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Network Working Group P. Saint-Andre Internet-Draft J. Miller Expires: August27,31, 2003 Jabber Software FoundationFebruary 26,March 2, 2003 XMPP Instant Messagingdraft-ietf-xmpp-im-04draft-ietf-xmpp-im-05 Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents asInternet- Drafts.Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http:// www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on August27,31, 2003. Copyright Notice Copyright (C) The Internet Society (2003). All Rights Reserved. Abstract This document describes the specific extensions to and applications of the Extensible Messaging and Presence Protocol (XMPP) that are necessary to create a basic instant messaging and presence application such as that provided by the servers, clients, and other applications that comprise the XMPP-based Jabber network. Saint-Andre & Miller Expires August27,31, 2003 [Page 1] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.2 Requirements . . . . . . . . . . . . . . . . . . . . . . . . 4 1.3 Terminology . . . . . . . . . . . . . . . . . . . . . . . . 5 1.4 Discussion Venue . . . . . . . . . . . . . . . . . . . . . . 5 1.5 Intellectual Property Notice . . . . . . . . . . . . . . . . 5 2. Authentication and Authorization . . . . . . . . . . . . . . 6 3. Exchanging Messages . . . . . . . . . . . . . . . . . . . .89 3.1 Specifying an Intended Recipient . . . . . . . . . . . . . .89 3.2 Specifying a Message Type . . . . . . . . . . . . . . . . .89 3.3 Specifying a Message Subject . . . . . . . . . . . . . . . .910 3.4 Specifying a Conversation Thread . . . . . . . . . . . . . .910 3.5 Specifying a Message Body . . . . . . . . . . . . . . . . .1011 3.6 Specifying Additional Information . . . . . . . . . . . . .1011 3.7 Message-Related Errors . . . . . . . . . . . . . . . . . . .1112 4. Exchanging Presence Information . . . . . . . . . . . . . .1213 4.1 Client and Server Responsibilities . . . . . . . . . . . . .1213 4.2 Sending Initial Presence . . . . . . . . . . . . . . . . . .1214 4.3 Specifying Availability Status . . . . . . . . . . . . . . .1314 4.4 Specifying Detailed Status Information . . . . . . . . . . .1314 4.5 Probing for Presence . . . . . . . . . . . . . . . . . . . .1315 4.6 Sending Final Presence . . . . . . . . . . . . . . . . . . .1315 4.7 Determining When a Contact Went Offline . . . . . . . . . .1415 5. Managing Subscriptions . . . . . . . . . . . . . . . . . . .1617 5.1 Requesting a Subscription . . . . . . . . . . . . . . . . .1617 5.2 Handling a Subscription Request . . . . . . . . . . . . . .1617 5.3 Cancelling a Subscription from Another Entity . . . . . . .1718 5.4 Unsubscribing from Another Entity's Presence . . . . . . . .1718 6. Managing One's Roster . . . . . . . . . . . . . . . . . . .1819 6.1 Retrieving One's Roster on Login . . . . . . . . . . . . . .1819 6.2 Adding a Roster Item . . . . . . . . . . . . . . . . . . . .1920 6.3 Deleting a Roster Item . . . . . . . . . . . . . . . . . . .2021 7. Integration of Roster Items and Presence Subscriptions . . .2223 7.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . .2223 7.2 User Subscribes to Contact . . . . . . . . . . . . . . . . .2223 7.2.1 Alternate Flow . . . . . . . . . . . . . . . . . . . . . . .2526 7.3 Creating a Mutual Subscription . . . . . . . . . . . . . . .2627 7.3.1 Alternate Flow . . . . . . . . . . . . . . . . . . . . . . .2829 7.4 Unsubscribing . . . . . . . . . . . . . . . . . . . . . . .2830 7.4.1 Case #1: Subscription Type 'to' . . . . . . . . . . . . . .2930 7.4.2 Case #2: Subscription Type 'both' . . . . . . . . . . . . .3032 7.5 Cancelling a Subscription . . . . . . . . . . . . . . . . .3234 7.5.1 Case #1: Subscription Type 'from' . . . . . . . . . . . . .3234 7.5.2 Case #2: Subscription Type 'both' . . . . . . . . . . . . .3335 7.6 Removing a Roster Item and Cancelling All Subscriptions . .3437 8. Blocking Communication . . . . . . . . . . . . . . . . . . .3638 Saint-Andre & Miller Expires August27,31, 2003 [Page 2] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 8.1 Syntax . . . . . . . . . . . . . . . . . . . . . . . . . . .3638 8.2Processing OrderBusiness Rules . . . . . . . . . . . . . . . . . . . . . .37. 40 8.3 Retrieving One's Privacy Lists . . . . . . . . . . . . . . .3841 8.4 Managing Active Lists . . . . . . . . . . . . . . . . . . .3943 8.5 Managing the Default List . . . . . . . . . . . . . . . . .4044 8.6 Editing a Privacy List . . . . . . . . . . . . . . . . . . .4146 8.7 Removing a Privacy List . . . . . . . . . . . . . . . . . .4146 8.8 Blocking Messages . . . . . . . . . . . . . . . . . . . . .4247 8.9 Blocking Inbound Presence Notifications . . . . . . . . . .4449 8.10 Blocking Outbound Presence Notifications . . . . . . . . . .4550 8.11 Blocking IQs . . . . . . . . . . . . . . . . . . . . . . . .4752 8.12 Blocking All Communication . . . . . . . . . . . . . . . . .4954 8.13 Blocked Entity Attempts to Communicate with User . . . . . .5055 8.14 Higher-Level Heuristics . . . . . . . . . . . . . . . . . .5156 9. Routing and Delivery Rules . . . . . . . . . . . . . . . . .5358 9.1 Client Generation of To Addresses . . . . . . . . . . . . .5358 9.2 Server Handling of XML Stanzas . . . . . . . . . . . . . . .5358 10. IANA Considerations . . . . . . . . . . . . . . . . . . . .5560 11. Security Considerations . . . . . . . . . . . . . . . . . .5661 References . . . . . . . . . . . . . . . . . . . . . . . . .5762 Authors' Addresses . . . . . . . . . . . . . . . . . . . . .5762 A. vCards . . . . . . . . . . . . . . . . . . . . . . . . . . .58 A.1 Retrieving One's vCard . . . . . . . . . . . . . . . . . . . 58 A.2 Updating One's vCard . . . . . . . . . . . . . . . . . . . . 59 A.3 Viewing Another User's vCard . . . . . . . . . . . . . . . . 6063 B. Formal Definitions . . . . . . . . . . . . . . . . . . . . .6164 B.1 Schema for jabber:iq:last . . . . . . . . . . . . . . . . .6164 B.2 Schema for jabber:iq:privacy . . . . . . . . . . . . . . . .6164 B.3 Schema for jabber:iq:roster . . . . . . . . . . . . . . . .63 B.4 DTD for vcard-temp . . . . .66 C. Provisional Namespace Names . . . . . . . . . . . . . . . .64 C.68 D. Revision History . . . . . . . . . . . . . . . . . . . . . .71 C.169 D.1 Changes fromdraft-ietf-xmpp-im-03draft-ietf-xmpp-im-04 . . . . . . . . . . . . .71 C.269 D.2 Changes fromdraft-ietf-xmpp-im-02draft-ietf-xmpp-im-03 . . . . . . . . . . . . .71 C.369 D.3 Changes fromdraft-ietf-xmpp-im-01draft-ietf-xmpp-im-02 . . . . . . . . . . . . .71 C.469 D.4 Changes fromdraft-ietf-xmpp-im-00draft-ietf-xmpp-im-01 . . . . . . . . . . . . .71 C.569 D.5 Changes fromdraft-miller-xmpp-im-02draft-ietf-xmpp-im-00 . . . . . . . . . . . .72 Full Copyright Statement. 70 D.6 Changes from draft-miller-xmpp-im-02 . . . . . . . . . . . . 70 Intellectual Property and Copyright Statements . . . . . . .7371 Saint-Andre & Miller Expires August27,31, 2003 [Page 3] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 1. Introduction 1.1 Overview The core features of the Extensible Messaging and Presence Protocol are defined in XMPP Core [1]. These features -- specifically XML streams, stream authentication and encryption, and the <message/>, <presence/>, and <iq/> children of the stream root -- provide the building blocks for many types of near-real-time applications, which may be layered on top of the core by sending application-specific data scoped by particular XML namespaces. This document describes the extensions to and applications of XMPP Core that are used to create the basic functionality expected of an instant messaging and presence application as defined in RFC 2779 [2].Extended namespaces for many other functionality areas have been defined1.2 Requirements For the purposes of this document, we stipulate that a basic instant messaging andcontinuepresence application needs tobe defined byenable a user to perform theJabber Software Foundation [3], including service discovery, multi-user chat, data gathering and forms submission, feature negotiation, message composing events, message expiration, delayed delivery, file transfer, publish-subscribe, and transports for XML-RPC and SOAP; however, such functionality is not described herein because it is not required by RFC 2779 [2]. 1.2 Requirements For the purposes of this document, we stipulate that a basic instant messaging and presence application needs to enable a user to perform the following high-level functionality by using a compliant client: o Authenticatefollowing high-level use cases: o Authenticate and authorize with a server o Exchange messages with other users o Exchange presence information with other users o Manage subscriptions to and from other users o Manage the items in the user's contact list (in XMPP this is called a "roster") o Block communications to or from specific other users Detailed definitions of these functionality areas are contained in RFC 2779[2];[2], and the interested reader is directed to that document regarding the requirements addressed herein. Note: although XMPP IM meetsthose requirements,the requirements of RFC 2779, it was not designed explicitly with RFC 2779 in mind, since the base protocol evolved through an open development process within the Jabberopen- sourceopen-source community, mainly in 1999. In addition, protocols addressing many other functionality areas have been defined and continue to be defined by the Jabber Software Foundation [3]. These include service discovery, multi-user chat, data gathering and forms submission, feature negotiation, message composing events, message expiration, delayed delivery, file transfer, XHTML message formatting, publish-subscribe, and transports for XML-RPC and SOAP. Saint-Andre & Miller Expires August27,31, 2003 [Page 4] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 However, such protocols are not described herein because they are not required by RFC 2779 [2]. 1.3 Terminology This document inherits the terminology defined in XMPP Core [1]. The capitalized 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 RFC 2119 [4]. 1.4 Discussion Venue The authors welcome discussion and comments related to the topics presented in this document. The preferred forum is the <xmppwg@jabber.org> mailing list, for which archives and subscription information are available at <http://www.jabber.org/cgi-bin/mailman/ listinfo/xmppwg/>. 1.5 Intellectual Property Notice This document is in full compliance with all provisions of Section 10 of RFC 2026. Parts of this specification use the term "jabber" for identifying namespaces and other protocol syntax. Jabber[tm] is a registered trademark of Jabber, Inc. Jabber, Inc. grants permission to the IETF for use of the Jabber trademark in association with this specification and its successors, if any. Saint-Andre & Miller Expires August27,31, 2003 [Page 5] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 2. Authentication and AuthorizationIn order to gain access to the network of XMPP-compliant applications and thus engage in standardBecause XMPP-based IMfunctionality such as exchanging messages and presence,applications are usually implemented via a client-server architecture, a user must first acquire an account on a server. Although account provisioning is outside the scope of XMPP, methods for doing so include account creation by a server administrator as well as in-band account registration using the 'jabber:iq:register' namespace; the latter method isdefineddocumented by the Jabber Software Foundation [3]and appropriate documentation is availableatthe JSF's website. In order to gain access to the network,<http://www.jabber.org/ protocol/>. Once a user has acquired an account, the user MUST authenticate with the server hosting his or heraccount.account in order to gain access to the network. If a user's client is capable of authenticating by means of SASL, it MUST include a 'version' attribute (set to a value of "1.0") within the opening<stream/> element<stream> tag with which itinitiatedinitiates communications with the server. The protocol describing how a client authenticates with a server using SASL is defined in XMPP Core [1]. (Note: the Jabber precursor to XMPP contained a client-server authentication protocol that was enforced after the stream was negotiated; this protocol is not supported in XMPP but is documented by the Jabber Software Foundation [3] at <http://www.jabber.org/ protocol/>. Once a client has authenticated with aserver using SASL,server, it MUST define a resource that the server can associate with the connection for purposes of authorization and addressing. This is necessary because stanzas sent to or received from the server within the context of an active IM session use a "full JID"(user@domain/resource)(<user@domain/resource>) for addressing. Authorizing a resource is accomplished by means of the 'jabber:iq:auth' namespace as described below. Step 1: Client queries server regarding information that is still required to begin a session: <iqtype="get" id="res_1">type='get' id='res_1'> <queryxmlns="jabber:iq:auth">xmlns='jabber:iq:auth'> <username>juliet</username> </query> </iq>Step 2: Server responds with the required fieldsSaint-Andre & Miller Expires August 31, 2003 [Page 6] Internet-Draft XMPP Instant Messaging March 2003 Step 2: Server responds with the required fields (in this case, only the username and authorized resource): <iqtype="result" id="res_1">type='result' id='res_1'> <queryxmlns="jabber:iq:auth">xmlns='jabber:iq:auth'> <username>juliet</username> <resource/> </query> </iq>Saint-Andre & Miller Expires August 27, 2003 [Page 6] Internet-Draft XMPP Instant Messaging February 2003Step 3: Client sends name of authorized resource: <iqtype="set" id="res_2">type='set' id='res_2'> <queryxmlns="jabber:iq:auth">xmlns='jabber:iq:auth'> <username>juliet</username> <resource>balcony</resource> </query> </iq> Step 4: Server informs client of successful session initiation: <iqtype="result" id="res_2"/>type='result' id='res_2'/> Step 4 (alt): Server informs client oferror encountered during session initiation:XML formatting error: <iq type='result' id='res_2'> <query xmlns='jabber:iq:auth'> <username>juliet</username> </query> <error class='app'> <auth-condition xmlns='jabber:iq:auth:error'> <no-resource-provided/> </auth-condition> </error> </iq> Saint-Andre & Miller Expires August 31, 2003 [Page 7] Internet-Draft XMPP Instant Messaging March 2003 Step 4 (alt): Server informs client of resource formatting error: <iqtype="result" id="res_2">type='result' id='res_2'> <queryxmlns="jabber:iq:auth">xmlns='jabber:iq:auth'> <username>juliet</username><resource></resource><resource> </username> </query> <errorcode='406'>Not Acceptable (empty resource)</error> </iq> NOTE: Earlier iterationsclass='app'> <auth-condition xmlns='jabber:iq:auth:error'> <bad-resource-format/> </auth-condition> </error> </iq> Step 4 (alt): Server informs client ofthe Jabber protocol contained a client- server authentication protocol that was enforced after the stream was negotiated; this protocolresource conflict (the desired resource name isnot suppotedalready inXMPP but is documenteduse bythe Jabber Software Foundation [3] for historical purposes.another active connection): <iq type='result' id='res_2'> <query xmlns='jabber:iq:auth'> <username>juliet</username> <resource>balcony</resource> </query> <error class='app'> <auth-condition xmlns='jabber:iq:auth:error'> <resource-conflict/> </auth-condition> </error> </iq> Saint-Andre & Miller Expires August27,31, 2003 [Page7]8] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 3. Exchanging Messages Exchanging messages is a basic use of XMPP and is effected when a user sends a message stanza to another user (or, more generally, another entity). As defined under Routing and Delivery Rules (Section 9), the sender's server is responsible for delivering the message to the intended recipient (if the recipient is on the same server) or for routing the message to the recipient's server (if the recipient is on a different server). Detailed information regarding the syntax of message stanzas and their defined attributes and child elements may be found in XMPP Core [1]. 3.1 Specifying an Intended Recipient A client SHOULD specify an intended recipient for the message by providing an appropriate JID in the 'to' attribute of the <message/> element. Normally, the value of the 'to' attribute specifies an entity other than the sendinguser.user (see Section 9 for exceptions). The intended recipient MAY be any valid JID(e.g., a(a user on the same server, a user on a different server, the server itself, another server,or a service).etc.). If the JID is invalid or cannot be contacted, the entity discovering that fact (usually the sender's or recipient's server) MUST return an error to the sender. 3.2 Specifying a Message Type As mentioned in XMPP Core [1], there are several defined types of messages (specified by means of a 'type' attribute within the <message/> element). In the context of an instant messaging application, a client MAY include a message type in order to capture the conversational context of the message, thus providing a hint regarding presentation (e.g., in a GUI). If included, the 'type' attribute SHOULD have one of the following values (any other value MAY be ignored): o chat -- The message is sent in the context of a one-to-one chat conversation. o groupchat -- The message is sent in the context of a multi-user chat environment. o headline -- The message is generated by an automated service that delivers content (news, sports, market information, RSS feeds, etc.). o error - A message returned to a sender specifying an error Saint-Andre & Miller Expires August27,31, 2003 [Page8]9] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 associated with a previous message sent by the sender (fora full list ofdetails regarding stanza errormessages,syntax, see XMPP Core [1]) Although the 'type' attribute is OPTIONAL, it is considered polite to mirror the type in any replies to a message; furthermore, some specialized applications (e.g., a multi-user chat service) MAY at their discretion enforce the use of a particular message type (e.g., type='groupchat'). 3.3 Specifying a Message Subject A message stanza MAY contain a child <subject/> element specifying the subject of the message. The subject MUST NOT contain mixed content. Multiple <subject/> elements MAY be included, as long as each contains an 'xml:lang' attribute with a distinct value. A message with a subject: <messageto="romeo@montague.net" from="juliet@capulet.com/balcony">to='romeo@montague.net' from="juliet@capulet.com/balcony'> <subject>Imploring</subject> <body>Wherefore art thou, Romeo?</body> </message> 3.4 Specifying a Conversation Thread A message stanza MAY contain a child <thread/> element specifying the conversation thread in which the message is situated, for the purpose of tracking the conversation. The content of the <thread/> element is a random string that is generated by the sender in accordance with the algorithm specified in XMPP Core [1]; this string SHOULD be copied back to the sender in subsequent replies. Saint-Andre & Miller Expires August27,31, 2003 [Page9]10] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 A threaded conversation: <messageto="romeo@montague.net/orchard" from="juliet@capulet.com/balcony" type="chat">to='romeo@montague.net/orchard' from='juliet@capulet.com/balcony' type='chat'> <body>Art thou not Romeo, and a Montague?</body> <thread>e0ffe42b28561960c6b12b944a092794b9683a38</thread> </message> <messageto="juliet@capulet.com/balcony" from="romeo@montague.net/orchard" type="chat">to='juliet@capulet.com/balcony' from='romeo@montague.net/orchard' type='chat'> <body>Neither, fair saint, if either thee dislike.</body> <thread>e0ffe42b28561960c6b12b944a092794b9683a38</thread> </message> <messageto="romeo@montague.net/orchard" from="juliet@capulet.com/balcony" type="chat">to='romeo@montague.net/orchard' from='juliet@capulet.com/balcony' type='chat'> <body>How cam'st thou hither, tell me, and wherefore?</body> <thread>e0ffe42b28561960c6b12b944a092794b9683a38</thread> </message> 3.5 Specifying a Message Body A message stanza MAY (and often will) contain a child <body/> element specifying the main content of the message as CDATA. The body MUST NOT contain mixed content. If it is necessary to provide the main message content in an alternate form (e.g., encrypted using the public key infrastructure or formatted using XHTML), the alternate form MUST be contained in an appropriately-namespaced child of the message stanza, as defined for any such extended namespace. Multiple <body/> elements MAY be included, as long as each contains an 'xml:lang' attribute with a distinct value. 3.6 Specifying Additional Information A message stanza MAY house an element containing content that extends the meaning of the message (e.g., an encrypted form of the message body). In common usage this child element is often the <x/> element but MAY be any element, as long as the 'xmlns' namespace declaration is something other than the streams namespace or the default namespace; this extended namespace defines all elements contained within the child element. Saint-Andre & Miller Expires August27,31, 2003 [Page10]11] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003within the child element.3.7 Message-Related Errors If a message sent by a sender cannot be delivered, the entity discovering that fact (usually either the sender's or recipient's server) MUST return that message to the sender in a message stanza of type "error" along with an appropriate error message (fora list ofdetails regarding stanza errormessages,syntax, see XMPP Core[1]).[1]) A message-related error: <messageto="juliet@capulet.com" from="romeo@montague.net"> <body>Sleep dwell upon thine eyes.</body> </message> <message to="romeo@montague.net" from="juliet@capulet.com" type="error">to='romeo@montague.net' from='juliet@capulet.com' type='error'> <body>Sleep dwell upon thine eyes.</body> <errorcode="404">We're sorry, Juliet just died</error>class='address'> <stanza-condition xmlns='urn:ietf:rfc:xmppcore-rfc-number:stanzas'> <jid-not-found/> </stanza-condition> </error> </message>An entity that receives a message stanza of type 'error' MUST NOT respond to the stanza by sending a further message stanza of type 'error'; this helps to prevent looping.Saint-Andre & Miller Expires August27,31, 2003 [Page11]12] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 4. Exchanging Presence Information Exchanging presence information is made relatively straightforward within XMPP by using presence stanzas. However, we see here a contrast to the handling of messages: although a client MAY send directed presence information to another entity, in general presence information is sent from a client to a server (with no 'to' address) and then broadcasted by the server to any entities that are subscribed to the presence of the sending entity. (Note: in the terminology of RFC 2778 [5], the only watchers in XMPP are subscribers.) Detailed information regarding the syntax of presence stanzas and their defined attributes and child elements may be found in XMPP Core [1]. 4.1 Client and Server Responsibilities When a client connects to a server, it SHOULD send an initial presence stanza to the server to express default availability. This presence stanza MUST possess no 'to' address (signalling that it is meant to be handled by the server on behalf of the user) and SHOULD have no type. Upon receiving initial presence from a client, the serversendsMUST send presence probes from the full JID (user@domain/resource) of the user to any remote entities that are subscribed to the user's presence (as represented in the user's roster) in order to determine if they are available. (The remote server is responsible for responding to the presence probe only when (1) the probing entity has been allowed to access the probed entity's presence, e.g., by server rules or user subscriptions, and (2) the probed entity isavailable; theavailable. The probing entity's server then informs the probing entity of the probed entity's last known available presence, for all of the probed entity's resources if applicable.) Throughout the active session of a connected resource, the server is responsible for broadcasting any changes in the availability status of the connected resource to the subscribed entities that are available, so that such entities are kept apprised of availability changes. Finally, when a connected resource becomes unavailable, the server MUST notify all of the subscribedand availableentitieswhen a connected resource becomes unavailable. 4.2 Sending Initial Presence Upon authenticating, a client SHOULD send initial presencethat are available, as well as any entities toitswhich the user sent directed presence during the active session for that connected resource. Saint-Andre & Miller Expires August27,31, 2003 [Page12]13] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 4.2 Sending Initial Presence Upon authenticating, a client SHOULD send initial presence to its server indicating that the connected resource is available for communications. This presence stanza MUST have no 'to' address and SHOULD have no type. Initial presence sent from client to server: <presence/> 4.3 Specifying Availability Status A client MAY provide further information about its availability status by using the <show/> element. Asdefinedmentioned in XMPP Core [1], the recognized values for the show elementare "away", "chat", "xa", and "dnd".are: o away -- The entity or resource is temporarily away. o chat -- The entity or resource is actively interested in chatting. o xa -- The entity or resource is away for an extended period (xa = "eXtended Away"). o dnd -- The entity or resource is busy (dnd = "Do Not Disturb"). Availability status: <presence> <show>away</show> </presence> 4.4 Specifying Detailed Status Information In conjunction with the <show/> element, a client MAY provide detailed status information by using the <status/> element. The content of this element is a natural-language description of the client's current availability status. Detailed status information: <presence> <show>dnd</show> <status>Busy fighting the Romans</status> </presence> Saint-Andre & Miller Expires August 31, 2003 [Page 14] Internet-Draft XMPP Instant Messaging March 2003 4.5 Probing for Presence A server MAY probe for the current presence of another entity. A user or client SHOULD NOT send presence stanzas of type 'probe'. 4.6 Sending Final Presence Upon ending its session with a server, a client SHOULD gracefully become unavailable by sending a final presence stanza that is explicitly of type unavailable.Saint-Andre & Miller Expires August 27, 2003 [Page 13] Internet-Draft XMPP Instant Messaging February 2003Sending final presence to express unavailable state: <presencetype="unavailable"/>type='unavailable'/> Optionally, final presence MAY contain one or more <status/> elements specifying the reason why the user is no longer available. The server MUST NOT depend on receiving final presence from a connected resource, since the resource may become unavailable unexpectedly. If a server detects that a resource has become unavailable for any reason (either gracefully or ungracefully), it MUST send <presence type="unavailable"/> to all online entities that are subscribed to the associated user's presence, as well as to any entities to which the user sent directed presence during the active session for that connected resource. 4.7 Determining When a Contact Went Offline The server MUST maintain a record of the time at which a user became unavailable (whether gracefully or ungracefully). An authorized subscriber to that user's presence MAY determine the time of last activity by sending an IQ stanza to the user's bare JID (user@domain) containing an empty <query/> element scoped by the 'jabber:iq:last' namespace: Requesting the last active time of a user: <iq type='get' to='user@domain'> <query xmlns='jabber:iq:last'/> </iq> If the entity requesting the time of last activity is an authorized subscriber to the user's presence, the serverMUSTSHOULD return an IQ stanza of type 'result' with the number of seconds since the user was lastactive:active (subject to service provisioning and privacy configuration at a particular deployment): Saint-Andre & Miller Expires August 31, 2003 [Page 15] Internet-Draft XMPP Instant Messaging March 2003 Returning the last active time of a user: <iq from='user@domain' type='result' to='subscriber@domain/resource'> <query seconds='76490' xmlns='jabber:iq:last'/> </iq> If the entity requesting the time of last activity is not an authorized subscriber to the user's presence, the server MUST return an IQ stanza of type 'error' with an errorcodecondition of403 (Forbidden): Saint-Andre & Miller Expires August 27, 2003 [Page 14] Internet-Draft XMPP Instant Messaging February 2003forbidden: Requester is forbidden to view the last active time of a user: <iq from='user@domain' type='result' to='subscriber@domain/resource'> <query xmlns='jabber:iq:last'/> <errorcode='403'>Forbidden</error>class='access'> <stanza-condition xmlns='urn:ietf:rfc:xmppcore-rfc-number:stanzas'> <forbidden/> </stanza-condition> </error> </iq> Saint-Andre & Miller Expires August27,31, 2003 [Page15]16] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 5. Managing Subscriptions In order to protect the privacy of instant messaging users and any other entities, presence and availability information is made available only to other entities that the user has approved. When a user has agreed that another entity may view its presence, the entity is said to have a subscription to the user's presence information.Note well that aA subscription lasts across sessions; indeed, it lasts until the subscriber unsubscribes or the subscribee cancels the previously-granted subscription. Subscriptions arecompletedmanaged within XMPP by sending presence stanzas containing specially-defined attributes.Note thatNote: there are important interactions between subscriptions and rosters; these are defined under Integration of Roster Items and Presence Subscriptions (Section7).7), and the reader must refer to that section for a complete understanding of presence subscriptions. 5.1 Requesting a Subscription A request to subscribe to another entity's presence is made by sending a presence stanza of type "subscribe". Sending a subscription request: <presenceto="juliet@capulet.com" type="subscribe"/>to='juliet@capulet.com' type='subscribe'/> 5.2 Handling a Subscription Request When a client receives a subscription request from another entity, it MAY accept the request by sending a presence stanza of type "subscribed" or decline the request by sending a presence stanza of type "unsubscribed". Accepting a subscription request: <presenceto="romeo@montague.net" type="subscribed"/>to='romeo@montague.net' type='subscribed'/> Denying a presence subscription request: <presenceto="romeo@montague.net" type="unsubscribed"/>to='romeo@montague.net' type='unsubscribed'/> A user's server MUST NOT automatically accept subscription requests on the user's behalf. All subscription requests MUST be directed to the user's client. If there is no connected resource associated with the user when the subscription request is received, the user's server MUST store the subscription request offline for delivery when theuser next becomes available.Saint-Andre & Miller Expires August27,31, 2003 [Page16]17] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 user next becomes available. 5.3 Cancelling a Subscription from Another Entity If a user would like to cancel a previously-granted subscription request, it sends a presence stanza of type "unsubscribed". Cancelling a previously granted subscription request: <presenceto="romeo@montague.net" type="unsubscribed"/>to='romeo@montague.net' type='unsubscribed'/> 5.4 Unsubscribing from Another Entity's Presence If a user would like to unsubscribe from the presence of another entity, it sends a presence stanza of type "unsubscribe". Unsubscribing from an entity's presence: <presenceto="juliet@capulet.com" type="unsubscribe"/>to='juliet@capulet.com' type='unsubscribe'/> Saint-Andre & Miller Expires August27,31, 2003 [Page17]18] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 6. Managing One's Roster In XMPP, one's contact list is called a roster. A roster is stored by the server on the user's behalf so thatathe user may access roster information from any connected resource.Note thatNote: there are important interactions between rosters and subscriptions; these are defined under Integration of Roster Items and Presence Subscriptions (Section7).7), and the reader must refer to that section for a complete understanding of roster management. 6.1 Retrieving One's Roster on Login Upon connecting to the server, a client MAY request the roster (however, because receiving the roster may not be desirable for all resources, e.g., a connection with limited bandwidth, the client's request for the roster is OPTIONAL).Note that ifIf a connected resource does not request the roster during a session, it SHOULD never receive presence subscriptions and associated roster pushes. Client requests current roster from server: <iqtype="get" id="roster_1">type='get' id='roster_1'> <queryxmlns="jabber:iq:roster"/>xmlns='jabber:iq:roster'/> </iq> Saint-Andre & Miller Expires August27,31, 2003 [Page18]19] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 Client receives roster from the server: <iqfrom="capulet.com" to="juliet@capulet.com/balcony" id="roster_1" type="result"> <query xmlns="jabber:iq:roster> <item jid="romeo@montague.net" name="Romeo" subscription="both"/> <item jid="mercutio@montague.net" name="Mercutio" subscription="both">from='capulet.com' to='juliet@capulet.com/balcony' id='roster_1' type='result'> <query xmlns='jabber:iq:roster'> <item jid='romeo@montague.net' name='Romeo' subscription='both'/> <item jid='mercutio@montague.net' name='Mercutio' subscription='both'> <group>Friends</group> </item> <itemjid="benvolio@montague.net" name="Benvolio" subscription="both">jid='benvolio@montague.net' name='Benvolio' subscription='both'> <group>Friends</group> </item> </query> </iq> 6.2 Adding a Roster Item At any time, a user MAY add an item to his or her roster. Client adds a new item: <iqtype="set" id="roster_2">type='set' id='roster_2'> <queryxmlns="jabber:iq:roster">xmlns='jabber:iq:roster'> <itemname="Nurse" jid="nurse@capulet.com">name='Nurse' jid='nurse@capulet.com'> <group>Servants</group> </item> </query> </iq> The server is responsible for updating the roster information in persistent storage, and also for pushing that change out to all connected resources associated with the user using an IQ stanza of type "set" (this is referred to as a "roster push"). This "roster Saint-Andre & Miller Expires August27,31, 2003 [Page19]20] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 push" enables all connected resources to remain in sync with the server-based roster information. Server replies with an IQ result to the sending resource and pushes the updated roster information to all connected resources: <iqfrom="capulet.com" to="juliet@capulet.com/balcony" type="result" id="roster_2"/> <iq from="capulet.com" to="juliet@capulet.com/balcony" type="set"/> <query xmlns="jabber:iq:roster"> <item name="Nurse" jid="nurse@capulet.com" subscription="none">from='capulet.com' to='juliet@capulet.com/balcony' type='result' id='roster_2'/> <iq from='capulet.com' to='juliet@capulet.com/balcony' type='set'/> <query xmlns='jabber:iq:roster'> <item name='Nurse' jid='nurse@capulet.com' subscription='none'> <group>Servants</group> </item> </query> </iq> <iqfrom="capulet.com" to="juliet@capulet.com/chamber" type="set"/> <query xmlns="jabber:iq:roster"> <item name="Nurse" jid="nurse@capulet.com" subscription="none">from='capulet.com' to='juliet@capulet.com/chamber' type='set'/> <query xmlns='jabber:iq:roster'> <item name='Nurse' jid='nurse@capulet.com' subscription='none'> <group>Servants</group> </item> </query> </iq> Updating an existing roster item (e.g., changing theGroup)group) is done in the same way as adding a new roster item, i.e., by sending the roster item in an IQ set to the server. 6.3 Deleting a Roster Item At any time, a user MAY delete an item from its roster by doing an IQ set and making sure that the value of the 'subscription' attribute is "remove" (a compliant server MUST ignore any other values of the 'subscription' attribute when received from a client). Saint-Andre & Miller Expires August27,31, 2003 [Page20]21] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 Client removes an item: <iqtype="set" id="roster_2">type='set' id='roster_2'> <queryxmlns="jabber:iq:roster">xmlns='jabber:iq:roster'> <itemname="Nurse" jid="nurse@capulet.com" subscription="remove">name='Nurse' jid='nurse@capulet.com' subscription='remove'> <group>Servants</group> </item> </query> </iq> As with adding a roster item, when deleting a roster item the server is responsible for updating the roster information in persistent storage, and also for initiating a "roster push" to all connected resources associated with the user. For further information about the implications of this command, see Section 7.6. Saint-Andre & Miller Expires August27,31, 2003 [Page21]22] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 7. Integration of Roster Items and Presence Subscriptions 7.1 Overview Some level of integration between roster items and presence subscriptions is normally expected by instant messaging users. This section describes the level of integration that must be supported within XMPP IM. There are four primary subscription states: o None -- Neither the user nor the contact is subscribed to the other's presence o To -- The user is subscribed to the contact's presence but there is no subscription from the contact to the user o From -- There is a subscription from the contact to the user, but the user has not subscribed to the contact's presence o Both -- Both the user and the contact are subscribed to each other's presence (i.e., the union of 'from' and 'to') Each of these states is reflected in the roster of both the user and the contact, thus resulting in durable subscription states. The details regarding how these subscription states interact with roster items is explained in the following sub-sections. As noted above, if a connected resource does not request the roster during a session, it SHOULD never receive presence subscriptions and the associated roster pushes. 7.2 User Subscribes to Contact The process by which a user subscribes to a contact, including the interaction between roster items and subscription states, is defined below. 1. In preparation for being able to render the contact in the user's client interface and for the server to keep track of the subscription, the user's clientMUSTSHOULD send an IQ stanza of type='set' in the 'jabber:iq:roster' namespace for the new roster item; the <item/> element MUST possess a 'jid' attribute, MAY possess a 'name' attribute, may containaone or more <group/> child, and MUST NOT posses a 'subscription' attribute: Saint-Andre & Miller Expires August27,31, 2003 [Page22]23] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 <iq type='set' id='int1'> <query xmlns='jabber:iq:roster'> <item jid='contact@domain' name='MyContact'/> </query> </iq> 2. The server then MUST (1) reply with an IQ stanza of type='result' and (2) initiate a "roster push" for the new roster item to all connected resources associated with this user, setting the subscription state set to 'none': <iq type='result' to='user@domain/resource' id='int1'/> <iq type='set' to='user@domain/resource'> <query xmlns='jabber:iq:roster'> <item jid='contact@domain' name='MyContact' subscription='none'/> </query> </iq> 3. In order to initiate the subscription, the user's client MUST then send a presence stanza of type='subscribe' to the contact: <presence to='contact@domain' type='subscribe'/> 4. The server MUST then initiate a second "roster push" to all connected resources associated with the user, setting the contact to the pending sub-state of the 'none' subscription state; this pending sub-state is denoted by the inclusion of the ask='subscribe' attribute in the roster item:<iq type='set' to='user@domain/resource'> <query xmlns='jabber:iq:roster'> <item jid='contact@domain' name='MyContact' subscription='none' ask='subscribe'/> </query> </iq>Saint-Andre & Miller Expires August27,31, 2003 [Page23]24] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 <iq type='set' to='user@domain/resource'> <query xmlns='jabber:iq:roster'> <item jid='contact@domain' name='MyContact' subscription='none' ask='subscribe'/> </query> </iq> Note: if the user did not create a roster item before sending the subscription request, the server MUST create one and send the above roster push to all of the user's connected resources. 5. The server MUST also deliver the presence stanza to the contact or route it to the contact's server for delivery to the contact, first stamping the stanza with the user's bare JID as the 'from' address: <presence to='contact@domain' from='user@domain' type='subscribe'/> 6. If the contact is online (i.e., there is a connected resource associated with the contact's account), the contact must now decide whether or not to accept the subscription request. (If the contact is offline, the contact's server MUST store the subscription request offline for delivery when the contact next becomes available.) Here we will assume the "happy path" that the contact accepts the subscription, in which case the contact's client MAY send a roster set to the server specifying the desired nickname and group for the user, and MUST send a presence stanza of type='subscribed' to the user. <iq type='set'> <query xmlns='jabber:iq:roster'> <item jid='user@domain' name='SomeUser'/> </query> </iq> <presence to='user@domain' type='subscribed'/> 7. The contact's server MUST now initiate a "roster push" to all connected resources associated with the contact, containing a roster item for the user with the subscription state set to Saint-Andre & Miller Expires August 31, 2003 [Page 25] Internet-Draft XMPP Instant Messaging March 2003 'from': <iq type='set' to='contact@domain/resource'> <query xmlns='jabber:iq:roster'> <item jid='user@domain' name='SomeUser' subscription='from'/> </query> </iq> 8. As a result of the fact that the contact has accepted the subscription request, the user's server MUST (1) deliver the presence stanza of type='subscribed' from the contact to theSaint-Andre & Miller Expires August 27, 2003 [Page 24] Internet-Draft XMPP Instant Messaging February 2003user, and (2) initiate a "roster push" to all connected resources associated with the user, containing an updated roster item for the contact with the subscription type set to a value of "to": <presence to='user@domain' type='subscribed' from='contact@domain'/> <iq type='set' to='user@domain/resource'> <query xmlns='jabber:iq:roster'> <item jid='contact@domain' name='MyContact' subscription='to'/> </query> </iq> From the perspective of the user, there is now a subscription to the contact; from the perspective of the contact, there is now a subscription from the user. The contact's server MUST now send the contact's current presence information to the user. (Note: If at this point the user sends another subscription request to the contact, the user's server MUST "swallow" that request and not send it on the contact.) 7.2.1 Alternate Flow The above activity flow represents the "happy path" related to the user's subscription request to the contact. The main alternate flow occurs if the contact denies the user's subscription request; in order to deny the request, the contact's client MUST send a presence stanza of type "unsubscribed" to the user: Saint-Andre & Miller Expires August 31, 2003 [Page 26] Internet-Draft XMPP Instant Messaging March 2003 <presence to='user@domain' type='unsubscribed'/> The user's server MUST then (1) deliver that presence stanza to the user and (2) initiate a "roster push" to all connected resources associated with the user, with the subscription attribute set to a value of "none":Saint-Andre & Miller Expires August 27, 2003 [Page 25] Internet-Draft XMPP Instant Messaging February 2003<presence to='user@domain' type='unsubscribed' from='contact@domain'/> <iq type='set' to='user@domain/resource'> <query xmlns='jabber:iq:roster'> <item jid='contact@domain' name='MyContact' subscription='none'/> </query> </iq> As a result of this activity, the contact is now in the user's roster with a subscription state of "none", whereas the user is not in the contact's roster at all. 7.3 Creating a Mutual Subscription The user and contaact can build on the foregoing to create a mutual subscription (i.e., a subscription of type "both"). The process is defined below. 1.TheIf the contact desires a mutual subscription, the contact MUST send a subscription request to the user (subject to user preferences, the contact's client MAY send this automatically): <presence to='user@domain' type='subscribe'/> 2. The contact's server MUST then initiate a "roster push" to all connected resources associated with the contact, with the user still in the 'from' subscription state but with a pending 'to' subscription denoted by the inclusion of the ask='subscribe' attribute in the roster item: Saint-Andre & Miller Expires August 31, 2003 [Page 27] Internet-Draft XMPP Instant Messaging March 2003 <iq type='set' to='contact@domain/resource'> <query xmlns='jabber:iq:roster'> <item jid='user@domain' name='SomeUser' subscription='from' ask='subscribe'/> </query> </iq> 3. If the user is online (i.e., there is a connected resource associated with the user's account), the user must now decideSaint-Andre & Miller Expires August 27, 2003 [Page 26] Internet-Draft XMPP Instant Messaging February 2003whether or not to accept the subscription request. (If the user is offline, the user's server MUST store the subscription request offline for delivery when the user next becomes available.) Here we will assume the "happy path" that the user accepts the subscription, in which case the user's client MUST send a presence stanza of type='subscribed' to the contact. <presence to='contact@domain' type='subscribed'/> 4. The user's server MUST then initiate a "roster push" to all connected resources associated with the user, containing a roster item for the contact with the subscription attribute set to a value of "both": <iq type='set' to='user@domain/resource'> <query xmlns='jabber:iq:roster'> <item jid='contact@domain' name='MyContact' subscription='both'/> </query> </iq> 5. As a result of the fact that the user has accepted the subscription request, the contact's server MUST (1) deliver the presence stanza of type='subscribed' from the user to the contact, and (2) initiate a "roster push" to all connected resources associated with the contact, containing an updated roster item for the user with the subscription type set to a value of "both": Saint-Andre & Miller Expires August 31, 2003 [Page 28] Internet-Draft XMPP Instant Messaging March 2003 <presence to='contact@domain' from='user@domain' type='subscribed'/> <iq type='set' to='contact@domain/resource'> <query xmlns='jabber:iq:roster'> <item jid='user@domain' name='SomeUser' subscription='both'/> </query> </iq> The user and the contact now have a mutual subscription to each other's presence -- i.e., the subscription is of type 'both'. The user's server MUST now send the user's current presence informationSaint-Andre & Miller Expires August 27, 2003 [Page 27] Internet-Draft XMPP Instant Messaging February 2003to the contact. (Note: If at this point the user sends a subscription request to the contact or the contact sends a subscription request to the user, the sending user's server will "swallow" that request and not send it on the intended recipient.) 7.3.1 Alternate Flow The above activity flow represents the "happy path" related to the contact's subscription request to the user. The main alternate flow occurs if the user denies thecontacts'scontact's subscription request; in order to deny the request, the user's client MUST send a presence stanza of type "unsubscribed" to the contact: <presence to='contact@domain' type='unsubscribed'/> The contact's server MUST then (1) deliver that presence stanza to the contact and (2) initiate a "roster push" to all connected resources associated with the contact, with the subscription attribute set to a value of "from" and with no 'ask' attribute: Saint-Andre & Miller Expires August 31, 2003 [Page 29] Internet-Draft XMPP Instant Messaging March 2003 <presence to='contact@domain' from='user@domain' type='unsubscribed'/> <iq type='set' to='contact@domain/resource'> <query xmlns='jabber:iq:roster'> <item jid='user@domain' name='SomeUser' subscription='from'/> </query> </iq> As a result of this activity, there has been no change in the subscription state; i.e., the contact is in the user's roster with a subscription state of "to" and the user is in the contact's roster with a subscription state of "from". 7.4 Unsubscribing At any time after subscribing to a contact's presence, a user MAY unsubscribe. While the XML that the user sends to make this happen is the same in all instances, the subsequent subscription state is different depending on the subscription state obtaining when the unsubscribe command is sent. Both possible scenarios are defined below.Saint-Andre & Miller Expires August 27, 2003 [Page 28] Internet-Draft XMPP Instant Messaging February 20037.4.1 Case #1: Subscription Type 'to' In the first case, the user has a subscription to the contact but the contact does not have a subscription to the user (i.e., the subscription is not yet mutual). 1. In order to unsubscribe from the contact's presence, the user MUST send a presence stanza of type "unsubscribe" to the contact: <presence to='contact@domain' type='unsubscribe'/> 2. As a result, the user's server MUST send a "roster push" to each connected resource associated with the user, containing a roster item for the contact with the 'ask' attribute set to unsubscribe to indicate that the unsubscribe is pending: Saint-Andre & Miller Expires August 31, 2003 [Page 30] Internet-Draft XMPP Instant Messaging March 2003 <iq type='set' to='user@domain/resource'> <query xmlns='jabber:iq:roster'> <item jid='contact@domain' name='MyContact' subscription='to' ask='unsubscribe'/> </query> </iq> 3. Since the unsubscribe command does not normally need to be approved by the contact, the contact's server then SHOULD auto-reply on behalf of the contact by sending a presence stanza of type "unsubscribed" to the user; additionally, it MUST send unavailable presence from the contact to the user: <presence to='user@domain' from='contact@domain' type='unsubscribed'/> <presence to='user@domain' from='contact@domain' type='unavailable'/> 4. The contact's server also MUST initiate a "roster push" to all connected resources associated with the contact, containing a roster item for the user with the 'subscription' attribute set to a value of "none" (if the contact is offline, the contact's server MUST modify the roster item and send that modified item the next time the contact requests the roster):Saint-Andre & Miller Expires August 27, 2003 [Page 29] Internet-Draft XMPP Instant Messaging February 2003<iq type='set' to='contact@domain/resource'> <query xmlns='jabber:iq:roster'> <item jid='user@domain' name='SomeUser' subscription='none'/> </query> </iq> 5. As aresult of the fact that the contact has acknowledged the unsubscribe command,result, the user's server MUST (1) deliver the presence stanza of type='unsubscribed' from the contact to the user,and(2) initiate a "roster push" to all connected resources associated with the user, containing an updated roster item for the contact with the subscription type set to a value of "none" and with no 'ask'attribute:attribute, and (3) deliver the unavailable presence from Saint-Andre & Miller Expires August 31, 2003 [Page 31] Internet-Draft XMPP Instant Messaging March 2003 the user to the contact: <presence to='user@domain' from='contact@domain' type='unsubscribed'/> <iq type='set'> <query xmlns='jabber:iq:roster'> <item jid='contact@domain' subscription='none' name='MyContact'/> </query> </iq> <presence to='user@domain' from='contact@domain' type='unavailable'/> 7.4.2 Case #2: Subscription Type 'both' In the second case, the user has a subscription to the contact and the contact also has a subscription to the user. 1. In order to unsubscribe from the contact's presence, the user MUST send a presence stanza of type "unsubscribe" to the contact: <presence to='contact@domain' type='unsubscribe'/> 2. As a result, the user's server MUST send a "roster push" to each connected resource associated with the user, containing a roster item for the contact with the 'ask' attribute set to unsubscribe to indicate that the unsubscribe is pending:Saint-Andre & Miller Expires August 27, 2003 [Page 30] Internet-Draft XMPP Instant Messaging February 2003<iq type='set' to='user@domain/resource'> <query xmlns='jabber:iq:roster'> <item jid='contact@domain' name='MyContact' subscription='both' ask='unsubscribe'/> </query> </iq> Saint-Andre & Miller Expires August 31, 2003 [Page 32] Internet-Draft XMPP Instant Messaging March 2003 3. Since the unsubscribe command does not normally need to be approved by the contact, the contact's server then SHOULD auto-reply on behalf of the contact by sending a presence stanza of type "unsubscribed" to the user; additionally, it MUST send unavailable presence from the contact to the user: <presence to='user@domain' from='contact@domain' type='unsubscribed'/> <presence to='user@domain' from='contact@domain' type='unavailable'/> 4. The contact's server also MUST initiate a "roster push" to all connected resources associated with the contact, containing a roster item for the user with the 'subscription' attribute set to a value of "to" (if the contact is offline, the contact's server MUST modify the roster item and send that modified item the next time the contact requests the roster): <iq type='set' to='contact@domain/resource'> <query xmlns='jabber:iq:roster'> <item jid='user@domain' name='SomeUser' subscription='to'/> </query> </iq> 5. As aresult of the fact that the contact has acknowledged the unsubscribe command,result, the user's server MUST (1) deliver the presence stanza of type='unsubscribed' from the contact to the user,and(2) initiate a "roster push" to all connected resources associated with the user, containing an updated roster item for the contact with the subscription type set to a value of "from" and with no 'ask'attribute:attribute, and (3) deliver the unavailable presence from the user to the contact: Saint-Andre & Miller Expires August27,31, 2003 [Page31]33] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 <presence to='user@domain' from='contact@domain' type='unsubscribed'/> <iq type='set'> <query xmlns='jabber:iq:roster'> <item jid='contact@domain' subscription='none' name='MyContact'/> </query> </iq>NOTE:<presence to='user@domain' from='contact@domain' type='unavailable'/> Note: Obviously this does not result in removal of the roster item from the user's roster, and the contact still has a subscription to the user's presence. In order to more completely cancel a mutual subscription and fully remove the roster item from the user's roster, the user should update the roster item with subscription='remove' as defined in Section 7.6. 7.5 Cancelling a Subscription At any time after approving a subscription request from a user, a contact MAY cancel that subscription. While the XML that the contact sends to make this happen is the same in all instances, the subsequent subscription state is different depending on the subscription state obtaining when the cancellation is sent. Both possible scenarios are defined below. 7.5.1 Case #1: Subscription Type 'from' In the first case, the user has a subscription to the contact but the contact does not have a subscription to the user (i.e., the subscription is not yet mutual). 1. In order to cancel the user's subscription, the contact MUST send a presence stanza of type "unsubscribed" to the user: <presence to='user@domain' type='unsubscribed'/> 2. As a result, the contact's server MUST (1) send a "roster push" to each connected resource associated with the contact, Saint-Andre & Miller Expires August 31, 2003 [Page 34] Internet-Draft XMPP Instant Messaging March 2003 containing a roster item for the user with the 'subscription' attribute set to a value of"none": Saint-Andre & Miller Expires August 27, 2003 [Page 32] Internet-Draft XMPP Instant Messaging February 2003"none", and (2) send unavailable presence from the contact to the user: <iq type='set' to='contact@domain/resource'> <query xmlns='jabber:iq:roster'> <item jid='user@domain' name='SomeUser' subscription='none'/> </query> </iq> <presence to='user@domain' from='contact@domain' type='unavailable'/> 3. The user's server MUST then initiate a "roster push" to all connected resources associated with the user, containing a roster item for the contact with the 'subscription' attribute set to a value of "none" (if the user is offline, the user's server MUST modify the roster item and send that modified item the next time the user requests theroster):roster); additionally, it MUST also deliver the unavailable presence from the contact to the user: <iq type='set' to='user@domain/resource'> <query xmlns='jabber:iq:roster'> <item jid='contact@domain' name='MyContact' subscription='none'/> </query> </iq> <presence to='user@domain' from='contact@domain' type='unavailable'/> 7.5.2 Case #2: Subscription Type 'both' In the second case, the user has a subscription to the contact and the contact also has a subscription to the user. 1. In order to cancel the user's subscription, the user MUST send a presence stanza of type "unsubscribed" to the user: Saint-Andre & Miller Expires August 31, 2003 [Page 35] Internet-Draft XMPP Instant Messaging March 2003 <presence to='user@domain' type='unsubscribed'/> 2. As a result, the contact's server MUST (1) send a "roster push" to each connected resource associated with the contact, containing a roster item for the user with the 'subscription' attribute set to a value of"to": Saint-Andre & Miller Expires August 27, 2003 [Page 33] Internet-Draft XMPP Instant Messaging February 2003"to", and (2) send unavailable presence from the contact to the user: <iq type='set' to='contact@domain/resource'> <query xmlns='jabber:iq:roster'> <item jid='user@domain' name='SomeUser' subscription='to'/> </query> </iq> <presence to='user@domain' from='contact@domain' type='unavailable'/> 3. The user's server MUST then initiate a "roster push" to all connected resources associated with the user, containing a roster item for the contact with the 'subscription' attribute set to a value of "from" (if the user is offline, the user's server MUST modify the roster item and send that modified item the next time the user requests theroster):roster); additionally, it MUST also deliver the unavailable presence from the contact to the user: <iq type='set' to='user@domain/resource'> <query xmlns='jabber:iq:roster'> <item jid='contact@domain' name='MyContact' subscription='from'/> </query> </iq>NOTE:<presence to='user@domain' from='contact@domain' type='unavailable'/> Note: Obviously this does not result in removal of the roster item from the contact's roster, and the contact still has a subscription to the user's presence. In order to more completely cancel a mutual subscription and fully remove the roster item from the contact'sroster, the contact should update the roster item with subscription='remove' as defined inSaint-Andre & Miller Expires August 31, 2003 [Page 36] Internet-Draft XMPP Instant Messaging March 2003 roster, the contact should update the roster item with subscription='remove' as defined in Section 7.6. 7.6 Removing a Roster Item and Cancelling All Subscriptions Because there may be many steps involved in completely removing a roster item and reverting the subscription state to "none", XMPP IM includes a "shortcut" method for doing so. The process may be initiated by either a contact or a user no matter what the current subscription state is, by means of sending a roster set with the subscription attribute set to a value of "remove". For example, a user may send the following XML:Saint-Andre & Miller Expires August 27, 2003 [Page 34] Internet-Draft XMPP Instant Messaging February 2003<iq type='set'> <query xmlns='jabber:iq:roster'> <item jid='contact@domain' name='MyContact' subscription='remove'/> </query> </iq> When the user removes a contact from his or her roster by setting the 'subscription' attribute to a value of "remove", the user's server MUST automatically cancel any existing presence subscription between the user and the contact by sending presence stanzas of type "unsubscribe" and "unsubscribed" from the user to the contact. A contact may also send such a command, resulting in the same type of system behavior. Saint-Andre & Miller Expires August27,31, 2003 [Page35]37] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 8. Blocking Communication Most instant messaging systems have found it necessary to implement some method for users to block communications from particular other users (this is also required by sections 5.1.5, 5.1.15, 5.3.2, and 5.4.10 of RFC 2779 [2]). In XMPP this is done using the 'jabber:iq:privacy' namespace by managing one's privacy lists. Server-side privacy lists enable successful completion of the following use cases: o Retrieving one's privacy lists. o Adding, removing, and editing one's privacy lists. o Setting, changing, or declining active lists. o Setting, changing, or declining the default list (i.e., the list that is active by default). o Allowing or denying messages based on JID, group, or subscription type (or globally). o Allowing or denying inbound presence notifications based on JID, group, or subscription type (or globally). o Allowing or denying outbound presence notifications based on JID, group, or subscription type (or globally). o Allowing or denying IQs based on JID, group, or subscription type (or globally). o Allowing or denying all communications based on JID, group, or subscription type (or globally).Note well thatNote: presence notifications do not include presence subscriptions, only presence information that is broadcasted to entities that are subscribed to a user's presence information. Thus this includes presence stanzas with no 'type' attribute or of"type='unavailable'"type='unavailable' only. 8.1 Syntax A user may define one or more privacy lists, which are stored by the user's server. Each <list/> element contains one or morerulerules in the form of <item/> elements, and each <item/> element uses attributes to define a privacy rule type, a specific value within the type, the relevant action, and the place of the item in the processing order. Saint-Andre & Miller Expires August27,31, 2003 [Page36]38] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 The syntax is as follows: <iq> <query xmlns='jabber:iq:privacy'> <list name='foo'> <item type='[jid|group|subscription]' value='bar' action='[accept|deny]' order='nonNegativeInteger'/> </list> </query> </iq> If the type is "jid", then the 'value' attribute MUST contain a valid Jabber ID. JIDs are matched in the following order: "user@domain/ resource", then "user@domain", then "domain/resource", then "domain". If the value is "user@domain", then any connected resource for that user@domain matches. If the value is "domain", then any user@domain matches. If the value is "domain/resource", then only that resource matches. If the type is "group", then the 'value' attribute MUST contain the name of a group in the user's roster. If the type is "subscription", then the 'value' attribute MUST be one of "both", "to", "from", or "none" as defined in XMPP Core [1]. If no 'type' attribute is included, the rule provides the"fall- through""fall-through" case. The 'action' attribute MUST be included and its value MUST be either "accept" or "deny". The 'order' attribute MUST be included and its value MUST be anon- negativenon-negative integer that is unique among all items in the list. (If a client attempts to create or update a list with non-unique order values, the server MUST returna 400 "Bad Request" errorto theclient.) 8.2 Processing Order The orderclient a <bad-request/> error of class "format" inwhich privacy list items are processed bytheserver is important. List items MUST be processed in ascending order determined by'urn:ietf:rfc:xmppcore-rfc-number:stanzas' namespace.) Within thevalues of'jabber:iq:privacy' namespace, the'order' attribute for each <item/>. As soon as<query/> child of a client-generated IQ stanzais matched againstof type "set" MUST NOT include more than one child element (i.e., the stanza must contain only one <active/> element, one <default/> element, or one <list/> element); if aprivacy list,client violates this rule, the servercan appropriately handleMUST return to thestanza and cease processing. If no fall-through item is provided inclient alist,<bad-request/> error of class "format" in thefall-through'urn:ietf:rfc:xmppcore-rfc-number:stanzas' namespace.) Saint-Andre & Miller Expires August27,31, 2003 [Page37]39] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003action is assumed to be "accept". 8.3 Retrieving One's Privacy Lists Client requests names ofWhen a client adds or updates a privacylists from server: <iq type='get' id='getlist1'> <query xmlns='jabber:iq:privacy'/> </iq> Server sends names oflist, the <list/> element MUST contain at least one <item/> child element. When a client updates a privacylists to client, including defaultlist, it must include all of the desired items (i.e., not a "delta"). 8.2 Business Rules The active list affects only the session/resource for which it is activated, andactive list: <iq type='result' id='getlist1' to='romeo@montague.net/orchard'> <query xmlns='jabber:iq:privacy'> <default name='public'/> <active name='private'/> <list name='public'> <list name='private'/> <list name='special'/> </query> </iq> Client requests complete privacy lists from server: <iq type='get' id='getlist2'> <query xmlns='jabber:iq:privacy'> <list name='public'> <list name='private'/> <list name='special'/> </query> </iq> Saint-Andre & Miller Expires August 27, 2003 [Page 38] Internet-Draft XMPP Instant Messaging February 2003 Server sends complete privacy lists to client: <iq type='result' id='getlist2' to='romeo@montague.net/orchard'> <query xmlns='jabber:iq:privacy'> <list name='public'> <item jid='tybalt@capulet.com' type='deny' order='1'/> <item action='allow' order='2'/> </list> <list name='private'> <item type='subscription' value='both' action='allow' order='10'/> <item action='deny' order='15'/> </list> <list name='special'> <item type='jid' value='juliet@capulet.com' action='allow' order='6'/> <item type='jid' value='benvolio@shakespeare.lit' action='allow' order='7'/> <item type='jid' value='mercutio@shakespeare.lit' action='allow' order='42'/> <item action='deny'/> </list> </query> </iq> In this example, the user has three lists: (1) 'public', which allows communications from everyone except one specific entity; (2) 'private', which allows communicationsonlyfrom contacts who have a bi-directional subscription withfor theuser; and (3) 'special', which allows communications only from three specific entities. The active list currently being applied byduration of theserversession. If a stanza isthe 'private' list. 8.4 Managing Active Lists In orderaddressed toset or changea specific resource, only the active listcurrently being applied byfor that session is processed (i.e., theserver,default list is ignored). The default list applies to the userMUST send an IQ stanza of type 'set' with a <query/> element scoped by the 'jabber:iq:privacy' namespace that contains an empty <active/> child element possessingas a'name' attribute whose valuewhole, and is processed if there is no active list set for the target session/resource to which a stanza is addressed, or if there are no current sessions for thedesired list name. Client requests change ofuser. If there is no activelist: <iq type='set' id='active1'> <query xmlns='jabber:iq:privacy'> <active name='special'/> </query> </iq>list set for a session (or there are no current sessions for the user), and there is no default list, then all stanzas SHOULD BE accepted or appropriately processed by the server on behalf of the user. Privacy lists SHOULD be the first routing and delivery rule applied by a server, trumping the other rules specified in Section 9. The order in which privacy list items are processed by the server is important. List items MUSTactivatebe processed in ascending order determined by the values of the 'order' attribute for each <item/>. As soon as a stanza is matched against a privacy list, the server SHOULD appropriately handle the stanza andapplycease processing. If no fall-through item is provided in a list, therequestedfall-through action is assumed to be "accept". When a user updates the definition for a listbefore sendingor adds a new list (whether or not it is active), theresultserver SHOULD NOT "push" that information out to all connected resources associated with the user's account, as issent backdone for rosters. If a client or user wants to retrieve theclient.current privacy list information, it SHOULD request the relevant list. Saint-Andre & Miller Expires August27,31, 2003 [Page39]40] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003Server acknowledges success of active list change: <iq type='result' id='active1' to='juliet@capulet.com/balcony'/> In order to decline the use of any active list (i.e., to use the domain's stanza routing rules), a user MUST send an empty <active/> element with no name.8.3 Retrieving One's Privacy Lists Clientdeclines the userequests names ofactive lists:privacy lists from server: <iqtype='set' id='active2'>type='get' id='getlist1'> <queryxmlns='jabber:iq:privacy'> <active/> </query>xmlns='jabber:iq:privacy'/> </iq>8.5 Managing the Default List In order to change the default list associated with an account, the user MUST send an IQ stanzaServer sends names oftype 'set' with a <query/> element scoped by the 'jabber:iq:privacy' namespace that contains an empty <default/> child element possessing a 'name' attribute whose value is setprivacy lists tothe desired list name. Client requests change ofclient, including default list and active list: <iqtype='set' id='default1'>type='result' id='getlist1' to='romeo@montague.net/orchard'> <query xmlns='jabber:iq:privacy'> <active name='private'/> <default name='public'/> <list name='public'/> <list name='private'/> <list name='special'/> </query> </iq>Server acknowledges success of defaultClient requests a privacy listchange:from server: <iqtype='result' id='default1' to='juliet@capulet.com/balcony'/> In order to decline the use of the defaulttype='get' id='getlist2'> <query xmlns='jabber:iq:privacy'> <list name='public'/> </query> </iq> Server sends a privacy list(i.e.,touse the domain's stanza routing rules), a user MUST send an empty <default/> element with no name.client: <iq type='result' id='getlist2' to='romeo@montague.net/orchard'> <query xmlns='jabber:iq:privacy'> <list name='public'> <item jid='tybalt@capulet.com' type='deny' order='1'/> <item action='allow' order='2'/> </list> </query> </iq> Saint-Andre & Miller Expires August27,31, 2003 [Page40]41] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 Clientdeclines the use of the default list:requests another privacy list from server: <iqtype='set' id='default2'>type='get' id='getlist3'> <query xmlns='jabber:iq:privacy'><default/><list name='private'/> </query> </iq>8.6 Editing a Privacy List In order to edit aServer sends another privacylist, the user MUST send an IQ stanza of type 'set' with a <query/> element scoped by the 'jabber:iq:privacy' namespace that contains one or more <list/> child elements possessing a 'name' attribute whose value is set to thelistname the user would like to edit. Each <list/> element MUST contain one or more <item/> elements, which specify the user's desired changestothe list by including all elements in the list (not the "delta"); the same protocol is used to create a new list.client: <iq type='result' id='getlist3' to='romeo@montague.net/orchard'> <query xmlns='jabber:iq:privacy'> <list name='private'> <item type='subscription' value='both' action='allow' order='10'/> <item action='deny' order='15'/> </list> </query> </iq> Clientedits arequests yet another privacylist:list from server: <iqtype='set' id='edit1'>type='get' id='getlist4'> <query xmlns='jabber:iq:privacy'> <listname='public'>name='special'/> </query> </iq> Server sends yet another privacy list to client: <iq type='result' id='getlist4' to='romeo@montague.net/orchard'> <query xmlns='jabber:iq:privacy'> <list name='special'> <item type='jid'value='tybalt@capulet.com' action='deny' order='3'/>value='juliet@capulet.com' action='allow' order='6'/> <item type='jid'value='paris@shakespeare.lit' action='deny' order='5'/>value='benvolio@shakespeare.lit' action='allow' order='7'/> <item type='jid' value='mercutio@shakespeare.lit' action='allow'order='68'/>order='42'/> <item action='deny'/> </list> </query> </iq>Server acknowledges success of list edit: <iq type='result' id='edit1' to='juliet@capulet.com/balcony'/>In this example, the user hasaddedthree lists: (1) 'public', which allows communications from everyone except oneadditional entity to the "blacklist" portion of this privacy list. 8.7 Removing a Privacy List In order to removespecific entity; (2) 'private', which allows communications only from contacts who have aprivacy list, the user MUST send an IQ stanza of type 'set'bi-directional subscription witha <query/> element scopedthe user; and (3) 'special', which allows communications only from three specific entities. The active list currently being applied by the'jabber:iq:privacy' namespace that contains one or more empty <list/> child elements possessing a 'name' attribute whose valueserver isset tothelist name'private' list. If the userwould likeattempts toremove.retrieve a list but a list by that name does Saint-Andre & Miller Expires August27,31, 2003 [Page41]42] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 not exist, the server MUST return an application-specific "list not found" error to the user: Clientremoves a privacyattempts to retrieve non-existent list: <iqtype='set' id='remove1'>type='result' id='getlist5'> <query xmlns='jabber:iq:privacy'> <listname='private'/>name='The Empty Set'/> </query> <error class='app'> <privacy-condition xmlns='jabber:iq:privacy:error'> <list-not-found/> </privacy-condition> </error> </iq>Server acknowledges success ofThe user may retrieve only one listremoval: <iq type='result' id='remove1' to='juliet@capulet.com/balcony'/> Ifat ausertime. If the user attempts toremove an activeretrieve more than one listorin thedefault list,same request, the server MUST returna 405 (Not Allowed)an application-specific <too-many-lists/> error to the user.8.8 Blocking Messages Server-side privacy lists enable a userClient attempts toblock incoming messages from other users based on the other user's JID, roster group, or subscription status, or globally. The following examples illustrate the required protocol. User blocks based on JID:retrieve more than one list: <iqtype='set' id='msg1'>type='result' id='getlist6'> <query xmlns='jabber:iq:privacy'> <listname='message-jid-example'> <item type='jid' value='tybalt@capulet.com' type='deny' order='3'> <message/> </item> </list>name='public'/> <list name='private'/> <list name='special'/> </query> <error class='app'> <privacy-condition xmlns='jabber:iq:privacy:error'> <too-many-lists/> </privacy-condition> </error> </iq>As a result of creating and applying8.4 Managing Active Lists In order to set or change theforegoing list,active list currently being applied by theuser will not receive messages fromserver, the user MUST send an IQ stanza of type 'set' with a <query/> element scoped by thespecified JID.'jabber:iq:privacy' namespace that contains an empty <active/> child element possessing a 'name' attribute whose value is set to the desired list name. Saint-Andre & Miller Expires August27,31, 2003 [Page42]43] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003User blocks based on roster group:Client requests change of active list: <iq type='set'id='msg2'>id='active1'> <query xmlns='jabber:iq:privacy'><list name='message-group-example'> <item type='group' value='Enemies' type='deny' order='4'> <message/> </item> </list><active name='special'/> </query> </iq>As a result of creatingThe server MUST activate andapplyingapply theforegoing list,requested list before sending the result back to the client. Server acknowledges success of active list change: <iq type='result' id='active1' to='juliet@capulet.com/balcony'/> If the userwillattempts to set an active list but a list by that name does notreceive messages from any users inexist, thespecified roster group. User blocks based on subscription type: <iq type='set' id='msg2'> <query xmlns='jabber:iq:privacy'> <list name='message-sub-example'> <item type='subscription' value='none' type='deny' order='5'> <message/> </item> </list>server MUST return an application-specific "list not found" error to the user: Client attempts to set a non-existent list as active: <iq type='result' id='active2'> <query xmlns='jabber:iq:privacy'> <list name='The Empty Set'/> </query> <error class='app'> <privacy-condition xmlns='jabber:iq:privacy:error'> <list-not-found/> </privacy-condition> </error> </iq>As a resultIn order to decline the use ofcreating and applyingany active list (i.e., to use theforegoing list,domain's stanza routing rules for the duration of the session), a userwill not receive messages from any usersMUST send an empty <active/> element with no name. Client declines thespecified subscription type. User blocks globally:use of active lists: <iq type='set'id='msg4'>id='active2'> <query xmlns='jabber:iq:privacy'><list name='message-global-example'> <item type='deny' order='6'> <message/> </item> </list><active/> </query> </iq>As a result of creating and applying8.5 Managing theforegoing list,Default List In order to change the default list associated with an account, theuser will not receive messages from any other users.Saint-Andre & Miller Expires August27,31, 2003 [Page43]44] Internet-Draft XMPP Instant MessagingFebruaryMarch 20038.9 Blocking Inbound Presence Notifications Server-side privacy lists enable auserto block incoming presence notifications from other users based onMUST send an IQ stanza of type 'set' with a <query/> element scoped by theother user's JID, roster group, or subscription status, or globally. The following examples illustrate'jabber:iq:privacy' namespace that contains an empty <default/> child element possessing a 'name' attribute whose value is set to therequired protocol. User blocks based on JID:desired list name. Client requests change of default list: <iq type='set'id='presin1'>id='default1'> <query xmlns='jabber:iq:privacy'><list name='presin-jid-example'> <item type='jid' value='tybalt@capulet.com' type='deny' order='7'> <presence-in/> </item> </list><default name='special'/> </query> </iq>As a resultServer acknowledges success ofcreating and applying the foregoing list,default list change: <iq type='result' id='default1' to='juliet@capulet.com/balcony'/> If the userwill not receive presence notifications fromattempts to set a default list but a list by that name does not exist, theuser withserver MUST return an application-specific "list not found" error to thespecified JID. User blocks based on roster group:user: Client attempts to set a non-existent list as default: <iqtype='set' id='presin2'>type='result' id='default2'> <query xmlns='jabber:iq:privacy'> <listname='presin-group-example'> <item type='group' value='Enemies' type='deny' order='8'> <presence-in/> </item> </list>name='The Empty Set'/> </query> <error class='app'> <privacy-condition xmlns='jabber:iq:privacy:error'> <list-not-found/> </privacy-condition> </error> </iq>As a result of creating and applyingIn order to decline theforegoing list,use of a default list (i.e., to use the domain's stanza routing rules at all times), a userwill not receive presence notifications from any users inMUST send an empty <default/> element with no name. Client declines thespecified roster group.use of the default list: <iq type='set' id='default2'> <query xmlns='jabber:iq:privacy'> <default/> </query> </iq> Saint-Andre & Miller Expires August27,31, 2003 [Page44]45] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003User blocks based on subscription type: <iq type='set' id='presin3'> <query xmlns='jabber:iq:privacy'> <list name='presin-sub-example'> <item type='subscription' value='none' type='deny' order='9'> <presence-in/> </item> </list> </query> </iq> As8.6 Editing aresult of creating and applying the foregoingPrivacy List In order to edit a privacy list, the userwill not receive presence notifications from any usersMUST send an IQ stanza of type 'set' with a <query/> element scoped by thespecified subscription type. User blocks globally: <iq type='set' id='presin4'> <query xmlns='jabber:iq:privacy'> <list name='presin-global-example'> <item type='deny' order='11'> <presence-in/> </item> </list> </query> </iq> As'jabber:iq:privacy' namespace that contains one <list/> child element possessing aresult of creating and applying'name' attribute whose value is set to theforegoing list,list name the userwill not receive presence notifications from any other users. 8.10 Blocking Outbound Presence Notifications Server-side privacy lists enable a userwould like toblock outgoing presence notifications to other users based onedit. The <list/> element MUST contain one or more <item/> elements, which specify theotheruser'sJID, roster group, or subscription status, or globally. The following examples illustratedesired changes to therequired protocol. Saint-Andre & Miller Expires August 27, 2003 [Page 45] Internet-Draft XMPP Instant Messaging February 2003 User blocks based on JID:list by including all elements in the list (not the "delta"); the same protocol is used to create a new list. Client edits a privacy list: <iq type='set'id='presout1'>id='edit1'> <query xmlns='jabber:iq:privacy'> <listname='presout-jid-example'>name='public'> <item type='jid' value='tybalt@capulet.com'type='deny' order='13'> <presence-out/> </item>action='deny' order='3'/> <item type='jid' value='paris@shakespeare.lit' action='deny' order='5'/> <item action='allow' order='68'/> </list> </query> </iq>As a resultNote: The value ofcreating and applyingthe 'order' attribute for any given item is not fixed. Thus in the foregoinglist,example if the userwill not send presence notificationswould like to add 4 items between theuser with the specified JID. User blocks based on roster group: <iq type='set' id='presout2'> <query xmlns='jabber:iq:privacy'> <list name='presout-group-example'> <item type='group' value='Enemies' type='deny' order='15'> <presence-out/> </item> </list> </query> </iq> As a result of creating"tybalt@capulet.com" item andapplyingtheforegoing list,"paris@shakespeare.lit" item, theuser will not send presence notificationsuser's client can simply renumber all the items before submitting the list toany users inthespecified roster group. User blocks based on subscription type: <iq type='set' id='presout3'> <query xmlns='jabber:iq:privacy'> <list name='presout-sub-example'> <item type='subscription' value='none' type='deny' order='17'> <presence-out/> </item> </list> </query> </iq> As a resultserver. Server acknowledges success ofcreating and applying the foregoing list,list edit: <iq type='result' id='edit1' to='juliet@capulet.com/balcony'/> In this example, the userwill not send presence notificationshas added one additional entity toany users withthespecified subscription type. Saint-Andre & Miller Expires"blacklist" portion of this privacy list. 8.7 Removing a Privacy List In order to remove a privacy list, the user MUST send an IQ stanza of type 'set' with a <query/> element scoped by the 'jabber:iq:privacy' namespace that contains one empty <list/> child elements possessing a 'name' attribute whose value is set to the list name the user would like to remove. Saint-Andre & Miller Expires August27,31, 2003 [Page 46] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003User blocks globally:Client removes a privacy list: <iq type='set'id='presout4'>id='remove1'> <query xmlns='jabber:iq:privacy'> <listname='presout-global-example'> <item type='deny' order='23'> <presence-out/> </item> </list>name='private'/> </query> </iq>As a resultServer acknowledges success ofcreating and applyinglist removal: <iq type='result' id='remove1' to='juliet@capulet.com/balcony'/> If a user attempts to remove an active list or theforegoingdefault list, the server MUST return an application-specific <cannot-be-removed/> error to the user. If the userwillattempts to remove a list but a list by that name does notsend presence notificationsexist, the server MUST return an application-specific <list-not-found/> error toany other users. 8.11the user. If the user attempts to remove more than one list in the same request, the server MUST return an application-specific <too-many-lists/> error to the user. 8.8 BlockingIQsMessages Server-side privacy lists enable a user to block incomingIQ requestsmessages from other users based on the other user's JID, roster group, or subscription status, or globally. The following examples illustrate the required protocol. User blocks based on JID: <iq type='set' id='msg1'> <query xmlns='jabber:iq:privacy'> <listname='iq-jid-example'>name='message-jid-example'> <item type='jid' value='tybalt@capulet.com' type='deny'order='29'> <iq/>order='3'> <message/> </item> </list> </query> </iq> As a result of creating and applying the foregoing list, the user will not receiveIQ requestsmessages from the user with the specified JID. Saint-Andre & Miller Expires August27,31, 2003 [Page 47] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 User blocks based on roster group: <iq type='set' id='msg2'> <query xmlns='jabber:iq:privacy'> <listname='iq-group-example'>name='message-group-example'> <item type='group' value='Enemies' type='deny'order='31'> <iq/>order='4'> <message/> </item> </list> </query> </iq> As a result of creating and applying the foregoing list, the user will not receiveIQ requestsmessages from any users in the specified roster group. User blocks based on subscription type: <iq type='set'id='msg2'>id='msg3'> <query xmlns='jabber:iq:privacy'> <listname='iq-sub-example'>name='message-sub-example'> <item type='subscription' value='none' type='deny'order='17'> <iq/>order='5'> <message/> </item> </list> </query> </iq> As a result of creating and applying the foregoing list, the user will not receiveIQ requestsmessages from any users with the specified subscription type. User blocks globally: <iq type='set' id='msg4'> <query xmlns='jabber:iq:privacy'> <listname='iq-global-example'>name='message-global-example'> <item type='deny'order='1'> <iq/>order='6'> <message/> </item> </list> </query> </iq> As a result of creating and applying the foregoing list, the user will not receiveIQ requestsmessages from any other users. Saint-Andre & Miller Expires August27,31, 2003 [Page 48] Internet-Draft XMPP Instant MessagingFebruaryMarch 20038.128.9 BlockingAll CommunicationInbound Presence Notifications Server-side privacy lists enable a user to blockall communications from andincoming presencetonotifications from other users based on the other user's JID, roster group, or subscription status, or globally. The following examples illustrate the required protocol.User blocks based on JID: <iq type='set' id='all1'> <query xmlns='jabber:iq:privacy'> <list name='all-jid-example'> <item type='jid' value='tybalt@capulet.com' type='deny' order='23'>Note: presence notifications do not include presence subscriptions, only presence information that is broadcasted to the user because the user previously subscribed to a contact's presence information. Thus this includes presence stanzas with no 'type' attribute or of type='unavailable' only. User blocks based on JID: <iq type='set' id='presin1'> <query xmlns='jabber:iq:privacy'> <list name='presin-jid-example'> <item type='jid' value='tybalt@capulet.com' type='deny' order='7'> <presence-in/> </item> </list> </query> </iq> As a result of creating and applying the foregoing list, the user will not receiveany communications from, nor sendpresenceto,notifications from the user with the specified JID. User blocks based on roster group: <iq type='set'id='all2'>id='presin2'> <query xmlns='jabber:iq:privacy'> <listname='all-group-example'>name='presin-group-example'> <item type='group' value='Enemies' type='deny'order='13'/>order='8'> <presence-in/> </item> </list> </query> </iq> As a result of creating and applying the foregoing list, the user will not receiveany communications from, nor sendpresenceto,notifications from any users in the specified roster group. Saint-Andre & Miller Expires August 31, 2003 [Page 49] Internet-Draft XMPP Instant Messaging March 2003 User blocks based on subscription type: <iq type='set'id='all3'>id='presin3'> <query xmlns='jabber:iq:privacy'> <listname='all-sub-example'>name='presin-sub-example'> <item type='subscription' value='none' type='deny'order='11'/>order='9'> <presence-in/> </item> </list> </query> </iq> As a result of creating and applying the foregoing list, the user will not receiveany communications from, nor sendpresenceto,notifications from any users with the specified subscription type.Saint-Andre & Miller Expires August 27, 2003 [Page 49] Internet-Draft XMPP Instant Messaging February 2003User blocks globally: <iq type='set'id='all4'>id='presin4'> <query xmlns='jabber:iq:privacy'> <listname='all-global-example'>name='presin-global-example'> <item type='deny'order='7'/>order='11'> <presence-in/> </item> </list> </query> </iq> As a result of creating and applying the foregoing list, the user will not receiveany communications from, nor sendpresenceto,notifications from any other users.8.13 Blocked Entity Attempts to Communicate with User If8.10 Blocking Outbound Presence Notifications Server-side privacy lists enable ablocked entity attemptsuser tosend messages orblock outgoing presence notifications to other users based on theuser, theother user'sserver SHOULD silently drop the stanza and MUST NOT return an error toJID, roster group, or subscription status, or globally. The following examples illustrate thesending entity. If a blocked entity attemptsrequired protocol. Note: presence notifications do not include presence subscriptions, only presence information that is broadcasted tosend an IQ stanza of type "get" or "set"contacts because those contacts previously subscribed to theuser, theuser'sserver MUST return a 501 (Not Implemented) error to the sending entity, sincepresence information. Thus thisis the standard error code sent from a client that does not understand the namespace of an IQ get or set. IQincludes presence stanzas with no 'type' attribute or ofother types SHOULD be silently dropped by the server. Blocked entity attempts to send IQ get: <iq type='get' to='romeo@montague.net' from='tybalt@capulet.com/pda' id='probing1'> <query xmlns='jabber:iq:version'/> </iq>type='unavailable' only. Saint-Andre & Miller Expires August27,31, 2003 [Page 50] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003Server returns error to blocked entity:User blocks based on JID: <iqtype='error' from='romeo@montague.net' to='tybalt@capulet.com/pda' id='probing1'>type='set' id='presout1'> <queryxmlns='jabber:iq:version'/> <error code='501'>Not Implemented</error> </message> 8.14 Higher-Level Heuristics When buildingxmlns='jabber:iq:privacy'> <list name='presout-jid-example'> <item type='jid' value='tybalt@capulet.com' type='deny' order='13'> <presence-out/> </item> </list> </query> </iq> As arepresentationresult ofa higher-level privacy heuristic, a client SHOULD usecreating and applying thesimplest possible representation. For example,foregoing list, theheuristic "block all communications with anyuser will notin my roster" could be constructed in any ofsend presence notifications to thefollowing ways: o accept communications from all JIDs in myuser with the specified JID. User blocks based on roster(i.e., listing each JID asgroup: <iq type='set' id='presout2'> <query xmlns='jabber:iq:privacy'> <list name='presout-group-example'> <item type='group' value='Enemies' type='deny' order='15'> <presence-out/> </item> </list> </query> </iq> As aseparate list item), but deny communications with everyone else o accept communications from anyresult of creating and applying the foregoing list, the userwho iswill not send presence notifications to any users inone ofthegroups that make up myspecified roster(i.e., listing each group as a separate list item), but deny communications from everyone else o accept communications from any user with whom I have a subscription of 'both' or 'to' or 'from' (i.e., listing eachgroup. User blocks based on subscriptionvalue separately), but deny communications from everyone else o deny communications from anyone whose subscription state is 'none' The final representation is the simplest and SHOULD be used; here is the XML that would be sent in this case: Client constructs simple representation of heuristic for accepting communications only with those in the user's roster:type: <iq type='set'id='heuristic1'>id='presout3'> <query xmlns='jabber:iq:privacy'> <listname='heuristic-example'>name='presout-sub-example'> <item type='subscription' value='none' type='deny'order='437'/>order='17'> <presence-out/> </item> </list> </query> </iq> As a result of creating and applying the foregoing list, the user will not send presence notifications to any users with the specified subscription type. Saint-Andre & Miller Expires August27,31, 2003 [Page 51] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003A more complete listUser blocks globally: <iq type='set' id='presout4'> <query xmlns='jabber:iq:privacy'> <list name='presout-global-example'> <item type='deny' order='23'> <presence-out/> </item> </list> </query> </iq> As a result ofsuch heuristicscreating andtheir simplest representations may be provided inapplying the foregoing list, the user will not send presence notifications to any other users. 8.11 Blocking IQs Server-side privacy lists enable afuture revisionuser to block incoming IQ requests ofthis document.type "get" or "set" from other users based on the other user's JID, roster group, or subscription status, or globally. The following examples illustrate the required protocol. User blocks based on JID: <iq type='set' id='iq1'> <query xmlns='jabber:iq:privacy'> <list name='iq-jid-example'> <item type='jid' value='tybalt@capulet.com' type='deny' order='29'> <iq/> </item> </list> </query> </iq> As a result of creating and applying the foregoing list, the user will not receive IQ requests of type "get" or "set" from the user with the specified JID. Saint-Andre & Miller Expires August27,31, 2003 [Page 52] Internet-Draft XMPP Instant MessagingFebruaryMarch 20039. Routing and Delivery Rules 9.1 Client Generation of To Addresses Many XMPP stanzas possess a 'to' address that specifies the intended recipient of the stanza. When a server receives a stanza possessing a 'to' attribute fromUser blocks based on roster group: <iq type='set' id='iq2'> <query xmlns='jabber:iq:privacy'> <list name='iq-group-example'> <item type='group' value='Enemies' type='deny' order='31'> <iq/> </item> </list> </query> </iq> As aconnected client, it is responsible for either directly deliveringresult of creating and applying thestanza toforegoing list, theintended recipient (ifuser will not receive IQ requests of type "get" or "set" from any users in therecipient is served byspecified roster group. User blocks based on subscription type: <iq type='set' id='iq3'> <query xmlns='jabber:iq:privacy'> <list name='iq-sub-example'> <item type='subscription' value='none' type='deny' order='17'> <iq/> </item> </list> </query> </iq> As a result of creating and applying thesame server)foregoing list, the user will not receive IQ requests of type "get" orfor routing"set" from any users with thestanza to another server (ifspecified subscription type. User blocks globally: <iq type='set' id='iq4'> <query xmlns='jabber:iq:privacy'> <list name='iq-global-example'> <item type='deny' order='1'> <iq/> </item> </list> </query> </iq> As a result of creating and applying therecipient is not served byforegoing list, thesame server). (This doesuser will notnecessary imply that the recipient is onreceive IQ requests of type "get" or "set" from any other users. Saint-Andre & Miller Expires August 31, 2003 [Page 53] Internet-Draft XMPP Instant Messaging March 2003 8.12 Blocking All Communication Server-side privacy lists enable adifferent domainuser to block all communications fromthe sender, since one server could host multiple domains.) If deliveryand presence to other users based on theintended recipient is unsuccessfulother user's JID, roster group, or subscription status, or globally. The following examples illustrate therecipient's server cannot be contacted, the sender's server is responsible for returning an error to the sender; if the recipient's server can be contacted but delivery by the recipient's server to the recipient is unsuccessful, the recipient's server is responsible for returning an error to the sender by wayrequired protocol. User blocks based on JID: <iq type='set' id='all1'> <query xmlns='jabber:iq:privacy'> <list name='all-jid-example'> <item type='jid' value='tybalt@capulet.com' type='deny' order='23'/> </list> </query> </iq> As a result of creating and applying thesender's server. If a client doesforegoing list, the user will notspecify a 'to' address on a stanza, it is implied thatreceive any communications from, nor send presence to, thestanza is meant to be handled byuser with thesender's serverspecified JID. User blocks based onbehalfroster group: <iq type='set' id='all2'> <query xmlns='jabber:iq:privacy'> <list name='all-group-example'> <item type='group' value='Enemies' type='deny' order='13'/> </list> </query> </iq> As a result of creating and applying thesender. Although this functionality is normallyforegoing list, the user will notusedreceive any communications from, nor send presence to, any users in thecasespecified roster group. User blocks based on subscription type: <iq type='set' id='all3'> <query xmlns='jabber:iq:privacy'> <list name='all-sub-example'> <item type='subscription' value='none' type='deny' order='11'/> </list> </query> </iq> As a result ofmessage stanzas, it is quite common with regard to both presencecreating andIQ stanzas. Inapplying thecase of presence stanzas,foregoing list, theuser'suser will not receive any communications from, nor send presenceinformation is normally sent from the client to the user's server without a 'to' attribute, and subsequently broadcasted to all entities that are subscribed toto, any users with thesender's presence information usingspecified subscription type. Saint-Andre & Miller Expires August 31, 2003 [Page 54] Internet-Draft XMPP Instant Messaging March 2003 User blocks globally: <iq type='set' id='all4'> <query xmlns='jabber:iq:privacy'> <list name='all-global-example'> <item type='deny' order='7'/> </list> </query> </iq> As aclassic publish-subscribe model. In the caseresult ofIQ stanzas, requests in many extended namespaces (e.g., jabber:iq:roster) are normally sent from the client to the server without a 'to' attribute,creating andhandled byapplying theserver on behalf offoregoing list, the user(e.g.,will not receive any communications from, nor send presence to, any other users. 8.13 Blocked Entity Attempts tomanage roster information stored by the server).Communicate with User If auser's client would likeblocked entity attempts torequest information aboutsend messages or presence notifications to the user, the user's serveritself (e.g., forSHOULD silently drop thepurpose of service discovery), itstanza and MUSTinclude the server's JID in the 'to' address ofNOT return an error to theIQ request. 9.2 Server Handling of XML Stanzas XML stanzas that are not handled directly bysending entity. If aserver (e.g., for the purposeblocked entity attempts to send an IQ stanza ofdata storage or rebroadcasting) are routedtype "get" ordelivered"set" to theintended recipient of the stanza as represented by a JID inuser, the'to' attribute. The following rules apply: o Ifuser's server MUST return to theJID containssending entity aresource identifier (to="user@domain/ resource"),<feature-not-implemented/> error of class "recipient" in thestanza'urn:ietf:rfc:xmppcore-rfc-number:stanzas' namespace, since this isdelivered first totheresourcestandard error code sent from a client thatexactly matchesdoes not understand theresource identifier. Saint-Andre & Miller Expires August 27, 2003 [Page 53] Internet-Draft XMPP Instant Messaging February 2003 o If the JID contains a resource identifier and there are no matching resources, but there are other connected resources associated with the user, then message stanzas are further processed as if no resource is specified (see next item). For all other stanzas, the server should return them to the sender with a typenamespace of"error" and an appropriate error code (503) and message. o If the JID contains only a user@domain and there is at least one connected resource available for the user, the server should deliver the stanza toanappropriate resource based on the availability state, priority, and connect time of the connected resource(s). (Existing XMPP implementations contain some hardcoded rules, based on <priority/> and most recent connection time, for the routingIQ get or set. IQ stanzas ofsuch stanzas. A more flexible approach to routing wouldother types SHOULD bedesirable.) o If the JID contains only a user@domain and there are no connected resources available for the user (e.g., an IM user is offline), the server MAY choose to store the stanza (usually only message and presence subscription stanzas) on behalf of the user and deliver the stanza when a resource becomes available for that user. If offline storage is not enabled,silently dropped by theserver MUST return a 503 (Service Unavailable) errorserver. Blocked entity attempts tothe sender.send IQ get: <iq type='get' to='romeo@montague.net' from='tybalt@capulet.com/pda' id='probing1'> <query xmlns='jabber:iq:version'/> </iq> Saint-Andre & Miller Expires August27,31, 2003 [Page54]55] Internet-Draft XMPP Instant MessagingFebruaryMarch 200310. IANA Considerations For IANA considerations, referServer returns error tothe relevant section of XMPP Core [1]. Saint-Andre & Miller Expires August 27, 2003 [Page 55] Internet-Draft XMPP Instant Messaging February 2003 11. Security Considerationsblocked entity: <iq type='error' from='romeo@montague.net' to='tybalt@capulet.com/pda' id='probing1'> <query xmlns='jabber:iq:version'/> <error class='recipient'> <stanza-condition xmlns='urn:ietf:rfc:xmppcore-rfc-number:stanzas'> <feature-not-implemented/> </stanza-condition> </error> </message> 8.14 Higher-Level Heuristics When building a representation of a higher-level privacy heuristic, a client SHOULD use the simplest possible representation. Forsecurity considerations, refer toexample, therelevant sectionheuristic "block all communications with any user not in my roster" could be constructed in any ofXMPP Core [1]. Saint-Andre & Miller Expires August 27, 2003 [Page 56] Internet-Draft XMPP Instant Messaging February 2003 References [1] Saint-Andre, P. and J. Miller, "XMPP Core (draft-ietf-xmpp-core- 04, workthe following ways: o accept communications from all JIDs inprogress)", February 2003. [2] Day, M., Aggarwal, S., Mohr, G. and J. Vincent, "A Model for Presence and Instant Messaging", RFC 2779, February 2000, <http://www.ietf.org/rfc/rfc2779.txt>. [3] Jabber Software Foundation, "Jabber Software Foundation", August 2001, <http://www.jabber.org/>. [4] Bradner, S., "Key words for usemy roster (i.e., listing each JID as a separate list item), but deny communications with everyone else o accept communications from any user who is inRFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [5] Day, M., Rosenberg, J. and H. Sugano, "A Model for Presence and Instant Messaging", RFC 2778, February 2000, <http:// www.ietf.org/rfc/rfc2778.txt>. [6] Dawson, F.one of the groups that make up my roster (i.e., listing each group as a separate list item), but deny communications from everyone else o accept communications from any user with whom I have a subscription of 'both' or 'to' or 'from' (i.e., listing each subscription value separately), but deny communications from everyone else o deny communications from anyone whose subscription state is 'none' The final representation is the simplest andT. Howes, "vCard MIME Directory Profile", RFC 2426, September 1998. Authors' Addresses PeterSHOULD be used; here is the XML that would be sent in this case: <iq type='set' id='heuristic1'> <query xmlns='jabber:iq:privacy'> <list name='heuristic-example'> <item type='subscription' value='none' type='deny' order='437'/> </list> </query> Saint-AndreJabber Software Foundation EMail: stpeter@jabber.org URI: http://www.jabber.org/people/stpeter.php Jeremie& MillerJabber Software Foundation EMail: jeremie@jabber.org URI: http://www.jabber.org/people/jer.phpExpires August 31, 2003 [Page 56] Internet-Draft XMPP Instant Messaging March 2003 </iq> Saint-Andre & Miller Expires August27,31, 2003 [Page 57] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003Appendix A. vCards This section9. Routing and Delivery Rules 9.1 Client Generation of To Addresses Many XMPP stanzas possess a 'to' address that specifies the intended recipient of the stanza. When a server receives a stanza possessing a 'to' attribute from a connected client, it is responsible for either directly delivering the stanza to the intended recipient (if the recipient is served by the same server) or for routing the stanza to another server (if the recipient is not served by the same server). (This does not necessary imply that the recipient is on a different domain from the sender, since one server could host multiple domains.) If delivery to the intended recipient is unsuccessful or the recipient's server cannot be contacted, the sender's server is responsible for returning an error to the sender; if the recipient's server can be contacted but delivery by the recipient's server to the recipient is unsuccessful, the recipient's server is responsible for returning an error to the sender by way of the sender's server. If a client does not specify a 'to' address on a stanza, it isprovided for informational purposes only andimplied that the stanza is meant to be handled by the sender's server on behalf of the sender. Although this functionality is normally notnormative. Sections 3.1.3 and 4.1.4used in the case ofRFC 2779 [2] require thatmessage stanzas, itbe possibleis quite common with regard toretrieve non-IM contact information for other users (e.g., telephone number or email address). An XML representationboth presence and IQ stanzas. In the case of presence stanzas, thevCard specification defined in RFC 2426 [6]user's presence information isin common use withinnormally sent from theJabber communityclient toprovide such information. Forthesake of completeness, this section describesuser's server without a 'to' attribute, and subsequently broadcasted to all entities thatprotocol. This section is non-normative. The basic functionality is forare subscribed to the sender's presence information using auserclassic publish-subscribe model. In the case of IQ stanzas, requests in many extended namespaces (e.g., jabber:iq:roster) are normally sent from the client tostorethe server without a 'to' attribute, andretrieve anhandled by the server on behalf of the user (e.g., to manage roster information stored by the server). If a user's client would like to request information about the user's server itself (e.g., for the purpose of service discovery), it MUST include the server's JID in the 'to' address of the IQ request. 9.2 Server Handling of XMLrepresentationStanzas Any appropriate privacy rules (Section 8) SHOULD be applied by the server first. Following the application ofhis or her vCard usingany privacy rules, XML stanzas that are not handled directly by a server (e.g., for the purpose of data storagecapabilities native to all existing Jabber server implementations. This is done by sending an <iq/> of type "set" (storage)or"get" (retrieval)rebroadcasting) MUST be routed or delivered toone's Jabber server containing a <vCard/> child scoped bythe'vcard-temp' namespace, with the <vCard/> element containingintended recipient of theactual vCard-XML elementsstanza asdefined by the vCard-XML DTD. Other users may then view one's vCard information. (There is currently no access control over who may view vCard information.) A.1 Retrieving One's vCard A user may retrieve his or her own vCardrepresented bysending XML ofa JID in thefollowing form to his or her own JID: <iq to='stpeter@jabber.org' type='get' id='vcard1'> <vCard xmlns='vcard-temp'/> </iq>'to' attribute. Theserver MUST then returnfollowing rules apply: o If thevCardJID contains a resource identifier (to="user@domain/ resource"), the stanza is delivered first to theuser: <iq from='stpeter@jabber.org' to='stpeter@jabber.org/Gabber' type='result' id='v1'> <vCard xmlns='vcard-temp'> <FN>Peter Saint-Andre</FN> <N> <FAMILY>Saint-Andre<FAMILY> <GIVEN>Peter</GIVEN> <MIDDLE/> </N> <NICKNAME>stpeter</NICKNAME> <URL>http://www.jabber.org/people/stpeter.php</URL>resource that Saint-Andre & Miller Expires August27,31, 2003 [Page 58] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003<BDAY>1966-08-06</BDAY> <ORG> <ORGNAME>Jabber Software Foundation</ORGNAME> <ORGUNIT/> </ORG> <TITLE>Executive Director</TITLE> <ROLE>Patron Saint</ROLE> <TEL><VOICE/><WORK/><NUMBER>303-308-3282</NUMBER></TEL> <TEL><FAX/><WORK/><NUMBER/></TEL> <TEL><MSG/><WORK/><NUMBER/></TEL> <ADR> <WORK/> <EXTADD>Suite 600</EXTADD> <STREET>1899 Wynkoop Street</STREET> <LOCALITY>Denver</LOCALITY> <REGION>CO</REGION> <PCODE>80202</PCODE> <CTRY>USA</CTRY> </ADR> <TEL><VOICE/><HOME/><NUMBER>303-555-1212</NUMBER></TEL> <TEL><FAX/><HOME/><NUMBER/></TEL> <TEL><MSG/><HOME/><NUMBER/></TEL> <ADR> <HOME/> <EXTADD/> <STREET/> <LOCALITY>Denver</LOCALITY> <REGION>CO</REGION> <PCODE>80209</PCODE> <CTRY>USA</CTRY> </ADR> <EMAIL><INTERNET/><PREF/><USERID>stpeter@jabber.org</USERID></EMAIL> <JABBERID>stpeter@jabber.org</JABBERID> <DESC> More information about meexactly matches the resource identifier. o If the JID contains a resource identifier and there are no matching resources, but there are other connected resources associated with the user, then message stanzas are further processed as if no resource islocated on my personal website: http://www.saint-andre.com/ </DESC> </vCard> </iq> A.2 Updating One's vCard A user may update his or her vCard by sendingspecified (see next item). For all other stanzas, the server SHOULD return to the sender a <recipient-unavailable/> error of class "recipient" in the 'urn:ietf:rfc:xmppcore-rfc-number:stanzas' namespace. o If the JID contains only a user@domain and there is at least one connected resource available for the user, the server SHOULD deliver the stanza to anIQappropriate resource based on the availability state, priority, and connect time oftype "set"the connected resource(s). (For instance, the server MAY deliver the stanza to theserver, followingresource with theformat inhighest value for theprevious use case. If a user attempts to perform an IQ set<priority/> element, and decide between resources of equal priority based onanother user's vCard,most recent connect time or most recent activity time; however, all such rules are implementation-specific.) o If theserver must returnJID contains only a403 "Forbidden" error. Saint-Andre & Miller Expires August 27, 2003 [Page 59] Internet-Draft XMPP Instant Messaging February 2003 A.3 Viewing Another User's vCard Auser@domain and there are no connected resources available for the usermay view another user's vCard by sending(e.g., anIQ of type "get" toIM user is offline), theother user's bare JID. A compliantservermust return the vCard to the requestor and not forward the IQMAY choose to store therequestee's connected resource. <iq to='jer@jabber.org' type='get' id='v3'> <vCard xmlns='vcard-temp'/> </iq> The server should then returnstanza on behalf of theother user's vCard touser and deliver therequestor: <iq from='jer@jabber.org' to='stpeter@jabber.org/home' type='result' id='v3'> <vCard xmlns='vcard-temp'> <FN>JeremieMiller</FN> <N> <GIVEN>Jeremie</GIVEN> <FAMILY>Miller</FAMILY> <MIDDLE/> </N> <NICKNAME>jer</NICKNAME> <EMAIL><INTERNET/><PREF/><USERID>jeremie@jabber.org</USERID></EMAIL> <JABBERID>jer@jabber.org</JABBERID> </vCard> </iq> Saint-Andre & Miller Expires August 27, 2003 [Page 60] Internet-Draft XMPP Instant Messaging February 2003 Appendix B. Formal Definitions B.1 Schema for jabber:iq:last <?xml version='1.0' encoding='UTF-8'?> <xsd:schema xmlns:xsd='http://www.w3.org/2001/XMLSchema' targetNamespace='http://www.jabber.org/protocol' xmlns='http://www.jabber.org/protocol' elementFormDefault='qualified'> <xsd:element name='query'> <xsd:complexType> <xsd:attribute name='seconds' type='xsd:unsignedLong' use='optional'/> </xsd:complexType> </xsd:element> </xsd:schema> B.2 Schemastanza when a resource becomes available forjabber:iq:privacy <?xml version='1.0' encoding='UTF-8'?> <xsd:schema xmlns:xsd='http://www.w3.org/2001/XMLSchema' targetNamespace='http://www.jabber.org/protocol' xmlns='http://www.jabber.org/protocol' elementFormDefault='qualified'> <xsd:element name='query'> <xsd:complexType> <xsd:choice minOccurs='0' maxOccurs='unbounded'> <xsd:element ref='active' minOccurs='0' maxOccurs='1'/> <xsd:element ref='default' minOccurs='0' maxOccurs='1'/> <xsd:element ref='list' minOccurs='0' maxOccurs='unbounded'/> </xsd:choice> </xsd:complexType> </xsd:element> <xsd:element name='active'> <xsd:complexType> <xsd:attribute name='name' type='xsd:string' use='required'/> </xsd:complexType> </xsd:element> <xsd:element name='default'> <xsd:complexType> <xsd:attribute name='name' type='xsd:string' use='required'/> Saint-Andre & Miller Expires August 27, 2003 [Page 61] Internet-Draft XMPP Instant Messaging February 2003 </xsd:complexType> </xsd:element> <xsd:element name='list'> <xsd:complexType> <xsd:choice minOccurs='0' maxOccurs='unbounded'> <xsd:element ref='item' minOccurs='0' maxOccurs='unbounded'/> </xsd:choice> <xsd:attribute name='name' type='xsd:string' use='required'/> </xsd:complexType> </xsd:element> <xsd:element name='item'> <xsd:complexType> <xsd:choice> <xsd:element ref='iq' minOccurs='0' maxOccurs='1'/> <xsd:element ref='message' minOccurs='0' maxOccurs='1'/> <xsd:element ref='presence-in' minOccurs='0' maxOccurs='1'/> <xsd:element ref='presence-out' minOccurs='0' maxOccurs='1'/> </xsd:choice> <xsd:attribute name='action' use='required'> <xsd:simpleType> <xsd:restriction base='xsd:NCName'> <xsd:enumeration value='allow'/> <xsd:enumeration value='deny'/> </xsd:restriction> </xsd:simpleType> </xsd:attribute> <xsd:attribute name='order' type='xsd:nonNegativeInteger' use='required'/> <xsd:attribute name='type' use='optional'> <xsd:simpleType> <xsd:restriction base='xsd:NCName'> <xsd:enumeration value='group'/> <xsd:enumeration value='jid'/> <xsd:enumeration value='subscription'/> </xsd:restriction> </xsd:simpleType> </xsd:attribute> <xsd:attribute name='value' type='xsd:string' use='optional'/> </xsd:complexType> </xsd:element> <xsd:element name='iq'/> <xsd:element name='message'/> <xsd:element name='presence'/> </xsd:schema>that user. If offline storage is not enabled, the server MUST return to the sender a <service-unavailable/> error of class "server" in the 'urn:ietf:rfc:xmppcore-rfc-number:stanzas' namespace. Note: offline storage is not defined in XMPP since it is a matter of implementation. Saint-Andre & Miller Expires August27,31, 2003 [Page62]59] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003B.3 Schema for jabber:iq:roster <?xml version='1.0' encoding='UTF-8'?> <xsd:schema xmlns:xsd='http://www.w3.org/2001/XMLSchema' targetNamespace='http://www.jabber.org/protocol' xmlns='http://www.jabber.org/protocol' elementFormDefault='qualified'> <xsd:element name='query'> <xsd:complexType> <xsd:sequence minOccurs='0' maxOccurs='unbounded'> <xsd:element ref='item'/> </xsd:sequence> </xsd:complexType> </xsd:element> <xsd:element name='item'> <xsd:complexType> <xsd:sequence minOccurs='0' maxOccurs='unbounded'> <xsd:element ref='group'/> </xsd:sequence> <xsd:attribute name='jid' type='xsd:string' use='required'/> <xsd:attribute name='name' type='xsd:string' use='optional'/> <xsd:attribute name='subscription' use='optional'> <xsd:simpleType> <xsd:restriction base='xsd:string'> <xsd:enumeration value='to'/> <xsd:enumeration value='from'/> <xsd:enumeration value='both'/> <xsd:enumeration value='none'/> <xsd:enumeration value='remove'/> </xsd:restriction> </xsd:simpleType> </xsd:attribute> <xsd:attribute name='ask' use='optional'> <xsd:simpleType> <xsd:restriction base='xsd:string'> <xsd:enumeration value='subscribe'/> <xsd:enumeration value='unsubscribe'/> </xsd:restriction> </xsd:simpleType> </xsd:attribute> </xsd:complexType> </xsd:element> <xsd:element name='group' type='xsd:string'/>10. IANA Considerations For IANA considerations, refer to the relevant section of XMPP Core [1]. Saint-Andre & Miller Expires August27,31, 2003 [Page63]60] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003</xsd:schema> B.4 DTD for vcard-temp The following DTD is a slightly modified version of that contained in the second vCard-XML Internet-Draft authored by Frank Dawson. The only modifications were11. Security Considerations For security considerations, refer toaddtheJABBERID and DESC elements. <?xml version="1.0" encoding="UTF-8"?> <!-- Copyright (C) The Internet Society (2000). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implmentation may be prepared, copied, published and distributed, in whole or in part, without restrictionrelevant section ofany kind, provided that the above copyright notice and this paragraph are included on all such copiesXMPP Core [1]. Saint-Andre & Miller Expires August 31, 2003 [Page 61] Internet-Draft XMPP Instant Messaging March 2003 References [1] Saint-Andre, P. andderivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standardsJ. Miller, "XMPP Core (draft-ietf-xmpp-core-05, work inwhich case the proceduresprogress)", March 2003. [2] Day, M., Aggarwal, S., Mohr, G. and J. Vincent, "A Model forcopyrights definedPresence and Instant Messaging", RFC 2779, February 2000, <http://www.ietf.org/rfc/rfc2779.txt>. [3] Jabber Software Foundation, "Jabber Software Foundation", August 2001, <http://www.jabber.org/>. [4] Bradner, S., "Key words for use inthe Internet Standards process MUST be followed, or as requiredRFCs totranslate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This documentIndicate Requirement Levels", BCP 14, RFC 2119, March 1997. [5] Day, M., Rosenberg, J. andthe information contained herein is provided on an "AS IS" basisH. Sugano, "A Model for Presence andTHE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. --> <!-- ==== --> <!-- Root elementInstant Messaging", RFC 2778, February 2000, <http:// www.ietf.org/rfc/rfc2778.txt>. [6] Dawson, F. andcontainer for one or more vCard objects --> <!ELEMENT xCard (vCard)+>T. Howes, "vCard MIME Directory Profile", RFC 2426, September 1998. Authors' Addresses Peter Saint-Andre Jabber Software Foundation EMail: stpeter@jabber.org URI: http://www.jabber.org/people/stpeter.php Jeremie Miller Jabber Software Foundation EMail: jeremie@jabber.org URI: http://www.jabber.org/people/jer.php Saint-Andre & Miller Expires August27,31, 2003 [Page64]62] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003<!-- Individual vCard container --> <!ELEMENT vCard ( (VERSION, FN, N), (NICKNAME?, PHOTO?, BDAY?, ADR?, LABEL?, TEL?, EMAIL?, JABBERID?, MAILER?, TZ?, GEO?, TITLE?, ROLE?, LOGO?, AGENT?, ORG?, CATEGORIES?, NOTE?, PRODID?, REV?, SORT-STRING?, SOUND?, UID?, URL?, CLASS?, KEY?, DESC? )*)> <!--Appendix A. vCards Sections 3.1.3 and 4.1.4 of RFC 2779 [2] require that it be possible to retrieve non-IM contact information for other users (e.g., telephone number or email address). An XML representation of the vCard specificationversion property. This MUST be 2.0, ifdefined in RFC 2426 [6] is in common use within thedocument conformsJabber community toRFC 2426. --> <!ELEMENT VERSION (#PCDATA)> <!-- Formatted or display name property. --> <!ELEMENT FN (#PCDATA)> <!-- Structured name property. Name components with multiple values must be specified as a comma separated listprovide such information. Documentation ofvalues. --> <!ELEMENT N ( FAMILY?, GIVEN?, MIDDLE?, PREFIX?, SUFFIX?)> <!ELEMENT FAMILY (#PCDATA)> <!ELEMENT GIVEN (#PCDATA)> <!ELEMENT MIDDLE (#PCDATA)> <!ELEMENT PREFIX (#PCDATA)>this protocol is maintained by the Jabber Software Foundation [3] at <http://www.jabber.org/protocol/>. Saint-Andre & Miller Expires August27,31, 2003 [Page65]63] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003<!ELEMENT SUFFIX (#PCDATA)> <!-- Nickname property. Multiple nicknames must be specified as a comma separated list value. --> <!ELEMENT NICKNAME (#PCDATA)> <!-- Photograph property. Value is either a BASE64 encoded binary value or a URI to the external content. --> <!ELEMENT PHOTO ((TYPE, BINVAL) | EXTVAL)> <!-- Birthday property. Value must be an ISO 8601 formatted date or date/time value. --> <!ELEMENT BDAY (#PCDATA)> <!-- Structured address property. Address components with multiple values must be specified as a comma separated list of values. --> <!ELEMENT ADR ( HOME?, WORK?, POSTAL?, PARCEL?, (DOM | INTL)?, PREF?, POBOX?, EXTADR?, STREET?, LOCALITY?, REGION?, PCODE?, CTRY? )> <!ELEMENT POBOX (#PCDATA)> <!ELEMENT EXTADR (#PCDATA)> <!ELEMENT STREET (#PCDATA)> <!ELEMENT LOCALITY (#PCDATA)> <!ELEMENT REGION (#PCDATA)> <!ELEMENT PCODE (#PCDATA)> <!ELEMENT CTRY (#PCDATA)> <!-- Address label property. --> <!ELEMENT LABEL ( HOME?, WORK?, POSTAL?, PARCEL?, (DOM | INTL)?,Appendix B. Formal Definitions B.1 Schema for jabber:iq:last <?xml version='1.0' encoding='UTF-8'?> <xs:schema xmlns:xs='http://www.w3.org/2001/XMLSchema' targetNamespace='jabber:iq:last' xmlns='jabber:iq:last' elementFormDefault='qualified'> <xs:element name='query'> <xs:complexType> <xs:attribute name='seconds' type='xs:unsignedLong' use='optional'/> </xs:complexType> </xs:element> </xs:schema> B.2 Schema for jabber:iq:privacy <?xml version='1.0' encoding='UTF-8'?> <xs:schema xmlns:xs='http://www.w3.org/2001/XMLSchema' targetNamespace='jabber:iq:privacy' xmlns='jabber:iq:privacy' elementFormDefault='qualified'> <xs:element name='query'> <xs:complexType> <xs:sequence> <xs:element ref='active' minOccurs='0' maxOccurs='1'/> <xs:element ref='default' minOccurs='0' maxOccurs='1'/> <xs:element ref='list' minOccurs='0' maxOccurs='unbounded'/> </xs:sequence> </xs:complexType> </xs:element> <xs:element name='active'> <xs:complexType> <xs:attribute name='name' type='xs:string' use='optional'/> </xs:complexType> </xs:element> <xs:element name='default'> <xs:complexType> <xs:attribute name='name' type='xs:string' use='optional'/> Saint-Andre & Miller Expires August27,31, 2003 [Page66]64] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003PREF?, LINE+ )> <!-- Individual label lines. --> <!ELEMENT LINE (#PCDATA)> <!-- Telephone number property. --> <!ELEMENT TEL ( HOME?, WORK?, VOICE?, FAX?, PAGER?, MSG?, CELL?, VIDEO?, BBS?, MODEM?, ISDN?, PCS?, PREF?, NUMBER )> <!-- Phone number value. --> <!ELEMENT NUMBER (#PCDATA)> <!-- Email address property. Default type is INTERNET. --> <!ELEMENT EMAIL ( HOME?, WORK?, INTERNET?, X400?, USERID )> <!ELEMENT USERID (#PCDATA)> <!-- Jabber ID. Value must be in the form of user@domain. --> <!ELEMENT JABBERID (#PCDATA)> <!-- Mailer (e.g., Mail User Agent Type) property. --> <!ELEMENT MAILER (#PCDATA)> <!-- Time zone's Standard Time UTC offset. Value must be an ISO 8601 formatted UTC offset. --> <!ELEMENT TZ (#PCDATA)></xs:complexType> </xs:element> <xs:element name='list'> <xs:complexType> <xs:choice minOccurs='0' maxOccurs='unbounded'> <xs:element ref='item' minOccurs='0' maxOccurs='unbounded'/> </xs:choice> <xs:attribute name='name' type='xs:string' use='required'/> </xs:complexType> </xs:element> <xs:element name='item'> <xs:complexType> <xs:sequence> <xs:element ref='iq' minOccurs='0' maxOccurs='1'/> <xs:element ref='message' minOccurs='0' maxOccurs='1'/> <xs:element ref='presence-in' minOccurs='0' maxOccurs='1'/> <xs:element ref='presence-out' minOccurs='0' maxOccurs='1'/> </xs:sequence> <xs:attribute name='action' use='required'> <xs:simpleType> <xs:restriction base='xs:NCName'> <xs:enumeration value='allow'/> <xs:enumeration value='deny'/> </xs:restriction> </xs:simpleType> </xs:attribute> <xs:attribute name='order' type='xs:nonNegativeInteger' use='required'/> <xs:attribute name='type' use='optional'> <xs:simpleType> <xs:restriction base='xs:NCName'> <xs:enumeration value='group'/> <xs:enumeration value='jid'/> <xs:enumeration value='subscription'/> </xs:restriction> </xs:simpleType> </xs:attribute> <xs:attribute name='value' type='xs:string' use='optional'/> </xs:complexType> </xs:element> <xs:element name='iq'/> <xs:element name='message'/> <xs:element name='presence-in'/> <xs:element name='presence-out'/> </xs:schema> Saint-Andre & Miller Expires August27,31, 2003 [Page67]65] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003<!-- Geographical position. Values are the decimal degress of LATitude and LONgitude. The value should be specified to six decimal places.--> <!ELEMENT GEO (LAT, LON)> <!-- Latitude value. --> <!ELEMENT LAT (#PCDATA)> <!-- Longitude value. --> <!ELEMENT LON (#PCDATA)> <!-- Title property. --> <!ELEMENT TITLE (#PCDATA)> <!-- Role property. --> <!ELEMENT ROLE (#PCDATA)> <!-- Organization logo property. --> <!ELEMENT LOGO ((TYPE, BINVAL) | EXTVAL)> <!-- Administrative agent property. --> <!ELEMENT AGENT (vCard | EXTVAL)> <!-- Organizational name and units property. --> <!ELEMENT ORG (ORGNAME, ORGUNIT*)> <!ELEMENT ORGNAME (#PCDATA)> <!ELEMENT ORGUNIT (#PCDATA)> <!-- Application specific categories property. --> <!ELEMENT CATEGORIES (KEYWORD+)> <!ELEMENT KEYWORD (#PCDATA)> <!-- Commentary note property. --> <!ELEMENT NOTE (#PCDATA)> <!-- Identifier of product that generated the vCard property. --> <!ELEMENT PRODID (#PCDATA)> <!-- Last revised property. The value must be an ISO 8601 formatted UTC date/time. --> <!ELEMENT REV (#PCDATA)> <!-- Sort string property. --> <!ELEMENT SORT-STRING (#PCDATA)>B.3 Schema for jabber:iq:roster <?xml version='1.0' encoding='UTF-8'?> <xs:schema xmlns:xs='http://www.w3.org/2001/XMLSchema' targetNamespace='http://www.jabber.org/protocol' xmlns='http://www.jabber.org/protocol' elementFormDefault='qualified'> <xs:element name='query'> <xs:complexType> <xs:sequence minOccurs='0' maxOccurs='unbounded'> <xs:element ref='item'/> </xs:sequence> </xs:complexType> </xs:element> <xs:element name='item'> <xs:complexType> <xs:sequence minOccurs='0' maxOccurs='unbounded'> <xs:element ref='group'/> </xs:sequence> <xs:attribute name='jid' type='xs:string' use='required'/> <xs:attribute name='name' type='xs:string' use='optional'/> <xs:attribute name='subscription' use='optional'> <xs:simpleType> <xs:restriction base='xs:string'> <xs:enumeration value='to'/> <xs:enumeration value='from'/> <xs:enumeration value='both'/> <xs:enumeration value='none'/> <xs:enumeration value='remove'/> </xs:restriction> </xs:simpleType> </xs:attribute> <xs:attribute name='ask' use='optional'> <xs:simpleType> <xs:restriction base='xs:string'> <xs:enumeration value='subscribe'/> <xs:enumeration value='unsubscribe'/> </xs:restriction> </xs:simpleType> </xs:attribute> </xs:complexType> </xs:element> <xs:element name='group' type='xs:string'/> Saint-Andre & Miller Expires August27, 2003 [Page 68] Internet-Draft XMPP Instant Messaging February 2003 <!-- Formatted name pronunciation property. The value is either a textual phonetic pronunciation, a BASE64 encoded binary digital audio pronunciation or a URI to an external binary digital audio pronunciation.--> <!ELEMENT SOUND (PHONETIC | BINVAL | EXTVAL)> <!-- Textual phonetic pronunciation. --> <!ELEMENT PHONETIC (#PCDATA)> <!-- Unique identifier property. --> <!ELEMENT UID (#PCDATA)> <!-- Directory URL property. --> <!ELEMENT URL (#PCDATA)> <!-- Description. --> <!ELEMENT DESC (#PCDATA)> <!-- Privacy classification property. --> <!ELEMENT CLASS (PUBLIC | PRIVATE | CONFIDENTIAL)> <!ELEMENT PUBLIC EMPTY> <!ELEMENT PRIVATE EMPTY> <!ELEMENT CONFIDENTIAL EMPTY> <!-- Authentication credential or encryption key property. --> <!ELEMENT KEY (TYPE?, CRED)> <!ELEMENT CRED (#PCDATA)> <!-- ==== --> <!-- Common elements. --> <!-- Addressing type indicators. --> <!ELEMENT HOME EMPTY> <!ELEMENT WORK EMPTY> <!ELEMENT POSTAL EMPTY> <!ELEMENT PARCEL EMPTY> <!ELEMENT DOM EMPTY> <!ELEMENT INTL EMPTY> <!ELEMENT PREF EMPTY> <!ELEMENT VOICE EMPTY> <!ELEMENT FAX EMPTY> <!ELEMENT PAGER EMPTY> <!ELEMENT MSG EMPTY>31, 2003 [Page 66] Internet-Draft XMPP Instant Messaging March 2003 </xs:schema> Saint-Andre & Miller Expires August27,31, 2003 [Page69]67] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003<!ELEMENT CELL EMPTY> <!ELEMENT VIDEO EMPTY> <!ELEMENT BBS EMPTY> <!ELEMENT MODEM EMPTY> <!ELEMENT ISDN EMPTY> <!ELEMENT PCS EMPTY> <!ELEMENT INTERNET EMPTY> <!ELEMENT X400 EMPTY> <!-- Format type parameter. --> <!ELEMENT TYPE (#PCDATA)> <!-- Base64 encoded binary value. --> <!ELEMENT BINVAL (#PCDATA)> <!-- URIAppendix C. Provisional Namespace Names Note toexternal binary value --> <!ELEMENT EXTVAL (#PCDATA)> <!-- ==== -->RFC editor: prior to publication, the string 'xmppcore-rfc-number' must be replaced in all instances by the RFC number assigned to draft-ietf-xmpp-core. (In addition, please remove this appendix prior to publication.) Saint-Andre & Miller Expires August27,31, 2003 [Page70]68] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 AppendixC.D. Revision History Note to RFC editor: please remove this entire appendix, and the corresponding entries in the table of contents, prior to publication.C.1D.1 Changes from draft-ietf-xmpp-im-04 o Specified sending of unavailable presence after unsubscribe and subscription-cancellation actions. o Further specified syntax and business rules for privacy lists. o Brought error codes into line with definitions in draft-ietf-xmpp-core. o Added note to RFC editor regarding provisional namespace names. o Removed vCard content and DTD, instead pointing to JSF documentation. D.2 Changes from draft-ietf-xmpp-im-03 o Fixed order processing on privacy rules per list discussion. o Made numerous small editorial changes.C.2D.3 Changes from draft-ietf-xmpp-im-02 o Added a great deal more detail to the narrative regardingserver- sideserver-side privacy rules as well as the interaction between rosters and subscriptions. o Removed DTDs in favor of schemas (with the exception of vCard XML). o Removed non-normative documentation of authentication using jabber:iq:auth and of in-band registration using jabber:iq:register, since these are maintained by the Jabber Software Foundation and are not part of the XMPP specification.C.3D.4 Changes from draft-ietf-xmpp-im-01 o Made numerous small editorial changes.C.4Saint-Andre & Miller Expires August 31, 2003 [Page 69] Internet-Draft XMPP Instant Messaging March 2003 D.5 Changes from draft-ietf-xmpp-im-00 o Moved registration and authentication via jabber:iq:auth tonon- normativenon-normative appendices. o Changed initial presence stanza from MUST be empty to SHOULD be empty. o Specified that user or clients should not send presence stanzas of type 'probe'. o Specified the algorithm for digest passwords.Saint-Andre & Miller Expires August 27, 2003 [Page 71] Internet-Draft XMPP Instant Messaging February 2003 C.5D.6 Changes from draft-miller-xmpp-im-02 o Added information about the 'jabber:iq:last' protocol to meet the requirement defined in section 3.2.4 of RFC 2779. o Added information about the 'jabber:iq:privacy' protocol to meet the requirement defined in section 2.3.5 of RFC 2779. o Added information about the vCard XML protocol to meet the requirement defined in sections 3.1.3 and 4.1.4 of RFC 2779. o Changed the material describing authentication (but not resource authorization) with 'jabber:iq:auth' to non-normative. o Noted that the only watchers are subscribers. o Nomenclature changes: (1) from "chunks" to "stanzas"; (2) from "host" to "server"; (3) from "node" to "client" or "user" (as appropriate). Saint-Andre & Miller Expires August27,31, 2003 [Page72]70] Internet-Draft XMPP Instant MessagingFebruaryMarch 2003 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any effort to identify any such rights. Information on the IETF's procedures with respect to rights in standards-track and standards-related documentation can be found in BCP-11. Copies of claims of rights made available for publication and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementors or users of this specification can be obtained from the IETF Secretariat. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights which may cover technology that may be required to practice this standard. Please address the information to the IETF Executive Director. Full Copyright Statement Copyright (C) The Internet Society (2003). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors orassigns.assignees. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION Saint-Andre & Miller Expires August 31, 2003 [Page 71] Internet-Draft XMPP Instant Messaging March 2003 HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Acknowledgement Funding for the RFC Editor function is currently provided by the Internet Society. Saint-Andre & Miller Expires August27,31, 2003 [Page73]72] ----