RFC 6352
CardDAV: vCard Extensions to Web Distributed Authoring and Versioning (WebDAV)
RFC 6352: CardDAV: vCard Extensions to Web Distributed Authoring and Versioning (WebDAV) 📇✨
okay bestie, this one's giving contacts energy 💅 It's an IETF Standards Track document, so it's the real deal, not a suggestion. It's by C. Daboo from Apple 🍎, dated August 2011, and it's ISSN 2070-1721. The title block doesn't list anything it obsoletes or updates, so there's no drama there 🙈
Abstract 🌸
okay so the whole point is that this doc extends WebDAV so there's a standard way to access, manage, and share contact info based on the vCard format 📇 no more everyone doing it their own way, it's giving consistency 🫶
Status of This Memo 📜
this is an Internet Standards Track document 🔥
it's a product of the IETF and represents the consensus of the IETF community. it got public review and was approved for publication by the IESG 👑 if you want more info on Internet Standards, check out Section 2 of RFC 5741. the current status, any errata, and how to give feedback live at http://www.rfc-editor.org/info/rfc6352 💖
Copyright Notice 🎀
okay this part is a little legal-y but it matters, so read it 🙈
the copyright is 2011 IETF Trust and the persons identified as the document authors, all rights reserved 🌈 the doc is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents, which you can find at http://trustee.ietf.org/license-info, as they were on the publication date. they describe your rights and restrictions, so please actually look at them 💜
any code components pulled out of this doc have to include Simplified BSD License text, as described in Section 4.e of the Trust Legal Provisions, and they come with no warranty, same as that license says 🧚
this doc might include material from IETF Documents or IETF Contributions published before November 10, 2008 🍓 the people who own the copyright on some of that stuff might not have let the IETF Trust allow changes outside the IETF Standards Process. so without a proper license from them, this doc can't be modified outside the IETF Standards Process, and derivative works can't be made outside it either. the only exceptions are formatting it for publication as an RFC or translating it into languages other than English ✨
Table of Contents 🦋
1. Introduction and Overview . . . . . . . . . . . . . . . . . . 4
2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Requirements Overview . . . . . . . . . . . . . . . . . . . . 6
4. Address Book Data Model . . . . . . . . . . . . . . . . . . . 7
4.1. Address Book Server . . . . . . . . . . . . . . . . . . . 7
5. Address Book Resources . . . . . . . . . . . . . . . . . . . . 7
5.1. Address Object Resources . . . . . . . . . . . . . . . . . 7
5.1.1. Data Type Conversion . . . . . . . . . . . . . . . . . 8
5.1.1.1. Additional Precondition for GET . . . . . . . . . 8
5.2. Address Book Collections . . . . . . . . . . . . . . . . . 9
6. Address Book Feature . . . . . . . . . . . . . . . . . . . . . 10
6.1. Address Book Support . . . . . . . . . . . . . . . . . . . 10
6.1.1. Example: Using OPTIONS for the Discovery of
Support for CardDAV . . . . . . . . . . . . . . . . . 10
6.2. Address Book Properties . . . . . . . . . . . . . . . . . 10
6.2.1. CARDDAV:addressbook-description Property . . . . . . . 10
6.2.2. CARDDAV:supported-address-data Property . . . . . . . 11
6.2.3. CARDDAV:max-resource-size Property . . . . . . . . . . 12
6.3. Creating Resources . . . . . . . . . . . . . . . . . . . . 13
6.3.1. Extended MKCOL Method . . . . . . . . . . . . . . . . 13
6.3.1.1. Example - Successful MKCOL Request . . . . . . . . 14
6.3.2. Creating Address Object Resources . . . . . . . . . . 15
6.3.2.1. Additional Preconditions for PUT, COPY, and
MOVE . . . . . . . . . . . . . . . . . . . . . . . 16
6.3.2.2. Non-Standard vCard Properties and Parameters . . . 17
6.3.2.3. Address Object Resource Entity Tag . . . . . . . . 18
7. Address Book Access Control . . . . . . . . . . . . . . . . . 18
7.1. Additional Principal Properties . . . . . . . . . . . . . 18
7.1.1. CARDDAV:addressbook-home-set Property . . . . . . . . 19
7.1.2. CARDDAV:principal-address Property . . . . . . . . . . 19
8. Address Book Reports . . . . . . . . . . . . . . . . . . . . . 20
8.1. REPORT Method . . . . . . . . . . . . . . . . . . . . . . 20
8.2. Ordinary Collections . . . . . . . . . . . . . . . . . . . 21
8.3. Searching Text: Collations . . . . . . . . . . . . . . . . 21
8.3.1. CARDDAV:supported-collation-set Property . . . . . . . 22
8.4. Partial Retrieval . . . . . . . . . . . . . . . . . . . . 23
8.5. Non-Standard Properties and Parameters . . . . . . . . . . 23
8.6. CARDDAV:addressbook-query Report . . . . . . . . . . . . . 23
8.6.1. Limiting Results . . . . . . . . . . . . . . . . . . . 25
8.6.2. Truncation of Results . . . . . . . . . . . . . . . . 25
8.6.3. Example: Partial Retrieval of vCards Matching
NICKNAME . . . . . . . . . . . . . . . . . . . . . . . 26
8.6.4. Example: Partial Retrieval of vCards Matching a
Full Name or Email Address . . . . . . . . . . . . . . 27
8.6.5. Example: Truncated Results . . . . . . . . . . . . . . 29
8.7. CARDDAV:addressbook-multiget Report . . . . . . . . . . . 31
8.7.1. Example: CARDDAV:addressbook-multiget Report . . . . . 32
8.7.2. Example: CARDDAV:addressbook-multiget Report . . . . . 33
9. Client Guidelines . . . . . . . . . . . . . . . . . . . . . . 34
9.1. Restrict the Properties Returned . . . . . . . . . . . . . 34
9.2. Avoiding Lost Updates . . . . . . . . . . . . . . . . . . 35
9.3. Client Configuration . . . . . . . . . . . . . . . . . . . 35
9.4. Finding Other Users' Address Books . . . . . . . . . . . . 35
10. XML Element Definitions . . . . . . . . . . . . . . . . . . . 36
10.1. CARDDAV:addressbook XML Element . . . . . . . . . . . . . 36
10.2. CARDDAV:supported-collation XML Element . . . . . . . . . 36
10.3. CARDDAV:addressbook-query XML Element . . . . . . . . . . 37
10.4. CARDDAV:address-data XML Element . . . . . . . . . . . . . 37
10.4.1. CARDDAV:allprop XML Element . . . . . . . . . . . . . 39
10.4.2. CARDDAV:prop XML Element . . . . . . . . . . . . . . . 39
10.5. CARDDAV:filter XML Element . . . . . . . . . . . . . . . . 40
10.5.1. CARDDAV:prop-filter XML Element . . . . . . . . . . . 40
10.5.2. CARDDAV:param-filter XML Element . . . . . . . . . . . 41
10.5.3. CARDDAV:is-not-defined XML Element . . . . . . . . . . 42
10.5.4. CARDDAV:text-match XML Element . . . . . . . . . . . . 42
10.6. CARDDAV:limit XML Element . . . . . . . . . . . . . . . . 43
10.6.1. CARDDAV:nresults XML Element . . . . . . . . . . . . . 44
10.7. CARDDAV:addressbook-multiget XML Element . . . . . . . . . 44
11. Service Discovery via SRV Records . . . . . . . . . . . . . . 45
12. Internationalization Considerations . . . . . . . . . . . . . 45
13. Security Considerations . . . . . . . . . . . . . . . . . . . 45
14. IANA Consideration . . . . . . . . . . . . . . . . . . . . . . 46
14.1. Namespace Registration . . . . . . . . . . . . . . . . . . 46
15. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 46
16. References . . . . . . . . . . . . . . . . . . . . . . . . . . 47
16.1. Normative References . . . . . . . . . . . . . . . . . . . 47
16.2. Informative References . . . . . . . . . . . . . . . . . . 481. Introduction and Overview 💖
okay so address books are literally the backbone of personal info tools 📇 think email, calendaring and scheduling, and instant messaging clients, they all need contacts. so far, a bunch of protocols have handled remote access to contact data, like LDAP [RFC4510], the Internet Message Support Protocol [IMSP], and the Application Configuration Access Protocol (ACAP) [RFC2244], plus SyncML for syncing that data 🔄
WebDAV [RFC4918] is giving main character energy as a base for address book access and management 👑 most of its perks come down to way cheaper design, implementation, interop testing, and deployment 💅
the key features of address book support with WebDAV are:
- Ability to use multiple address books with hierarchical layout.
- Ability to control access to individual address books and address entries as per WebDAV Access Control List (ACL) [RFC3744].
- Principal collections can be used to enumerate and query other users on the system as per WebDAV ACL [RFC3744].
- 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.
- Well-defined internationalization support through WebDAV's use of XML 🌍
- Use of vCards [RFC2426] for well-defined address schema to enhance client interoperability 🫶
- Many limited clients (e.g., mobile devices) contain an HTTP stack that makes implementing WebDAV much easier than other protocols 📱
the one key downside of address book support in WebDAV is:
- Lack of change notification. Many of the alternative protocols also lack this ability. However, an extension for push notifications could easily be developed 🔔 not the end of the world, bestie 🥹
vCard is a MIME directory profile meant to encapsulate personal addressing and contact information about people 📇 it was originally specified by the Versit consortium, and then the IETF standardized a 3.0 version [RFC2426]. vCard is everywhere in email clients and mobile devices for carrying address info around, whether that's sending it through email or importing, exporting, and syncing 🌸
and lowkey the update is coming too: vCard v4 is being developed [RFC6350] and it's compatible with this spec 🦋 slay ✨
2. Conventions ✨
okay bestie, first the ground rules 📜 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 15 of [RFC4918]. 🔒
This document uses XML DTD fragments ([W3C.REC-xml-20081126], Section 3.2) as a purely notational convention. ✍️ WebDAV request and response bodies cannot be validated by a DTD because of the specific extensibility rules defined in Section 17 of [RFC4918], and because all XML elements defined by that specification use the XML namespace name "DAV:". 🙈 In particular:
- Element names use the "DAV:" namespace.
- Element ordering is irrelevant unless explicitly stated.
- Extension elements (elements not already defined as valid child elements) may be added anywhere, except when explicitly stated otherwise.
- Extension attributes (attributes not already defined as valid for this element) may be added anywhere, except when explicitly stated otherwise.
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. 🫶
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 strings "DAV:" and "CARDDAV:" will be prefixed to the element types, respectively. 💅
This document inherits, and sometimes extends, DTD productions from Section 14 of [RFC4918]. 🧚
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. Trust me, it's a whole thing. 💀
3. Requirements Overview 👑
This section lists what functionality is required of a CardDAV server. ✨ To advertise support for CardDAV, a server:
- MUST support vCard v3 [RFC2426] as a media type for the address object resource format;
- MUST support WebDAV Class 3 [RFC4918];
- MUST support WebDAV ACL [RFC3744];
- MUST support secure transport as defined in [RFC2818] using Transport Layer Security (TLS) [RFC5246] and using the certificate validation procedures described in [RFC5280];
- MUST support ETags [RFC2616] with additional requirements specified in Section 6.3.2.3 of this document;
- MUST support all address book reports defined in Section 8 of this document; and
- MUST advertise support on all address book collections and address object resources for the address book reports in the DAV:supported-report-set property, as defined in Versioning Extensions to WebDAV [RFC3253].
In addition, a server:
- SHOULD support vCard v4 [RFC6350] as a media type for the address object resource format;
- SHOULD support the extended MKCOL method [RFC5689] to create address book collections as defined in Section 6.3.1 of this document.
- SHOULD support the DAV:current-user-principal-URL property as defined in [RFC5397] to give clients a fast way to locate user principals. 🔍
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 contains a number of resources representing address objects as their direct child resources. Each resource representing an address object is called an "address object resource". Each address object resource and each address book collection can be individually locked and have individual WebDAV properties. 🔐 Requirements derived from this model are provided in Sections 5.1 and 5.2. 🦋
4.1. Address Book Server 🖥️
A CardDAV server is an address-aware engine combined with a WebDAV server. 🧠 The server may include address data in some parts of its URL namespace and non-address data in other parts.
A WebDAV server can advertise itself as a CardDAV server if it supports the functionality defined in this specification at any point within the root of its repository. 🌈 That might mean that address data is spread throughout the repository and mixed with non-address data in nearby collections (e.g., address data may be found in /lisa/addressbook/ as well as in /bernard/addressbook/, and non-address data in /lisa/calendars/). Or, it might mean that address 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 address objects. So, a repository confining address data to the /carddav/ collection would only need to support the CardDAV required features within that collection. 🎯
The CardDAV server is the canonical location for address data and state information. 👑 Clients may submit requests to change data or download data. Clients may store address objects offline and attempt to synchronize at a later time. Address data on the server can 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 locking help this work. 💜
5. Address Book Resources 📦
5.1. Address Object Resources 🌷
This specification uses vCard as the default format for address or contact information being stored on the server. ✨ However, this specification does allow other formats for address data provided that the server advertises support for those additional formats as described below. The requirements in this section pertain to vCard address data or formats that follow the semantics of vCard data.
Address 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. 🆔
5.1.1. Data Type Conversion 🔄
Servers might support more than one primary media type for address object resources, for example, vCard v3.0 and vCard v4.0. In such cases, servers have to accept all media types that they advertise via the CARDDAV:supported-address-data WebDAV property (see Section 6.2.2). 📣
However, clients can use standard HTTP content negotiation behavior (the Accept request header defined in Section 14.1 of [RFC2616]) to request that an address object resource's data be returned in a specific media type format. 🎯 For example, a client merely capable of handling vCard v3.0 would only want to have address object resources returned in v3.0 format. 💖
Additionally, REPORT requests, defined later in this specification, allow for the return of address object resource data within an XML response body. 📨 Again, the client can use content negotiation to request that data be returned in a specific media type by specifying appropriate attributes on the CARDDAV:address-data XML element used in the request body (see Section 10.4). 🧁
In some cases, it might not be possible for a server to convert from one media type to another. 😬 When that happens, the server MUST return the CARDDAV:supported-address-data-conversion precondition (see below) in the response body (when the failure to convert applies to the entire response) or use that same precondition code in the DAV:response XML element in the response for the targeted address object resource when one of the REPORTs defined below is used. See Section 8.7.2 for an example of this. 🔥
5.1.1.1. Additional Precondition for GET 🙌
This specification creates additional preconditions for the GET method. 🧚
The new precondition is:
(CARDDAV:supported-address-data-conversion): The resource targeted
by the GET request can be converted to the media type specified in
the Accept request header included with the request.5.2. Address Book Collections 📚
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:addressbook XML elements in the value of the DAV:resourcetype property. 🏷️ The element type declaration for CARDDAV:addressbook is:
<!ELEMENT addressbook 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 extended MKCOL method (see Section 6.3.1). 🛠️ This can be used by 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"). 🥅 However, note 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:addressbook-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 address object resources and collections that are not address book collections. That is, the only "top-level" non-collection resources allowed in an address book collection are address object resources. This ensures that address book clients do not have to deal with non-address data in an address book collection, though they do have to distinguish between address 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. That is, "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 address object resources contained in the address book collection. 🚫
Multiple address book collections MAY be children of the same collection. 👯♀️
6. Address Book Feature 🎀
6.1. Address Book Support 📣
A server supporting the features described in this document MUST include "addressbook" 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 "addressbook" in the DAV response header MUST indicate that the server supports all MUST level requirements and REQUIRED features specified in this document. ✅
6.1.1. Example: Using OPTIONS for the Discovery of Support for CardDAV 🔍
>> Request <<
OPTIONS /addressbooks/users/ HTTP/1.1
Host: addressbook.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, ACL
DAV: 1, 2, 3, access-control, addressbook
DAV: extended-mkcol
Date: Sat, 11 Nov 2006 09:32:12 GMT
Content-Length: 0In 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 extended MKCOL method is available and as a possible target for REPORT requests for address book reports. 🧁✨
6.2. Address Book Properties 💖
6.2.1. CARDDAV:addressbook-description Property 💖
Name: addressbook-description 🎀
Namespace: urn:ietf:params:xml:ns:carddav ✨
Purpose: Gives you a human-readable description of the address book collection 📖
Value: Any text 💅
Protected: SHOULD NOT be protected so that users can specify a description 🙈
COPY/MOVE behavior: This property value SHOULD be preserved in COPY and MOVE operations 🦋
allprop behavior: SHOULD NOT be returned by a PROPFIND DAV:allprop request 🌸
Description: Okay so this property is the address book's little bio, and it's meant to be shown to actual humans 🫶 You can slap an xml:lang attribute on it to tag what language it's in, which is so cute for multilingual besties 🌈
Definition:
<!ELEMENT addressbook-description (#PCDATA)>
<!-- PCDATA value: string -->Example:
<C:addressbook-description xml:lang="fr-CA"
xmlns:C="urn:ietf:params:xml:ns:carddav"
>Adresses de Oliver Daboo</C:addressbook-description>6.2.2. CARDDAV:supported-address-data Property 🧚
Name: supported-address-data 💜
Namespace: urn:ietf:params:xml:ns:carddav ✨
Purpose: Tells you which media types are allowed for address object resources in an address book collection 📋
Protected: MUST be protected, because it shows the level of support the server is offering 🔐
COPY/MOVE behavior: This property value MUST be preserved in COPY and MOVE operations 🫶
allprop behavior: SHOULD NOT be returned by a PROPFIND DAV:allprop request 🙈
Description: This one is giving "here's what I accept" energy 💅 It tells you the media type supported for the address object resources in a given address book collection (e.g., vCard version 3.0). If a client tries to store an address object resource with a media type that isn't listed here, that MUST result in an error, with the CARDDAV:supported-address-data precondition (Section 6.3.2.1) being violated. 💀 If this property isn't there at all, the server MUST only accept data with the media type "text/vcard" and vCard version 3.0, and clients can assume that's all the server will take 🍓
Definition:
<!ELEMENT supported-address-data (address-data-type+)>
<!ELEMENT address-data-type EMPTY>
<!ATTLIST address-data-type content-type CDATA "text/vcard"
version CDATA "3.0">
<!-- content-type value: a MIME media type -->
<!-- version value: a version string -->Example:
<C:supported-address-data
xmlns:C="urn:ietf:params:xml:ns:carddav">
<C:address-data-type content-type="text/vcard" version="3.0"/>
</C:supported-address-data>6.2.3. CARDDAV:max-resource-size Property 🍓
Name: max-resource-size 🌷
Namespace: urn:ietf:params:xml:ns:carddav ✨
Purpose: Gives a numeric value for the biggest resource, in octets, that the server is willing to accept when an address object resource gets stored in an address book collection 📏
Value: Any text representing a numeric value 🔢
Protected: MUST be protected, because it shows the limits the server has set 🔒
COPY/MOVE behavior: This property value MUST be preserved in COPY and MOVE operations 🦋
allprop behavior: SHOULD NOT be returned by a PROPFIND DAV:allprop request 🌸
Description: Okay this is the size limit, bestie 🎀 It's a numeric value for the maximum size in octets that the server will accept when an address object resource is stored in an address book collection. Trying to store an address book object resource bigger than this MUST result in an error, with the CARDDAV:max-resource-size precondition (Section 6.3.2.1) being violated. And if the property isn't set, the client can assume the server will allow a resource of any reasonable size ✨
Definition:
<!ELEMENT max-resource-size (#PCDATA)>
<!-- PCDATA value: a numeric value (positive decimal integer) -->Example:
<C:max-resource-size xmlns:C="urn:ietf:params:xml:ns:carddav"
>102400</C:max-resource-size>6.3. Creating Resources 🌈
Address book collections and address object resources can be created by either a CardDAV client or the CardDAV server 🧁 This specification defines restrictions and a data model that both clients and servers MUST adhere to when manipulating such address data 💅
6.3.1. Extended MKCOL Method 🦋
An HTTP request using the extended MKCOL method [RFC5689] can be used to create a new address book collection resource 🌸 A server MAY restrict address book collection creation to particular collections 🙈
To create an address book, the client sends an extended MKCOL request to the server, and in the body of the request it sets the DAV:resourcetype property to the resource type for an address book collection as defined in Section 5.2 ✨
Support for creating address books on the server is only RECOMMENDED and not REQUIRED, because some address book stores only support one address book per user (or principal), and those are typically pre-created for each account 📚 That said, servers and clients are strongly encouraged to support address book creation whenever possible, so users can make multiple address book collections and keep their data super organized 🗂️🫶
The DAV:displayname property is for a human-readable name of the address book 🏷️ Clients can either put the DAV:displayname value in the request body of the extended MKCOL request, or issue a PROPPATCH request to change the DAV:displayname property to the right value right after the extended MKCOL request 💅 When clients display address book collections to users, they SHOULD check the DAV:displayname property and use that value as the name of the address book 💖 If DAV:displayname isn't set, the client MAY use the last part of the address book collection URI as the name. Heads up though, that path segment may be "opaque" and not mean anything human-readable at all 💀
6.3.1.1. Example - Successful MKCOL Request 🎀
This example creates an address book collection called /home/lisa/addressbook/ on the server addressbook.example.com, with specific values for the properties DAV:resourcetype, DAV:displayname, and CARDDAV:addressbook-description 📖
Request <<
MKCOL /home/lisa/addressbook/ HTTP/1.1
Host: addressbook.example.com
Content-Type: text/xml; charset="utf-8"
Content-Length: xxx
<?xml version="1.0" encoding="utf-8" ?>
<D:mkcol xmlns:D="DAV:"
xmlns:C="urn:ietf:params:xml:ns:carddav">
<D:set>
<D:prop>
<D:resourcetype>
<D:collection/>
<C:addressbook/>
</D:resourcetype>
<D:displayname>Lisa's Contacts</D:displayname>
<C:addressbook-description xml:lang="en"
>My primary address book.</C:addressbook-description>
</D:prop>
</D:set>
</D:mkcol>Response <<
HTTP/1.1 201 Created
Cache-Control: no-cache
Date: Sat, 11 Nov 2006 09:32:12 GMT
Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:mkcol-response xmlns:D="DAV:"
xmlns:C="urn:ietf:params:xml:ns:carddav">
<D:propstat>
<D:prop>
<D:resourcetype/>
<D:displayname/>
<C:addressbook-description/>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:mkcol-response>6.3.2. Creating Address Object Resources 💌
Clients fill up address book collections with address object resources 🗃️ The URL for each address object resource is totally arbitrary. It doesn't have to match up with (although it might!) the address object resource's vCard properties or other metadata 🧚 New address object resources MUST be created with a PUT request aimed at an unmapped URI. A PUT request aimed at a mapped URI updates an existing address object resource instead 🔄
When servers create new resources, picking a unique URL is no big deal for them 😌 It's slightly trickier for clients, because a client might not want to look through every resource in the collection, and it might not want to lock the whole collection just to make sure a new one doesn't end up with a name collision 😭 Good news though, there's an HTTP feature to help with this 🙌 If the client intends to create a new address resource, it 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 going to be created, plus the name of the resource in the last path segment. The If-None-Match header makes sure the client won't accidentally overwrite an existing resource, even if that last path segment turned out to already be taken 🛡️
Request <<
PUT /lisa/addressbook/newvcard.vcf HTTP/1.1
If-None-Match: *
Host: addressbook.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@example.com
NICKNAME:me
NOTE:Example VCard.
ORG:Self Employed
TEL;TYPE=WORK,VOICE:412 605 0499
TEL;TYPE=FAX:412 605 0705
URL:http://www.example.com
UID:1234-5678-9000-1
END:VCARDResponse <<
HTTP/1.1 201 Created
Date: Thu, 02 Sep 2004 16:53:32 GMT
Content-Length: 0
ETag: "123456789-000-111"If you want to change an existing address object resource without overwriting a change someone made on the server, you use a specific ETag in an If-Match header, not the If-None-Match header 🎯 That's the move 💅
File names for vCards are commonly suffixed by ".vcf", and clients may choose to use the same convention for URLs 📇🌈
6.3.2.1. Additional Preconditions for PUT, COPY, and MOVE ✨
okay so this spec adds some extra preconditions 💅 for the PUT, COPY, and MOVE methods. they kick in when:
- a PUT of an address object resource into an address book collection happens 🎀
- a COPY or MOVE of an address object resource into an address book collection happens 🦋
the new preconditions are:
(CARDDAV:supported-address-data) the resource you PUT, or the one a COPY or MOVE is targeting, MUST be a supported media type (i.e., vCard) for address object resources. 📇
(CARDDAV:valid-address-data) the resource you PUT, or the one a COPY or MOVE is targeting, MUST be valid data for the media type being specified (i.e., MUST contain valid vCard data). no messy data allowed bestie 🧹
(CARDDAV:no-uid-conflict) the resource you PUT, or the one a COPY or MOVE is targeting, MUST NOT specify a vCard UID property value that's already in use in the targeted address book collection, and it MUST NOT overwrite an existing address object resource with one that has a different UID property value. no UID drama 🙅♀️ servers SHOULD report the URL of the resource that's already using the same UID property value in the DAV:href element 🔗
<!ELEMENT no-uid-conflict (DAV:href)>(CARDDAV:addressbook-collection-location-ok) in a COPY or MOVE request, when the Request-URI is an address book collection, the URI targeted by the Destination HTTP Request header MUST identify a location where an address book collection can be created. 🏡
(CARDDAV:max-resource-size) the resource you PUT, or the one a COPY or MOVE is targeting, MUST have a size in octets 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. size check, we love a boundary 📏
6.3.2.2. Non-Standard vCard Properties and Parameters
vCard gives you a "standard mechanism for doing non-standard things" 🧃 this extension support lets implementers play with non-standard vCard properties and parameters whose names start with the text "X-" 🌈
Servers MUST support the use of non-standard properties and parameters in address object resources stored via the PUT method. no skipping the weird stuff 🙌
servers may need to enforce rules for their own "private" properties or parameters, so servers MAY reject any attempt by the client to change those or to use values for those outside of any restrictions the server may have. that's just boundaries, and boundaries are iconic 💅
A server SHOULD ensure that any "private" properties or parameters it uses follow the convention of including a vendor ID in the "X-" name, as described in Section 3.8 of [RFC2426], e.g., X-ABC-PRIVATE 🏷️
6.3.2.3. Address Object Resource Entity Tag
The DAV:getetag property MUST be defined and set to a strong entity tag on all address object resources. every address object gets its strong ETag, no exceptions 🫶
A response to a GET request targeted at an address object resource MUST contain an ETag response header field that shows the current value of the strong entity tag of that address object resource. 👀
Servers SHOULD return a strong entity tag (ETag header) in a PUT response when the stored address object resource is equivalent by octet equality to the address object resource submitted in the body of the PUT request. this is the part that makes sync reliable 🔁 the client can do a PROPFIND request on the stored address object resource, get the DAV:getetag property back, and compare that value with the strong entity tag it got in the PUT response. if they match, the address object resource on the server hasn't changed. ✨ so clean.
if the data a server stores after a PUT is not equivalent by octet equality to the submitted address object resource, the behavior of the ETag response header isn't specified here. the one exception: a strong entity tag MUST NOT be returned in the response. so the client might need to fetch the modified address object resource (and its ETag) and use that as the base for further changes, instead of the copy it sent with the PUT request. 🙈
7. Address Book Access Control ✨
CardDAV servers MUST support and adhere to the requirements of WebDAV ACL [RFC3744]. WebDAV ACL gives you a framework for an extensible set of privileges that can be applied to WebDAV collections and ordinary resources. permissions era 🔐
7.1. Additional Principal Properties
This section defines some extra properties for WebDAV principal resources, as defined in [RFC3744]. 🧑🤝🧑
7.1.1. CARDDAV:addressbook-home-set Property
Name: addressbook-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.
Protected: MAY be protected if the server has fixed locations in which address books are created. 🏠
COPY/MOVE behavior: this property value MUST be preserved in COPY and MOVE operations. 📦
allprop behavior: SHOULD NOT be returned by a PROPFIND DAV:allprop request. 🙅♀️
Description: the CARDDAV:addressbook-home-set property lets users easily find the address book collections owned by the principal. usually people group all their address book collections under one common collection 🗂️ this property gives the URL of collections that are either address book collections or ordinary collections with child or descendant address book collections owned by the principal.
Definition:
<!ELEMENT addressbook-home-set (DAV:href*)>Example:
<C:addressbook-home-set xmlns:D="DAV:"
xmlns:C="urn:ietf:params:xml:ns:carddav">
<D:href>/bernard/addresses/</D:href>
</C:addressbook-home-set>7.1.2. CARDDAV:principal-address Property
Name: principal-address
Namespace: urn:ietf:params:xml:ns:carddav
Purpose: identifies the URL of an address object resource that corresponds to the user the principal represents. 🧾
Protected: MAY be protected if the server provides a fixed location for principal addresses. 📍
COPY/MOVE behavior: this property value MUST be preserved in COPY and MOVE operations. 📦
allprop behavior: SHOULD NOT be returned by a PROPFIND DAV:allprop request. 🙅♀️
Description: the CARDDAV:principal-address property helps users find contact info for the users represented by principals on the system 💌 it gives the URL of the resource with that contact info. the resource could be an address object resource in an address book collection, or it could be a resource in a "regular" collection.
Definition:
<!ELEMENT principal-address (DAV:href)>Example:
<C:principal-address xmlns:D="DAV:"
xmlns:C="urn:ietf:params:xml:ns:carddav">
<D:href>/system/cyrus.vcf</D:href>
</C:principal-address>8. Address Book Reports 📊
This section defines the reports that CardDAV servers MUST support on address book collections and address object resources. these are the non-negotiables 🫡
CardDAV servers MUST advertise support for these reports on all address book collections and address object resources, using 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 let address data (from possibly multiple resources) come back in the response. 📬
8.1. REPORT Method
The REPORT method (defined in Section 3.6 of [RFC3253]) gives you an extensible way to get information about a resource. unlike PROPFIND, which returns the value of one or more named properties, REPORT can handle more complex processing. REPORT is super useful when the server has access to all the info needed for a complex request (like a query), and the client would otherwise need multiple requests to get that same info. efficiency bestie 🧠
A server that supports this specification 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 address object resources. 🗃️ when computing responses to the reports on ordinary collections, servers MUST only consider address object resources contained in address book collections that are targeted by the REPORT, based on the value of the Depth request header. no sneaky extra resources 👀
8.3. Searching Text: Collations
some of the reports in this section do text matches of character strings the client sends, compared against stored address data. vCard data is encoded in the UTF-8 charset by default, and some property and parameter values can include characters outside the US-ASCII range. so text matching has to follow well-defined rules, or things get messy 🌍💀
to handle this, this specification uses the IANA Collation Registry defined in [RFC4790] to specify collations that can be used to carry out text comparison operations with a well-defined rule. 🧩
Collations supported by the server MUST support "equality" and "substring" match operations as per [RFC4790], Section 4.2, including the "prefix" and "suffix" options for "substring" matching. CardDAV uses these match options for "equals", "contains", "starts-with", and "ends-with" match operations. ⚖️
CardDAV servers are REQUIRED to support the i;ascii-casemap [RFC4790] and i;unicode-casemap [RFC5051] collations, and MAY support other collations. 🔤
Servers MUST advertise the set of collations they support via the CARDDAV:supported-collation-set property, defined on any resource that supports reports that use collations. 📣
if the client doesn't explicitly specify a collation, or it specifies the "default" collation identifier (as defined in [RFC4790], Section 3.1), the server MUST default to using i;unicode-casemap as the collation. 🫠
Wildcards (as defined in [RFC4790], Section 3.2) MUST NOT be used in the collation identifier. no wildcards in here, sorry not sorry 🚫
If the client chooses a collation the server doesn't support, 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: This is how the server tells clients which collations it supports for text matching 💅
Protected: This MUST be protected, because it's the server basically showing off what it can do 👑
COPY/MOVE behavior: The value MUST be preserved in COPY and MOVE operations 🫶
allprop behavior: It SHOULD NOT come back in a PROPFIND DAV:allprop request 🙈
Description: It holds two or more CARDDAV:supported-collation elements, and each one names a collation the server supports 🎀
Definition:
<!ELEMENT supported-collation-set (
supported-collation
supported-collation
supported-collation*)>
<!-- Both "i;ascii-casemap" and "i;unicode-casemap"
will be present -->
<!ELEMENT supported-collation (#PCDATA)>Bonus detail from that comment: i;ascii-casemap and i;unicode-casemap both have to show up in the list 🌈
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>i;unicode-casemap</C:supported-collation>
</C:supported-collation-set>8.4. Partial Retrieval 🌸
Okay so some of the address book reports in this doc let you do partial retrieval of address object resources, which means you don't have to grab everything. A CardDAV client gets to say what info it wants back in the body of an address book REPORT request 🦋
A CardDAV client can ask for specific WebDAV property values, all of them, or just a list of the names of the resource's WebDAV properties. It can also ask for the address data itself, and say whether it wants every vCard property or only certain ones. Check out CARDDAV:address-data in Section 10.4 for the details 💖
8.5. Non-Standard Properties and Parameters 🌈
Servers MUST support non-standard vCard property or parameter names inside the CARDDAV:address-data XML element in address book REPORT requests. That way, clients can ask for non-standard properties and parameters to come back in the address data in the response ✨
Servers MAY support non-standard vCard property or parameter names in the CARDDAV:prop-filter and CARDDAV:param-filter XML elements, which live inside the CARDDAV:filter XML element of address book REPORT requests. Totally optional, bestie 🧚
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 references a non-standard vCard property or parameter name the server doesn't support querying on 💀
8.6. CARDDAV:addressbook-query Report 🔥
The CARDDAV:addressbook-query REPORT searches for all address object resources that match a given filter. The response includes all the WebDAV properties and address object resource data you asked for in the request. With the CARDDAV:address-data XML element, you can get super specific and pick exactly which vCard properties come back for the matching address object resources 💅
This report is modeled on the PROPFIND method, so its request and response bodies use XML elements that PROPFIND also uses. The request can ask for WebDAV properties to be returned too. When it does, the response should behave the same way PROPFIND does with the DAV:multistatus response elements used for specific WebDAV property results. For example, asking for the value of a WebDAV property that doesn't exist is an error, and it MUST be noted with a response XML element containing a 404 (Not Found) status value 🙈
Support for the CARDDAV:addressbook-query REPORT is REQUIRED 👑
Marshalling:
The request body MUST be a CARDDAV:addressbook-query XML element, as defined in Section 10.3 🎀
The request MUST include a Depth header. The Depth header decides how wide the query's scope is. For example, if you want to query every address object resource in an address book collection, you'd use the address book collection as the Request-URI and set a Depth of 1 or infinity 🦋
The response body for a successful request MUST be a DAV:multistatus XML element (basically, the response uses the same format as a PROPFIND response). If there are no response elements, the returned DAV:multistatus XML element is empty 🫶
The response body for a successful CARDDAV:addressbook-query REPORT request MUST contain a DAV:response element for each address object that matched the search filter. The address data comes back in the CARDDAV:address-data XML element inside the DAV:propstat XML element 🌸
Preconditions:
(CARDDAV:supported-address-data): The "content-type" and "version" attributes of the CARDDAV:address-data XML element (see Section 10.4) have to specify a media type the server supports for address object resources 🧚
(CARDDAV:supported-filter): The CARDDAV:prop-filter (see Section 10.5.1) and CARDDAV:param-filter (see Section 10.5.2) XML elements used inside the CARDDAV:filter XML element (see Section 10.5) in the REPORT request can only reference vCard properties and parameters the server supports querying on. So if the CARDDAV:filter element tries to reference an unsupported vCard property or parameter, this precondition is violated 😭 A server SHOULD report the CARDDAV:prop-filter or CARDDAV:param-filter it doesn't support, so the client knows what went wrong 💜
<!ELEMENT supported-filter (prop-filter*,
param-filter*)>(CARDDAV:supported-collation): Any XML attribute that specifies a collation MUST specify a collation the server supports, as described in Section 8.3 ✨
Postconditions:
(DAV:number-of-matches-within-limits): The number of matching address object resources must fall within server-specific, predefined limits. For example, this condition might get triggered if a search would return an absolutely huge number of responses 💀
8.6.1. Limiting Results 🍓
A client can cap the number of results the server returns by using the CARDDAV:limit element in the request body. This is super handy when clients only care about a few matches, or only have limited space to show results to users, so they don't need the overhead of receiving more than that. When the server truncates the results, it MUST follow the rules below for telling the client about the truncation 🫶
8.6.2. Truncation of Results 🌈
A server MAY limit the number of resources in a response. It might do this to cap how much work goes into processing a query, or because the client set an explicit limit. If the result set gets truncated because of a limit like that, the response MUST use status code 207 (Multi-Status), return a DAV:multistatus response body, and show a status of 507 (Insufficient Storage) for the Request-URI. That DAV:response element SHOULD include a DAV:error element with the DAV:number-of-matches-within-limits precondition, as defined in [RFC3744], Section 9.2 🔥
The server SHOULD also include the partial results in additional DAV:response elements. If a client-requested limit is being applied, the 507 response for the Request-URI MUST NOT be counted toward that limit. For example, if the client asks for only a single result and there are multiple matches, the DAV:multistatus response will have one DAV:response for the matching resource and one DAV:response for the 507 status on the Request-URI 🧚
8.6.3. Example: Partial Retrieval of vCards Matching NICKNAME 💖
In this example, the client asks the server to search for address object resources that have a NICKNAME property whose value equals some specific text, and to return specific vCard properties for the vCards it finds. The DAV:getetag property is requested too, and it comes back as part of the response 🦋
>> Request <<
REPORT /home/bernard/addressbook/ HTTP/1.1
Host: addressbook.example.com
Depth: 1
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<C:addressbook-query xmlns:D="DAV:"
xmlns:C="urn:ietf:params:xml:ns:carddav">
<D:prop>
<D:getetag/>
<C:address-data>
<C:prop name="VERSION"/>
<C:prop name="UID"/>
<C:prop name="NICKNAME"/>
<C:prop name="EMAIL"/>
<C:prop name="FN"/>
</C:address-data>
</D:prop>
<C:filter>
<C:prop-filter name="NICKNAME">
<C:text-match collation="i;unicode-casemap"
match-type="equals"
>me</C:text-match>
</C:prop-filter>
</C:filter>
</C:addressbook-query>>> Response <<
HTTP/1.1 207 Multi-Status
Date: Sat, 11 Nov 2006 09:32:12 GMT
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>/home/bernard/addressbook/v102.vcf</D:href>
<D:propstat>
<D:prop>
<D:getetag>"23ba4d-ff11fb"</D:getetag>
<C:address-data>BEGIN:VCARD
VERSION:3.0
NICKNAME:me
UID:34222-232@example.com
FN:Cyrus Daboo
EMAIL:daboo@example.com
END:VCARD
</C:address-data>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
</D:multistatus>8.6.4. Example: Partial Retrieval of vCards Matching a Full Name or Email Address ✨
okay bestie, this one is full detective work 🕵️💜 the client asks the server to search for address object resources whose FN property contains some specific text, OR whose EMAIL property contains other text. then it wants back only certain vCard properties for whatever matches. the DAV:getetag property comes along too 🎀
Request <<
REPORT /home/bernard/addressbook/ HTTP/1.1
Host: addressbook.example.com
Depth: 1
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<C:addressbook-query xmlns:D="DAV:"
xmlns:C="urn:ietf:params:xml:ns:carddav">
<D:prop>
<D:getetag/>
<C:address-data>
<C:prop name="VERSION"/>
<C:prop name="UID"/>
<C:prop name="NICKNAME"/>
<C:prop name="EMAIL"/>
<C:prop name="FN"/>
</C:address-data>
</D:prop>
<C:filter test="anyof">
<C:prop-filter name="FN">
<C:text-match collation="i;unicode-casemap"
match-type="contains"
>daboo</C:text-match>
</C:prop-filter>
<C:prop-filter name="EMAIL">
<C:text-match collation="i;unicode-casemap"
match-type="contains"
>daboo</C:text-match>
</C:prop-filter>
</C:filter>
</C:addressbook-query>Response <<
HTTP/1.1 207 Multi-Status
Date: Sat, 11 Nov 2006 09:32:12 GMT
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>/home/bernard/addressbook/v102.vcf</D:href>
<D:propstat>
<D:prop>
<D:getetag>"23ba4d-ff11fb"</D:getetag>
<C:address-data>BEGIN:VCARD
VERSION:3.0
NICKNAME:me
UID:34222-232@example.com
FN:David Boo
EMAIL:daboo@example.com
END:VCARD
</C:address-data>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
<D:response>
<D:href>/home/bernard/addressbook/v104.vcf</D:href>
<D:propstat>
<D:prop>
<D:getetag>"23ba4d-ff11fc"</D:getetag>
<C:address-data>BEGIN:VCARD
VERSION:3.0
NICKNAME:oliver
UID:34222-23222@example.com
FN:Oliver Daboo
EMAIL:oliver@example.com
END:VCARD
</C:address-data>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
</D:multistatus>the server sends back a 207 with two responses. v102 gets picked up through its EMAIL, and v104 gets picked up through its FN. both come back with their etags and the requested address data 💅
8.6.5. Example: Truncated Results 🧚
this time the client wants the FN match, but only the first two results, so it adds a limit 🍓 the DAV:getetag property is the only thing it asks for. the server replies with a 507 status on the Request-URI. that tells the client there were more than two matching resources, but the server cut the set down to two like the client asked 😭
Request <<
REPORT /home/bernard/addressbook/ HTTP/1.1
Host: addressbook.example.com
Depth: 1
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<C:addressbook-query xmlns:D="DAV:"
xmlns:C="urn:ietf:params:xml:ns:carddav">
<D:prop>
<D:getetag/>
</D:prop>
<C:filter test="anyof">
<C:prop-filter name="FN">
<C:text-match collation="i;unicode-casemap"
match-type="contains"
>daboo</C:text-match>
</C:prop-filter>
</C:filter>
<C:limit>
<C:nresults>2</C:nresults>
</C:limit>
</C:addressbook-query>Response <<
HTTP/1.1 207 Multi-Status
Date: Sat, 11 Nov 2006 09:32:12 GMT
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>/home/bernard/addressbook/</D:href>
<D:status>HTTP/1.1 507 Insufficient Storage</D:status>
<D:error><D:number-of-matches-within-limits/></D:error>
<D:responsedescription xml:lang="en">
Only two matching records were returned
</D:responsedescription>
</D:response>
<D:response>
<D:href>/home/bernard/addressbook/v102.vcf</D:href>
<D:propstat>
<D:prop>
<D:getetag>"23ba4d-ff11fb"</D:getetag>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
<D:response>
<D:href>/home/bernard/addressbook/v104.vcf</D:href>
<D:propstat>
<D:prop>
<D:getetag>"23ba4d-ff11fc"</D:getetag>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
</D:multistatus>8.7. CARDDAV:addressbook-multiget Report 🦋
the CARDDAV:addressbook-multiget REPORT is for grabbing specific address object resources. if the Request-URI is a collection, you get them from inside it. if the Request-URI is an address object resource, you get that one 💖 it's kind of like the CARDDAV:addressbook-query REPORT (see Section 8.6), except instead of a CARDDAV:filter element, it takes a list of DAV:href elements to decide what to return 🌸
Support for the addressbook-multiget REPORT is REQUIRED. 🫶
Marshalling:
The request body MUST be a CARDDAV:addressbook-multiget XML element (see Section 10.7), which MUST contain at least one DAV:href XML element and one optional CARDDAV:address-data element as defined in Section 10.4. If DAV:href elements are present, the scope of the request is the set of resources identified by these elements. all of them need to be members (not necessarily internal members) of the resource identified by the Request-URI. otherwise, the scope is just the resource identified by the Request-URI itself 🧠
The request MUST include a Depth: 0 header. however, the actual scope of the REPORT is determined as described above 🙈
The response body for a successful request MUST be a DAV:multistatus XML element.
The response body for a successful CARDDAV:addressbook-multiget REPORT request MUST contain a DAV:response element for each address object resource referenced by the provided set of DAV:href elements. Address data comes back in the CARDDAV:address-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:
(CARDDAV:supported-address-data): The attributes "content-type" and "version" of the CARDDAV:address-data XML elements (see Section 10.4) specify a media type supported by the server for address object resources.
Postconditions:
None.
8.7.1. Example: CARDDAV:addressbook-multiget Report 💜
in this example, the client asks the server for specific vCard properties from the address components at specific URIs. the DAV:getetag property is requested too and comes back in the response. heads up: the resource at http://addressbook.example.com/home/bernard/addressbook/vcf1.vcf doesn't exist, so it gets an error status response 👀
Request <<
REPORT /home/bernard/addressbook/ HTTP/1.1
Host: addressbook.example.com
Depth: 1
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<C:addressbook-multiget xmlns:D="DAV:"
xmlns:C="urn:ietf:params:xml:ns:carddav">
<D:prop>
<D:getetag/>
<C:address-data>
<C:prop name="VERSION"/>
<C:prop name="UID"/>
<C:prop name="NICKNAME"/>
<C:prop name="EMAIL"/>
<C:prop name="FN"/>
</C:address-data>
</D:prop>
<D:href>/home/bernard/addressbook/vcf102.vcf</D:href>
<D:href>/home/bernard/addressbook/vcf1.vcf</D:href>
</C:addressbook-multiget>Response <<
HTTP/1.1 207 Multi-Status
Date: Sat, 11 Nov 2006 09:32:12 GMT
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>/home/bernard/addressbook/vcf102.vcf</D:href>
<D:propstat>
<D:prop>
<D:getetag>"23ba4d-ff11fb"</D:getetag>
<C:address-data>BEGIN:VCARD
VERSION:3.0
NICKNAME:me
UID:34222-232@example.com
FN:Cyrus Daboo
EMAIL:daboo@example.com
END:VCARD
</C:address-data>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
<D:response>
<D:href>/home/bernard/addressbook/vcf1.vcf</D:href>
<D:status>HTTP/1.1 404 Resource not found</D:status>
</D:response>
</D:multistatus>8.7.2. Example: CARDDAV:addressbook-multiget Report 🌈
in this one, the client asks for vCard v4.0 data from the address components at specific URIs. the DAV:getetag property is requested too. the twist: the resource at http://addressbook.example.com/home/bernard/addressbook/vcf3.vcf exists, but it's in a media type format the server can't convert, so it gets an error status response 😭
Request <<
REPORT /home/bernard/addressbook/ HTTP/1.1
Host: addressbook.example.com
Depth: 1
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<C:addressbook-multiget xmlns:D="DAV:"
xmlns:C="urn:ietf:params:xml:ns:carddav">
<D:prop>
<D:getetag/>
<C:address-data content-type='text/vcard' version='4.0'/>
</D:prop>
<D:href>/home/bernard/addressbook/vcf3.vcf</D:href>
</C:addressbook-multiget>Response <<
HTTP/1.1 207 Multi-Status
Date: Sat, 11 Nov 2006 09:32:12 GMT
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>/home/bernard/addressbook/vcf3.vcf</D:href>
<D:status>HTTP/1.1 415 Unsupported Media Type</D:status>
<D:error><C:supported-address-data-conversion/></D:error>
<D:responsedescription>Unable to convert from vCard v3.0
to vCard v4.0</D:responsedescription>
</D:response>
</D:multistatus>9. Client Guidelines ✨
9.1. Restrict the Properties Returned ✨
Okay so clients don't always need every single property in a vCard 💅 Like when they're just showing info to the user, or looking up one specific thing like an email address. Some property data can be huge (hello, PHOTO or SOUND with in-line content 😭), so clients can totally skip that stuff by only asking for the specific items they know they'll use, through the CARDDAV:address-data XML element in the relevant reports. 🎀
BUT (plot twist) if a client wants to change a vCard, it can only replace the entire vCard data with a PUT request. There's no way to tweak a few properties inside a vCard object resource 🙈 So the client has to cache the whole set of properties on any resource it's about to change. Main character cache energy 💜
9.2. Avoiding Lost Updates 🫶
When multiple clients touch the same resources, they can end up overwriting each other's changes, and that's giving chaos 💀 To ease this, clients SHOULD use the If-Match request header on PUT requests, with the ETag of the previously retrieved resource data, to check whether the resource was modified since it was retrieved. If a precondition failure happens, clients need to reload the resource and go through their own merge or conflict resolution process before writing back the data (again using the If-Match check). ✨
9.3. Client Configuration 🧚
When CardDAV clients need setting up, the key thing they need is the principal-URL of the user whose address book info they want. Servers SHOULD support the DAV:current-user-principal-URL property as defined in [RFC5397] so clients have a fast way to find user principals. 🔥
Once you've got SRV records (Section 11) and DAV:current-user-principal-URL [RFC5397] working, users literally only need to enter a user identifier, host name, and password 🥹 The client takes the host name, does an SRV lookup to find the CardDAV server, then sends an authenticated PROPFIND on the root/resource looking for the DAV:current-user-principal-URL property. The value it gets back gives the client direct access to the user's principal-URL, and from there all the related CardDAV properties needed to locate address books. Easy peasy 🌸
9.4. Finding Other Users' Address Books 👀
For address book sharing, you might want to find someone else's address book. To find other users' address books on the same server, the DAV:principal-property-search REPORT [RFC3744] can search principals for matching properties and return specified properties for the matching principal resources. To search for an address book owned by a user named "Laurie", the REPORT request body would look like this:
<?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:addressbook-home-set
xmlns:C="urn:ietf:params:xml:ns:carddav"/>
<D:displayname/>
</D:prop>
</D:principal-property-search>The server does a case-sensitive or caseless search for a matching string subset of "Laurie" within the DAV:displayname property. So the server might return "Laurie Dusseault", "Laurier Desruisseaux", or "Wilfrid Laurier" as matching DAV:displayname values, and the address books for each of them. 🌈
10. XML Element Definitions 🎀
10.1. CARDDAV:addressbook XML Element 📒
- Name:
addressbook - Namespace:
urn:ietf:params:xml:ns:carddav - Purpose: Specifies the resource type of an address book collection.
- Description: See Section 5.2.
- Definition:
<!ELEMENT addressbook EMPTY>10.2. 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 [RFC4790].
- Description: The
CARDDAV:supported-collationcontains the text of a collation identifier as described in Section 8.3.1. - Definition:
<!ELEMENT supported-collation (#PCDATA)>
<!-- PCDATA value: collation identifier -->10.3. CARDDAV:addressbook-query XML Element 🔍
- Name:
addressbook-query - Namespace:
urn:ietf:params:xml:ns:carddav - Purpose: Defines a report for querying address book data.
- Description: See Section 8.6.
- Definition:
<!ELEMENT addressbook-query ((DAV:allprop |
DAV:propname |
DAV:prop)?, filter, limit?)>10.4. CARDDAV:address-data XML Element 🍓
- Name:
address-data - Namespace:
urn:ietf:params:xml:ns:carddav - Purpose: Specifies one of the following:
- The parts of an address object resource that should be returned by a given address book REPORT request, and the media type and version for the returned data; or
- The content of an address object resource in a response to an address book REPORT request.
- Description: When used in an address book REPORT request, the
CARDDAV:address-dataXML element specifies which parts of address object resources need to be returned in the response. If theCARDDAV:address-dataXML element doesn't contain anyCARDDAV:propelements, address object resources will be returned in their entirety. You can also specify a media type and version to ask the server to return the data in that format, if possible. 💅
When used in an address book REPORT response, the CARDDAV:address-data XML element specifies the content of an address object resource. 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), so the CR character (US-ASCII decimal 13) MAY be omitted in address object resources specified in the CARDDAV:address-data XML element. Also, address object resources specified in the CARDDAV:address-data XML element MAY be invalid per their media type specification if the CARDDAV:address-data XML element part of the address book REPORT request did not specify required vCard properties (e.g., UID, etc.) or specified a CARDDAV:prop XML element with the "novalue" attribute set to "yes". 🙈
Note: TheCARDDAV:address-dataXML element is specified in requests and responses inside theDAV:propXML element as if it were a WebDAV property. However, theCARDDAV:address-dataXML element is not a WebDAV property, so it is not returned in PROPFIND responses nor used in PROPPATCH requests.
Note: The address data embedded within theCARDDAV:address-dataXML 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 latter case, the vCard data cannot contain the character sequence]]>, which is the end delimiter for the CDATA section.
- Definition:
<!ELEMENT address-data (allprop | prop*)>
when nested in the DAV:prop XML element in an address book
REPORT request to specify which parts of address object
resources should be returned in the response;
<!ELEMENT address-data (#PCDATA)>
<!-- PCDATA value: address data -->
when nested in the DAV:prop XML element in an address book
REPORT response to specify the content of a returned
address object resource.
<!ATTLIST address-data content-type CDATA "text/vcard"
version CDATA "3.0">
<!-- content-type value: a MIME media type -->
<!-- version value: a version string -->
attributes can be used on each variant of the
CALDAV:address-data XML element.10.4.1. CARDDAV:allprop XML Element 🌟
- Name:
allprop - Namespace:
urn:ietf:params:xml:ns:carddav - Purpose: Specifies that all vCard properties shall be returned.
- Description: Use this element when the client wants all vCard properties of components returned by a report.
- Definition:
<!ELEMENT allprop EMPTY>Note: TheCARDDAV:allpropelement has the same name as theDAV:allpropelement defined in WebDAV, but it uses the "urn:ietf:params:xml:ns:carddav" namespace, whileDAV:allpropuses the "DAV:" namespace. Same name, different family 👯
10.4.2. CARDDAV:prop XML Element 🧁
- Name:
prop - Namespace:
urn:ietf:params:xml:ns:carddav - Purpose: Defines which vCard properties to return in the response.
- Description: The "name" attribute specifies the name of the vCard 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 returns just the vCard property name, any vCard parameters, and a trailing ":" without the subsequent value data.
vCard allows a "group" prefix to appear before a property name in the vCard data. When the "name" attribute does not specify a group prefix, it MUST match properties in the vCard data without a group prefix or with any group prefix. When the "name" attribute includes a group prefix, it MUST match properties that have exactly the same group prefix and name. For example, a "name" set to "TEL" matches "TEL", "X-ABC.TEL", and "X-ABC-1.TEL" vCard properties. A "name" set to "X-ABC.TEL" matches an "X-ABC.TEL" vCard property only; it will not match "TEL" or "X-ABC-1.TEL". 🫠
- 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: TheCARDDAV:propelement has the same name as theDAV:propelement defined in WebDAV, but it uses the "urn:ietf:params:xml:ns:carddav" namespace, whileDAV:propuses the "DAV:" namespace. Twins, but make sure you pick the right one 💖
10.5. 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 address objects that should be returned by a report. The "test" attribute specifies whether any (logical OR,
anyof) or all (logical AND,allof) of the prop-filter tests need to match in order for the overall filter to match. 👑 - Definition:
<!ELEMENT filter (prop-filter*)>
<!ATTLIST filter test (anyof | allof) "anyof">
<!-- test value:
anyof logical OR for prop-filter matches
allof logical AND for prop-filter matches -->10.5.1. CARDDAV:prop-filter XML Element ✨
Name: prop-filter
Namespace: urn:ietf:params:xml:ns:carddav
Purpose: Limits the search to specific vCard properties.
Description: okay so the prop-filter is how you zoom in on one specific vCard property, like "NICKNAME" 💅. An address object counts as a match for a prop-filter if:
- A vCard property of the type named in the "name" attribute exists, and the CARDDAV:prop-filter is empty, or it matches any specified CARDDAV:text-match or CARDDAV:param-filter conditions. The "test" attribute decides whether any (logical OR) or all (logical AND) of the text-filter and param-filter tests need to match for the overall filter to match. 🎀
or:
- A vCard property of the type named in the "name" attribute does not exist, and the CARDDAV:is-not-defined element is specified. 🙈
vCard lets a "group" prefix show up before a property name in the vCard data, so this part gets a little spicy 🌶️. When the "name" attribute doesn't include a group prefix, it MUST match properties in the vCard data without a group prefix or with any group prefix. When the "name" attribute does include a group prefix, it MUST match properties that have exactly the same group prefix and name. For example, a "name" set to "TEL" will match "TEL", "X-ABC.TEL", and "X-ABC-1.TEL" vCard properties. A "name" set to "X-ABC.TEL" will match an "X-ABC.TEL" vCard property only. It will not match "TEL" or "X-ABC-1.TEL". Be precise, bestie 🫶
Definition:
<!ELEMENT prop-filter (is-not-defined |
(text-match*, param-filter*))>
<!ATTLIST prop-filter name CDATA #REQUIRED
test (anyof | allof) "anyof">
<!-- name value: a vCard property name (e.g., "NICKNAME")
test value:
anyof logical OR for text-match/param-filter matches
allof logical AND for text-match/param-filter matches -->10.5.2. 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 element digs into a specific vCard property parameter (like TYPE) inside the scope of a given CARDDAV:prop-filter. A vCard property matches a CARDDAV:param-filter if:
- A parameter of the type named in the "name" attribute exists, and the CARDDAV:param-filter is empty, or it matches the CARDDAV:text-match conditions if they're specified. ✨
or:
- A parameter of the type named in the "name" attribute does not exist, and the CARDDAV:is-not-defined element is specified. 🌸
Definition:
<!ELEMENT param-filter (is-not-defined | text-match)?>
<!ATTLIST param-filter name CDATA #REQUIRED>
<!-- name value: a property parameter name (e.g., "TYPE") -->10.5.3. 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 vCard property or parameter does not exist.
Description: The CARDDAV:is-not-defined element says a match happens when the enclosing vCard property or parameter value, the one named in an address book REPORT request, is missing from the address data being tested. It's giving "absence is a feature" 💀✨
Definition:
<!ELEMENT is-not-defined EMPTY>10.5.4. CARDDAV:text-match XML Element 🔍
Name: text-match
Namespace: urn:ietf:params:xml:ns:carddav
Purpose: Specifies a substring match on a vCard property or parameter value.
Description: The CARDDAV:text-match element holds the text used for a substring match against the vCard property or parameter value named in an address book REPORT request. 🧚
The "collation" attribute picks the collation the server uses for character string matching. The server MUST use this collation when the attribute is set. If the attribute is absent, the server MUST use the "i;unicode-casemap" collation. Yes, the collation is the boss 👑
The "negate-condition" attribute says whether the test returns a match when the text matches (set to "no") or when the text does NOT match (set to "yes"). For example, you could use this to match components whose CATEGORIES property is not set to PERSON. Flipping the vibe, bestie 🙃
The "match-type" attribute picks the kind of match operation to use. The possible choices are:
- "equals" - an exact match to the target string 🎯
- "contains" - a substring match, matching anywhere within the target string 🍓
- "starts-with" - a substring match, matching only at the start of the target string 🌅
- "ends-with" - a substring match, matching only at the end of the target string 🌙
Definition:
<!ELEMENT text-match (#PCDATA)>
<!-- PCDATA value: string -->
<!ATTLIST text-match
collation CDATA "i;unicode-casemap"
negate-condition (yes | no) "no"
match-type (equals|contains|starts-with|ends-with) "contains">10.6. CARDDAV:limit XML Element 🚧
Name: limit
Namespace: urn:ietf:params:xml:ns:carddav
Purpose: Specifies different types of limits that can be applied to the results returned by the server.
Description: The CARDDAV:limit element is how a client can ask the server to cap the results it sends back. Right now, only the CARDDAV:nresults limit exists, but other types of limit could be defined in the future. Stay tuned, babe 💜
Definition:
<!ELEMENT limit (nresults)>10.6.1. CARDDAV:nresults XML Element 🔢
Name: nresults
Namespace: urn:ietf:params:xml:ns:carddav
Purpose: Specifies a limit on the number of results returned by the server.
Description: The CARDDAV:nresults element holds the maximum number of DAV:response elements the client would like back in the response body of a query. The server MAY disregard this limit, so it's a request, not a guarantee 🤷♀️ The value is an unsigned integer.
Definition:
<!ELEMENT nresults (#PCDATA)>
<!-- nresults value: unsigned integer, must be digits -->10.7. CARDDAV:addressbook-multiget XML Element 🍬
Name: addressbook-multiget
Namespace: urn:ietf:params:xml:ns:carddav
Purpose: CardDAV report used to retrieve specific address objects via their URIs.
Description: See Section 8.7. Go check it out, it's a whole vibe 🌈
Definition:
<!ELEMENT addressbook-multiget ((DAV:allprop |
DAV:propname |
DAV:prop)?,
DAV:href+)>11. Service Discovery via SRV Records 📡
[RFC2782] defines a DNS-based service discovery protocol that's been widely adopted for finding particular services on a local area network and beyond, using SRV RRs. It's literally the find-my-friends of DNS 🧭
This specification adds two service types for use with SRV records:
carddav:Identifies a CardDAV server that uses HTTP without TLS [RFC2818].carddavs:Identifies a CardDAV server that uses HTTP with TLS [RFC2818]. The "s" stands for SAFE 🔒
Example: non-TLS service record
_carddav._tcp SRV 0 1 80 addressbook.example.com.Example: TLS service
_carddavs._tcp SRV 0 1 443 addressbook.example.com.12. Internationalization Considerations 🌍
CardDAV lets internationalized strings be stored and retrieved for the description of address book collections (see Section 6.2.1). Every language gets a seat at the table 🪑💖
The CARDDAV:addressbook-query REPORT (Section 8.6) includes a text searching option controlled by the CARDDAV:text-match element. The details of character handling are covered in the description of that element (see Section 10.5.4). Read that section, it's where the magic happens ✨
13. Security Considerations 🔐
⚠️ Okay bestie, this section is SERIOUS. Read every word. Your data's safety depends on it. 😭
HTTP protocol transactions are sent in the clear over the network unless protection from snooping is negotiated. This can be done by using TLS as defined in [RFC2818]. In particular, if HTTP Basic authentication [RFC2617] is available, the server MUST allow TLS to be used at the same time, and it SHOULD prevent use of Basic authentication when TLS is not in use. Clients SHOULD use TLS whenever possible. Nobody gets to send passwords naked over the internet, periodt 🙅♀️
With the ACL extension [RFC3744] present, WebDAV allows control over who can access (read or write) any resource on the WebDAV server. WebDAV ACL also has an "inheritance" mechanism, where resources can inherit access privileges from other resources. Often, the "other" resource is the parent collection of the resource itself. Servers can support address books that are "private" (accessible only to the "owner"), "shared" (accessible to the owner and other specified authenticated users), and "public" (accessible to any authenticated or unauthenticated users). When provisioning address books of a particular type, servers MUST ensure that the correct privileges are applied on creation. In particular, private and shared address books MUST NOT be accessible by unauthenticated users, so that data can't be automatically searched or indexed by web "crawlers" 🕷️ Keep your diary away from the spiders, no cap 📓
Clients SHOULD warn users in an appropriate fashion when they copy or move address data from a private address book to a shared address book or public address book. Clients SHOULD provide a clear indication as to which address books are private, shared, or public. Clients SHOULD provide an appropriate warning when changing access privileges for a private or shared address book that holds data, so as to allow unauthenticated users access. Think before you share, bestie 🫣
This specification currently relies on standard HTTP authentication mechanisms for identifying users. These comprise Basic and Digest authentication [RFC2617], as well as TLS [RFC2818] using client-side certificates. Identity check, iykyk 🪪
14. IANA Consideration 🗂️
This document uses a URN to describe a new XML namespace, following the registry mechanism described in [RFC3688]. Very organized, very iconic 📋
14.1. Namespace Registration 📝
Registration request for the carddav namespace:
- URI:
urn:ietf:params:xml:ns:carddav - Registrant Contact: The IESG
<iesg@ietf.org> - XML: None - not applicable for namespace registrations.
15. Acknowledgments 🫶
Thanks go to Lisa Dusseault and Bernard Desruisseaux for their work on CalDAV, which CardDAV is heavily based on. Main character origin story right there 🎬 The following individuals contributed their ideas and support for writing this specification: Mike Douglass, Stefan Eissing, Helge Hess, Arnaud Quillaud, Julian Reschke, Elias Sinderson, Greg Stein, Wilfredo Sanchez, and Simon Vaillancourt. Legends, every single one 🌟
16. References 📚
16.1. Normative References 📚
okay bestie, these are the docs this spec literally cannot function without 🫶 every one of them is a must-read, no skipping, periodt 💅
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2426] Dawson, F. and T. Howes, "vCard MIME Directory Profile",
RFC 2426, September 1998.
[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.
[RFC2617] Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, S.,
Leach, P., Luotonen, A., and L. Stewart, "HTTP
Authentication: Basic and Digest Access Authentication",
RFC 2617, June 1999.
[RFC2782] Gulbrandsen, A., Vixie, P., and L. Esibov, "A DNS RR for
specifying the location of services (DNS SRV)", RFC 2782,
February 2000.
[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.
[RFC4790] Newman, C., Duerst, M., and A. Gulbrandsen, "Internet
Application Protocol Collation Registry", RFC 4790,
March 2007.
[RFC4918] Dusseault, L., "HTTP Extensions for Web Distributed
Authoring and Versioning (WebDAV)", RFC 4918, June 2007.
[RFC5051] Crispin, M., "i;unicode-casemap - Simple Unicode Collation
Algorithm", RFC 5051, October 2007.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246, August 2008.
[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
Housley, R., and W. Polk, "Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 5280, May 2008.
[RFC5397] Sanchez, W. and C. Daboo, "WebDAV Current Principal
Extension", RFC 5397, December 2008.
[RFC5689] Daboo, C., "Extended MKCOL for Web Distributed Authoring
and Versioning (WebDAV)", RFC 5689, September 2009.
[RFC6350] Perreault, S., "vCard Format Specification", RFC 6350,
August 2011.
[W3C.REC-xml-20081126]
Bray, T., Paoli, J., Sperberg-McQueen, C., Maler, E., and
F. Yergeau, "Extensible Markup Language (XML) 1.0 (Fifth
Edition)", World Wide Web Consortium Recommendation REC-
xml-20081126, November 2008,
<http://www.w3.org/TR/2008/REC-xml-20081126>.16.2. Informative References 🧚
these ones are the extra reading, super helpful for the full picture ✨
[IMSP] Myers, J., "IMSP - Internet Message Support Protocol",
Work in Progress, June 1995.
[RFC2244] Newman, C. and J. Myers, "ACAP -- Application
Configuration Access Protocol", RFC 2244, November 1997.
[RFC4510] Zeilenga, K., "Lightweight Directory Access Protocol
(LDAP): Technical Specification Road Map", RFC 4510,
June 2006.Author's Address 🎀
and here's who wrote it, the main character behind the whole spec 👑
Author's Address
Cyrus Daboo
Apple, Inc.
1 Infinite Loop
Cupertino, CA 95014
USA
EMail: cyrus@daboo.name
URI: http://www.apple.com/📦 where this page comes from
- ietf: rfc6352 2011-08
- 💖 girlified by claude-haiku-5-5 on : a language model's rewrite of the original, under its terms