TOC 
Network Working GroupP. Saint-Andre
Internet-DraftJabber Software Foundation
Expires: March 8, 2005September 7, 2004

A Uniform Resource Identifier (URI) Scheme for the Extensible Messaging and Presence Protocol (XMPP)

draft-saintandre-xmpp-uri-05

Status of this Memo

This document is an Internet-Draft and is subject to all provisions of section 3 of RFC 3667. By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she become aware will be disclosed, in accordance with RFC 3668.

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This Internet-Draft will expire on March 8, 2005.

Copyright Notice

Copyright (C) The Internet Society (2004).

Abstract

This document defines a Uniform Resource Identifier (URI) scheme for use in identifying entities that can communicate via the Extensible Messaging and Presence Protocol (XMPP).



Table of Contents

1.  Introduction
    1.1  Terminology
2.  Description of xmpp: URI Scheme
    2.1  Rationale
    2.2  Form
    2.3  Generation of xmpp: URIs
    2.4  Processing of xmpp: URIs
    2.5  Internationalization
3.  IANA Registration of xmpp: URI Scheme
    3.1  URI scheme name
    3.2  URI scheme syntax
    3.3  Character encoding considerations
    3.4  Intended usage
    3.5  Security considerations
    3.6  Relevant publications
    3.7  Person and email address to contact for further information
    3.8  Author/change controller
    3.9  Applications and/or protocols which use this URI scheme name
4.  IANA Considerations
5.  Security Considerations
6.  References
6.1  Normative References
6.2  Informative References
§  Author's Address
A.  Revision History
    A.1  Changes from draft-saintandre-xmpp-uri-04
    A.2  Changes from draft-saintandre-xmpp-uri-03
    A.3  Changes from draft-saintandre-xmpp-uri-02
    A.4  Changes from draft-saintandre-xmpp-uri-01
    A.5  Changes from draft-saintandre-xmpp-uri-00
§  Intellectual Property and Copyright Statements




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1. Introduction

The Extensible Messaging and Presence Protocol (XMPP) is a streaming XML technology that enables any two entities on a network to exchange well-defined but extensible XML elements (called "XML stanzas") in close to real time. [XMPP-CORE]Saint-Andre, P., Extensible Messaging and Presence Protocol (XMPP): Core, May 2004. specifies that on an XMPP network itself, the address of an XMPP entity MUST NOT be prepended with a Uniform Resource Identifier (URI) scheme (as defined in [URI]Berners-Lee, T., Fielding, R. and L. Masinter, Uniform Resource Identifier (URI): Generic Syntax, July 2004.). However, many applications external to an XMPP network may need to identify XMPP entities as full URIs; examples are databases that need to store XMPP addresses and non-native user agents (e.g., web browsers and calendaring applications) that provide interfaces to XMPP services. This memo defines an xmpp: URI scheme for use by such applications, and conforms to both the requirements in Registration Procedures for URL Scheme NamesPetke, R. and I. King, Registration Procedures for URL Scheme Names, November 1999.[URL-REG] and the recommendations in Guidelines for new URL SchemesMasinter, L., Alvestrand, H., Zigmond, D. and R. Petke, Guidelines for new URL Schemes, November 1999.[URL-GUIDE].

1.1 Terminology

This document inherits terminology described in [XMPP-CORE]Saint-Andre, P., Extensible Messaging and Presence Protocol (XMPP): Core, May 2004..

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 2119Bradner, S., Key words for use in RFCs to Indicate Requirement Levels, March 1997.[TERMS].



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2. Description of xmpp: URI Scheme

2.1 Rationale

Many types of application can be built using XMPP. As specified in [XMPP-IM]Saint-Andre, P., Extensible Messaging and Presence Protocol (XMPP): Instant Messaging and Presence, April 2004., instant messaging and presence applications of XMPP must handle the im: and pres: URI schemes specified by [CPIM]Peterson, J., Common Profile for Instant Messaging (CPIM), August 2004. and [CPP]Peterson, J., Common Profile for Presence (CPP), August 2004.. However, it is appropriate to define an XMPP-specific URI scheme for other applications of XMPP (such as network management, workflow applications, generic publish-subscribe, remote procedure calls, content syndication, gaming, and middleware) since these applications do not implement instant messaging and presence semantics. Therefore, this document defines a generic URI scheme that will enable applications to address as a URI any entity that can communicate via XMPP.

The xmpp: URI format is provided for use by non-native interfaces and applications only, and primarily for the purpose of identification rather than interaction (on the latter distinction, see Section 1.2.2 of [URI]Berners-Lee, T., Fielding, R. and L. Masinter, Uniform Resource Identifier (URI): Generic Syntax, July 2004.). In order to ensure interoperability on XMPP networks, when data is routed to an XMPP entity (e.g., when an XMPP address is contained in the 'to' or 'from' attribute of an XML stanza) or an XMPP entity is otherwise identified in standard XMPP protocol elements, the entity MUST be addressed as <[node@]domain[/resource]> (i.e., without a URI scheme), where the "node identifier", "domain identifer", and "resource identifier" portions of an XMPP address conform to the definitions provided in Section 3 of [XMPP-CORE]Saint-Andre, P., Extensible Messaging and Presence Protocol (XMPP): Core, May 2004..

(Note: For historical reasons, the term "resource identifier" is used in XMPP to refer to the optional portion of an XMPP address that follows the domain identifier and the "/" separator character; for details, refer to Section 3.4 of [XMPP-CORE]Saint-Andre, P., Extensible Messaging and Presence Protocol (XMPP): Core, May 2004.. In the terms of [URI]Berners-Lee, T., Fielding, R. and L. Masinter, Uniform Resource Identifier (URI): Generic Syntax, July 2004., the resource identifier portion of an XMPP address can be seen as equivalent to (and indeed maps to) the path component of an xmpp: URI, and therefore is not to be confused with the meanings of "resource" and "identifier" provided in Section 1.1 of [URI]Berners-Lee, T., Fielding, R. and L. Masinter, Uniform Resource Identifier (URI): Generic Syntax, July 2004..)

2.2 Form

As described in [XMPP-CORE]Saint-Andre, P., Extensible Messaging and Presence Protocol (XMPP): Core, May 2004., an XMPP address (also known as a "JID") used natively on an XMPP network is a string of Unicode characters that conforms to a certain set of [STRINGPREP]Hoffman, P. and M. Blanchet, Preparation of Internationalized Strings ("STRINGPREP"), December 2002. profiles and [IDNA]Faltstrom, P., Hoffman, P. and A. Costello, Internationalizing Domain Names in Applications (IDNA), March 2003. restrictions, following a certain set of syntax rules, encoded as [UTF-8]Yergeau, F., UTF-8, a transformation format of ISO 10646, November 2003.. The form of such an address can be represented using Augmented Backus-Naur Form ([ABNF]Crocker, D. and P. Overell, Augmented BNF for Syntax Specifications: ABNF, November 1997.) as:

   [ node "@" ] domain [ "/" resource ]
          

However, the "node" and "resource" rules rely on distinct profiles of [STRINGPREP]Hoffman, P. and M. Blanchet, Preparation of Internationalized Strings ("STRINGPREP"), December 2002. and the "domain" rule relies on the concept of an internationalized domain name as described in [IDNA]Faltstrom, P., Hoffman, P. and A. Costello, Internationalizing Domain Names in Applications (IDNA), March 2003.. Furthermore, a URI is allowed to contain [US-ASCII]American National Standards Institute, Coded Character Set - 7-bit American Standard Code for Information Interchange, 1986. characters only, and certain characters are reserved in URIs. Therefore an XMPP address must be properly handled when transformed into an xmpp: URI (see Section 2.3Generation of xmpp: URIs of this memo) and the ABNF syntax needs to be adjusted in order to accurately capture the form of an xmpp: URI as opposed to a native XMPP address.

Using the "unreserved", "pct-encoded", "host", "path-absolute", and "query" rules defined in [URI]Berners-Lee, T., Fielding, R. and L. Masinter, Uniform Resource Identifier (URI): Generic Syntax, July 2004., the ABNF syntax for an xmpp: URI can be defined as follows:

   xmppuri = "xmpp:" [ nodeid "@" ] host [ path-absolute ] 
             [ "?" query ]
   nodeid  = *( unreserved / pct-encoded / allowed )
   allowed = "!" / "$" / "(" / ")" / "*" / "+" / ";" / "="
          

The nature of the query component is not specified herein but is reserved for future standardization or application-specific uses that are outside the scope of this memo; however, the encoding of the query component MUST be [UTF-8]Yergeau, F., UTF-8, a transformation format of ISO 10646, November 2003., converting non-US-ASCII octets to percent-encoded octets as explained below for other components.

Note: While it would have been desirable to re-use the "userinfo" rule from [URI]Berners-Lee, T., Fielding, R. and L. Masinter, Uniform Resource Identifier (URI): Generic Syntax, July 2004., this was not possible since the "userinfo" rule allows characters that conform to the "sub-delims" rule, but the "&" and "'" characters (which are allowed by the "sub-delims" rule) are disallowed in XMPP node identifiers by the Nodeprep profile of [STRINGPREP]Hoffman, P. and M. Blanchet, Preparation of Internationalized Strings ("STRINGPREP"), December 2002. as specified in Appendix A of [XMPP-CORE]Saint-Andre, P., Extensible Messaging and Presence Protocol (XMPP): Core, May 2004..

2.3 Generation of xmpp: URIs

2.3.1 URI Generation Method

As should be obvious from the foregoing, when generating a conformant xmpp: URI from an XMPP address, it is necessary to use consistent methods for transforming an XMPP "node identifier" into a URI "nodeid component", an XMPP "domain identifier" into a URI "host component", and an XMPP "resource identifer" into a URI "path-absolute component"; such methods are described below. Naturally, if the XMPP address exists in a non-UTF-8 form (e.g., having been written on a piece of paper or having been represented internally in a computer program as UTF-16), it MUST first be converted to [UTF-8]Yergeau, F., UTF-8, a transformation format of ISO 10646, November 2003. before the xmpp: URI is generated.

In order to transform an XMPP "node identifier" into a URI "nodeid component", it MUST first be constructed in accordance with the rules specified in [XMPP-CORE]Saint-Andre, P., Extensible Messaging and Presence Protocol (XMPP): Core, May 2004., including application of the Nodeprep profile of [STRINGPREP]Hoffman, P. and M. Blanchet, Preparation of Internationalized Strings ("STRINGPREP"), December 2002. (see Appendix A of [XMPP-CORE]Saint-Andre, P., Extensible Messaging and Presence Protocol (XMPP): Core, May 2004.) and encoding as a [UTF-8]Yergeau, F., UTF-8, a transformation format of ISO 10646, November 2003. string; the [UTF-8]Yergeau, F., UTF-8, a transformation format of ISO 10646, November 2003. encoded characters of the XMPP "node identifier" MUST then be converted into US-ASCII characters, making sure to represent any reserved character and any character that is outside the range of the US-ASCII coded character set as a percent-encoded octet (see Section 2.1 of [URI]Berners-Lee, T., Fielding, R. and L. Masinter, Uniform Resource Identifier (URI): Generic Syntax, July 2004.).

In order to transform an XMPP "domain identifier" into a URI "host component", it MUST first be constructed in accordance with the rules specified in [XMPP-CORE]Saint-Andre, P., Extensible Messaging and Presence Protocol (XMPP): Core, May 2004., including application of the [NAMEPREP]Hoffman, P. and M. Blanchet, Nameprep: A Stringprep Profile for Internationalized Domain Names (IDN), March 2003. profile of [STRINGPREP]Hoffman, P. and M. Blanchet, Preparation of Internationalized Strings ("STRINGPREP"), December 2002. and encoding as a [UTF-8]Yergeau, F., UTF-8, a transformation format of ISO 10646, November 2003. string; the [UTF-8]Yergeau, F., UTF-8, a transformation format of ISO 10646, November 2003. encoded characters of the XMPP "domain identifier" MUST then be converted into US-ASCII characters, making sure to represent any reserved character and any character that is outside the range of the US-ASCII coded character set as a percent-encoded octet (see Section 2.1 of [URI]Berners-Lee, T., Fielding, R. and L. Masinter, Uniform Resource Identifier (URI): Generic Syntax, July 2004.).

In order to transform an XMPP "resource identifier" into a URI "path-absolute component", it MUST first be constructed in accordance with the rules specified in [XMPP-CORE]Saint-Andre, P., Extensible Messaging and Presence Protocol (XMPP): Core, May 2004., including application of the Resourceprep profile of [STRINGPREP]Hoffman, P. and M. Blanchet, Preparation of Internationalized Strings ("STRINGPREP"), December 2002. (see Appendix B of [XMPP-CORE]Saint-Andre, P., Extensible Messaging and Presence Protocol (XMPP): Core, May 2004.) and encoding as a [UTF-8]Yergeau, F., UTF-8, a transformation format of ISO 10646, November 2003. string; after prepending the "/" character, the [UTF-8]Yergeau, F., UTF-8, a transformation format of ISO 10646, November 2003. encoded characters of the XMPP "resource identifier" MUST then be converted into US-ASCII characters, making sure to represent any reserved character and any character that is outside the range of the US-ASCII coded character set as a percent-encoded octet (see Section 2.1 of [URI]Berners-Lee, T., Fielding, R. and L. Masinter, Uniform Resource Identifier (URI): Generic Syntax, July 2004.).

In order to form an xmpp: URI from the foregoing components, the generating application MUST concatenate:

  1. the "xmpp:" scheme
  2. optionally the URI "nodeid component" and the "@" character (if the XMPP address contained an XMPP "node identifier")
  3. the URI "host component"
  4. optionally the "path-absolute component" (if any)
  5. optionally the "?" character and query component (if a query component is to be included)

2.3.2 URI Generation Example

Consider the following XMPP address:

      <ji&#x159;i@&#x10C;echy.example/v Praze>
            

(Note: The string "&#x159;" stands for the Unicode character LATIN SMALL LETTER R WITH CARON and the string "&#x10C;" stands for the Unicode character LATIN CAPITAL LETTER C WITH CARON, following the "XML Notation" used in [IRI]Duerst, M. and M. Suignard, Internationalized Resource Identifiers (IRI), July 2004.. The '<' and '>' characters are not part of the address itself, but are provided to set off the address for legibility. For those who do not read Czech, this example could be Anglicized as "george@czech-lands.example/In Prague".)

In accordance with the process specified above, the generating application would do the following in order to generate a valid xmpp: URI from this address:

  1. First ensure that the XMPP address conforms to the rules specified in [XMPP-CORE]Saint-Andre, P., Extensible Messaging and Presence Protocol (XMPP): Core, May 2004., including application of the relevant [STRINGPREP]Hoffman, P. and M. Blanchet, Preparation of Internationalized Strings ("STRINGPREP"), December 2002. profiles and encoding as a [UTF-8]Yergeau, F., UTF-8, a transformation format of ISO 10646, November 2003. string.
  2. Split the address into an XMPP "node identifier" ("ji&#x159;i"), XMPP "domain identifier" ("&#x10C;echy.example"), and XMPP "resource identifier" ("v Praze").
  3. Transform the XMPP "node identifier" into a URI "nodeid component" by converting the [UTF-8]Yergeau, F., UTF-8, a transformation format of ISO 10646, November 2003. string to US-ASCII, including conversion of the LATIN SMALL LETTER R WITH CARON character to its percent-encoded representation "%C5%99"; the result is a URI "nodeid component" of "ji%C5%99i".
  4. Transform the XMPP "domain identifier" into a URI "host component" by converting the [UTF-8]Yergeau, F., UTF-8, a transformation format of ISO 10646, November 2003. string to US-ASCII, including conversion of the LATIN CAPITAL LETTER C WITH CARON character to its percent-encoded representation "%C4%8C"; the result is a URI "host component" of "&#x10C;echy.example".
  5. Transform the XMPP "resource identifier" into a URI "path-absolute component" by converting the [UTF-8]Yergeau, F., UTF-8, a transformation format of ISO 10646, November 2003. string to US-ASCII, including conversion of the " " (SP) character to its percent-encoded representation "%20", and prepending the "/" character; the result is a URI "path-absolute component" of "/v%20Praze".
  6. Concatenate the following:
    1. the "xmpp:" scheme
    2. the URI "nodeid component"
    3. the "@" character
    4. the URI "host component"
    5. the "/" character
    6. the URI "path-absolute component"

The result is this xmpp: URI:

    <xmpp:ji%C5%99i@%C4%8Cechy.example/v%20Praze>
            

2.4 Processing of xmpp: URIs

2.4.1 URI Processing Method

As with the generation of an xmpp: URI from an XMPP address, so also with the processing of an xmpp: URI (including the extraction of an XMPP address therefrom): it is necessary to use consistent methods; such methods are described below.

In order to decompose an xmpp: URI, a processing application MUST separate:

  1. the "xmpp:" scheme
  2. optionally the URI "nodeid component" using the "@" character as a separator (if the xmpp: URI address contains a URI "nodeid component)
  3. the URI "host component
  4. optionally the URI "path-absolute component" (if any)
  5. optionally the "?" character and query component (if a query component is included)

In order to reconstruct the XMPP address from the foregoing components, the processing application MUST:

At this point, the processing application would either (1) complete further XMPP handling itself or (2) invoke a helper application to complete XMPP handling; such XMPP handling would most likely consist of the following steps:

  1. Authenticating with an appropriate XMPP server (e.g., a server that a user has configured as his or her registered service provider) if not already authenticated.
  2. Optionally determining the nature of the intended recipient (e.g., via [DISCO]Hildebrand, J., Millard, P., Eatmon, R. and P. Saint-Andre, Service Discovery, July 2004.).
  3. Optionally presenting an appropriate interface to a user based on the nature of the intended recipient and/or the contents of the query component (however, if the application does not understand the query component, it MUST ignore the query component and treat the URI as consisting of, for example, <xmpp:juliet@example.com> rather than <xmpp:juliet@example.com?query>).
  4. Generating an XMPP stanza that translates any user or application inputs into their corresponding XMPP equivalents.
  5. Sending the XMPP stanza via the authenticated server connection for delivery to the intended recipient.

2.4.2 URI Processing Example

Consider the xmpp: URI that resulted from the previous example:

      <xmpp:ji%C5%99i@%C4%8Cechy.example/v%20Praze>
            

In accordance with the process specified above, the processing application would do the following in order to extract the XMPP address from this xmpp: URI:

  1. Split the URI into a URI "nodeid component" ("ji%C5%99i"), a URI "host component" ("%C4%8Cechy.example"), and a URI "path-absolute component" ("/v%20Praze").
  2. Transform the URI "nodeid component" into an XMPP "node identifier" by converting the percent-encoded representation "%C5%99" to its equivalent [UTF-8]Yergeau, F., UTF-8, a transformation format of ISO 10646, November 2003. character (LATIN SMALL LETTER R WITH CARON), and ensuring that the entire string is encoded as [UTF-8]Yergeau, F., UTF-8, a transformation format of ISO 10646, November 2003.; the result is an XMPP "node identifier" of "ji&#x159i".
  3. Transform the URI "host component" into an XMPP "domain identifier" by converting the US-ASCII string to [UTF-8]Yergeau, F., UTF-8, a transformation format of ISO 10646, November 2003. by converting the percent-encoded representation "%C4%8C" to its equivalent [UTF-8]Yergeau, F., UTF-8, a transformation format of ISO 10646, November 2003. character (LATIN CAPITAL LETTER C WITH CARON), and ensuring that the entire string is encoded as [UTF-8]Yergeau, F., UTF-8, a transformation format of ISO 10646, November 2003.; the result is an XMPP "domain identifier" of "%C4%8Cechy.example" (encoded as a [UTF-8]Yergeau, F., UTF-8, a transformation format of ISO 10646, November 2003. string).
  4. Transform the URI "path-absolute component" into an XMPP "resource identifier" by removing the initial "/" character, converting the percent-encoded representation "%20" to its equivalent [UTF-8]Yergeau, F., UTF-8, a transformation format of ISO 10646, November 2003. character (SP), and ensuring that the entire string is encoded as [UTF-8]Yergeau, F., UTF-8, a transformation format of ISO 10646, November 2003.; the result is an XMPP "resource identifier" of "v Praze".
  5. Concatenate the following (ensuring that the resulting string is encoded as [UTF-8]Yergeau, F., UTF-8, a transformation format of ISO 10646, November 2003.):
    1. the XMPP "node identifier"
    2. the "@" character
    3. the XMPP "domain identifier"
    4. the "/" character
    5. the XMPP "resource identifier"

The result is this XMPP address:

    <ji&#x159;i@&#x10C;echy.example/v Praze>
            

2.5 Internationalization

Because XMPP addresses are [UTF-8]Yergeau, F., UTF-8, a transformation format of ISO 10646, November 2003. strings and because the non-US-ASCII octets in XMPP addresses can be easily converted to percent-encoded octets, XMPP addresses are designed to work well with Internationalized Resource Identifiers ([IRI]Duerst, M. and M. Suignard, Internationalized Resource Identifiers (IRI), July 2004.). In particular, with the exception of stringprep verification and the conversion of syntax-relevant US-ASCII characters (e.g., "?"), an XMPP IRI can be constructed directly by prepending "xmpp:" to an XMPP address.



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3. IANA Registration of xmpp: URI Scheme

This section provides the information required to register the xmpp: URI scheme.

3.1 URI scheme name

xmpp

3.2 URI scheme syntax

The syntax for an xmpp: URI is defined below using Augmented Backus-Naur Form as specified by [ABNF]Crocker, D. and P. Overell, Augmented BNF for Syntax Specifications: ABNF, November 1997.. The "unreserved", "pct-encoded", "host", "path-absolute", and "query" rules are defined in [URI]Berners-Lee, T., Fielding, R. and L. Masinter, Uniform Resource Identifier (URI): Generic Syntax, July 2004..

   xmppuri = "xmpp:" [ nodeid "@" ] host [ path-absolute ] 
             [ "?" query ]
   nodeid  = *( unreserved / pct-encoded / allowed )
   allowed = "!" / "$" / "(" / ")" / "*" / "+" / ";" / "="
          

3.3 Character encoding considerations

Prior to any conversion into a URI, an XMPP address MUST be represented as [UTF-8]Yergeau, F., UTF-8, a transformation format of ISO 10646, November 2003. by the generating application (e.g., by transforming an application's internal representation of the address as a UTF-16 string into a UTF-8 string) in accordance with [XMPP-CORE]Saint-Andre, P., Extensible Messaging and Presence Protocol (XMPP): Core, May 2004.. The UTF-8 string MUST then be converted into a US-ASCII string in order to be included in a URI; as part of this conversion, non-US-ASCII octets MUST be percent-encoded as described in Section 2.1 of [URI]Berners-Lee, T., Fielding, R. and L. Masinter, Uniform Resource Identifier (URI): Generic Syntax, July 2004..

3.4 Intended usage

The xmpp: URI is intended to be used by interfaces to an XMPP network from non-native user agents such as web browsers, as well as by non-native applications that need to address XMPP entities as full URIs.

3.5 Security considerations

See Security ConsiderationsSecurity Considerations of XXXX.

3.6 Relevant publications

[XMPP-CORE]Saint-Andre, P., Extensible Messaging and Presence Protocol (XMPP): Core, May 2004.

3.7 Person and email address to contact for further information

Peter Saint-Andre [mailto:stpeter@jabber.org]

3.8 Author/change controller

This scheme is registered under the IETF tree. As such, the IETF maintains change control.

3.9 Applications and/or protocols which use this URI scheme name

Applications (other than native native XMPP applications) that provide an interface to XMPP services or that need to address XMPP entities as full URIs.



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4. IANA Considerations

This document registers a URI scheme. The registration template can be found in Section 3IANA Registration of xmpp: URI Scheme of this document.



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5. Security Considerations

Detailed security considerations for XMPP are given in [XMPP-CORE]Saint-Andre, P., Extensible Messaging and Presence Protocol (XMPP): Core, May 2004.. Providing an interface to XMPP services from non-native applications introduces new security concerns. For example, the ability to interact with XMPP entities via a web browser may expose sensitive information to attacks that are not possible or that are unlikely on a native XMPP network. Due care must be taken in deciding what information is appropriate for representing in xmpp: URIs.



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6. References



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6.1 Normative References

[ABNF] Crocker, D. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", RFC 2234, November 1997.
[IMF] Resnick, P., "Internet Message Format", RFC 2822, April 2001.
[TERMS] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[URI] Berners-Lee, T., Fielding, R. and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", draft-fielding-uri-rfc2396bis-06 (work in progress), July 2004.
[URL-GUIDE] Masinter, L., Alvestrand, H., Zigmond, D. and R. Petke, "Guidelines for new URL Schemes", RFC 2718, November 1999.
[URL-REG] Petke, R. and I. King, "Registration Procedures for URL Scheme Names", BCP 35, RFC 2717, November 1999.
[UTF-8] Yergeau, F., "UTF-8, a transformation format of ISO 10646", STD 63, RFC 3629, November 2003.
[XMPP-CORE] Saint-Andre, P., "Extensible Messaging and Presence Protocol (XMPP): Core", draft-ietf-xmpp-core-24 (work in progress), May 2004.
[XMPP-IM] Saint-Andre, P., "Extensible Messaging and Presence Protocol (XMPP): Instant Messaging and Presence", draft-ietf-xmpp-im-22 (work in progress), April 2004.


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6.2 Informative References

[CPIM] Peterson, J., "Common Profile for Instant Messaging (CPIM)", RFC 3860, August 2004.
[CPP] Peterson, J., "Common Profile for Presence (CPP)", RFC 3859, August 2004.
[DISCO] Hildebrand, J., Millard, P., Eatmon, R. and P. Saint-Andre, "Service Discovery", JSF JEP 0030, July 2004.
[IDNA] Faltstrom, P., Hoffman, P. and A. Costello, "Internationalizing Domain Names in Applications (IDNA)", RFC 3490, March 2003.
[IMP-MODEL] Day, M., Rosenberg, J. and H. Sugano, "A Model for Presence and Instant Messaging", RFC 2778, February 2000.
[IMP-REQS] Day, M., Aggarwal, S. and J. Vincent, "Instant Messaging / Presence Protocol Requirements", RFC 2779, February 2000.
[IRI] Duerst, M. and M. Suignard, "Internationalized Resource Identifiers (IRI)", draft-duerst-iri-09 (work in progress), July 2004.
[MAILTO] Hoffman, P., Masinter, L. and J. Zawinski, "The mailto URL scheme", RFC 2368, July 1998 (TXT, HTML, XML).
[NAMEPREP] Hoffman, P. and M. Blanchet, "Nameprep: A Stringprep Profile for Internationalized Domain Names (IDN)", RFC 3491, March 2003.
[STRINGPREP] Hoffman, P. and M. Blanchet, "Preparation of Internationalized Strings ("STRINGPREP")", RFC 3454, December 2002.
[US-ASCII] American National Standards Institute, "Coded Character Set - 7-bit American Standard Code for Information Interchange", ANSI X3.4, 1986.


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Author's Address

  Peter Saint-Andre
  Jabber Software Foundation
EMail:  stpeter@jabber.org


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Appendix A. Revision History

Note to RFC Editor: please remove this entire appendix, and the corresponding entries in the table of contents, prior to publication.

A.1 Changes from draft-saintandre-xmpp-uri-04

A.2 Changes from draft-saintandre-xmpp-uri-03

A.3 Changes from draft-saintandre-xmpp-uri-02

A.4 Changes from draft-saintandre-xmpp-uri-01

A.5 Changes from draft-saintandre-xmpp-uri-00



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Intellectual Property Statement

Disclaimer of Validity

Copyright Statement

Acknowledgment