Network Working Group C. Daboo
Internet-Draft Apple Computer
Intended status: Informational October 22, 2006
Expires: April 25, 2007
vCard Extensions to WebDAV (CardDAV)
draft-daboo-carddav-01
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Copyright Notice
Copyright (C) The Internet Society (2006).
Abstract
This document specifies a set of methods, headers and resource types
that define an extension to the WebDAV protocol to support vCard data
stored as address books on the server. The new protocol elements are
intended to make WebDAV-based address book management an
interoperable standard that supports address book access, address
book sharing, and address book publishing.
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Change History (to be removed prior to publication as an RFC)
Changes from -00
1. Fixed various incorrect references and typos.
2. Major changes to sync with latest CalDAV spec behaviors.
Table of Contents
1. Introduction and Overview . . . . . . . . . . . . . . . . . . 4
1.1. IMSP . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2. ACAP . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.3. LDAP . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.4. WebDAV for Address Books . . . . . . . . . . . . . . . . . 6
1.5. vCard . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1. Notational Conventions . . . . . . . . . . . . . . . . . . 7
2.2. XML Namespaces and Processing . . . . . . . . . . . . . . 8
2.3. Method Preconditions and Postconditions . . . . . . . . . 8
3. Requirements Overview . . . . . . . . . . . . . . . . . . . . 9
4. Address Book Data Model . . . . . . . . . . . . . . . . . . . 9
4.1. Address Book Server . . . . . . . . . . . . . . . . . . . 10
5. Address Book Resources . . . . . . . . . . . . . . . . . . . . 10
5.1. vCard Object Resources . . . . . . . . . . . . . . . . . . 10
5.2. Address Book Collection . . . . . . . . . . . . . . . . . 11
6. Address Book Feature . . . . . . . . . . . . . . . . . . . . . 12
6.1. Address Book Support . . . . . . . . . . . . . . . . . . . 12
6.1.1. Example: Using OPTIONS for the Discovery of
Support for CardDAV . . . . . . . . . . . . . . . . . 12
6.2. Address Book Properties . . . . . . . . . . . . . . . . . 13
6.2.1. CARDDAV:adbk-description Property . . . . . . . . . . 13
6.2.2. CARDDAV:supported-adbk-data Property . . . . . . . . . 13
6.2.3. CARDDAV:max-resource-size Property . . . . . . . . . . 14
6.3. Creating Resources . . . . . . . . . . . . . . . . . . . . 15
6.3.1. MKADBK Method . . . . . . . . . . . . . . . . . . . . 15
6.3.1.1. Status Codes . . . . . . . . . . . . . . . . . . . 17
6.3.1.2. Example - Successful MKADBK request . . . . . . . 18
6.3.2. Creating vCard Object Resources . . . . . . . . . . . 18
6.3.2.1. Additional Preconditions for PUT, COPY and MOVE . 20
7. Address Book Access Control . . . . . . . . . . . . . . . . . 21
7.1. Additional Principal Property . . . . . . . . . . . . . . 21
7.1.1. CARDDAV:adbk-home-set Property . . . . . . . . . . . . 21
8. Address Book Reports . . . . . . . . . . . . . . . . . . . . . 22
8.1. REPORT Method . . . . . . . . . . . . . . . . . . . . . . 22
8.2. Ordinary collections . . . . . . . . . . . . . . . . . . . 22
8.3. Searching Text: Collations . . . . . . . . . . . . . . . . 22
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8.3.1. CARDDAV:supported-collation-set Property . . . . . . . 23
8.4. Partial Retrieval . . . . . . . . . . . . . . . . . . . . 24
8.5. Non-standard properties and parameters . . . . . . . . . . 24
8.6. CARDDAV:adbk-query Report . . . . . . . . . . . . . . . . 25
8.6.1. Example: Partial retrieval of vCards matching a
NICKNAME . . . . . . . . . . . . . . . . . . . . . . . 26
8.6.2. Example: Partial retrieval of vCards matching a
full name . . . . . . . . . . . . . . . . . . . . . . 28
8.7. CARDDAV:adbk-multiget Report . . . . . . . . . . . . . . . 31
8.7.1. Example: CARDDAV:adbk-multiget Report . . . . . . . . 32
8.8. CARDDAV:adbk-sync Report . . . . . . . . . . . . . . . . . 33
8.8.1. Example: Initial CARDDAV:adbk-sync Report . . . . . . 35
8.8.2. Example: CARDDAV:adbk-sync Report with token . . . . . 36
9. Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . 38
9.1. Restrict the Properties Returned . . . . . . . . . . . . . 38
9.2. Use of Locking . . . . . . . . . . . . . . . . . . . . . . 38
9.3. Finding address books . . . . . . . . . . . . . . . . . . 38
10. XML Element Definitions . . . . . . . . . . . . . . . . . . . 40
10.1. CARDDAV:adbk XML Element . . . . . . . . . . . . . . . . . 40
10.2. CARDDAV:mkadbk XML Element . . . . . . . . . . . . . . . . 40
10.3. CARDDAV:mkadbk-response XML Element . . . . . . . . . . . 41
10.4. CARDDAV:supported-collation XML Element . . . . . . . . . 41
10.5. CARDDAV:adbk-query XML Element . . . . . . . . . . . . . . 41
10.6. CARDDAV:adbk-data XML Element . . . . . . . . . . . . . . 42
10.6.1. CARDDAV:allprop XML Element . . . . . . . . . . . . . 43
10.6.2. CARDDAV:prop XML Element . . . . . . . . . . . . . . . 43
10.7. CARDDAV:filter XML Element . . . . . . . . . . . . . . . . 44
10.7.1. CARDDAV:prop-filter XML Element . . . . . . . . . . . 44
10.7.2. CARDDAV:param-filter XML Element . . . . . . . . . . . 45
10.7.3. CARDDAV:is-not-defined XML Element . . . . . . . . . . 46
10.7.4. CARDDAV:text-match XML Element . . . . . . . . . . . . 46
10.8. CARDDAV:adbk-multiget XML Element . . . . . . . . . . . . 47
10.9. CARDDAV:adbk-sync XML Element . . . . . . . . . . . . . . 47
10.9.1. CARDDAV:sync-token XML Element . . . . . . . . . . . . 47
11. Internationalization Considerations . . . . . . . . . . . . . 48
12. Security Considerations . . . . . . . . . . . . . . . . . . . 48
13. IANA Consideration . . . . . . . . . . . . . . . . . . . . . . 49
13.1. Namespace Registration . . . . . . . . . . . . . . . . . . 49
14. References . . . . . . . . . . . . . . . . . . . . . . . . . . 49
14.1. Normative References . . . . . . . . . . . . . . . . . . . 49
14.2. Informative References . . . . . . . . . . . . . . . . . . 50
Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . . 50
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 51
Intellectual Property and Copyright Statements . . . . . . . . . . 52
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1. Introduction and Overview
Address books are a key component of personal information management
tools, such as email or calendaring and scheduling clients. To date
several protocols have been used for remote access to address data,
including LDAP [RFC2251], IMSP and ACAP [RFC2244].
1.1. IMSP
IMSP, which was the predecessor to ACAP [RFC2244], received limited
support from vendors, but those that did implement solutions based on
it, found it to be a useful feature for large deployments of email
clients at sites where users may roam from machine to machine. IMSP
provided for multiple personal, shared or public address books,
organized in a hierarchy, and gave individual users the ability to
control access to their address books so that they could grant read
or write access rights to other specific users or groups. This
provided an easy and convenient way for users or workgroups to
quickly setup and manage shared address information. Address book
support in IMSP suffers from a number of problems, including a
limited format for the address data itself, and scalability issues
with large address books.
The key features of address book support in IMSP are:
1. Ability to use multiple address books with hierarchical layout.
2. Ability to control access to individual address books.
3. Server-side searching of address data, avoiding the need for
clients to download an entire address book in order to do a quick
address 'expansion' operation.
4. Ability to download/upload an individual address in an address
book.
The key disadvantages of address book support in IMSP are:
1. Limited schema for address data.
2. Does not scale to large address books (e.g. no way to page
through the list of addresses in an address book).
3. Does not provide any type of synchronization capability, which
easily leads to 'lost update' problems when multiple users are
editing the same address book entries.
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4. Lack of internationalization support.
5. Does not provide per-address access control
6. Does not provide a simple way to lookup users on the system.
1.2. ACAP
ACAP [RFC2244] was meant as the successor to IMSP and as such was
designed to be a more 'generic' data access protocol for general
application use. ACAP defined specific 'datasets' (basically formal
schema definitions) for different anticipated areas of use, including
address books, email accounts, application preferences, mime types
etc. The use of such formal schema definitions was intended to
enhance interoperability between clients. However, ACAP proved
difficult to implement due to over complexity in the protocol itself,
and this lead to few implementations.
The key features of address book support in ACAP are:
1. Ability to use multiple address books with hierarchical layout.
2. Ability to control access to individual address books and
address entries.
3. Server-side searching of address data, avoiding the need for
clients to download an entire address book in order to do a
quick address 'expansion' operation.
4. Ability to inherit address book data from others.
5. Ability to watch changes in address book data through use of
'contexts'.
6. Ability to page through address book data through use of
'contexts'.
7. Internationalization support through use of UTF-8 for all data.
8. Well defined address schema to enhance client interoperability.
9. Compatibility with vCard data format.
10. Users and groups dataset can be used to enumerate and find other
users on the system.
The key disadvantages of address book support in ACAP are:
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1. Inheritance, access control and contexts all together is hard,
and ultimately proved one of the major hurdles to
implementations.
1.3. LDAP
LDAP [RFC2251] is a generic directory access protocol that is
specifically targeted at management applications and browser
applications that provide read/write interactive access to
directories. Often such directories contain information about
people, including contact/address data.
The key features of address book support in LDAP are:
1. To do
The key disadvantages of address book support in LDAP are:
1. Lack of schemas require overly complex client configuration to
map expected fields in the client to directory entries in the
server.
2. General reluctance to give 'ordinary' users write access to even
a small portion of the directory as often sensitive information
is included in directory entries and a small mistake in
configuring access control can lead to a major security breach.
1.4. WebDAV for Address Books
WebDAV [RFC2518] offers a number of advantages as a framework or
basis for address book access and management. Most of these
advantages boil down to a significant reduction in design costs,
implementation costs, interoperability test costs and deployment
costs.
The key features of address book support with WebDAV are:
1. Ability to use multiple address books with hierarchical layout.
2. Ability to control access to individual address books and address
entries.
3. Principal namespace can be used to enumerate and find other users
on the system.
4. Server-side searching of address data, avoiding the need for
clients to download an entire address book in order to do a quick
address 'expansion' operation.
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5. Well-defined internationalization support through standard HTTP.
6. Use of vCards for well defined address schema to enhance client
interoperability.
7. Many limited clients (e.g. mobile devices) contain an HTTP stack
which makes implementing WebDAV much easier than other protocols.
The key disadvantages of address book support in WebDAV are:
1. Lack of change notification.
2. Stateless nature of protocol can result in more data being sent
with each transaction to maintain per-user session across
requests.
1.5. vCard
vCard [RFC2426] is a MIME directory profile aimed at encapsulating
personal addressing and contact information about people. The
specification of vCard was originally done by the Versit consortium,
with a subsequent 3.0 version standardized by the IETF [RFC2426].
vCard is in wide spread use in email clients and mobile devices as a
means of encapsulating address information for transport via email,
or for import/export and synchronization operations.
2. Conventions
2.1. Notational Conventions
The augmented BNF used by this document to describe protocol elements
is described in Section 2.1 of [RFC2616]. Because this augmented BNF
uses the basic production rules provided in Section 2.2 of [RFC2616],
those rules apply to this document as well.
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].
The term "protected" is used in the Conformance field of property
definitions as defined in Section 1.4.2 of [RFC3253].
When XML element types in the namespaces "DAV:" and
"urn:ietf:params:xml:ns:carddav" are referenced in this document
outside of the context of an XML fragment, the string "DAV:" and
"CARDDAV:" will be prefixed to the element type names respectively.
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2.2. XML Namespaces and Processing
Definitions of XML elements in this document use XML element type
declarations (as found in XML Document Type Declarations), described
in Section 3.2 of [W3C.REC-xml-20060816].
The namespace "urn:ietf:params:xml:ns:carddav" is reserved for the
XML elements defined in this specification, its revisions, and
related CardDAV specifications. XML elements defined by individual
implementations MUST NOT use the "urn:ietf:params:xml:ns:carddav"
namespace, and instead should use a namespace that they control.
The XML declarations used in this document do not include namespace
information. Thus, implementers must not use these declarations as
the only way to create valid CardDAV properties or to validate
CardDAV XML element type. Some of the declarations refer to XML
elements defined by WebDAV [RFC2518] which use the "DAV:" namespace.
Wherever such XML elements appear, they are explicitly prefixed with
"DAV:" to avoid confusion.
Also note that some CardDAV XML element names are identical to WebDAV
XML element names, though their namespace differs. Care must be
taken not to confuse the two sets of names.
Processing of XML by CardDAV clients and servers MUST follow the
rules described in [RFC2518], in particular Section 14, and Appendix
3 of that specification.
2.3. Method Preconditions and Postconditions
A "precondition" of a method describes the state of the server that
must be true for that method to be performed. A "postcondition" of a
method describes the state of the server that must be true after that
method has been completed. If a method precondition or postcondition
for a request is not satisfied, the response status of the request
MUST be either 403 (Forbidden) if the request should not be repeated
because it will always fail, or 409 (Conflict) if it is expected that
the user might be able to resolve the conflict and resubmit the
request.
In order to allow better client handling of 403 and 409 responses, a
distinct XML element type is associated with each method precondition
and postcondition of a request. When a particular precondition is
not satisfied or a particular postcondition cannot be achieved, the
appropriate XML element MUST be returned as the child of a top-level
DAV:error element in the response body, unless otherwise negotiated
by the request. In a 207 Multi-Status response, the DAV:error
element would appear in the appropriate DAV:responsedescription
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element.
3. Requirements Overview
This section lists what functionality is required of a CardDAV
server.
To advertise support for the 'adbk-access' features of CardDAV, a
server:
o MUST support WebDAV Class 1 [RFC2518] (note that
[I-D.ietf-webdav-rfc2518bis] describes clarifications to [RFC2518]
that aid interoperability);
o MUST support WebDAV ACLs [RFC3744].
o MUST support transport over TLS [RFC2246] as defined in [RFC2818]
(note that [RFC2246] has been obsoleted by [RFC4346]);
o MUST support strong ETags to support disconnected operations.
o MUST support address book REPORTs as described in this document.
o MUST support the MKADBK method.
To advertise support for the 'adbk-sync' features of CardDAV, a
server:
o MUST support the 'adbk-access' features described above.
o MUST support the 'adbk-sync' REPORT on address book collections.
4. Address Book Data Model
As a brief overview, a CardDAV address book is modeled as a WebDAV
collection with a well defined structure; each of these address book
collections contain a number of resources representing vCard objects
as their direct child resources. Each resource representing a vCard
object is called a "vCard object resource". Each vCard object
resource and each address book collection can be individually locked
and have individual WebDAV properties. Requirements derived from
this model are provided in Section 5.1 and Section 5.2.
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4.1. Address Book Server
A CardDAV server is a vCard-aware engine combined with a WebDAV
repository. A WebDAV repository is a set of WebDAV collections,
containing other WebDAV resources, within a unified URL namespace.
For example, the repository "http://example.org/webdav/" may contain
WebDAV collections and resources, all of which have URLs beginning
with "http://example.org/webdav/". Note that the root URL
"http://example.org/" may not itself be a WebDAV repository (for
example, if the WebDAV support is implemented through a servlet or
other Web server extension).
A WebDAV repository MAY include address book data in some parts of
its URL namespace, and non-address book data in other parts.
A WebDAV repository can advertise itself as a CardDAV server if it
supports the functionality defined in this specification at any point
within the root of the repository. That might mean that vCard data
is spread throughout the repository and mixed with non-vCard data in
nearby collections (e.g. vCard data may be found in /lisa/
addressbook/ as well as in /bernard/addressbook/, and non-vCard data
in /lisa/calendars/). Or, it might mean that vCard data can be found
only in certain sections of the repository (e.g. /addressbooks/
user/). Address book features are only required in the repository
sections that are or contain vCard objects. So a repository
confining vCard data to the /carddav/ collection would only need to
support the CardDAV required features within that collection.
The CardDAV server or repository is the canonical location for vCard
data and state information. Clients may submit requests to change
data or download data. Clients may store vCard objects offline and
attempt to synchronize at a later time. However, clients MUST be
prepared for vCard data on the server to change between the time of
last synchronization and when attempting an update, as address book
collections may be shared and accessible via multiple clients.
Entity tags and other features help this work.
5. Address Book Resources
5.1. vCard Object Resources
vCard object resources contained in address book collections MUST
contain a single vCard component only.
vCard components in an address book collection MUST have a UID
property value that MUST be unique in the scope of the address book
collection in which it is contained.
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5.2. Address Book Collection
CardDAV defines the following new resource type for use in WebDAV
repositories holding vCard data.
Address book collections appear to clients as a WebDAV collection
resource, identified by a URL. An address book collection MUST
report the DAV:collection and CARDDAV:adbk XML elements in the value
of the DAV:resourcetype property. The element type declaration for
CARDDAV:adbk is:
<!ELEMENT adbk EMPTY>
An address book collection can be created through provisioning (e.g.,
automatically created when a user's account is provisioned), or it
can be created with the MKADBK method (see Section 6.3.1). This
method can be useful for a user to create additional address books
(e.g., "soccer team members") or for users to share an address book
(e.g., "sales team contacts"). Note however that this document
doesn't define what extra address book collections are for. Users
must rely on non-standard cues to find out what an address book
collection is for, or use the CARDDAV:adbk-description property
defined in Section 6.2.1 to provide such a cue.
The following restrictions are applied to the resources within an
address book collection:
a. Address book collections MUST only contain vCard object resources
and collections that are not address book collections. i.e., the
only "top-level" non-collection resources allowed in an address
book collection are vCard object resources. This ensures that
address book clients do not have to deal with non-vCard data in
an address book collection, though they do have to distinguish
between vCard object resources and collections when using
standard WebDAV techniques to examine the contents of a
collection.
b. Collections contained in address book collections MUST NOT
contain address book collections at any depth. i.e., "nesting" of
address book collections within other address book collections at
any depth is not allowed. This specification does not define how
collections contained in an address book collection are used or
how they relate to any vCard object resources contained in the
address book collection.
Multiple address book collections MAY be children of the same
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collection.
6. Address Book Feature
6.1. Address Book Support
If the server supports the CardDAV features described in this
document, it MUST include "adbk-access" as a field in the DAV
response header from an OPTIONS request on any resource that supports
any address book properties, reports, or methods. A value of "adbk-
access" in the DAV header MUST indicate that the server supports all
MUST level requirements and REQUIRED features specified in this
document, with the exception of the CARDDAV:adbk-sync REPORT.
CardDAV includes a special report to allow better client/server
synchronization performance. Support for this feature is OPTIONAL,
though RECOMMENDED. If a server supports this feature then it MUST
include "adbk-sync" as a field in the DAV response header from an
OPTIONS request on any address book collection resource that supports
the report.
6.1.1. Example: Using OPTIONS for the Discovery of Support for CardDAV
>> Request <<
OPTIONS /addressbooks/users/ HTTP/1.1
Host: adbk.example.com
>> Response <<
HTTP/1.1 200 OK
Allow: OPTIONS, GET, HEAD, POST, PUT, DELETE, TRACE, COPY, MOVE
Allow: MKCOL, PROPFIND, PROPPATCH, LOCK, UNLOCK, REPORT
Allow: MKADBK, ACL
DAV: 1, 2, access-control, adbk-access
Content-Length: 0
In this example, the OPTIONS response indicates that the server
supports CardDAV in this namespace, therefore the '/addressbooks/
users/' collection may be used as a parent for address book
collections as the MKADBK method is available, and as a possible
target for REPORT requests for address book reports.
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6.2. Address Book Properties
6.2.1. CARDDAV:adbk-description Property
Name: adbk-description
Namespace: urn:ietf:params:xml:ns:carddav
Purpose: Provides a human-readable description of the address book
collection.
Conformance: This property MAY be defined on any address book
collection. If defined, it MAY be protected and SHOULD NOT be
returned by a PROPFIND DAV:allprop request (as defined in Section
12.14.1 of [RFC2518]). An xml:lang attribute indicating the human
language of the description SHOULD be set for this property by
clients or through server provisioning. Servers MUST return any
xml:lang attribute if set for the property.
Description: If present, the property contains a description of the
address book collection that is suitable for presentation to a
user. If not present, the client should assume no description for
the address book collection.
<!ELEMENT adbk-description (#PCDATA)>
PCDATA value: string
<C:adbk-description xml:lang="fr-CA"
xmlns:C="urn:ietf:params:xml:ns:carddav"
>Address de Oliver Daboo</C:adbk-description>
6.2.2. CARDDAV:supported-adbk-data Property
Name: supported-adbk-data
Namespace: urn:ietf:params:xml:ns:carddav
Purpose: Specifies what media types are allowed for address book
object resources in an address book collection.
Conformance: This property MAY be defined on any address book
collection. If defined, it MUST be protected and SHOULD NOT be
returned by a PROPFIND DAV:allprop request (as defined in Section
12.14.1 of [RFC2518] ).
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Description: The CARDDAV:supported-adbk-data property is used to
specify the media type supported for the address (vCard) object
resources contained in a given address book collection (e.g.,
vCard version 3.0). Any attempt by the client to store vCard
object resources with a media type not listed in this property
MUST result in an error, with the CARDDAV:supported-adbk-data
precondition ( Section 6.3.2.1 ) being violated. In the absence
of this property the server MUST only accept data with the media
type "text/vcard" and vCard version 3.0, and clients can assume
that.
Definition:
<!ELEMENT supported-adbk-data (adbk-data*)>
Example:
<C:supported-adbk-data xmlns:C="urn:ietf:params:xml:ns:carddav">
<C:adbk-data content-type="text/vcard" version="3.0"/>
</C:supported-adbk-data>
6.2.3. CARDDAV:max-resource-size Property
Name: max-resource-size
Namespace: urn:ietf:params:xml:ns:carddav
Purpose: Provides a numeric value indicating the maximum size of a
resource in octets that the server is willing to accept when a
vCard object resource is stored in an address book collection.
Conformance: This property MAY be defined on any address book
collection. If defined, it MUST be protected and SHOULD NOT be
returned by a PROPFIND DAV:allprop request (as defined in Section
12.14.1 of [RFC2518] ).
Description: The CARDDAV:max-resource-size is used to specify a
numeric value that represents the maximum size in octets that the
server is willing to accept when a vCard object resource is stored
in an address book collection. Any attempt to store an address
book object resource exceeding this size MUST result in an error,
with the CARDDAV:max-resource-size precondition ( Section 6.3.2.1
) being violated. In the absence of this property the client can
assume that the server will allow storing a resource of any
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reasonable size.
Definition:
<!ELEMENT max-resource-size (#PCDATA)>
PCDATA value: a numeric value (positive integer)
Example:
<C:max-resource-size xmlns:C="urn:ietf:params:xml:ns:carddav"
>102400</C:max-resource-size>
6.3. Creating Resources
The creation of address book collections and vCard object resources
may be initiated by either a CardDAV client or by the CardDAV server.
For example, a server might come pre-configured with a user's address
book collection, or the CardDAV client might request the server to
create a new address book collection for a given user. Servers might
populate vCard objects inside an address book collection, or clients
might request the server to create vCards. Either way, both client
and server MUST comply with the requirements in this document, and
MUST understand objects appearing in address book collections or
according to the data model defined here.
6.3.1. MKADBK Method
An HTTP request using the MKADBK method creates a new address book
collection resource. A server MAY restrict address book collection
creation to particular collections.
Clients SHOULD use the DAV:displayname property for a human-readable
name of the address book. Clients can either specify the value of
the DAV:displayname property in the request body of the MKADBK
request, or alternatively issue a PROPPATCH request to change the
DAV:displayname property to the appropriate value immediately after
using the MKADBK request. Clients SHOULD NOT set the DAV:
displayname property to be the same as any other address book
collection at the same URI "level". When displaying address book
collections to users, clients SHOULD check the DAV:displayname
property and use that value as the name of the address book. In the
event that the DAV: displayname property is empty, the client MAY use
the last part of the address book collection URI as the name, however
that path segment may be "opaque" and not represent any meaningful
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human-readable text.
If a MKADBK request fails, the server state preceding the request
MUST be restored.
Marshalling:
If a request body is included, it MUST be a CARDDAV:mkadbk XML
element. Instruction processing MUST occur in the order
instructions are received (i.e., from top to bottom).
Instructions MUST either all be executed or none executed. Thus
if any error occurs during processing all executed instructions
MUST be undone and a proper error result returned. Instruction
processing details can be found in the definition of the DAV:set
instruction in section 12.13 of [RFC2518].
<!ELEMENT mkadbk (DAV:set)>
If a response body for a successful request is included, it MUST
be a CARDDAV:mkadbk-response XML element.
<!ELEMENT mkadbk-response ANY>
The response MUST include a Cache-Control:no-cache header.
Preconditions:
(DAV:resource-must-be-null): A resource MUST NOT exist at the
Request-URI.
(CARDDAV:adbk-collection-location-bad): The Request-URI MUST
identify a location where an address book collection can be
created.
(DAV:needs-privilege): The DAV:bind privilege MUST be granted to
the current user.
Postconditions:
(CARDDAV:initialize-adbk-collection): A new address book
collection exists at the Request-URI. The DAV:resourcetype of the
address book collection MUST contain both DAV:collection and
CARDDAV:adbk XML elements.
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6.3.1.1. Status Codes
The following are examples of response codes one would expect to get
in a response to a MKADBK request. Note that this list is by no
means exhaustive.
201 (Created) - The address book collection resource was created
in its entirety.
207 (Multi-Status) - The address book collection resource was not
created since one or more DAV:set instructions specified in the
request body could not be processed successfully. The following
are examples of response codes one would expect to be used in a
207 (Multi-Status) response:
403 (Forbidden) - The client, for reasons the server chooses
not to specify, cannot alter one of the properties.
409 (Conflict) - The client has provided a value whose
semantics are not appropriate for the property. This includes
trying to set read-only properties.
424 (Failed Dependency) - The DAV:set instruction on the
specified resource would have succeeded if it were not for the
failure of another DAV:set instruction specified in the request
body.
423 (Locked) - The specified resource is locked and the client
either is not a lock owner or the lock type requires a lock
token to be submitted and the client did not submit it.
507 (Insufficient Storage) - The server did not have sufficient
space to record the property.
403 (Forbidden) - This indicates at least one of two conditions:
1) the server does not allow the creation of address book
collections at the given location in its namespace, or 2) the
parent collection of the Request-URI exists but cannot accept
members.
405 (Method Not Allowed) - MKADBK can only be executed on a null
resource.
409 (Conflict) - A collection cannot be made at the Request-URI
until one or more intermediate collections have been created.
415 (Unsupported Media Type) - The server does not support the
request type of the body.
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507 (Insufficient Storage) - The resource does not have sufficient
space to record the state of the resource after the execution of
this method.
6.3.1.2. Example - Successful MKADBK request
This example creates an address book collection called /home/lisa/
addressbook/ on the server adbk.example.com with specific values for
the properties DAV:displayname and CARDDAV:adbk-description.
>> Request <<
MKADBK /home/lisa/addressbook/ HTTP/1.1
Host: adbk.example.com
Content-Type: text/xml; charset="utf-8"
Content-Length: xxx
<?xml version="1.0" encoding="utf-8" ?>
<C:mkadbk xmlns:D="DAV:"
xmlns:C="urn:ietf:params:xml:ns:carddav">
<D:set>
<D:prop>
<D:displayname>Lisa's Address Book</D:displayname>
<C:adbk-description xml:lang="en"
>My primary address book.</C:adbk-description>
</D:prop>
</D:set>
</C:mkadbk>
>> Response <<
HTTP/1.1 201 Created Date: Fri, 22 Oct 2004 12:17:08 GMT
Content-Length: 0
Cache-Control: no-cache
6.3.2. Creating vCard Object Resources
Clients populate address book collections with vCard object
resources. The URL for each vCard object resource is entirely
arbitrary, and does not need to bear a specific relationship (but
might) to the vCard object resource's vCard properties or other
metadata. New vCard object resources MUST be created with a PUT
request targeted at an unmapped URI. A PUT request targeted at a
mapped URI updates an existing vCard object resource.
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When servers create new resources, it's not hard for the server to
choose a unique URL. It's slightly tougher for clients, because a
client might not want to examine all resources in the collection, and
might not want to lock the entire collection to ensure that a new one
isn't created with a name collision. However, there is an HTTP
feature to mitigate this. If the client intends to create a new
vCard resource the client SHOULD use the HTTP header "If-None-Match:
*" on the PUT request. The Request-URI on the PUT request MUST
include the target collection, where the resource is to be created,
plus the name of the resource in the last path segment. The "If-
None-Match" header ensures that the client will not inadvertently
overwrite an existing resource even, if the last path segment turned
out to already be used.
>> Request <<
PUT /lisa/addressbook/newvcard.vcf HTTP/1.1
If-None-Match: *
Host: adbk.example.com
Content-Type: text/vcard
Content-Length: xxx
BEGIN:VCARD
VERSION:3.0
FN:Cyrus Daboo
N:Daboo;Cyrus
ADR;TYPE=POSTAL:;2822 Email HQ;Suite 2821;RFCVille;PA;15213;USA
EMAIL;TYPE=INTERNET,PREF:cyrus@daboo.name
NICKNAME:me
NOTE:Example VCard.
ORG:Self Employed
TEL;TYPE=WORK,VOICE:412 605 0499
TEL;TYPE=FAX:412 605 0705
URL:http://www.daboo.name
END:VCARD
>> Response <<
HTTP/1.1 201 Created
Date: Thu, 02 Sep 2004 16:53:32 GMT
Content-Length: 0
ETag: "123456789-000-111"
The request to change an existing vCard is the same, but with a
specific ETag in the "If-Match" header, rather than the "If-None-
Match" header.
File names for vCards are commonly suffixed by ".vcf", and clients
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may choose to use the same convention for URLs.
6.3.2.1. Additional Preconditions for PUT, COPY and MOVE
This specification creates additional Preconditions for PUT, COPY and
MOVE methods. These preconditions apply:
When a PUT operation of a vCard object resource into an address
book collection occurs.
When a COPY or MOVE operation of a vCard object resource into an
address book collection occurs.
The new preconditions are:
(CARDDAV:supported-adbk-data): The resource submitted in the PUT
request, or targeted by a COPY or MOVE request MUST be a supported
media type (i.e., vCard) for vCard object resources;
(CARDDAV:valid-adbk-data): The resource submitted in the PUT
request, or targeted by a COPY or MOVE request MUST be valid data
for the media type being specified (i.e., MUST contain valid vCard
data);
(CARDDAV:no-uid-conflict): The resource submitted in the PUT
request, or targeted by a COPY or MOVE request MUST NOT specify a
vCard UID property value already in use in the targeted address
book collection or overwrite an existing vCard object resource
with one that has a different UID property value. Servers SHOULD
report the URL of the resource that is already making use of the
same UID property value in the DAV:href element;
<!ELEMENT no-uid-conflict (DAV:href)>
(CARDDAV:adbk-collection-location-ok): In a COPY or MOVE request,
when the Request-URI is an address book collection, the
Destination-URI MUST identify a location where an address book
collection can be created;
(CARDDAV:max-resource-size): The resource submitted in the PUT
request, or targeted by a COPY or MOVE request MUST have an octet
size less than or equal to the value of the CARDDAV:max-resource-
size property value ( Section 6.2.3 ) on the address book
collection where the resource will be stored;
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7. Address Book Access Control
CardDAV servers MUST support and adhere to the requirements of WebDAV
ACL [RFC3744]. WebDAV ACL provides a framework for an extensible set
of privileges that can be applied to WebDAV collections and ordinary
resources.
7.1. Additional Principal Property
This section defines an additional property for WebDAV principal
resources as defined in [RFC3744].
7.1.1. CARDDAV:adbk-home-set Property
Name: adbk-home-set
Namespace: urn:ietf:params:xml:ns:carddav
Purpose: Identifies the URL of any WebDAV collections that contain
address book collections owned by the associated principal
resource.
Conformance: This property SHOULD be defined on a principal
resource. If defined, it MAY be protected and SHOULD NOT be
returned by a PROPFIND DAV:allprop request (as defined in Section
12.14.1 of [RFC2518]).
Description: The CARDDAV:adbk-home-set property is meant to allow
users to easily find the address book collections owned by the
principal. Typically, users will group all the address book
collections that they own under a common collection. This
property specifies the URL of collections that either are address
book collections or ordinary collections that have child or
descendant address book collections owned by the principal.
Definition:
<!ELEMENT adbk-home-set (DAV:href*)>
Example:
<C:adbk-home-set xmlns:D="DAV:"
xmlns:C="urn:ietf:params:xml:ns:carddav">
<D:href>http://adbk.example.com/bernard/addressbooks/</D:href>
</C:addk-home-set>
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8. Address Book Reports
This section defines the reports that CardDAV servers MUST support on
address book collections and vCard object resources.
CardDAV servers MUST advertise support for these REPORTs on all
address book collections and vCard object resources with the DAV:
supported-report-set property defined in Section 3.1.5 of [RFC3253].
CardDAV servers MAY also advertise support for these REPORTs on
ordinary collections.
Some of these REPORTs allow vCard data (from possibly multiple
resources) to be returned.
8.1. REPORT Method
The REPORT method (defined in Section 3.6 of [RFC3253]) provides an
extensible mechanism for obtaining information about a resource.
Unlike the PROPFIND method, which returns the value of one or more
named properties, the REPORT method can involve more complex
processing. REPORT is valuable in cases where the server has access
to all of the information needed to perform the complex request (such
as a query), and where it would require multiple requests for the
client to retrieve the information needed to perform the same
request.
A server that supports adbk-access MUST support the DAV:expand-
property report (defined in Section 3.8 of [RFC3253]).
8.2. Ordinary collections
Servers MAY support the REPORTs defined in this document on ordinary
collections (collections that are not address book collections) in
addition to address book collections or vCard object resources. In
computing responses to the REPORTs on ordinary collections, servers
MUST only consider vCard object resources contained in address book
collections that are targeted by the REPORT based on the value of the
Depth request header.
8.3. Searching Text: Collations
Some of the reports defined in this section do text matches of
character strings provided by the client and compared to stored vCard
data. Since vCard data is by default encoded in the UTF-8 charset
and may include characters outside of the US-ASCII charset range in
some property and parameter values, there is a need to ensure that
text matching follows well-defined rules.
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To deal with this, this specification makes use of the IANA Collation
Registry defined in [I-D.newman-i18n-comparator] to specify
collations that may be used to carry out the text comparison
operations with a well-defined rule.
The comparisons used in CardDAV are all "substring" matches as per
[I-D.newman-i18n-comparator] Section 4.2. Collations supported by
the server MUST support "substring" match operations.
CardDAV servers are REQUIRED to support the "i;ascii-casemap" and
"i;octet" collations as described in [I-D.newman-i18n-comparator],
and MAY support other collations.
Servers MUST advertise the set of collations that they support via
the CARDDAV:supported-collation-set property defined on any resource
that supports reports that use collations.
Clients MUST only use collations from the list advertised by the
server.
In the absence of a collation explicitly specified by the client, or
if the client specifies the "default" collation identifier (as
defined in [I-D.newman-i18n-comparator] Section 3.1), the server MUST
default to using "i;ascii-casemap" as the collation.
Wildcards (as defined in [I-D.newman-i18n-comparator] Section 3.2)
MUST NOT be used in the collation identifier.
If the client chooses a collation not supported by the server, the
server MUST respond with a CARDDAV:supported-collation precondition
error response.
8.3.1. CARDDAV:supported-collation-set Property
Name: supported-collation-set
Namespace: urn:ietf:params:xml:ns:carddav
Purpose: Identifies the set of collations supported by the server
for text matching operations.
Conformance: This property MUST be defined on any resource that
supports a REPORT that does text matching. If defined, it MUST be
protected and SHOULD NOT be returned by a PROPFIND DAV:allprop
request (as defined in Section 12.14.1 of [RFC2518]).
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Description: The CARDDAV:supported-collation-set property contains
zero or more CARDDAV:supported-collation elements which specify
the collection identifiers of the collations supported by the
server.
Definition:
<!ELEMENT supported-collation-set (supported-collation*)>
<!ELEMENT supported-collation (#PCDATA)>
Example:
<C:supported-collation-set
xmlns:C="urn:ietf:params:xml:ns:carddav">
<C:supported-collation>i;ascii-casemap</C:supported-collation>
<C:supported-collation>i;octet</C:supported-collation>
</C:supported-collation-set>
8.4. Partial Retrieval
Some address book REPORTs defined in this document allow partial
retrieval of vCard object resources. A CardDAV client can specify
what information to return in the body of an address book REPORT
request.
A CardDAV client can request particular WebDAV property values, all
WebDAV property values, or a list of the names of the resource's
WebDAV properties. A CardDAV client can also request vCard data to
be returned and whether all vCard properties should be returned or
only particular ones. See CARDDAV:abbk-data in Section 10.6.
8.5. Non-standard properties and parameters
Servers MUST support the use of non-standard property or parameter
names in the CARDDAV:adbk-data XML element in address book REPORT
requests to allow clients to request that non-standard properties and
parameters be returned in the vCard data provided in the response.
Servers MAY support the use of non-standard property or parameter
names in the CARDDAV:prop-filter and CARDDAV:param-filter XML
elements specified in the CARDDAV:filter XML element of address book
REPORT requests.
Servers MUST fail with the CARDDAV:supported-filter precondition if
an address book REPORT request uses a CARDDAV:prop-filter or CARDDAV:
param-filter XML element that makes reference to a non-standard
property or parameter name which the server does not support queries
on.
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8.6. CARDDAV:adbk-query Report
The CARDDAV:adbk-query REPORT performs a search for all vCard object
resources that match a specified filter. The response of this REPORT
will contain all the WebDAV properties and vCard object resource data
specified in the request. In the case of the CARDDAV:adbk-data XML
element, one can explicitly specify the vCard properties that should
be returned in the vCard object resource data that matches the
filter.
The format of this report is modeled on the PROPFIND method. The
request and response bodies of the CARDAV:adbk-query report use XML
elements that are also used by PROPFIND. In particular the request
can include XML elements to request WebDAV properties to be returned.
When that occurs the response should follow the same behavior as
PROPFIND with respect to the DAV:multistatus response elements used
to return specific property results. For instance, a request to
retrieve the value of a property which does not exist is an error and
MUST be noted with a response XML element which contains a 404 (Not
Found) status value.
Support for the CARDDAV:adbk-query REPORT is REQUIRED.
Marshalling:
The request body MUST be a CARDDAV:adbk-query XML element as
defined in Section 10.5.
The request MAY include a Depth header. If no Depth header is
included, Depth:0 is assumed.
The response body for a successful request MUST be a DAV:
multistatus XML element (i.e., the response uses the same format
as the response for PROPFIND). In the case where there are no
response elements, the returned DAV:multistatus XML element is
empty.
The response body for a successful CARDDAV:adbk-query REPORT
request MUST contain a DAV:response element for each vCard object
that matched the search filter. vCard data is being returned in
the CARDDAV:adbk-data XML element inside the DAV:propstat XML
element.
Preconditions:
(CARDDAV:supported-adbk-data): The attributes "content-type" and
"version" of the CARDDAV:adbk-data XML element (see Section 10.6)
specify a media type supported by the server for vCard object
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resources.
(CARDDAV:supported-filter): The CARDDAV:prop-filter (see
Section 10.7.1) and CARDDAV:param-filter (see Section 10.7.2) XML
elements used in the CARDDAV:filter XML element (see Section 10.7)
in the REPORT request only make reference to properties and
parameters for which queries are supported by the server. i.e., if
the CARDDAV:filter element attempts to reference an unsupported
property or parameter, this precondition is violated. Servers
SHOULD report the CARDDAV:prop-filter or CARDDAV:param-filter for
which it does not provide support.
<!ELEMENT supported-filter (prop-filter*,
param-filter*)>
(CARDDAV:supported-collation): Any XML attribute specifying a
collation MUST specify a collation supported by the server as
described in Section 8.3.
Postconditions:
(DAV:number-of-matches-within-limits): The number of matching
vCard object resources must fall within server-specific,
predefined limits. For example, this condition might be triggered
if a search specification would cause the return of an extremely
large number of responses.
8.6.1. Example: Partial retrieval of vCards matching a
NICKNAME
In this example, the client requests the server to search for vCard
object resources that contain a NICKNAME property whose value equals
some specific text, and to return specific vCard properties for those
vCards found. In addition the DAV:getetag property is also requested
and returned as part of the response.
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>> Request <<
REPORT /home/bernard/addressbook/ HTTP/1.1
Host: adbk.example.com
Depth: 1
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<C:adbk-query xmlns:D="DAV:"
xmlns:C="urn:ietf:params:xml:ns:carddav">
<D:prop>
<D:getetag/>
<C:adbk-data>
<C:prop name="VERSION"/>
<C:prop name="UID"/>
<C:prop name="NICKNAME"/>
<C:prop name="EMAIL"/>
<C:prop name="FN"/>
</C:adbk-data>
</D:prop>
<C:filter>
<C:prop-filter name="NICKNAME">
<C:text-match collation="i;octet"
match-type="equality"
>me</C:text-match>
</C:prop-filter>
</C:filter>
</C:adbk-query>
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>> Response <<
HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:multistatus xmlns:D="DAV:"
xmlns:C="urn:ietf:params:xml:ns:carddav">
<D:response>
<D:href
>http://adbk.example.com/home/bernard/addressbook/v102.vcf</D:href>
<D:propstat>
<D:prop>
<D:getetag>"23ba4d-ff11fb"</D:getetag>
<C:adbk-data>BEGIN:VCARD
VERSION:3.0
NICKNAME:me
UID:34222-232@example.com
FN:Cyrus Daboo
EMAIL:daboo@example.com
END:VCARD
</C:adbk-data>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
</D:multistatus>
8.6.2. Example: Partial retrieval of vCards matching a full
name
In this example, the client requests the server to search for vCard
object resources that contain a FN property whose value contains some
specific text, and to return specific vCard properties for those
vCards found. In addition the DAV:getetag property is also requested
and returned as part of the response.
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>> Request <<
REPORT /home/bernard/addressbook/ HTTP/1.1
Host: adbk.example.com
Depth: 1
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<C:adbk-query xmlns:D="DAV:"
xmlns:C="urn:ietf:params:xml:ns:carddav">
<D:prop>
<D:getetag/>
<C:adbk-data>
<C:prop name="VERSION"/>
<C:prop name="UID"/>
<C:prop name="NICKNAME"/>
<C:prop name="EMAIL"/>
<C:prop name="FN"/>
</C:adbk-data>
</D:prop>
<C:filter>
<C:prop-filter name="FN">
<C:text-match collation="i;ascii-casemap"
match-type="substring"
>Daboo</C:text-match>
</C:prop-filter>
</C:filter>
</C:adbk-query>
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>> Response <<
HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:multistatus xmlns:D="DAV:"
xmlns:C="urn:ietf:params:xml:ns:carddav">
<D:response>
<D:href
>http://adbk.example.com/home/bernard/addressbook/v102.vcf</D:href>
<D:propstat>
<D:prop>
<D:getetag>"23ba4d-ff11fb"</D:getetag>
<C:adbk-data>BEGIN:VCARD
VERSION:3.0
NICKNAME:me
UID:34222-232@example.com
FN:Cyrus Daboo
EMAIL:daboo@example.com
END:VCARD
</C:adbk-data>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
<D:response>
<D:href
>http://adbk.example.com/home/bernard/addressbook/v104.vcf</D:href>
<D:propstat>
<D:prop>
<D:getetag>"23ba4d-ff11fc"</D:getetag>
<C:adbk-data>BEGIN:VCARD
VERSION:3.0
NICKNAME:oliver
UID:34222-23222@example.com
FN:Oliver Daboo
EMAIL:oliver@example.com
END:VCARD
</C:adbk-data>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
</D:multistatus>
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8.7. CARDDAV:adbk-multiget Report
The CARDDAV:adbk-multiget REPORT is used to retrieve specific vCard
object resources from within a collection, if the Request-URI is a
collection, or to retrieve a specific vCard object resource, if the
Request-URI is a vCard object resource. This report is similar to
the CARDDAV:adbk-query REPORT (see Section 8.6), except that it takes
a list of DAV:href elements instead of a CARDDAV:filter element to
determine which vCard object resources to return.
Support for the adbk-multiget REPORT is REQUIRED.
Marshalling:
The request body MUST be a CARDDAV:adbk-multiget XML element (see
Section 10.8, which MUST contain at least one DAV:href XML
element, and one optional CARDDAV:adbk-data element as defined in
Section 10.6. If the Request-URI is a collection resource, then
the DAV:href elements MUST refer to resources within that
collection, and they MAY refer to resources at any depth within
the collection. As a result the "Depth" header MUST be ignored by
the server and SHOULD NOT be sent by the client. If the Request-
URI refers to a non-collection resource, then there MUST be a
single DAV:href element that is equivalent to the Request-URI.
The response body for a successful request MUST be a DAV:
multistatus XML element.
The response body for a successful CARDDAV:adbk-multiget REPORT
request MUST contain a DAV:response element for each vCard object
resource referenced by the provided set of DAV:href elements.
vCard data is being returned in the CARDDAV:adbk-data element
inside the DAV:prop element.
In the case of an error accessing any of the provided DAV:href
resources, the server MUST return the appropriate error status
code in the DAV:status element of the corresponding DAV:response
element.
Preconditions:
(CARDAV:supported-adbk-data): The attributes "content-type" and
"version" of the CARDDAV:adbk-data XML elements (see Section 10.6
) specify a media type supported by the server for vCard object
resources.
Postconditions:
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None.
8.7.1. Example: CARDDAV:adbk-multiget Report
In this example, the client requests the server to return specific
properties of the vCards components referenced by specific URIs. In
addition the DAV:getetag property is also requested and returned as
part of the response. Note that in this example, the resource at
http://adbk.example.com/home/bernard/addressbook/vcf1.vcf does not
exist, resulting in an error status response.
>> Request <<
REPORT /home/bernard/addressbook/ HTTP/1.1
Host: adbk.example.com
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<C:adbk-multiget xmlns:D="DAV:"
xmlns:C="urn:ietf:params:xml:ns:carddav">
<D:prop>
<D:getetag/>
<C:adbk-data>
<C:prop name="VERSION"/>
<C:prop name="UID"/>
<C:prop name="NICKNAME"/>
<C:prop name="EMAIL"/>
<C:prop name="FN"/>
</C:adbk-data>
</D:prop>
<D:href
>http://adbk.example.com/home/bernard/addressbook/vcf102.vcf</D:href>
<D:href
>http://adbk.example.com/home/bernard/addressbook/vcf1.vcf</D:href>
</C:adbk-multiget>
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>> Response <<
HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:multistatus xmlns:D="DAV:"
xmlns:C="urn:ietf:params:xml:ns:carddav">
<D:response>
<D:href
>http://adbk.example.com/home/bernard/addressbook/vcf102.vcf</D:href>
<D:propstat>
<D:prop>
<D:getetag>"23ba4d-ff11fb"</D:getetag>
<C:adbk-data>BEGIN:VCARD
VERSION:3.0
NICKNAME:me
UID:34222-232@example.com
FN:Cyrus Daboo
EMAIL:daboo@example.com
END:VCARD
</C:adbk-data>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
<D:response>
<D:href
>http://adbk.example.com/home/bernard/addressbook/vcf1.vcf</D:href>
<D:status>HTTP/1.1 404 Resource not found</D:status>
</D:response>
</D:multistatus>
8.8. CARDDAV:adbk-sync Report
Support for this report is OPTIONAL but RECOMMENDED.
The CARDDAV:adbk-sync REPORT is used to provide an overview of what
has changed on the server since a previous execution of this report.
The primary purpose of this is to aid the client in synchronizing its
local cache of data with the server, in an efficient manner with as
few round trips as possible.
Support for the adbk-sync REPORT is OPTIONAL. If this report is
implemented by the CardDAV server, then the server MUST include
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"adbk-sync" in any DAV: response header to an OPTIONS request as per
Section 6.1 . If the report is not available, clients MUST NOT
attempt to execute one.
To implement the behaviour for this report a server needs to keep
track of changes to vCard data in an address book collection. This
includes noting the addition of new vCards, noting changes to vCards
and noting removal of vCards (where "removal" could be the result of
a DELETE or MOVE operation). The server will track each change and
provide a synchronization "token" to the client that describes the
state of the server at a specific point in time. This "token" is
returned as part of the response to the "adbk-sync" report. Clients
include the last token they got from the server in the next "adbk-
sync" report that they execute and the server provides the changes
from the previous state represented by the token to the current
state, represented by the new token returned.
The synchronization token itself is an "opaque" string - i.e., the
actual string data has no specific meaning or syntax. A simple
implementation of such a token would be a numeric counter that counts
each change as it occurs and relates that change to the specific
object that changed.
The "adbk-sync" reports allows the client to specify whether it
should receive vCard data for those objects that are new or have
changed, and it uses the "adbk-data" element (also used in the "adbk-
query" and "adbk-multiget" reports) for that purpose.
Marshalling:
The request URI MUST be an address book collection. The "Depth"
header MUST be ignored by the server and SHOULD NOT be sent by the
client. The request body MUST be a CARDDAV:adbk-sync XML element
(see Section 10.9 , which MUST contain one CARDDAV:sync-token XML
element, and one optional CARDDAV:adbk-data element as defined in
Section 10.6 .
The response body for a successful request MUST be a DAV:
multistatus XML element, which MUST contain one CADRDDAV:sync-
token element in addition to any DAV:response elements.
The response body for a successful CARDDAV:adbk-multiget REPORT
request MUST contain a DAV:response element for each vCard object
resource that was created, has changed or been deleted since the
last syncrhonization operation as specified by the CARDDAV:sync-
token provided in the request. vCard data is returned in the
CARDDAV:adbk-data element inside the DAV:prop element.
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The DAV:status element in each DAV:response element is used to
indicate how the vCard resource may have changed:
A status code of '201 Created' is used to indicate vCards that
are new.
A status code of '200 OK' is used to indicate vCards that have
changed.
A status code of '404 Not Found' is used to indicate vCards
that have been removed.
If the synchronization token element is not empty and not
recognized by the server, then the server MUST respond with 400
Bad Request response.
Preconditions:
None.
Postconditions:
None.
8.8.1. Example: Initial CARDDAV:adbk-sync Report
In this example, the client is making its first synchronization
request to the server, so the CARDDAV:sync-token element in the
request is empty. The server responds with the items currently in
the targetted address book collection (indicating that they are 'new'
via the '201 Created' status code). The current synchronzation token
is also returned.
>> Request <<
REPORT /home/bernard/addressbook/ HTTP/1.1
Host: adbk.example.com
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<C:adbk-sync xmlns:D="DAV:"
xmlns:C="urn:ietf:params:xml:ns:carddav">
<C:sync-token/>
</C:adbk-sync>
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>> Response <<
HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:multistatus xmlns:D="DAV:"
xmlns:C="urn:ietf:params:xml:ns:carddav">
<D:response>
<D:href
>http://adbk.example.com/home/bernard/addressbook/vcf100.vcf</D:href>
<D:status>HTTP/1.1 201 Created</D:status>
</D:response>
<D:response>
<D:href
>http://adbk.example.com/home/bernard/addressbook/vcf105.vcf</D:href>
<D:status>HTTP/1.1 201 Created</D:status>
</D:response>
<D:response>
<D:href
>http://adbk.example.com/home/bernard/addressbook/vcf106.vcf</D:href>
<D:status>HTTP/1.1 201 Created</D:status>
</D:response>
<C:sync-token>1234</C:sync-token>
</D:multistatus>
8.8.2. Example: CARDDAV:adbk-sync Report with token
In this example, the client is making a synchronization request to
the server and is using the CARDDAV:sync-token element returned from
the last report it ran on this address book collection. The server
responds listing the items that have been added, changed or removed.
The (new) current synchronzation token is also returned.
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>> Request <<
REPORT /home/bernard/addressbook/ HTTP/1.1
Host: adbk.example.com
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<C:adbk-sync xmlns:D="DAV:"
xmlns:C="urn:ietf:params:xml:ns:carddav">
<C:sync-token>1234</C:sync-token>
</C:adbk-sync>
>> Response <<
HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:multistatus xmlns:D="DAV:"
xmlns:C="urn:ietf:params:xml:ns:carddav">
<D:response>
<D:href
>http://adbk.example.com/home/bernard/addressbook/vcf107.vcf</D:href>
<D:status>HTTP/1.1 201 Created</D:status>
</D:response>
<D:response>
<D:href
>http://adbk.example.com/home/bernard/addressbook/vcf100.vcf</D:href>
<D:status>HTTP/1.1 200 OK</D:status>
</D:response>
<D:response>
<D:href
>http://adbk.example.com/home/bernard/addressbook/vcf105.vcf</D:href>
<D:status>HTTP/1.1 404 Not Found</D:status>
</D:response>
<C:sync-token>1238</C:sync-token>
</D:multistatus>
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9. Guidelines
9.1. Restrict the Properties Returned
Clients may not need all the properties in a vCard object when
presenting information to the user, or looking up specific items for
their email address, for example. Since some property data can be
large (e.g., PHOTO or SOUND with inline content) clients can choose
to ignore those by only requesting the specific items it knows it
will use, through use of the CARDDAV:adbk-data XML element in the
relevant reports.
However, if a client needs to make a change to a vCard, it can only
change the entire vCard data via a PUT request. There is no way to
incrementally make a change to a set of properties within a vCard
object resource. As a result the client will have to cache the
entire set of properties on a resource that is being changed.
9.2. Use of Locking
WebDAV locks can be used to prevent two clients modifying the same
resource from either overwriting each others' changes (though that
problem can also be solved by using ETags) and also to prevent the
user from making changes that will conflict with another set of
changes. In a multi-user address book system, the address book
client could lock a vCard while the user is editing the vCard data,
and unlock the vCard when the user finishes or cancels. Locks can
also be used to prevent changes while data is being reorganized. For
example, an address book client might lock two address book
collections prior to moving a bunch of vCard object resources from
one to another.
Clients may request a lock timeout period that is appropriate to the
use case. When the user explicitly decides to reserve a resource and
prevent other changes, a long timeout might be appropriate, but in
cases when the client automatically decides to lock the resource the
timeout should be short (and the client can always refresh the lock
should it need to). A short lock timeout means that if the client is
unable to remove the lock, the other address book users aren't
prevented from making changes.
9.3. Finding address books
Much of the time an address book client (or agent) will discover a
new address book's location by being provided directly with the URL.
E.g. a user will type his or her own address book location into
client configuration information, or cut and paste a URL from email
into the address book application. The client need only confirm that
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the URL points to a resource which is an address book. The client
may also be able to browse WebDAV collections to find address book
collections.
The choice of HTTP URLs means that vCard object resources are
backward compatible with existing software, but does have the
disadvantage that existing software does not usually know to look at
the OPTIONS response to that URL to determine what can be done with
it. This is somewhat of a barrier for WebDAV usage as well as with
CardDAV usage. This specification does not offer a way through this
other than making the information available in the OPTIONS response
should this be requested.
For address book sharing use cases, one might wish to find the
address book belonging to another user. If the other user has an
address book in the same repository, that address book can be found
by using the principal namespace required by WebDAV ACL support.
Because CardDAV requires servers to support WebDAV ACL [RFC3744]
including principal namespaces, and with the addition of the CARDDAV:
adbk-home-set property, there are a couple options for CardDAV
clients to find one's own address book or another user's address
book.
In this case, a DAV:principal-match REPORT is used to find a named
property (the CARDDAV:adbk-home-set) on the Principal-URL of the
current user. Using this, a WebDAV client can learn "who am I" and
"where are my address books". The REPORT request body looks like
this:
<?xml version="1.0" encoding="utf-8" ?>
<D:principal-match xmlns:D="DAV:">
<D:self/>
<D:prop>
<C:adbk-home-set
xmlns:C="urn:ietf:params:xml:ns:carddav"/>
</D:prop>
</D:principal-match>
To find other users' address books, the DAV:principal-property-search
REPORT can be used to filter on some properties and return others.
To search for an address book owned by a user named "Laurie", the
REPORT request body would look like this:
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<?xml version="1.0" encoding="utf-8" ?>
<D:principal-property-search xmlns:D="DAV:">
<D:property-search>
<D:prop>
<D:displayname/>
</D:prop>
<D:match>Laurie</D:match>
</D:property-search>
<D:prop>
<C:adbk-home-set
xmlns:C="urn:ietf:params:xml:ns:carddav"/>
<D:displayname/>
</D:prop>
</D:principal-property-search>
The server performs a case-sensitive or caseless search for a
matching string subset of "Laurie" within the DAV:displayname
property. Thus, the server might return "Laurie Dusseault", "Laurier
Desruisseaux" or "Wilfrid Laurier" all as matching DAV:displayname
values, and the address books for each of these.
10. XML Element Definitions
10.1. CARDDAV:adbk XML Element
Name: adbk
Namespace: urn:ietf:params:xml:ns:carddav
Purpose: Specifies the resource type of an address book collection.
Description: See Section 5.2.
Definition:
<!ELEMENT adbk EMPTY>
10.2. CARDDAV:mkadbk XML Element
Name: mkadbk
Namespace: urn:ietf:params:xml:ns:carddav
Purpose: Specifies a request that includes the WebDAV property
values to be set for an address book collection resource when it
is created.
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Description: See Section 6.3.1 .
Definition:
<!ELEMENT mkadbk (DAV:set)>
10.3. CARDDAV:mkadbk-response XML Element
Name: mkadbk-response
Namespace: urn:ietf:params:xml:ns:carddav
Purpose: Specifies a response body for a successful MKADBK request.
Description: See Section 6.3.1 .
Definition:
<!ELEMENT mkadbk-response ANY>
10.4. CARDDAV:supported-collation XML Element
Name: supported-collation
Namespace: urn:ietf:params:xml:ns:carddav
Purpose: Identifies a single collation via its collation identifier
as defined by [I-D.newman-i18n-comparator].
Description: The CARDDAV:supported-collation contains the text of a
collation identifier as described in Section 8.3.1.
Definition:
<!ELEMENT supported-collation (#PCDATA)>
PCDATA value: collation identifier
10.5. CARDDAV:adbk-query XML Element
Name: adbk-query
Namespace: urn:ietf:params:xml:ns:carddav
Purpose: Defines a report for querying address book data
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Description: See Section 8.6.
Definition:
<!ELEMENT adbk-query ((DAV:allprop | DAV:propname | DAV:prop)?,
filter)>
10.6. CARDDAV:adbk-data XML Element
Name: adbk-data
Namespace: urn:ietf:params:xml:ns:carddav
Purpose: Used to (1) specify a supported media type for vCard object
resources when nested in the CARDDAV:supported-adbk-data property;
(2) specify which parts of a vCard object resource should be
returned by a given address book REPORT; and (3) specify the
content of a vCard object resource in a response to an address
book REPORT.
Description: When nested in the CARDDAV:supported-adbk-data
property, the CARDDAV:adbk-data XML element specifies a media type
supported by the CardDAV server for vCard object resources.
When used in an address book REPORT request, the CARDDAV:adbk-data
XML element specifies which parts of vCard object resources need
to be returned in the response. If the CARDDAV:adbk-data XML
element doesn't contain any CARDDAV:prop elements, vCard object
resources will be returned in their entirety.
Finally, when used in an address book REPORT response, the
CARDDAV:adbk-data XML element specifies the content of a vCard
object resource. Given that XML parsers normalize the two-
character sequence CRLF (US-ASCII decimal 13 and US-ASCII decimal
10) to a single LF character (US-ASCII decimal 10), the CR
character (US-ASCII decimal 13) MAY be omitted in vCard object
resources specified in the CARDDAV:adbk-data XML element.
Furthermore, vCard object resources specified in the CARDDAV:adbk-
data XML element MAY be invalid per their media type specification
if the CARDAV:adbk-data XML element part of the address book
REPORT request did not specify required properties (e.g., UID,
etc.) or specified a CARDDAV:prop XML element with the "novalue"
attribute set to "yes".
Note: The CARDDAV:adbk-data XML element is specified in requests and
responses inside the DAV:prop XML element as if it were a WebDAV
property. However, the CARDDAV:adbk-data XML element is not a
WebDAV property and as such it is not returned in PROPFIND
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responses nor used in PROPPATCH requests.
Note: The vCard data embedded within the CARDDAV:adbk-data XML
element MUST follow the standard XML character data encoding
rules, including use of <, >, & etc entity encoding or
the use of a <![CDATA[ ... ]]> construct. In the later case the
vCard data cannot contain the character sequence "]]>" which is
the end delimiter for the CDATA section.
Definition:
<!ELEMENT adbk-data ((allprop | prop*) | #PCDATA)?>
PCDATA value: vCard object
<!ATTLIST adbk-data content-type CDATA "text/vcard">
version CDATA "3.0">
content-type value: a MIME media type
version value: a version string
10.6.1. CARDDAV:allprop XML Element
Name: allprop
Namespace: urn:ietf:params:xml:ns:carddav
Purpose: Specifies that all properties shall be returned.
Description: This element can be used when the client wants all
properties of components returned by a report.
Definition:
<!ELEMENT allprop EMPTY>
NOTE: The CARDDAV:allprop element defined here has the same name as
the DAV:allprop element defined in WebDAV. However, the CARDDAV:
allprop element defined here uses the
"urn:ietf:params:xml:ns:carddav" namespace, as opposed to the "DAV:"
namespace used for the DAV:allprop element defined in WebDAV.
10.6.2. CARDDAV:prop XML Element
Name: prop
Namespace: urn:ietf:params:xml:ns:carddav
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Purpose: Defines which properties to return in the response.
Description: The "name" attribute specifies the name of the adbk
property to return (e.g., "NICKNAME"). The "novalue" attribute
can be used by clients to request that the actual value of the
property not be returned (if the "novalue" attribute is set to
"yes"). In that case the server will return just the vCard
property name and any vCard parameters and a trailing ":" without
the subsequent value data.
Definition:
<!ELEMENT prop EMPTY>
<!ATTLIST prop name CDATA #REQUIRED
novalue (yes|no) "no">
name value: a vCard property name
novalue value: "yes" or "no"
NOTE: The CARDDAV:prop element defined here has the same name as the
DAV:prop element defined in WebDAV. However, the CARDDAV:prop
element defined here uses the "urn:ietf:params:xml:ns:carddav"
namespace, as opposed to the "DAV:" namespace used for the DAV:prop
element defined in WebDAV.
10.7. CARDDAV:filter XML Element
Name: filter
Namespace: urn:ietf:params:xml:ns:carddav
Purpose: Determines which matching objects are returned.
Description: The "filter" element specifies the search filter used
to match vCard objects that should be returned by a report.
Definition:
<!ELEMENT filter prop-filter>
10.7.1. CARDDAV:prop-filter XML Element
Name: prop-filter
Namespace: urn:ietf:params:xml:ns:carddav
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Purpose: Limits the search to specific properties.
Description: The CARDDAV:prop-filter XML element specifies a search
criteria on a specific vCard property (e.g., NICKNAME). A vCard
object is said to match a CARDDAV:prop-filter if:
* A property of the type specified by the "name" attribute
exists, and the CARDDAV:prop-filter is empty, or it matches the
CARDDAV:text-match conditions if specified, and that any
CARDDAV:param-filter child elements also match.
or:
* A property of the type specified by the "name" attribute does
not exist, and the CARDAV:is-not-defined element is specified.
Definition:
<!ELEMENT prop-filter (is-not-defined |
(text-match?, param-filter*))>
<!ATTLIST prop-filter name CDATA #REQUIRED>
name value: a vCard property name (e.g., "NICKNAME")
10.7.2. CARDDAV:param-filter XML Element
Name: param-filter
Namespace: urn:ietf:params:xml:ns:carddav
Purpose: Limits the search to specific parameter values.
Description: The CARDDAV:param-filter XML element specifies a search
criteria on a specific vCard property parameter (e.g., TYPE) in
the scope of a given CARDDAV:prop-filter. A vCard property is
said to match a CARDDAV:param-filter if:
* A parameter of the type specified by the "name" attribute
exists, and the CARDDAV:param-filter is empty, or it matches
the CARDDAV:text-match conditions if specified.
or:
* A parameter of the type specified by the "name" attribute does
not exist, and the CARDDAV:is-not-defined element is specified.
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Definition:
<!ELEMENT param-filter (is-not-defined | text-match)?>
<!ATTLIST param-filter name CDATA #REQUIRED>
name value: a property parameter name (e.g., "TYPE")
10.7.3. CARDDAV:is-not-defined XML Element
Name: is-not-defined
Namespace: urn:ietf:params:xml:ns:carddav
Purpose: Specifies that a match should occur if the enclosing
property or parameter does not exist.
Description: The CARDDAV:is-not-defined XML element specifies that a
match occurs if the enclosing property or parameter value
specified in an address book REPORT request does not exist in the
vCard data being tested.
Definition:
<!ELEMENT is-not-defined EMPTY>
10.7.4. CARDDAV:text-match XML Element
Name: text-match
Namespace: urn:ietf:params:xml:ns:carddav
Purpose: Specifies a substring match on a property or parameter
value.
Description: The CARDDAV:text-match XML element specifies text used
for a substring match against the property or parameter value
specified in an address book REPORT request.
The "collation" attribute is used to select the collation that the
server MUST use for character string matching. In the absence of
this attribute the server MUST use the "i;ascii-casemap"
collation.
The "negate-condition" attribute is used to indicate that this
test returns a match if the text matches, when the attribute value
is set to "no", or return a match if the text does not match, if
the attribute value is set to "yes". For example, this can be
used to match components with a CATEGORIES property not set to
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PERSON.
Definition:
<!ELEMENT text-match (#PCDATA)>
PCDATA value: string
<!ATTLIST text-match collation CDATA "i;ascii-casemap"
negate-condition (yes | no) "no">
10.8. CARDDAV:adbk-multiget XML Element
Name: adbk-multiget
Namespace: urn:ietf:params:xml:ns:carddav
Purpose: CardDAV report used to retrieve specific vCard objects via
their URIs.
Description: See Section 8.7.
Definition:
<!ELEMENT adbk-multiget (DAV:allprop | DAV:propname | DAV:prop)?
DAV:href+>
10.9. CARDDAV:adbk-sync XML Element
Name: adbk-sync
Namespace: urn:ietf:params:xml:ns:carddav
Purpose: CardDAV report used to synchronize data between client and
server.
Description: See Section 8.8.
Definition:
<!ELEMENT adbk-sync (sync-token)>
10.9.1. CARDDAV:sync-token XML Element
Name: sync-token
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Namespace: urn:ietf:params:xml:ns:carddav
Purpose: The synchronization token provided by the server and
returned by the client.
Description: See Section 8.8.
Definition:
<!ELEMENT sync-token CDATA>
11. Internationalization Considerations
CardDAV allows internationalized strings to be stored and retrieved
for the description of address book collections (see Section 6.2.1).
The CARDDAV:adbk-query report ( Section 8.6 ) includes a text
searching option controlled by the CARDDAV:text-match element and
details of character handling are covered in the description of that
element (see Section 10.7.4 ).
12. Security Considerations
HTTP protocol transactions are sent in the clear over the network
unless protection from snooping is negotiated. This can be
accomplished by use of TLS as defined in [RFC2818]. In particular,
if HTTP Basic authentication is available, the server MUST allow TLS
to be used at the same time, and SHOULD prevent use of Basic
authentication when TLS is not in use.
With the ACL extension present, WebDAV allows control over who can
access (read or write) any resource on the WebDAV server. In
addition, WebDAV ACL provides for an "inheritance" mechanism, whereby
resources may inherit access privileges from other resources. Often
the "other" resource is a parent collection of the resource itself.
Clients MUST take care to ensure users are aware of which address
books may be "private" (i.e. only accessible to them) and which are
"shared" (i.e. accessible to others).
Since webservers are often the target of automated indexing
applications that gather data from the server, analyse it and extract
'interesting' parts, great care must be taken when allowing
unauthenticated access to any address book or vCard object data.
Clients MAY choose to warn users when they create vCard data in a
public address book, copy or move vCard data into public address
books, or change access privileges in such a way as to expose vCard
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data to unauthenticated users.
This specification currently relies on standard HTTP authentication
mechanisms for identifying users. These comprise Basic and Digest
authentication as well as SSL using client-side certificates.
13. IANA Consideration
In addition to the namespaces defined by RFC2518 [RFC2518] for XML
elements, this document uses a URN to describe a new XML namespace
conforming to a registry mechanism described in RFC3688 [RFC3688] .
All other IANA considerations mentioned in RFC2518 [RFC2518] also
apply to this document.
13.1. Namespace Registration
Registration request for the carddav namespace:
URI: urn:ietf:params:xml:ns:carddav
Registrant Contact: See the "Author's Address" section of this
document.
XML: None. Namespace URIs do not represent an XML specification.
14. References
14.1. Normative References
[I-D.newman-i18n-comparator]
Newman, C., "Internet Application Protocol Collation
Registry", draft-newman-i18n-comparator-13 (work in
progress), August 2006.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2246] Dierks, T. and C. Allen, "The TLS Protocol Version 1.0",
RFC 2246, January 1999.
[RFC2426] Dawson, F. and T. Howes, "vCard MIME Directory Profile",
RFC 2426, September 1998.
[RFC2518] Goland, Y., Whitehead, E., Faizi, A., Carter, S., and D.
Jensen, "HTTP Extensions for Distributed Authoring --
WEBDAV", RFC 2518, February 1999.
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[RFC2616] Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext
Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.
[RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, May 2000.
[RFC3253] Clemm, G., Amsden, J., Ellison, T., Kaler, C., and J.
Whitehead, "Versioning Extensions to WebDAV (Web
Distributed Authoring and Versioning)", RFC 3253,
March 2002.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
January 2004.
[RFC3744] Clemm, G., Reschke, J., Sedlar, E., and J. Whitehead, "Web
Distributed Authoring and Versioning (WebDAV) Access
Control Protocol", RFC 3744, May 2004.
[RFC4346] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.1", RFC 4346, April 2006.
[W3C.REC-xml-20060816]
Yergeau, F., Paoli, J., Bray, T., Sperberg-McQueen, C.,
and E. Maler, "Extensible Markup Language (XML) 1.0
(Fourth Edition)", World Wide Web Consortium
Recommendation REC-xml-20060816, August 2006,
<http://www.w3.org/TR/2006/REC-xml-20060816>.
14.2. Informative References
[I-D.ietf-webdav-rfc2518bis]
Dusseault, L., "HTTP Extensions for Distributed Authoring
- WebDAV", draft-ietf-webdav-rfc2518bis-15 (work in
progress), May 2006.
[RFC2244] Newman, C. and J. Myers, "ACAP -- Application
Configuration Access Protocol", RFC 2244, November 1997.
[RFC2251] Wahl, M., Howes, T., and S. Kille, "Lightweight Directory
Access Protocol (v3)", RFC 2251, December 1997.
Appendix A. Acknowledgments
Thanks go to Lisa Dusseault and Bernard Desruisseaux for their work
on CalDAV, on which CardDAV is heavily based.
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Author's Address
Cyrus Daboo
Apple Computer, Inc.
1 Infinite Loop
Cupertino, CA 95014
USA
Email: cyrus@daboo.name
URI: http://www.apple.com/
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Full Copyright Statement
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