[Docs] [txt|pdf] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits] [IPR]

Versions: 00 01 02 03 04 05 06 07 RFC 5139

GEOPRIV WG                                                    M. Thomson
Internet-Draft                                           J. Winterbottom
Updates: 4119 (if approved)                                       Andrew
Intended status: Standards Track                       February 15, 2007
Expires: August 19, 2007


               Revised Civic Location Format for PIDF-LO
               draft-ietf-geopriv-revised-civic-lo-05.txt

Status of this Memo

   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 becomes
   aware will be disclosed, in accordance with Section 6 of BCP 79.

   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 as 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 August 19, 2007.

Copyright Notice

   Copyright (C) The IETF Trust (2007).













Thomson & Winterbottom   Expires August 19, 2007                [Page 1]

Internet-Draft              Revised Civic LO               February 2007


Abstract

   This document defines an XML format for the representation of civic
   location.  This format is designed for use with PIDF Location Object
   (PIDF-LO) documents.  The format is based on the civic address
   definition in PIDF-LO, but adds several new elements based on the
   civic types defined for DHCP, and adds a hierarchy to address complex
   road identity schemes.  The format also includes support for the
   xml:lang language tag and restricts the types of elements where
   appropriate.


Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  4
   3.  Changes from PIDF-LO . . . . . . . . . . . . . . . . . . . . .  5
     3.1.  Additional Civic Address Types . . . . . . . . . . . . . .  5
     3.2.  New Thoroughfare Elements  . . . . . . . . . . . . . . . .  6
       3.2.1.  Street Numbering . . . . . . . . . . . . . . . . . . .  7
       3.2.2.  Directionals and other Qualifiers  . . . . . . . . . .  7
     3.3.  Country Element  . . . . . . . . . . . . . . . . . . . . .  7
     3.4.  A1 Element . . . . . . . . . . . . . . . . . . . . . . . .  7
     3.5.  Languages and Scripts  . . . . . . . . . . . . . . . . . .  8
       3.5.1.  Converting from the DHCP Format  . . . . . . . . . . .  8
       3.5.2.  Combining Multiple Elements Based on Language
               Preferences  . . . . . . . . . . . . . . . . . . . . .  8
     3.6.  Whitespace . . . . . . . . . . . . . . . . . . . . . . . .  9
   4.  Civic Address Schema . . . . . . . . . . . . . . . . . . . . . 10
   5.  Example  . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
   6.  Security Considerations  . . . . . . . . . . . . . . . . . . . 13
   7.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 14
     7.1.  URN sub-namespace registration for
           'urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr'  . . . . 14
     7.2.  XML Schema Registration  . . . . . . . . . . . . . . . . . 14
     7.3.  CAtype Registry Update . . . . . . . . . . . . . . . . . . 15
   8.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 16
     8.1.  Normative References . . . . . . . . . . . . . . . . . . . 16
     8.2.  Informative References . . . . . . . . . . . . . . . . . . 16
   Appendix A.  Acknowledgements  . . . . . . . . . . . . . . . . . . 17
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 18
   Intellectual Property and Copyright Statements . . . . . . . . . . 19









Thomson & Winterbottom   Expires August 19, 2007                [Page 2]

Internet-Draft              Revised Civic LO               February 2007


1.  Introduction

   Since the publication of the original PIDF-LO civic specification, in
   [RFC4119], it has been found that the specification is lacking a
   number of additional parameters that can be used to more precisely
   specify a civic location.  These additional parameters have been
   largely captured in [RFC4776].

   This document revises the GEOPRIV civic form to include the
   additional civic parameters captured in [RFC4776].  The document also
   introduces a hierarchical structure for thoroughfare (road)
   identification which is employed in some countries.  New elements are
   defined to allow for even more precision in specifying a civic
   location.





































Thomson & Winterbottom   Expires August 19, 2007                [Page 3]

Internet-Draft              Revised Civic LO               February 2007


2.  Terminology

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

   The term "thoroughfare" is used in this document to describe a road
   or part of a road or other access route along which a final point is
   identified.  This is consistent with the definition used in
   [UPU-S42].









































Thomson & Winterbottom   Expires August 19, 2007                [Page 4]

Internet-Draft              Revised Civic LO               February 2007


3.  Changes from PIDF-LO

3.1.  Additional Civic Address Types

   [RFC4776] provides a full set of parameters that may be used to
   describe a civic location.  Specifically [RFC4776] lists several
   civic address types (CAtypes) that require support in the formal
   PIDF-LO definition that are not in [RFC4119].

   These changes include and new elements that are required to support
   more complex structures for naming street addresses, this is
   described in more detail in Section 3.2.

   +---------------+--------+----------------------------+-------------+
   | New Civic     | CAtype | Description                | Example     |
   | Field         |        |                            |             |
   +---------------+--------+----------------------------+-------------+
   | BLD           |   25   | Building (structure)       | Hope        |
   |               |        |                            | Theatre     |
   |               |        |                            |             |
   | UNIT          |   26   | Unit (apartment, suite)    | 12a         |
   |               |        |                            |             |
   | ROOM          |   28   | Room                       | 450F        |
   |               |        |                            |             |
   | PLC           |   29   | Place-type                 | office      |
   |               |        |                            |             |
   | PCN           |   30   | Postal community name      | Leonia      |
   |               |        |                            |             |
   | POBOX         |   31   | Post office box (P.O. box) | U40         |
   |               |        |                            |             |
   | ADDCODE       |   32   | Additional Code            | 13203000003 |
   |               |        |                            |             |
   | SEAT          |   33   | Seat (desk, cubicle,       | WS 181      |
   |               |        | workstation)               |             |
   |               |        |                            |             |
   | RD            |   34   | Primary road or street     | Broadway    |
   |               |        |                            |             |
   | RDSEC         |   35   | Road section               | 14          |
   |               |        |                            |             |
   | RDBR          |   36   | Road branch                | Lane 7      |
   |               |        |                            |             |
   | RDSUBBR       |   37   | Road sub-branch            | Alley 8     |
   |               |        |                            |             |
   | PRM           |   38   | Road pre-modifier          | Old         |
   |               |        |                            |             |
   | POM           |   39   | Road post-modifier         | Extended    |
   +---------------+--------+----------------------------+-------------+




Thomson & Winterbottom   Expires August 19, 2007                [Page 5]

Internet-Draft              Revised Civic LO               February 2007


                     Table 1: New Civic PIDF-LO Types

   A complete description of these types is included in [RFC4776].

3.2.  New Thoroughfare Elements

   In some countries a thoroughfare can be broken up into sections, and
   it is not uncommon for street numbers to be repeated between
   sections.  A road section identifier is required to ensure that an
   address is unique.  For example, "West Alice Parade" has 5 sections,
   each numbered from 1; unless the section is specified "7 West Alice
   Parade" could exist in 5 different places.  The "RDSEC" element is
   used to specify the section.

   Minor streets can share the same name, so that they can only be
   distinguished by the major thoroughfare with which they intersect.
   For example, both "West Alice Parade, Section 3" and "Bob Street"
   could both be interested by a "Carol Lane".  The "RDBR" element is
   used to specify a road branch where the name of the branch does not
   uniquely identify the road.  Road branches MAY also be used where a
   major thoroughfare is split into sections.

   Similar to the way that a road branch is associated with a road, a
   road sub-branch is associated with a road branch.  The "RDSUBBR"
   element is used to identify road sub-branches.

   The "A6" element is retained for use in those countries that require
   this level of detail.  Where "A6" was previously used for street
   names in [RFC4119], it MUST NOT be used, the "RD" element MUST be
   used for thoroughfare data.  However, without additional information
   these fields MUST not be interchanged when converting between
   different civic formats.  Where civic address information is obtained
   from another format, such as the DHCP form [RFC4776], the "A6"
   element MUST be copied directly from the source format.

   The following example figure shows a fictional arrangement of roads
   where these new thoroughfare elements are applicable.

         |                                                 ||
         |                                  ---------------||
         | Carol La.                           Carol La.   || Bob
         |                                                 || St.
         |              West Alice Pde.                    ||
    ==========/=================/===============/==========||===========
       Sec.1       Sec.2           Sec.3   |       Sec.4   ||   Sec.5
                                           |               ||
                                 ----------| Carol         ||
                                  Alley 2  |  La.          ||



Thomson & Winterbottom   Expires August 19, 2007                [Page 6]

Internet-Draft              Revised Civic LO               February 2007


                                           |               ||

3.2.1.  Street Numbering

   The introduction of new thoroughfare elements affects the
   interpretation of several of more specific civic address data.  In
   particular, street numbering (the "HNO" element) applies to the most
   specific road element specified.  That is, the first specified
   element from: "RDSUBBR", "RDBR", "RDSEC", or "RD".

3.2.2.  Directionals and other Qualifiers

   The "PRM", "POM", "PRD", "POD" and "STS" elements always apply to the
   value of the "RD" element only.  If road branches or sub-branches
   require street suffixes or qualifiers, they MUST be included in the
   "RDBR" or "RDSUBBR" element text.

3.3.  Country Element

   The "country" element differs from that defined in [RFC4119] in that
   it now restricts the value space of the element to two upper case
   characters, which correspond to the alpha-2 codes in [ISO.3166-1].

3.4.  A1 Element

   The "A1" element is used for the top level subdivision within a
   country.  In the absence of a country-specific guide on how to use
   the A-series of elements, the second part of the ISO 3166-2 code
   [ISO.3166-2] for a country subdivision SHOULD be used.  The ISO
   3166-2 code is a formed of a country code and hyphen plus a code of
   one, two or three characters or numerals.  For the "A1" element, the
   leading country code and hyphen are omitted and only the subdivision
   code is included.

   For example, the codes for Canada include CA-BC, CA-ON, CA-QC;
   Luxembourg has just three single character codes: LU-D, LU-G and
   LU-L; Australia uses both two and three character codes: AU-ACT, AU-
   NSW, AU-NT; France uses numerical codes for mainland France and
   letters for territories: FR-75, FR-NC.  This results in the following
   fragments:

      <country>CA</country><A1>ON</A1>

      <country>LU</country><A1>L</A1>

      <country>AU</country><A1>ACT</A1>





Thomson & Winterbottom   Expires August 19, 2007                [Page 7]

Internet-Draft              Revised Civic LO               February 2007


      <country>FR</country><A1>75</A1>

3.5.  Languages and Scripts

   The XML schema defined for civic addresses allows for the addition of
   the "xml:lang" attribute to all elements except "country" and "PLC",
   which both contain enumerated values.

   The "script" field defined in [RFC4776] is omitted in favour of using
   the "xml:lang" attribute.

   It is RECOMMENDED that each "civicAddress" element use one language
   only, or a combination of languages that is consistent.  Where a
   civic location is represented in multiple languages multiple
   "civicAddress" elements SHOULD be included in the PIDF-LO document.
   For civic addresses that form a complex to describe the same
   location, these SHOULD be inserted into the same tuple.

3.5.1.  Converting from the DHCP Format

   The DHCP format for civic addresses [RFC4776] permits the inclusion
   of an element multiple times with different languages or scripts.
   However, this XML form only permits a single instance of each
   element.  Multiple "civicAddress" elements are required if any
   element is duplicated with different languages.  If the same language
   and script is used for all elements, or no elements are duplicated,
   the format can be converted into a single civic address.

   Where there are duplicated elements in different languages, a
   "civicAddress" element is created for each language that is present.
   All elements that are in that language are included.  Elements that
   are language independent, like the "country" and "PLC" elements, are
   added to all "civicAddress" elements.

3.5.2.  Combining Multiple Elements Based on Language Preferences

   If the receiver of the XML representation is known, and that receiver
   has indicated language preferences, a single XML format can be
   constructed using those preferences.  For example, language
   preferences can be indicated by the "Accept-Language" header in the
   SIP or HTTP protocols.

   All elements that have only one value, irrespective of language, are
   used.  Where multiple values exist, each value is assigned a
   weighting based on the language preferences.  The value with the
   highest weighting is selected.  An arbitrary value is selected if two
   values have the same preference, if there is no preference for the
   available languages, or if there are conflicting values with the same



Thomson & Winterbottom   Expires August 19, 2007                [Page 8]

Internet-Draft              Revised Civic LO               February 2007


   language.

3.6.  Whitespace

   The XML schema [W3C.REC-xmlschema-2-20041028] defined in Section 4
   uses a base type of "token" instead of "string" as used in [RFC4119].

   The "token" type ensures that whitespace within instance documents is
   normalized and collapsed before being passed to a processor.  This
   ensures that the following fragments are considered equivalent by XML
   processors:

   <A4>North Wollongong</A4>

   <A1>North
     Wollongong</A1>

   <A1>
     North   Wollongong
     </A1>

   Whitespace may still be included in values by using character
   references, such as "&#x20;".




























Thomson & Winterbottom   Expires August 19, 2007                [Page 9]

Internet-Draft              Revised Civic LO               February 2007


4.  Civic Address Schema

   <?xml version="1.0"?>
   <xs:schema
     targetNamespace="urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr"
     xmlns:xs="http://www.w3.org/2001/XMLSchema"
     xmlns:ca="urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr"
     xmlns:xml="http://www.w3.org/XML/1998/namespace"
     elementFormDefault="qualified" attributeFormDefault="unqualified">

     <xs:import namespace="http://www.w3.org/XML/1998/namespace"
                schemaLocation="http://www.w3.org/2001/xml.xsd"/>

     <xs:simpleType name="iso3166a2">
       <xs:restriction base="xs:token">
         <xs:pattern value="[A-Z]{2}"/>
       </xs:restriction>
     </xs:simpleType>

     <xs:complexType name="caType">
       <xs:simpleContent>
         <xs:extension base="xs:token">
           <xs:attribute ref="xml:lang" use="optional"/>
         </xs:extension>
       </xs:simpleContent>
     </xs:complexType>

     <xs:element name="civicAddress" type="ca:civicAddress"/>
     <xs:complexType name="civicAddress">
       <xs:sequence>
         <xs:element name="country" type="ca:iso3166a2" minOccurs="0"/>
         <xs:element name="A1" type="ca:caType" minOccurs="0"/>
         <xs:element name="A2" type="ca:caType" minOccurs="0"/>
         <xs:element name="A3" type="ca:caType" minOccurs="0"/>
         <xs:element name="A4" type="ca:caType" minOccurs="0"/>
         <xs:element name="A5" type="ca:caType" minOccurs="0"/>
         <xs:element name="A6" type="ca:caType" minOccurs="0"/>
         <xs:element name="PRM" type="ca:caType" minOccurs="0"/>
         <xs:element name="PRD" type="ca:caType" minOccurs="0"/>
         <xs:element name="RD" type="ca:caType" minOccurs="0"/>
         <xs:element name="STS" type="ca:caType" minOccurs="0"/>
         <xs:element name="POD" type="ca:caType" minOccurs="0"/>
         <xs:element name="POM" type="ca:caType" minOccurs="0"/>
         <xs:element name="RDSEC" type="ca:caType" minOccurs="0"/>
         <xs:element name="RDBR" type="ca:caType" minOccurs="0"/>
         <xs:element name="RDSUBBR" type="ca:caType" minOccurs="0"/>
         <xs:element name="HNO" type="ca:caType" minOccurs="0"/>
         <xs:element name="HNS" type="ca:caType" minOccurs="0"/>



Thomson & Winterbottom   Expires August 19, 2007               [Page 10]

Internet-Draft              Revised Civic LO               February 2007


         <xs:element name="LMK" type="ca:caType" minOccurs="0"/>
         <xs:element name="LOC" type="ca:caType" minOccurs="0"/>
         <xs:element name="FLR" type="ca:caType" minOccurs="0"/>
         <xs:element name="NAM" type="ca:caType" minOccurs="0"/>
         <xs:element name="PC" type="ca:caType" minOccurs="0"/>
         <xs:element name="BLD" type="ca:caType" minOccurs="0"/>
         <xs:element name="UNIT" type="ca:caType" minOccurs="0"/>
         <xs:element name="ROOM" type="ca:caType" minOccurs="0"/>
         <xs:element name="SEAT" type="ca:caType" minOccurs="0"/>
         <xs:element name="PLC" type="xs:token" minOccurs="0"/>
         <xs:element name="PCN" type="ca:caType" minOccurs="0"/>
         <xs:element name="POBOX" type="ca:caType" minOccurs="0"/>
         <xs:element name="ADDCODE" type="ca:caType" minOccurs="0"/>
         <xs:any namespace="##other" processContents="lax"
                 minOccurs="0" maxOccurs="unbounded"/>
       </xs:sequence>
       <xs:attribute ref="xml:lang" use="optional"/>
     </xs:complexType>
   </xs:schema>
































Thomson & Winterbottom   Expires August 19, 2007               [Page 11]

Internet-Draft              Revised Civic LO               February 2007


5.  Example


   <?xml version="1.0"?>
   <civicAddress xml:lang="en-AU"
     xmlns="urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr">
     <country>AU</country>
     <A1>NSW</A1>
     <A3>     Wollongong
     </A3><A4>North Wollongong
     </A4>
     <RD>Flinders</RD><STS>Street</STS>
     <RDBR>Campbell Street</RDBR>
     <LMK>
       Gilligan's Island
     </LMK> <LOC>Corner</LOC>
     <NAM> Video Rental Store </NAM>
     <PC>2500</PC>
     <ROOM> Westerns and Classics </ROOM>
     <PLC>store</PLC>
     <POBOX>Private Box 15</POBOX>
   </civicAddress>





























Thomson & Winterbottom   Expires August 19, 2007               [Page 12]

Internet-Draft              Revised Civic LO               February 2007


6.  Security Considerations

   The XML representation described in this document is designed for
   inclusion in a PIDF-LO document.  As such, it is subject to the same
   security considerations as are described in [RFC4119].
   Considerations relating to the inclusion of this representation in
   other XML documents are outside the scope of this document.












































Thomson & Winterbottom   Expires August 19, 2007               [Page 13]

Internet-Draft              Revised Civic LO               February 2007


7.  IANA Considerations

7.1.  URN sub-namespace registration for
      'urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr'

   This document calls for IANA to register a new XML namespace, as per
   the guidelines in [RFC3688].

   URI:  urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr

   Registrant Contact:  IETF, GEOPRIV working group (geopriv@ietf.org),
      Martin Thomson (martin.thomson@andrew.com).

   XML:

         BEGIN
           <?xml version="1.0"?>
           <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
             "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
           <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
             <head>
               <title>GEOPRIV Civic Address</title>
             </head>
             <body>
               <h1>Format for Distributing Civic Address in GEOPRIV</h1>
               <h2>urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr</h2>
   [[NOTE TO IANA/RFC-EDITOR: Please update RFC URL and replace XXXX
       with the RFC number for this specification.]]
               <p>See <a href="[[RFC URL]]">RFCXXXX</a>.</p>
             </body>
           </html>
         END

7.2.  XML Schema Registration

   This section registers an XML schema as per the procedures in
   [RFC3688].

   URI:  urn:ietf:params:xml:schema:pidf:geopriv10:civicAddr

   Registrant Contact:  IETF, GEOPRIV working group, (geopriv@ietf.org),
      Martin Thomson (martin.thomson@andrew.com).

      The XML for this schema can be found as the entirety of Section 4
      of this document.






Thomson & Winterbottom   Expires August 19, 2007               [Page 14]

Internet-Draft              Revised Civic LO               February 2007


7.3.  CAtype Registry Update

   This document updates the civic address type registry established by
   [RFC4776].  The "PIDF" column of the CAtypes table has been updated
   to include the types shown in the first column of Table 1.














































Thomson & Winterbottom   Expires August 19, 2007               [Page 15]

Internet-Draft              Revised Civic LO               February 2007


8.  References

8.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [W3C.REC-xmlschema-2-20041028]
              Biron, P. and A. Malhotra, "XML Schema Part 2: Datatypes
              Second Edition", World Wide Web Consortium
              Recommendation REC-xmlschema-2-20041028, October 2004,
              <http://www.w3.org/TR/2004/REC-xmlschema-2-20041028>.

   [RFC4776]  Schulzrinne, H., "Dynamic Host Configuration Protocol
              (DHCPv4 and DHCPv6) Option for Civic Addresses
              Configuration Information", RFC 4776, November 2006.

   [ISO.3166-1]
              International Organization for Standardization, "Codes for
              the representation of names of countries and their
              subdivisions - Part 1: Country codes", ISO Standard 3166-
              1:1997, 1997,
              <http://www.iso.org/iso/en/prods-services/iso3166ma/>.

   [ISO.3166-2]
              International Organization for Standardization, "Codes for
              the representation of names of countries and their
              subdivisions - Part 2: Country subdivision code",
              ISO Standard 3166-2:1998, 1998,
              <http://www.iso.org/iso/en/prods-services/iso3166ma/>.

8.2.  Informative References

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              January 2004.

   [RFC4119]  Peterson, J., "A Presence-based GEOPRIV Location Object
              Format", RFC 4119, December 2005.

   [UPU-S42]  Universal Postal Union (UPU), "International Postal
              Address Components and Templates", UPS SB42-4, July 2004.










Thomson & Winterbottom   Expires August 19, 2007               [Page 16]

Internet-Draft              Revised Civic LO               February 2007


Appendix A.  Acknowledgements

   The authors would like to thank Henning Schulzrinne for his
   assistance in defining the additional civic address types,
   particularly his research into different addressing schemes that lead
   to the introduction of the thoroughfare elements.  Rohan Mahy
   suggested the ISO 3166-2 recommendation for A1.  In addition we would
   like to thank Jon Peterson for his work in defining the PIDF-LO.











































Thomson & Winterbottom   Expires August 19, 2007               [Page 17]

Internet-Draft              Revised Civic LO               February 2007


Authors' Addresses

   Martin Thomson
   Andrew
   PO Box U40
   Wollongong University Campus, NSW  2500
   AU

   Phone: +61 2 4221 2915
   Email: martin.thomson@andrew.com
   URI:   http://www.andrew.com/


   James Winterbottom
   Andrew
   PO Box U40
   Wollongong University Campus, NSW  2500
   AU

   Phone: +61 2 4221 2938
   Email: james.winterbottom@andrew.com
   URI:   http://www.andrew.com/





























Thomson & Winterbottom   Expires August 19, 2007               [Page 18]

Internet-Draft              Revised Civic LO               February 2007


Full Copyright Statement

   Copyright (C) The IETF Trust (2007).

   This document is subject to the rights, licenses and restrictions
   contained in BCP 78, and except as set forth therein, the authors
   retain all their rights.

   This document and the information contained herein are provided on an
   "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
   THE INTERNET ENGINEERING TASK FORCE DISCLAIM 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.


Intellectual Property

   The IETF takes no position regarding the validity or scope of any
   Intellectual Property Rights 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; nor does it represent that it has
   made any independent effort to identify any such rights.  Information
   on the procedures with respect to rights in RFC documents can be
   found in BCP 78 and BCP 79.

   Copies of IPR disclosures made to the IETF Secretariat 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 implementers or users of this
   specification can be obtained from the IETF on-line IPR repository at
   http://www.ietf.org/ipr.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights that may cover technology that may be required to implement
   this standard.  Please address the information to the IETF at
   ietf-ipr@ietf.org.


Acknowledgment

   Funding for the RFC Editor function is provided by the IETF
   Administrative Support Activity (IASA).





Thomson & Winterbottom   Expires August 19, 2007               [Page 19]


Html markup produced by rfcmarkup 1.108, available from http://tools.ietf.org/tools/rfcmarkup/