If set to TRUE, the CS supports
                                            The expansion of recurrence
                                            rules. If set to FALSE, the CS
                                            is incapable of expanding
                                            recurrence rules. If not
                                            specified a CUA MUST assume
                                            TRUE.

             RECUR_LIMIT    Y   INTEGER     This numeric value describes
                                            How the server handles
                                            unbounded recurrences. The
                                            value is only valid if
                                            RECURRENCE is TRUE. If the
                                            value is 0 it means that the
                                            server supports unbounded
                                            recurrence rules. If it is non-
                                            zero, it is a positive integer
                                            indicating the number of
                                            instances that will be created
                                            when the server expands an
                                            unbounded recurrence rule when
                                            fetched from the CS. A CUA MUST
                                            query for date ranges when this
                                            value is zero.

             VERSION        Y   TEXT        The version of the CS. The
                                            Default and the only currently
                                            Supported version is "2.0" to
                                            match the [iCAL] VERSION.

          11.2

10.2 Calendar Properties

             Name           Read  Value     Description
                            Only  Type
             --------------------------------------------------------------
             ALLOW-CONFLICTS N    BOOLEAN   This boolean value indicates
                                            Whether or not the calendar
                                            supports event conflicts. That
                                            is, whether or not any of the
                                            events in the calendar can
                                            overlap. If not specified the

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
                                            default value is TRUE meaning
                                            that conflicts are allowed.

             CALSCALE        N    TEXT      The CALSCALE for this calendar.
                                            If not specified the default is
                                            GREGORIAN.

             CHARSET         N    TEXT      The default charset for
                                            Localized strings in this
                                            calendar. If not specified, the
                                            default is UTF-8.

             CHILDREN        Y    TEXT      The list of sub-calendars
                                            Belonging to this calendar. An
                                            empty list means no children.
                                            The results may be a comma
                                            separated list of children.
                                            Each entry returned is a CALID.
                                            The default is an empty list.

             CREATED         Y    DATE-TIME The timestamp of the calendar's
                                            create date.

             DEFAULT_VCAR    N    TEXT      The default VCARs for newly
                                            Created top level calendars.
                                            This is a CARID. The default
                                            value is the value of
                                            DEFAULT_VCAR in the CALSTORE
                                            table.

             LANGUAGE        N    TEXT      The default language for
                                            localizable strings in this
                                            calendar. There is no default.
                                            This value MUST NOT be empty.

             LAST-MODIFIED   N    DATE-TIME The timestamp when the
                                            Properties of the calendar were
                                            last updated. Default is the
                                            same as CREATED.

             NAME            N    TEXT      The display name for this
                                            calendar. It is a localizable
                                            string. If not provided, an
                                            empty value will be returned.

             OWNERS          N    URI       A multi-instanced property
                                            indicating the calendar owner.
                                            Each entry returned will be a
                                            UPN. There must be at least one

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001
                                            owner.

             PARENT          N    URI       The CALID of this calendars
                                            Parent maintained by a CAP
                                            server. An empty value means
                                            the calendar is the top level
                                            parent. The default value is no
                                            parent.

             RELCALID        N    URI       A unique name for the calendar.
                                            There is no default value and
                                            This value MUST NOT be empty.

             TOMBSTONE       N    BOOLEAN   TRUE indicator that this
                                            Calendar has been marked as
                                            deleted. The default value is
                                            FALSE.

             TZID            N    TEXT      The id of the timezone
                                            Associated with this calendar.
                                            See TZID in [iCAL]. The default
                                            value is GMT.

          12

11. Security Considerations

   For the mandatory SASL mechanism that CAP specifies, the mechanism
   support is:

      MUST authentication

      MUST authorization

      MAY impersonation

          13

12. CAP Item Registration

   This section provides the process for registration of new or modified
   CAP entities.

          13.1

12.1 Registration of New and Modified CAP Entities

   New CAP entities are registered by the publication of an IETF Request
   for Comment (RFC).  Changes to a CAP item are registered by the
   publication of a revision of the RFC defining the method.

          13.2

12.2 Registration of New Entities

   This section defines procedures by which new entities (i.e.,
   components, properties, parameters, enumerated values or

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001 restriction
   tables) for a CAP item can be registered with the IANA.

   Non-standard, experimental entities can be used by bilateral
   agreement, provided the associated properties names follow the "X-"
   convention.  Such non-standard and experimental entities are non-IANA
   entities and need not be registered using this process.

   The procedures defined here are designed to allow public comment and
   review of new CAP entities, while posing only a small impediment to
   the definition of new properties.

   Registration of a new CAP item is accomplished by the following
   steps.

          13.2.1

12.2.1 Define the Item

   A CAP item is defined by completing the following template.

               To: ietf-calendar@imc.org
               Subject: Registration of CAP item XXX
               Item name:
               Item purpose:
               Description:
               CAP terminology changes:
               CAP data model changes:
               CAP system model changes:
               Conformance considerations:
               Format definition:
               Examples:

   The meaning of each field in the template is as follows.

      Item name: The name of the item.

      Item purpose: The purpose of the item (e.g., Extends the CAP
      command set to poll for notifications, etc.).  Give a short but
      clear description.

      Description: Any special notes about the item, how it is to be
      used, etc.

      CAP terminology changes: Any change or additions to the existing
      CAP terminology needs to be specified.

      CAP data model changes: Any of the valid property parameters for
      the property needs to be specified.

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

      CAP system model changes:

      Conformance: A clear summary of how and where this CAP item
      extension MUST, MAY, SHOULD or can be used.  Any changes or impact
      to the existing conformance definition for CAP should be
      explained.  The impact to implementations conforming to the
      existing CAP specification should be clearly described.

      Format definition: The ABNF for each element of the CAP item needs
      to be specified.

      Examples: One or more examples of instances of the CAP item and
      each of its usage scenarios needs to be specified.

          13.2.2

12.2.2 Post the item definition

   The item description MUST be posted to the new item discussion list,
   ietf-calendar@imc.org.

          13.2.3

12.2.3 Allow a comment period

   Discussion on the new item MUST be allowed to take place on the list
   for a minimum of two weeks.  Consensus MUST be reached on the
   property before proceeding to the next step.

          13.2.4

12.2.4 Submit the proposal for approval

   Once the two-week comment period has elapsed, and the proposer is
   convinced consensus has been reached on the proposal, the
   registration application should be submitted to the Method Reviewer
   for approval.  The Method Reviewer is appointed by the Application
   Area Directors and can either accept or reject the proposal
   registration.  An accepted registration should be passed on by the
   Method Reviewer to the IANA for inclusion in the official IANA method
   registry.  The registration can be rejected for any of the following
   reasons.  1) Insufficient comment period; 2) Consensus not reached;
   3) Technical deficiencies raised on the list or elsewhere have not
   been addressed.  The Method Reviewers decision to reject a proposal
   can be appealed by the proposer to the IESG, or the objections raised
   can be addressed by the proposer and the proposal resubmitted.

   [EDITORS NOTE: John Stracke to review any updates]

          13.3

12.3 Property Change Control

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

   Existing CAP entities can be changed using the same process by which
   they were registered.

      1.  Define the change

      2.  Post the change

      3.  Allow a comment period

      4.  Submit the proposal for approval

   Note that the original author or any other interested party can
   propose a change to an existing CAP object, but that such changes
   should only be proposed when there are serious omissions or errors in
   the published memo.  The Method Reviewer can object to a change if it
   is not backward compatible, but is not required to do so.

   CAP objects definitions can never be deleted from the IANA registry,
   but objects which are no longer believed to be useful can be declared
   OBSOLETE by adding this text to their "Item purpose" field.

          14

13. IANA Considerations

   This memo defines IANA registered extensions to the attributes
   defined by iCalendar, as defined in [iCAL], and [iTIP], as defined in
   [VCARD].

   [EDITORS NOTE (DR): RFC2426 - is vCard.  This needs more explanation.
   What does vCARD have todo with this?]

   IANA registration proposals for iCalendar and iTIP are to be mailed
   to the registration agent for the "text/calendar" [MIME] content-type, content-
   type, <MAILTO: ietf-calendar@imc.org> using the format defined in
   section 7 of [iCAL].

          15 Acknowledgments

Authors' Addresses

   Steve Mansour
   Netscape, iPlanet
   501 E Middlfield Road
   Mountain View, CA  94043
   US

   Phone: +1-408-276-4268
   EMail: sman@netscape.com

   Doug Royer

   EMail: Doug@royer.com

   George Babics
   Steltor
   2000 Peel Street
   Montreal, Quebec  H3A 2W5
   CA

   Phone: +1-514-733-8500 x4201
   Fax:   +1-514-733-8878
   EMail: georgeb@steltor.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

Appendix A. Acknowledegements

   The following have individuals were major contributors in the
   drafting and discussion of this memo:

      Harald Alvestrand, Mario Bonin, Andre Courtemanche, Dave Crocker,
      Pat Egen, Gilles Fortin, Jeff Hodges, Alex Hoppman, Bruce Kahn,
      Lisa Lippert, David Madeo, Bob Mahoney, Bob Morgan, Pete O'Leary,
      Richard Shusterman, Tony Small, John Stracke, Mark Wahl, Alexander
      Taler.

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

          16

Appendix B. Bibliography

      [MIME] N.  Borenstein and N.  Freed, "MIME (Multipurpose Internet
      Mail Extensions) Part One: Mechanisms for Internet Draft UTF-825
      Specifying and Describing the Format of Internet Message Bodies",
      RFC 1521, Bellcore, Innosoft, September 1993.

      [TLS] Dierks, Allen, "The TLS Protocol", RFC 2246, January 1999

      [RFC2119] TODO...

      [SASL] RFC2222 TODO...

      [URL] Berners-Lee, Fielding, Masinter, "Uniform Resource
      Identifiers

      (URI): Generic Syntax", RFC 2396, August 1998.

      [iCAL] Dawson, Stenerson, "Internet Calendaring and Scheduling
      Core Object Specification (iCalendar)", RFC 2445, November 1998

      [iTIP] Silverberg, Mansour, Dawson, Hopson, "iCalendar
          Transport-Independent Transport-
      Independent Interoperability Protocol (iTIP)", RFC 2446, November
      1998

      [iMIP] Dawson, Mansour, Silverberg, "iCalendar Message-Based
      Interoperability Protocol (iMIP)", RFC 2445, November 1998

      [SQL] "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

      [UNICODE] The Unicode Consortium, "The Unicode Standard -
                                                                  -

      Worldwide Character Encoding -- Version 1.0", Addison-Wesley,
      Volume 1, 1991, Volume 2, 1992.  UTF-8 is described in Unicode
      Technical Report #4.

      [US-ASCII] Coded Character Set--7-bit American Standard Code for
      Information Interchange, ANSI X3.4-1986.

      [VCARD] RFC....  TODO

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001

          17 Author's Address
          The following address information is provided in a vCard v3.0,
          the [VCARD] electronic business card format.

          Steve Mansour
          Judge, Jury, and Executioner
          Netscape, iPlanet
          501 E Middlfield Road
          Mountain View, CA 94043 USA
          Phone:  +1-408-276-4268
          mailto:sman@netscape.com

          Paul Hill
          Senior Programmer Analyst
          Massachusetts Institute of Technology
          W92-172
          77 Massachusetts Avenue
          Cambridge, MA, USA
          02139
          Phone:  +1-617-253-0124
          Fax: +1-617-258-8736
          mailto:pbh@mit.edu

          Doug Royer
          mailto:Doug@Royer.com

          George Babics
          Steltor (formerly CS&T/Lexacom)
          2000 Peel Street
          Montreal, Quebec, Canada
          H3A 2W5
          Tel: (514) 733-8500 x4201
          Fax: (514) 733-8878
          Mailto: georgeb@steltor.com

          18

Full Copyright Statement

          "Copyright

   Copyright (C) The Internet Society (2000). (2001).  All Rights Reserved.

   This document and translations of it may be copied and furnished to
   others, and derivative works that comment on or otherwise explain it
   or assist in its implementation may be prepared, copied, published
   and distributed, in whole or in part, without restriction of any
   kind, provided that the above copyright notice and this paragraph are
   included on all such copies and derivative works.  However, this
   document itself may not be modified in any way, such as by removing
   the copyright notice or references to the Internet Society or other
   Internet

          <draft-ietf-calsch-cap-04.txt>   CAP   Expires September 2001 organizations, except as needed for the purpose of
   developing Internet standards in which case the procedures for
   copyrights defined in the Internet Standards process MUST must be
   followed, or as required to translate it into languages other than
   English.

   The limited permissions granted above are perpetual and will not be
   revoked by the Internet Society or its successors or assigns.

   This document and the information contained herein is provided on an
   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Acknowledgement

   Funding for the RFC Editor function is currently provided by the
   Internet Society.