GEOPRIV J. Winterbottom
Internet-Draft CommScope
Updates: 5222 (if approved) M. Thomson
Intended status: Standards Track Skype
Expires: August 4, 2012 R. Barnes
BBN Technologies
B. Rosen
NeuStar, Inc.
R. George
Huawei Technologies
Feb 2012
Specifying Civic Address Extensions in PIDF-LO
draft-ietf-geopriv-local-civic-03
Abstract
New fields are occasionally added to civic addresses. A backwardly-
compatible mechanism for adding civic address elements to the Geopriv
civic address format is described. A formal mechanism for handling
unsupported extensions when translating between XML and DHCP civic
address forms is defined for entities that need to perform this
translation. Intial extensions for some new elements are also
defined. The LoST protocol mechanism that returns civic address
element names used for validation of location information is
clarified to require a namespace on each element.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
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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."
This Internet-Draft will expire on August 4, 2012.
Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the
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document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Motivating Example . . . . . . . . . . . . . . . . . . . . 4
1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
2. Specifying Civic Address Extensions . . . . . . . . . . . . . 4
3. Translating Unsupported Elements . . . . . . . . . . . . . . . 6
3.1. XML to DHCP Format Translation . . . . . . . . . . . . . . 6
3.2. Extension Civic Address Type (CAtype) . . . . . . . . . . 6
3.3. DHCP to XML Format Translation . . . . . . . . . . . . . . 7
3.4. Conversion Example . . . . . . . . . . . . . . . . . . . . 7
4. CAtypes Registry . . . . . . . . . . . . . . . . . . . . . . . 8
5. Civic Extensions . . . . . . . . . . . . . . . . . . . . . . . 9
5.1. Pole Number . . . . . . . . . . . . . . . . . . . . . . . 9
5.2. Mile Post . . . . . . . . . . . . . . . . . . . . . . . . 10
5.3. Street Type Prefix . . . . . . . . . . . . . . . . . . . . 10
5.4. House Number Prefix . . . . . . . . . . . . . . . . . . . 10
5.5. XML Extension Schema . . . . . . . . . . . . . . . . . . . 11
5.6. Extension examples . . . . . . . . . . . . . . . . . . . . 11
6. Using Local Civic Extension with the LoST Protocol . . . . . . 12
7. Security Considerations . . . . . . . . . . . . . . . . . . . 13
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
8.1. CAtype Registration for Extensions . . . . . . . . . . . . 14
8.2. Changes to the CAtype Registry . . . . . . . . . . . . . . 14
8.3. URN sub-namespace registration for
'urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr:ext' . . 14
8.4. XML Schema Registration . . . . . . . . . . . . . . . . . 15
8.5. Registration Template . . . . . . . . . . . . . . . . . . 15
8.6. Registration Policy and Expert Guidance . . . . . . . . . 17
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 17
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 17
10.1. Normative References . . . . . . . . . . . . . . . . . . . 17
10.2. Informative References . . . . . . . . . . . . . . . . . . 18
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 18
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1. Introduction
The Geopriv civic location specifications ([RFC4776], [RFC5139])
define an XML and binary representations for civic addresses that
allow for the expression of civic addresses. Guidance for the use of
these formats for the civic addresses in different countries is
included in [RFC5774].
Subsequent to these specifications being produced, use cases for
extending the civic address format with new elements have emerged.
Extension elements do not readily fit existing elements, as
recommended in [RFC5774].
The XML format for civic addresses [RFC5139] provides a mechanism
that allows for the addition of standardized or privately understood
elements. A similar facility for private extension is not provided
for the DHCP format [RFC4776], though new specifications are able to
define new CAtypes (civic address types).
A recipient of a civic address in either format currently has no
option other than to ignore elements that it does not understand.
This results in any elements that are unknown to that recipient being
discarded if a recipient performs a translation between the two
formats. In order for a new extension to be preserved through
translation by any recipient, the recipient has to understand the
extension and know how to correlate an XML element with a CAtype.
This document describes how new civic address elements are added.
Extensions always starts with the definition of XML elements. A
mechanism for carrying the extension in the DHCP format is described.
A new XML namespace containing a small number of additional civic
elements is also defined and can be used as a template to illustrate
how other extensions can be defined as required.
These mechanisms ensure that any translation between formats can be
performed consistently and without loss of information. Translation
between formats can occur without knowledge of every extension that
is present.
The registry of numeric CAtypes is modified so that creators of
extension can advertise new namespaces and the civic elements to
encourage maximum reuse.
The additions described in this document are backwardly compatible.
Existing implementations may cause extension information to be lost,
but the presence of extensions does not affect an implementation that
conforms to either [RFC4776] or [RFC5139].
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This document also normatively updates [RFC5222] to clarify that the
namespace must be included with the element name in the lists of
valid, invalid and not checked elements in the <locationValidation>
part of a LoST response. While the LoST schema does not need to be
changed, the example in the document is updated to show the
namespaces in the lists.
1.1. Motivating Example
One instance where translation might be necessary is where a device
receives location configuration using DHCP [RFC4776]. Conversion of
DHCP information to an XML form is necessary if the device wishes to
use the DHCP-provided information in a range of applications,
including location-based presence services [RFC4079], and emergency
calling [RFC5012].
+--------+ +--------+ +-----------+
| DHCP | DHCP | Device | XML | Recipient | e.g., Presence
| Server |--------->| |-------->| | Agent
+--------+ +--------+ +-----------+
Conversion Scenario
The Device that performs the translation between the DHCP and XML
formats might not be aware of some of the extensions that are in use.
Without knowledge of these extensions and how they are represented in
XML, the Device is forced to discard them.
These extensions could be useful - or critical - to the ultimate
consumers of this information. For instance, an extension element
might provide a presence watcher with important information in
locating the Device or an extension might be significant in choosing
a particular call route.
1.2. 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].
2. Specifying Civic Address Extensions
The civic schema in [RFC5139] defines an ordered structure of
elements that can be combined to describe a civic address. The XML
extension point at the end of this sequence is used to extend the
address.
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New elements are defined in a new XML namespace [XMLNS]. This is
true of address elements with significance within private or
localized domains, as well as those that are intended for global
applicability.
New elements SHOULD use the basic "caType" schema type defined in
[RFC5139]. This type provides an optional "xml:lang" attribute.
For example, suppose the (fictitious) Central Devon Canals Authority
wishes to introduce a new civic element called "bridge". The
authority defines an XML namespace that includes a "bridge" element.
The namespace needs to be a unique URI, for example
"http://devon.canals.org.uk/civic".
A civic address that includes the new "bridge" element is shown in
Figure 1.
<civicAddress xml:lang="en-GB"
xmlns="urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr"
xmlns:cdc="http://devon.canals.org.uk/civic">
<country>UK</country>
<A1>Devon</A1>
<A3>Monkokehampton</A3>
<RD>Deckport</RD>
<STS>Cross</STS>
<cdc:bridge>21451338</cdc:bridge>
</civicAddress>
Figure 1: Extended Civic Address Example
An entity that receives this location information might not
understand the extension address element. As long as the added
element is able to be safely ignored, the remainder of the civic
address can be used. The result is that the information is not as
useful as it could be, but the added element does not prevent the use
of the remainder of the address.
The address can be passed to other applications, such as a LoST
server [RFC5222], without modification. If the application
understands the added elements, it is able to make use of that
information. For example, if this civic address is acquired using
HELD [RFC5985], it can be included in a LoST request directly.
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3. Translating Unsupported Elements
Unsupported civic address elements can be carried without consequence
only as long as the format of the address does not change. When
converting between the XML and DHCP formats, these unsupported
elements are necessarily discarded: the entity performing the
translation has no way to know the correct element to use in the
target format.
All extensions MUST be defined using the mechanism described in this
document. Extensions that use numeric CAtypes or other mechanisms
cannot be safely translated between XML and DHCP representations.
An entity that does not support these extension mechanisms is
expected to remove elements it doesn't understand when performing
conversions.
3.1. XML to DHCP Format Translation
Extensions to the XML format [RFC5139] are defined in a new XML
namespace [XMLNS].
Extensions in the XML format can be added to a DHCP format civic
address using an extension CAtype.
3.2. Extension Civic Address Type (CAtype)
The extension CAtype (CAtype code XX) [Note to IANA/RFC-Editor:
please replace XX here and in the figure below with the assigned
code] includes three values that uniquely identify the XML extension
and its value: a namespace URI, the local name of the XML element,
and the text content of that element. These three values are all
included in the value of the CAtype, each separated by a single
whitespace character.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| CAtype (XX) | Length | Namespace URI ... .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. Namespace URI (continued) ... .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Space (U+20) | XML element local name ... .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Space (U+20) | Extension type value ... .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: XML Civic Address Extension CAtype
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The content of a CAtype (after the CAtype code and length) is UTF-8
encoded Unicode text [RFC3629]. A maximum of 255 octets is allowed.
Octets consumed by the namespace URI and local name reduce the space
available for values.
This conversion only works for elements that have textual content and
an optional "xml:lang" attribute. Elements with complex content or
other attributes - aside from namespace bindings - MUST be ignored if
they are not understood.
3.3. DHCP to XML Format Translation
The registration of a new CAtype following the process in [RFC4776]
means that a recipient that does not know the equivalent XML is
unable to produce a complete XML representation of the DHCP civic
address. For this reason, this document ends the registration of new
numeric CAtypes. No new registrations of numeric CAtypes can be
made.
In lieu of making new numerical CAtype assignments, this document
creates a new extensionCA type which is defined in a manner that lets
new civic elements be described in DHCP form by carrying the name
space and type name of the extension in parameters of the extensionCA
type.
When converting to XML, the namespace prefix used for the extension
element is selected by the entity that performs the conversion.
3.4. Conversion Example
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The following example civic address contains two extensions:
<civicAddress xml:lang="en-US"
xmlns="urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr"
xmlns:post="http://postsoftheworld.net/ns"
xmlns:ap="http://example.com/airport/5.0">
<country>US</country>
<A1>CA</A1>
<post:lamp>2471</post:lamp>
<post:pylon>AQ-374-4(c)</post:pylon>
<ap:airport>LAX</ap:airport>
<ap:terminal>Tom Bradley</ap:terminal>
<ap:concourse>G</ap:concourse>
<ap:gate>36B</ap:gate>
</civicAddress>
Figure 3: XML Example with Multiple Extensions
This is converted to a DHCP form as follows:
country = US
CAtype[0] = en-US
CAtype[1] = CA
CAtype[XX] = http://postsoftheworld.net/ns lamp 2471
CAtype[XX] = http://postsoftheworld.net/ns lamp AQ-374-4(c)
CAtype[XX] = http://example.com/airport/5.0 airport LAX
CAtype[XX] = http://example.com/airport/5.0 terminal Tom Bradley
CAtype[XX] = http://example.com/airport/5.0 concourse G
CAtype[XX] = http://example.com/airport/5.0 gate 36B
Figure 4: Converted DHCP Example with Multiple Extensions
4. CAtypes Registry
[RFC4776] created the CAtype registry. Among other things, this
registry advertised available civic elements. While it has always
been possible to use an extension namespace to define civic elements
that are not in the CAtype registry, and this document does not
change that, the registry is valuable to alert implementors of
commonly used civic elements and provides guidance to clients of what
elements they should suppport.
This document alters the CAtype registry in several ways. It closes
the registry to new numeric CAtypes. It deletes the "NENA" column,
which is not needed. It adds columns for a namespace and contact,
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and changes the name of the column currently called "PIDF" to "Local
Name". It also adds a column to the registry called "Type". "Type"
can have one of two values "A" and "B". Type A elements are intended
for wide use with many applications and SHOULD be implemented by all
clients unless the client is certain the element will not be
encountered. Type "B" civic elements MAY be implemented by any
client.
Type A civic elements require IETF review, while Type B elements only
require an expert review.
5. Civic Extensions
We use this new extension method to define some additional civic
address elements which are needed to correctly encode civic locations
in several countries. The definition of these new civic address
elements also serves as an example of how to define additional
elements using the mechanisms described in this document.
5.1. Pole Number
In some areas, utility and lamp posts carry a unique identifier,
which we call a pole number in this document. In some countries, the
label on the lamp post also carries the local emergency service
number, such as "110", encouraging callers to use the pole number to
identify their location.
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_.-----,===.
| | (''''')
| | `---'
| |
| | ,---------,
| | ,---, |Emergency|
| | /|,-.|----->| Number |
| | / |110| '---------'
| | / |`-'|
|_|/ | 2 | ,---------,
| | | 1 | |Lamp Post|
| | | 2 |----->| Number |
|-| | 1 | '---------'
| |\ | 0 |
| | \ | 1 |
| | \ | 4 |
| | \|,,,|
_ | |
``-..|.|
``--.._
`'--.._
Figure 5: Lamp post with emergency number
5.2. Mile Post
On some roads, trails, railroad rights of way and other linear
features, a post with a mile or kilometer distance from one end of
the feature may be found (a "milepost"). There are other cases of
poles or markers with numeric indications that are not the same as a
"house number" or street address number.
5.3. Street Type Prefix
The civic schema defined in [RFC5139] allows the definition of
address "123 Colorado Boulevard", but it does not allow for the easy
expression of "123 Boulevard Colorado". Adding a street-type prefix,
allows street named in this manner to be more easily represented.
5.4. House Number Prefix
The civic schema defined in [RFC5139] provides house number suffix
element, allowing one to express an address like "123A Main Street",
but it does not contain a corresponding house number prefix. The
house number prefix element allows the expression of address such as
"Z123 Main Street".
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5.5. XML Extension Schema
<?xml version="1.0"?>
<xs:schema
targetNamespace="urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr:ext"
xmlns:ca="urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:cae="urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr:ext"
xmlns:xml="http://www.w3.org/XML/1998/namespace"
elementFormDefault="qualified" attributeFormDefault="unqualified">
<xs:import namespace="urn:ietf:params:xml:pidf:geopriv10:civicAddr"/>
<!-- Post Number -->
<xs:element name="PN" type="ca:caType"/>
<!-- Milepost -->
<xs:element name="MP" type="ca:caType"/>
<!-- Street-Type prefix -->
<xs:element name="STP" type="ca:caType"/>
<!-- House Number Prefix -->
<xs:element name="HNP" type="ca:caType"/>
</xs:schema>
5.6. Extension examples
<civicAddress xml:lang="en-US"
xmlns="urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr"
xmlns:cae="urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr:ext"
<country>US</country>
<A1>CA</A1>
<A2>Sacramento</A2>
<RD>I5</RD>
<cae:MP>248</cae:MP>
<cae:PN>22-109-689</cae:PN>
</civicAddress>
XML Example with Post Number and Mile Post
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<civicAddress xml:lang="en-US"
xmlns="urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr"
xmlns:cae="urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr:ext"
<country>US</country>
<A1>CA</A1>
<A2>Sacramento</A2>
<RD>Colorado</RD>
<HNO>223</HNO>
<cae:STP>Boulevard</cae:STP>
<cae:HNP>A</cae:HNP>
</civicAddress>
XML Example with Street prefix and House Number Prefix
6. Using Local Civic Extension with the LoST Protocol
One critical use of civic location information is in next generation
emergency services applications, in particular call routing
applications. In such cases location information is provided to a
location-based routing service using the location to service
transtion (LoST) protcol [RFC5222]. LoST is used to provide call
routing information, but it is also used to validate location
information to ensure that it can route to an emergency center when
required.
LoST is an XML-based protocol and so the namespace extension
mechansims described in this document do not impact LoST. When LoST
is used for validation a <locationValidation> element is returned
containing a list of valid, a list of invalid, and a list of
unchecked civic elements. Figure 6 is an extract of the validation
response in Figure 6 from [RFC5222].
<locationValidation>
<valid>country A1 A3 A6</valid>
<invalid>PC</invalid>
<unchecked>HNO</unchecked>
</locationValidation>
Figure 6: Location Validation Example from LoST (RFC5222)
The RelaxNG schema in [RFC5222] requires the elements in each of
these lists to be namespace qualified, which makes the example in
Figure 6 from [RFC5222] in error. This issue is especially
significant when local-civic extensions are used as the domain to
which the extensions are attributed may impact their interpretation
by the server or client. To ensure that local-civic extensions do
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not cause issues with LoST server and client implementations, all
elements listed in a <valid>, <invalid>, or <unchecked> element MUST
be qualified with a namespace. To illustrate this the extract above
from figure 6 in [RFC5222] becomes Figure 7.
<locationValidation
xmlns:ca="urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr">
<valid>ca:country ca:A1 ca:A3 ca:A6</valid>
<invalid>ca:PC</invalid>
<unchecked>ca:HNO</unchecked>
</locationValidation>
Figure 7: Corrected Location Validation Example
If validation request has also included the extensions defined in
section Section 5 then the validation would response would look like
Figure 8.
<locationValidation
xmlns:ca="urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr"
xmlns:cae="urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr:ext">
<valid>ca:country ca:A1 ca:A3 ca:A6 cae:PN cae:STP</valid>
<invalid>ca:PC</invalid>
<unchecked>ca:HNO cae:MP cae:HNP</unchecked>
</locationValidation>
Figure 8: Corrected Location Validation Example
7. Security Considerations
This document defines a formal way to extend the existing Geopriv
civic address schema. No security threats are introduced by this
document.
Security threats applicable to the civic address formats are
described in [RFC4776] (DHCP) and [RFC5139] (XML).
8. IANA Considerations
This document alters the "CAtypes" registry established by [RFC4776].
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8.1. CAtype Registration for Extensions
IANA has allocated a CAtype code of XX for the extension CAtype.
[[IANA/RFC-EDITOR: Please replace XX with the allocated CAtype]]
8.2. Changes to the CAtype Registry
No further registration of numeric CAtypes is permitted.
The column called "NENA" is removed.
The column called "PIDF" is renamed to "Local Name".
New columns are added named "Namespace URI", "Contact", "Schema" and
"Type".
New registrations use the registration template in Section 8.5.
8.3. URN sub-namespace registration for
'urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr:ext'
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:ext
Registrant Contact: IETF, GEOPRIV working group (geopriv@ietf.org),
James Winterbottom (james.winterbottom@commscope.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 Extensions</title>
</head>
<body>
<h1>Additional Fields for GEOPRIV Civic Address</h1>
<h2>urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr:ext</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>
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END
8.4. XML Schema Registration
This section registers an XML schema as per the procedures in
[RFC3688].
URI: urn:ietf:params:xml:schema:pidf:geopriv10:civicAddr:ext
Registrant Contact: IETF, GEOPRIV working group, (geopriv@ietf.org),
James Winterbottom (james.Winterbottom@commscope.com).
The XML for this schema can be found as the entirety of
Section 5.5 of this document.
8.5. Registration Template
New registrations in the "CAtypes" registry require the following
information:
CAtype: The assigned numeric CAtype. All new registrations use the
value XX. [[IANA/RFC-Editor: update XX] Existing registrations
use their assigned value.
Namespace URI: A unique identifier for the XML namespace used for
the extension element.
Local Name: The local name of an XML element that carries the civic
address element.
Description: A brief description of the semantics of the civic
address element.
(Optional) Example: One or more simple examples of the element.
Contact: Contact details for the person providing the extension.
(Optional) Specification: A reference to a specification for the
civic address element.
(Optional) Schema: A reference to a formal schema (XML schema,
RelaxNG, or other form) that defines the extension.
Type: If Type is "A", all clients SHOULD implement this element. If
Type is "B", clients MAY implement this element.
Registrations from [RFC4776] and [RFC5139] are registered with the
following form:
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CAtype: (The existing CAtype.)
Namespace URI: urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr
Local Name: (The contents of the PIDF column.)
Description: (The existing description for the element.)
Contact: The IESG (iesg@ietf.org); the GEOPRIV working group
(geopriv@ietf.org).
Specification: RFC4776 and RFC5139
Schema: urn:ietf:params:xml:schema:pidf:geopriv10:civicAddr
Type: A
Registration of the schema defined in this document in Section 5.5.
CAtype: The assigned numeric CAtype value is XX. [[IANA/RFC-Editor:
update XX]
Namespace URI: urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr:ext
Local Name: PN, MP, STP, HNP
Description: PN: Post number that is attributed to a lamp post or
utility pole.
Description: MP: Mile Post a marker indicating distance to or from a
place (often a town).
Description: STP: Street Type Prefix.
Description: HNP: House Number Prefix.
Contact: The IESG (iesg@ietf.org); the GEOPRIV working group
(geopriv@ietf.org).
Specification: RFCXXXX [[NOTE TO IANA/RFC-EDITOR: Please update RFC
URL and replace XXXX with the RFC number for this specification.]]
Schema: urn:ietf:params:xml:schema:pidf:geopriv10:civicAddr:ext
Type: A
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8.6. Registration Policy and Expert Guidance
The "CAtypes" registry is altered to operate on a registration policy
of "Expert Review", and optionally "Specification Required" [RFC5226]
if the element being registered has a Type value of "B".
The registration rules for "Specification Required" are followed only
if a registration includes a reference to a specification.
Registrations can be made without a specification reference.
If the element being registered has a Type value of "A" then the
registration policy is "IETF Review".
All registrations are reviewed to identify potential duplication
between registered elements. Duplicated semantics are not prohibited
in the registry, though it is preferred if existing elements are
used. The expert review is advised to recommend the use of existing
elements following the guidance in [RFC5774]. Any registration that
is a duplicate or could be considered a close match for the semantics
of an existing element SHOULD include a discussion of the reasons
that the existing element was not reused.
9. Acknowledgements
Thanks to anyone who has tried to extend the civic schema and found
it a little unintuitive.
10. References
10.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
January 2004.
[RFC4776] Schulzrinne, H., "Dynamic Host Configuration Protocol
(DHCPv4 and DHCPv6) Option for Civic Addresses
Configuration Information", RFC 4776, November 2006.
[RFC5139] Thomson, M. and J. Winterbottom, "Revised Civic Location
Format for Presence Information Data Format Location
Object (PIDF-LO)", RFC 5139, February 2008.
[RFC5222] Hardie, T., Newton, A., Schulzrinne, H., and H.
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Internet-Draft Civic Extensions Feb 2012
Tschofenig, "LoST: A Location-to-Service Translation
Protocol", RFC 5222, August 2008.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008.
[XMLNS] Hollander, D., Layman, A., Tobin, R., and T. Bray,
"Namespaces in XML 1.1 (Second Edition)", World Wide Web
Consortium Recommendation REC-xml-names11-20060816,
August 2006,
<http://www.w3.org/TR/2006/REC-xml-names11-20060816>.
10.2. Informative References
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
10646", STD 63, RFC 3629, November 2003.
[RFC4079] Peterson, J., "A Presence Architecture for the
Distribution of GEOPRIV Location Objects", RFC 4079,
July 2005.
[RFC5012] Schulzrinne, H. and R. Marshall, "Requirements for
Emergency Context Resolution with Internet Technologies",
RFC 5012, January 2008.
[RFC5774] Wolf, K. and A. Mayrhofer, "Considerations for Civic
Addresses in the Presence Information Data Format Location
Object (PIDF-LO): Guidelines and IANA Registry
Definition", BCP 154, RFC 5774, March 2010.
[RFC5985] Barnes, M., "HTTP-Enabled Location Delivery (HELD)",
RFC 5985, September 2010.
Authors' Addresses
James Winterbottom
CommScope
Suit 1, Level 2
iC Enterprise 1, Innovation Campus
Squires Way
North Wollongong, NSW 2500
AU
Phone: +61 242 212938
Email: james.winterbottom@commscope.com
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Martin Thomson
Skype
3210 Porter Drive
Palo Alto, California 94304
US
Email: martin.thomson@gmail.com
Richard Barnes
BBN Technologies
9861 Broken Land Parkway
Columbia, MD 21046
US
Phone: +1 410 290 6169
Email: rbarnes@bbn.com
Brian Rosen
NeuStar, Inc.
470 Conrad Dr
Mars, PA 16046
US
Email: br@brianrosen.net
Robins George
Huawei Technologies
Huawei Base, Bantian, Longgan District
Shenzhen, Guangdong 518129
P. R. China
Phone: +86 755 2878 8314
Email: robinsg@huawei.com
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