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Inventory and Analysis of WHOIS Registration Objects
RFC 7485

Document Type RFC - Informational (March 2015)
Authors Steve Sheng , Linlin Zhou , Ning Kong , Sean Shen , Arturo L. Servin
Last updated 2015-10-14
RFC stream Internet Engineering Task Force (IETF)
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IESG Responsible AD Pete Resnick
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RFC 7485
Internet Engineering Task Force (IETF)                           L. Zhou
Request for Comments: 7485                                       N. Kong
Category: Informational                                          S. Shen
ISSN: 2070-1721                                                    CNNIC
                                                                S. Sheng
                                                                   ICANN
                                                               A. Servin
                                                                  LACNIC
                                                              March 2015

          Inventory and Analysis of WHOIS Registration Objects

Abstract

   WHOIS output objects from registries, including both Regional
   Internet Registries (RIRs) and Domain Name Registries (DNRs), were
   collected and analyzed.  This document describes the process and
   results of the statistical analysis of existing WHOIS information.
   The purpose of this document is to build an object inventory to
   facilitate discussions of data objects included in Registration Data
   Access Protocol (RDAP) responses.

Status of This Memo

   This document is not an Internet Standards Track specification; it is
   published for informational purposes.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Not all documents
   approved by the IESG are a candidate for any level of Internet
   Standard; see Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc7485.

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Copyright Notice

   Copyright (c) 2015 IETF Trust and the persons identified as the
   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.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   4
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   5
   3.  Methodology . . . . . . . . . . . . . . . . . . . . . . . . .   5
   4.  RIR Objects Analysis  . . . . . . . . . . . . . . . . . . . .   7
     4.1.  WHOIS Data for Organizations Holding a Resource . . . . .   7
     4.2.  WHOIS Data for Contacts . . . . . . . . . . . . . . . . .   9
     4.3.  WHOIS Data for IP Addresses . . . . . . . . . . . . . . .  10
     4.4.  WHOIS Data for ASNs . . . . . . . . . . . . . . . . . . .  12
     4.5.  Conclusion  . . . . . . . . . . . . . . . . . . . . . . .  13
   5.  DNR Object Analysis . . . . . . . . . . . . . . . . . . . . .  14
     5.1.  Overview  . . . . . . . . . . . . . . . . . . . . . . . .  14
     5.2.  Public Objects  . . . . . . . . . . . . . . . . . . . . .  14
       5.2.1.  WHOIS Data for Domains  . . . . . . . . . . . . . . .  15
       5.2.2.  WHOIS Data for Contacts . . . . . . . . . . . . . . .  16
         5.2.2.1.  Registrant  . . . . . . . . . . . . . . . . . . .  16
         5.2.2.2.  Admin Contact . . . . . . . . . . . . . . . . . .  18
         5.2.2.3.  Tech Contact  . . . . . . . . . . . . . . . . . .  19
         5.2.2.4.  Billing Contact . . . . . . . . . . . . . . . . .  20
       5.2.3.  WHOIS Data for Nameservers  . . . . . . . . . . . . .  21
       5.2.4.  WHOIS Data for Registrars . . . . . . . . . . . . . .  21
     5.3.  Other Objects . . . . . . . . . . . . . . . . . . . . . .  22
     5.4.  Conclusion  . . . . . . . . . . . . . . . . . . . . . . .  24
       5.4.1.  Preliminary Statistics  . . . . . . . . . . . . . . .  24
       5.4.2.  Data Element Analysis . . . . . . . . . . . . . . . .  26
       5.4.3.  Label Analysis  . . . . . . . . . . . . . . . . . . .  28
       5.4.4.  Analysis of Other Objects . . . . . . . . . . . . . .  28
     5.5.  Limitations . . . . . . . . . . . . . . . . . . . . . . .  29
   6.  Reference Extension Objects . . . . . . . . . . . . . . . . .  30
     6.1.  RIR Reference Extension Objects . . . . . . . . . . . . .  30
     6.2.  DNR Reference Extension Objects . . . . . . . . . . . . .  30
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .  30
   8.  Informative References  . . . . . . . . . . . . . . . . . . .  31
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .  32
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  32

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1.  Introduction

   Regional Internet Registries (RIRs) and Domain Name Registries (DNRs)
   have historically maintained a lookup service to permit public access
   to some portion of the registry database.  Most registries offer the
   service via the WHOIS protocol [RFC3912], with additional services
   being offered via World Wide Web pages, bulk downloads, and other
   services, such as Routing Policy Specification Language (RPSL)
   [RFC2622].

   Although the WHOIS protocol is widely adopted and supported, it has
   several shortcomings that limit its usefulness to the evolving needs
   of the Internet community.  Specifically:

   o  It has no query and response format.

   o  It does not support user authentication or access control for
      differentiated access.

   o  It has not been internationalized and thus does not consistently
      support Internationalized Domain Names (IDNs) as described in
      [RFC5890].

   This document records an inventory of registry data objects to
   facilitate discussions of registration data objects.  The
   Registration Data Access Protocol (RDAP) ([RFC7480], [RFC7482],
   [RFC7483], and [RFC7484]) was developed using this inventory as
   input.

   In the number space, there were altogether five RIRs.  Although all
   RIRs provided information about IP addresses, Autonomous System
   Numbers (ASNs), and contacts, the data model used was different for
   each RIR.  In the domain name space, there were over 200 country code
   Top-Level Domains (ccTLDs) and over 400 generic Top-Level Domains
   (gTLDs) when this document was published.  Different Domain Name
   Registries may have different WHOIS response objects and formats.  A
   common understanding of all these data formats was critical to
   construct a single data model for each object.

   This document describes the WHOIS data collection procedures and
   gives an inventory analysis of data objects based on the collected
   data from the five RIRs, 106 ccTLDs, and 18 gTLDs from DNRs.  The RIR
   data objects are classified by the five RIRs into IP address, ASN,
   person or contact, and the organization that held the resource.
   According to SPECIFICATION 4 ("SPECIFICATION FOR REGISTRATION DATA
   PUBLICATION SERVICES") of the new gTLD applicant guidebook
   [ICANN.AGB-201206] and the Extensible Provisioning Protocol (EPP)
   ([RFC5730], [RFC5731], [RFC5732], and [RFC5733]), the DNR data

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   objects are classified by whether they relate to the domain, contact,
   nameserver, or registrar.  Objects that do not belong to the
   categories above are viewed as privately specified objects.  In this
   document, there is no intent to analyze all the query and response
   types that exist in RIRs and DNRs.  The most common query objects are
   discussed, but other objects such as RPSL data structures used by
   Internet Routing Registries (IRRs) can be documented later if the
   community feels it is necessary.

2.  Terminology

   o  Data element - The name of a specific response object.

   o  Label - The name given to a particular data element; it may vary
      between registries.

   o  Most popular label - The label that is most supported by the
      registries.

   o  Number of labels - The number of different labels.

   o  No. of TLDs - The number of registries that support a certain data
      element.

3.  Methodology

   WHOIS information, including port 43 response and web response data,
   was collected between July 9, 2012, and July 20, 2012, following the
   procedures described below.

   (1)  First, find the RIR WHOIS servers of the five RIRs, which are
        AFRINIC, APNIC, ARIN, LACNIC, and RIPE NCC.  All the RIRs
        provide information about IP addresses, ASNs, and contacts.

   (2)  Query the corresponding IP addresses, ASNs, contacts, and
        organizations registered in the five RIRs.  Then, make a
        comparative analysis of the response data.

   (3)  Group together the data elements that have the same meaning but
        use different labels.

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   DNR object collection process:

   (1)  A programming script was applied to collect port 43 response
        data from 294 ccTLDs. "nic.ccTLD" was used as the query string,
        which is usually registered in a domain registry.  Responses for
        106 ccTLDs were received. 18 gTLDs' port 43 response data was
        collected from their contracts with ICANN.  Thus, the sample
        size of port 43 WHOIS response data is 124 registries in total.

   (2)  WHOIS data from the web was collected manually from the 124
        registries that send port 43 WHOIS responses.

   (3)  Some of the response that which were collected by the program
        did not seem to be correct, so data for the top 10 ccTLD
        registries, like .de, .eu, and .uk, was re-verified by querying
        domain names other than "nic.ccTLD".

   (4)  In accordance with SPECIFICATION 4 of the new gTLD applicant
        guidebook [ICANN.AGB-201206] and EPP ([RFC5730], [RFC5731],
        [RFC5732] and [RFC5733]), the response data objects are
        classified into public and other data objects.  Public data
        objects are those that are defined in the above references.
        Other objects are those that are privately specified data
        elements or objects in different registries.

   (5)  Data elements with the same meaning, but using different labels,
        were grouped together.  The number of registries that support
        each data element is shown in the "No. of TLDs" column.

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4.  RIR Objects Analysis

4.1.  WHOIS Data for Organizations Holding a Resource

   Table 1 shows the organization objects of the five RIRs.

 +--------------+------------+-----+----------+-----------+------------+
 |     RIR      |  AFRINIC   |APNIC|    ARIN  |   LACNIC  |  RIPE NCC  |
 |   Objects    |            |     |          |           |            |
 +--------------+------------+-----+----------+-----------+------------+
 | Organization |organisation|  NA |    Name  |   Owner   |  org-name  |
 |     name     |            |     |          |           |            |
 +--------------+------------+-----+----------+-----------+------------+
 | Organization |  org-name  |  NA |   Handle |  owner-id |organisation|
 |     ID       |            |     |          |           |            |
 +--------------+------------+-----+----------+-----------+------------+
 |   Company    |     NA     |  NA |  Company |     NA    |     NA     |
 +--------------+------------+-----+----------+-----------+------------+
 |   Name of    |     NA     |  NA |     NA   |responsible|     NA     |
 |    person    |            |     |          |           |            |
 |  responsible |            |     |          |           |            |
 +--------------+------------+-----+----------+-----------+------------+
 |    Type of   |  org-type  |  NA |     NA   |     NA    |  org-type  |
 | organization |            |     |          |           |            |
 +--------------+------------+-----+----------+-----------+------------+
 |   Country    |  country   |  NA |  country |  country  |  country   |
 +--------------+------------+-----+----------+-----------+------------+
 |    Postal    |  address   |  NA |  address |  address  |  address   |
 |   Address    |            |     |          |           |            |
 +--------------+------------+-----+----------+-----------+------------+
 |     City     |     NA     |  NA |    city  |     NA    |  address   |
 +--------------+------------+-----+----------+-----------+------------+
 |    State     |     NA     |  NA | StateProv|     NA    |  address   |
 +--------------+------------+-----+----------+-----------+------------+
 |    Postal    |     NA     |  NA |PostalCode|     NA    |  address   |
 |     Code     |            |     |          |           |            |
 +--------------+------------+-----+----------+-----------+------------+
 |    Phone     |   phone    |  NA |   NA     |   phone   |   phone    |
 +--------------+------------+-----+----------+-----------+------------+
 |  Fax Number  |   fax-no   |  NA |   NA     |     NA    |   fax-no   |
 +--------------+------------+-----+----------+-----------+------------+
 |    ID of     |  admin-c   |  NA |   Admin  |  owner-c  |  admin-c   |
 |administrative|            |     |    POC   |           |            |
 |   contact    |            |     |          |           |            |
 +--------------+------------+-----+----------+-----------+------------+
 |    ID of     |   tech-c   |  NA | Tech POC |   tech-c  |   tech-c   |
 |  technical   |            |     |          |           |            |
 |   contact    |            |     |          |           |            |

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 +--------------+------------+-----+----------+-----------+------------+
 |  Maintainer  |  mnt-ref   |  NA |  NOC POC |     NA    |  mnt-ref   |
 | organization |            |     |          |           |            |
 +--------------+------------+-----+----------+-----------+------------+
 |  Maintainer  |   mnt-by   |  NA |   Abuse  |     NA    |   mnt-by   |
 |   object     |            |     |    POC   |           |            |
 +--------------+------------+-----+----------+-----------+------------+
 |   Remarks    |  remarks   |  NA |     NA   |     NA    |  remarks   |
 +--------------+------------+-----+----------+-----------+------------+
 |   Date of    |  Changed   |  NA |  RegDate |  created  |  Changed   |
 |    record    |            |     |          |           |            |
 |   creation   |            |     |          |           |            |
 +--------------+------------+-----+----------+-----------+------------+
 |   Date of    |  changed   |  NA |  Updated |  changed  |  changed   |
 |    record    |            |     |          |           |            |
 |   changed    |            |     |          |           |            |
 +--------------+------------+-----+----------+-----------+------------+
 |   List of    |     NA     |  NA |     NA   |  list of  |     NA     |
 |  resources   |            |     |          | resources |            |
 +--------------+------------+-----+----------+-----------+------------+
 |    Source    |   source   |  NA |     NA   |     NA    |   source   |
 +--------------+------------+-----+----------+-----------+------------+
 |  Reference   |     NA     |  NA |    Ref   |     NA    |     NA     |
 +--------------+------------+-----+----------+-----------+------------+

         Table 1.  WHOIS Data for Organizations Holding a Resource

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4.2.  WHOIS Data for Contacts

   Table 2 shows the contact objects of the five RIRs.

   +--------------+---------+---------+------------+---------+---------+
   | Data Element | AFRINIC |  APNIC  |    ARIN    |  LACNIC |   RIPE  |
   |              |         |         |            |         |   NCC   |
   +--------------+---------+---------+------------+---------+---------+
   |     Name     |  person |  person |    Name    |  person |  person |
   +--------------+---------+---------+------------+---------+---------+
   |   Company    |    NA   |    NA   |  Company   |    NA   |    NA   |
   +--------------+---------+---------+------------+---------+---------+
   |    Postal    | address | address |  Address   | address | address |
   |   Address    |         |         |            |         |         |
   +--------------+---------+---------+------------+---------+---------+
   |     City     |    NA   |    NA   |    City    |    NA   | address |
   +--------------+---------+---------+------------+---------+---------+
   |    State     |    NA   |    NA   | StateProv  |    NA   | address |
   +--------------+---------+---------+------------+---------+---------+
   | Postal Code  |    NA   |    NA   | PostalCode |    NA   | address |
   +--------------+---------+---------+------------+---------+---------+
   |   Country    |    NA   | country |  Country   | country |    NA   |
   +--------------+---------+---------+------------+---------+---------+
   |    Phone     |  phone  |  phone  |   Mobile   |  phone  |  phone  |
   +--------------+---------+---------+------------+---------+---------+
   |  Fax Number  |  fax-no |  fax-no |    Fax     |    NA   |  fax-no |
   +--------------+---------+---------+------------+---------+---------+
   |    Email     |  e-mail |  e-mail |   Email    |  e-mail |    NA   |
   +--------------+---------+---------+------------+---------+---------+
   |      ID      | nic-hdl | nic-hdl |   Handle   | nic-hdl | nic-hdl |
   +--------------+---------+---------+------------+---------+---------+
   |   Remarks    | remarks | remarks |  Remarks   |    NA   | remarks |
   +--------------+---------+---------+------------+---------+---------+
   |    Notify    |  notify |  notify |     NA     |    NA   |  notify |
   +--------------+---------+---------+------------+---------+---------+
   |    ID of     |  mnt-by |  mnt-by |     NA     |    NA   |  mnt-by |
   |  maintainer  |         |         |            |         |         |
   +--------------+---------+---------+------------+---------+---------+
   | Registration | changed |    NA   |  RegDate   | created | changed |
   |     Date     |         |         |            |         |         |
   +--------------+---------+---------+------------+---------+---------+
   | Registration | changed | changed |  Updated   | changed | changed |
   |    update    |         |         |            |         |         |
   +--------------+---------+---------+------------+---------+---------+
   |    Source    |  source |  source |     NA     |    NA   |  source |

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   +--------------+---------+---------+------------+---------+---------+
   |  Reference   |    NA   |    NA   |    Ref     |    NA   |    NA   |
   +--------------+---------+---------+------------+---------+---------+

                     Table 2.  WHOIS Data for Contacts

4.3.  WHOIS Data for IP Addresses

   Table 4 shows the IP address objects of the five RIRs.

   Note: Due to the 72-character limit on line length, strings in some
   cells of the table are split into two or more parts, which are placed
   on separate lines within the same cell.  A hyphen in the final
   position of a string indicates that the string has been split due to
   the length limit.

                      +----------+----------+----------+
                      | Adminis- |          |  abuse-- |
                      | trative  |  admin-c |  mailbox |
                      | contact  |          |          |
                      +----------+----------+----------+

                   Table 3.  Example of String Splitting

   For instance, the original strings in the cells of Table 3 are
   "Administrative contact", "admin-c", and "abuse-mailbox",
   respectively.

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+------------+--------+----------+--------------+--------+-------------+
|    Data    | AFRINIC|  APNIC   |     ARIN     | LACNIC |   RIPE NCC  |
|   Element  |        |          |              |        |             |
+------------+--------+----------+--------------+--------+-------------+
|      IP    | inetnum| inetnum  |   NetRange   |   NA   |   inetnum   |
|   address  |        |          |              |        |             |
|    range   |        |          |              |        |             |
+------------+--------+----------+--------------+--------+-------------+
|     IPv6   |inet6num| inet6num |     CIDR     |inetnum |  inet6num   |
|   address  |        |          |              |        |             |
|    range   |        |          |              |        |             |
+------------+--------+----------+--------------+--------+-------------+
| Description| descr  |  descr   |   NetName    |   NA   |    descr    |
|            |        |          |              |        |             |
+------------+--------+----------+--------------+--------+-------------+
|   Remarks  | remarks| remarks  |      NA      |   NA   |   remarks   |
|            |        |          |              |        |             |
+------------+--------+----------+--------------+--------+-------------+
|  Origin AS |   NA   |    NA    |   OriginAS   |OriginAS|      NA     |
|            |        |          |              |(future)|             |
+------------+--------+----------+--------------+--------+-------------+
|   Network  | netname| netname  |  NetHandle   |inetrev |   netname   |
|   name/ID  |        |          |              |        |             |
+------------+--------+----------+--------------+--------+-------------+
| Maintainer | mnt-by |    NA    |      NA      |   NA   |    mnt-by   |
| Object     |        |          |              |        |             |
+------------+--------+----------+--------------+--------+-------------+
| Maintainer | mnt--  |    NA    |      NA      |   NA   |      NA     |
| Sub-       | lower  |          |              |        |             |
| assignments|        |          |              |        |             |
+------------+--------+----------+--------------+--------+-------------+
|  Adminis-  | admin-c| admin-c  |    OrgId     | ownerid|   admin-c   |
|  trative   |        |          |              |        |             |
|  contact   |        |          |              |        |             |
+------------+--------+----------+--------------+--------+-------------+
|    Parent  | parent |    NA    |    Parent    |   NA   |      NA     |
|    range   |        |          |              |        |             |
+------------+--------+----------+--------------+--------+-------------+
|    Status  | status |  status  |   NetType    | status |    status   |
+------------+--------+----------+--------------+--------+-------------+
|Registration| changed|    NA    |   RegDate    | created|   changed   |
|   Date     |        |          |              |        |             |
+------------+--------+----------+--------------+--------+-------------+
|Registration| changed| changed  |   Updated    | changed|   changed   |
|   update   |        |          |              |        |             |
+------------+--------+----------+--------------+--------+-------------+
|  Reference |   NA   |    NA    |     Ref      |   NA   |      NA     |

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+------------+--------+----------+--------------+--------+-------------+
|      ID    |  org   |    NA    |    OrgId     | owner  |organisation |
|organization|        |          |              |        |             |
|holding the |        |          |              |        |             |
|   resource |        |          |              |        |             |
+------------+--------+----------+--------------+--------+-------------+
|   Referral |   NA   |    NA    |ReferralServer|   NA   |      NA     |
|    server  |        |          |              |        |             |
+------------+--------+----------+--------------+--------+-------------+
|  Technical | tech-c |  tech-c  |OrgTechHandle | tech-c |    tech-c   |
|   contact  |        |          |              |        |             |
+------------+--------+----------+--------------+--------+-------------+
|    Abuse   |   NA   |    NA    |OrgAbuseHandle| abuse-c|abuse-mailbox|
|   contact  |        |          |              |        |             |
+------------+--------+----------+--------------+--------+-------------+
|   Referral |   NA   |    NA    | RTechHandle  |   NA   |      NA     |
|  technical |        |          |              |        |             |
|   contact  |        |          |              |        |             |
+------------+--------+----------+--------------+--------+-------------+
|   Referral | mnt-irt| mnt-irt  | RAbuseHandle |   NA   |      NA     |
|    abuse   |        |          |              |        |             |
|   contact  |        |          |              |        |             |
+------------+--------+----------+--------------+--------+-------------+
|   Referral |   NA   |    NA    |  RNOCHandle  |   NA   |      NA     |
|     NOC    |        |          |              |        |             |
|   contact  |        |          |              |        |             |
+------------+--------+----------+--------------+--------+-------------+
|     Name   |   NA   |    NA    |      NA      | nserver|      NA     |
|    server  |        |          |              |        |             |
+------------+--------+----------+--------------+--------+-------------+

                   Table 4.  WHOIS Data for IP Addresses

4.4.  WHOIS Data for ASNs

+--------------+---------+----------+-------------+---------+----------+
|    Data      | AFRINIC |  APNIC   |     ARIN    |  LACNIC | RIPE NCC |
|  Element     |         |          |             |         |          |
+--------------+---------+----------+-------------+---------+----------+
|     ID       | aut-num | aut-num  |   ASNumber  | aut-num | aut-num  |
|              |         |          |             |         |          |
+--------------+---------+----------+-------------+---------+----------+
| Description  | descr   |  descr   |      NA     |    NA   |  descr   |
|              |         |          |             |         |          |
+--------------+---------+----------+-------------+---------+----------+
|Organization  |  org    |    NA    |    OrgId    |  owner  |   org    |
|              |         |          |             |         |          |

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+--------------+---------+----------+-------------+---------+----------+
|  Comment     | remarks |    NA    |   Comment   |    NA   | remarks  |
+--------------+---------+----------+-------------+---------+----------+
|Administrative| admin-c | admin-c  |   ASHandle  |owner-id | admin-c  |
|   contact ID |         |          |             |         |          |
+--------------+---------+----------+-------------+---------+----------+
| Technical    | tech-c  |  tech-c  |OrgTechHandle|routing-c|  tech-c  |
| contact ID   |         |          |             |         |          |
+--------------+---------+----------+-------------+---------+----------+
| Organization |   NA    | nic-hdl  |      NA     | owner-c |  organi- |
|     ID       |         |          |             |         |  sation  |
+--------------+---------+----------+-------------+---------+----------+
|  Notify      | notify  |  notify  |      NA     |    NA   |    NA    |
+--------------+---------+----------+-------------+---------+----------+
|  Abuse       |   NA    |    NA    |   OrgAbuse  | abuse-c |    NA    |
|  contact     |         |          |    Handle   |         |          |
+--------------+---------+----------+-------------+---------+----------+
| Maintainer   | mnt-by  |  mnt-by  |      NA     |    NA   |  mnt-by  |
| Object       |         |          |             |         |          |
+--------------+---------+----------+-------------+---------+----------+
| Maintainer   |mnt-lower| mnt-lower|      NA     |    NA   |mnt-lower |
| Sub-         |         |          |             |         |          |
| assignments  |         |          |             |         |          |
+--------------+---------+----------+-------------+---------+----------+
| Maintainer   |   NA    |    NA    |      NA     |    NA   | mnt-ref  |
| Organization |         |          |             |         |          |
+--------------+---------+----------+-------------+---------+----------+
|Registration  | changed |    NA    |   RegDate   | created |    NA    |
|    Date      |         |          |             |         |          |
+--------------+---------+----------+-------------+---------+----------+
|Registration  | changed | changed  |   Updated   | changed |    NA    |
|   update     |         |          |             |         |          |
+--------------+---------+----------+-------------+---------+----------+
|   Source     | source  |  source  |      NA     |    NA   |  source  |
+--------------+---------+----------+-------------+---------+----------+

                       Table 5.  WHOIS Data for ASNs

4.5.  Conclusion

   As can be observed, some data elements were not supported by all
   RIRs, and some were given different labels by different RIRs.  Also,
   there were identical labels used for different data elements by
   different RIRs.  In order to construct a single data model for each
   object, a selection of the most common and useful fields was made.
   That initial selection was the starting point for [RFC7483].

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5.  DNR Object Analysis

5.1.  Overview

   WHOIS data was collected from 124 registries, including 106 ccTLDs
   and 18 gTLDs.  All 124 registries support domain queries.  Among 124
   registries, eight ccTLDs and 15 gTLDs support queries for specific
   contact persons or roles. 10 ccTLDs and 18 gTLDs support queries by
   nameserver.  Four ccTLDs and 18 gTLDs support registrar queries.
   Domain WHOIS data contain 68 data elements that use a total of 550
   labels.  There is a total of 392 other objects for domain WHOIS data.

5.2.  Public Objects

   As mentioned above, public objects are those data elements selected
   according to the new gTLD applicant guidebook and EPP.  They are
   generally classified into four categories by whether they are related
   to the domain, contact, nameserver, or registrar.

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5.2.1.  WHOIS Data for Domains

   WHOIS replies about domains include "Domain Name", "Creation Date",
   "Domain Status", "Expiration Date", "Updated Date", "Domain ID",
   "DNSSEC", and "Last Transferred Date".  Table 6 gives the element
   name, most popular label, and the corresponding numbers of TLDs and
   labels.

   +-------------------+-------------------+------------+--------------+
   |    Data Element   |   Most Popular    |   No. of   |    No. of    |
   |                   |      Label        |    TLDs    |    Labels    |
   +-------------------+-------------------+------------+--------------+
   |    Domain Name    |    Domain Name    |    118     |      6       |
   +-------------------+-------------------+------------+--------------+
   |   Creation Date   |      Created      |    106     |      24      |
   +-------------------+-------------------+------------+--------------+
   |   Domain Status   |       Status      |     95     |      8       |
   +-------------------+-------------------+------------+--------------+
   |  Expiration Date  |  Expiration Date  |     81     |      21      |
   +-------------------+-------------------+------------+--------------+
   |    Updated Date   |      Modified     |     70     |      20      |
   +-------------------+-------------------+------------+--------------+
   |     Domain ID     |     Domain ID     |     34     |      5       |
   +-------------------+-------------------+------------+--------------+
   |       DNSSEC      |       DNSSEC      |     14     |      4       |
   +-------------------+-------------------+------------+--------------+
   |  Last Transferred |  Last Transferred |     4      |      3       |
   |        Date       |        Date       |            |              |
   +-------------------+-------------------+------------+--------------+

                     Table 6.  WHOIS Data for Domains

   Several statistical conclusions obtained from above data are:

   o  95.16% of the 124 registries support a "Domain Name" data element.

   o  85.48% of the 124 registries support a "Creation Date" data
      element.

   o  76.61% of the 124 registries support a "Domain Status" data
      element.

   o  On the other hand, some elements such as "DNSSEC" and "Last
      Transferred Date" are only supported by 11.29% and 3.23% of the
      registries, respectively.

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5.2.2.  WHOIS Data for Contacts

   In the domain name space, contacts are typically divided into
   registrant, administrative contact, technical contact, and billing
   contact.

5.2.2.1.  Registrant

   Table 7 shows all the contact information for a registrant. 14 data
   elements are listed below.

   +--------------------+---------------------+-----------+------------+
   |    Data Element    |  Most Popular Label |   No. of  |   No. of   |
   |                    |                     |    TLDs   |   Labels   |
   +--------------------+---------------------+-----------+------------+
   |  Registrant Name   |         Name        |     65    |     7      |
   +--------------------+---------------------+-----------+------------+
   |  Registrant Email  |   Registrant Email  |     59    |     7      |
   +--------------------+---------------------+-----------+------------+
   |   Registrant ID    |    Registrant ID    |     50    |     12     |
   +--------------------+---------------------+-----------+------------+
   |  Registrant Phone  |   Registrant Phone  |     48    |     6      |
   +--------------------+---------------------+-----------+------------+
   |   Registrant Fax   |    Registrant Fax   |     44    |     6      |
   +--------------------+---------------------+-----------+------------+
   |     Registrant     |      Registrant     |     42    |     4      |
   |    Organization    |     Organization    |           |            |
   +--------------------+---------------------+-----------+------------+
   | Registrant Country |       Country       |     42    |     6      |
   |        Code        |                     |           |            |
   +--------------------+---------------------+-----------+------------+
   |  Registrant City   |   Registrant City   |     38    |     4      |
   +--------------------+---------------------+-----------+------------+
   | Registrant Postal  |  Registrant Postal  |     37    |     5      |
   |        Code        |         Code        |           |            |
   +--------------------+---------------------+-----------+------------+
   |     Registrant     |      Registrant     |     32    |     4      |
   |   State/Province   |    State/Province   |           |            |
   +--------------------+---------------------+-----------+------------+
   | Registrant Street  |  Registrant Street1 |     31    |     16     |
   +--------------------+---------------------+-----------+------------+
   | Registrant Country |  Registrant Country |     19    |     4      |
   +--------------------+---------------------+-----------+------------+
   |  Registrant Phone  |   Registrant Phone  |     18    |     2      |
   |        Ext.        |         Ext.        |           |            |

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   +--------------------+---------------------+-----------+------------+
   | Registrant Fax Ext |  Registrant Fax Ext |     17    |     2      |
   +--------------------+---------------------+-----------+------------+

                           Table 7.  Registrant

   Among all the data elements, only "Registrant Name" is supported by
   more than one half of registries.  Those supported by more than one
   third of registries are: "Registrant Name", "Registrant Email",
   "Registrant ID", "Registrant Phone", "Registrant Fax", "Registrant
   Organization", and "Registrant Country Code".

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5.2.2.2.  Admin Contact

   Table 8 shows all the contact information for an administrative
   contact. 14 data elements are listed below.

   +--------------------+--------------------+-----------+-------------+
   |    Data Element    | Most Popular Label |   No. of  |    No. of   |
   |                    |                    |    TLDs   |    Labels   |
   +--------------------+--------------------+-----------+-------------+
   |    Admin Street    |      Address       |     64    |      19     |
   +--------------------+--------------------+-----------+-------------+
   |     Admin Name     |     Admin Name     |     60    |      9      |
   +--------------------+--------------------+-----------+-------------+
   |    Admin Email     |    Admin Email     |     54    |      12     |
   +--------------------+--------------------+-----------+-------------+
   |      Admin ID      |      Admin ID      |     52    |      16     |
   +--------------------+--------------------+-----------+-------------+
   |     Admin Fax      |     Admin Fax      |     44    |      8      |
   +--------------------+--------------------+-----------+-------------+
   |    Admin Phone     |    Admin Phone     |     43    |      9      |
   +--------------------+--------------------+-----------+-------------+
   | Admin Organization | Admin Organization |     42    |      9      |
   +--------------------+--------------------+-----------+-------------+
   | Admin Country Code |      Country       |     42    |      7      |
   +--------------------+--------------------+-----------+-------------+
   |     Admin City     |     Admin City     |     35    |      5      |
   +--------------------+--------------------+-----------+-------------+
   | Admin Postal Code  | Admin Postal Code  |     35    |      7      |
   +--------------------+--------------------+-----------+-------------+
   |       Admin        |       Admin        |     28    |      5      |
   |   State/Province   |   State/Province   |           |             |
   +--------------------+--------------------+-----------+-------------+
   |   Admin Country    |   Admin Country    |     17    |      5      |
   +--------------------+--------------------+-----------+-------------+
   |  Admin Phone Ext.  |  Admin Phone Ext.  |     17    |      3      |
   +--------------------+--------------------+-----------+-------------+
   |   Admin Fax Ext.   |   Admin Fax Ext.   |     17    |      3      |
   +--------------------+--------------------+-----------+-------------+

                          Table 8.  Admin Contact

   Among all the data elements, only "Admin Street" is supported by more
   than one half of registries.  Those supported by more than one third
   of registries are: "Admin Street", "Admin Name", "Admin Email",
   "Admin ID", "Admin Fax", "Admin Phone", "Admin Organization", and
   "Admin Country Code".

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5.2.2.3.  Tech Contact

   Table 9 shows all the information for a domain name technical
   contact. 14 data elements are listed below.

   +--------------------+--------------------+-----------+-------------+
   |    Data Element    | Most Popular Label |   No. of  |    No. of   |
   |                    |                    |    TLDs   |    Labels   |
   +--------------------+--------------------+-----------+-------------+
   |     Tech Email     |     Tech Email     |     59    |      9      |
   +--------------------+--------------------+-----------+-------------+
   |      Tech ID       |      Tech ID       |     55    |      16     |
   +--------------------+--------------------+-----------+-------------+
   |     Tech Name      |     Tech Name      |     47    |      6      |
   +--------------------+--------------------+-----------+-------------+
   |      Tech Fax      |      Tech Fax      |     45    |      9      |
   +--------------------+--------------------+-----------+-------------+
   |     Tech Phone     |     Tech Phone     |     45    |      10     |
   +--------------------+--------------------+-----------+-------------+
   | Tech Country Code  |      Country       |     43    |      9      |
   +--------------------+--------------------+-----------+-------------+
   | Tech Organization  | Tech Organization  |     39    |      7      |
   +--------------------+--------------------+-----------+-------------+
   |     Tech City      |     Tech City      |     36    |      4      |
   +--------------------+--------------------+-----------+-------------+
   |  Tech Postal Code  |  Tech Postal Code  |     36    |      7      |
   +--------------------+--------------------+-----------+-------------+
   |        Tech        |        Tech        |     30    |      4      |
   |   State/Province   |   State/Province   |           |             |
   +--------------------+--------------------+-----------+-------------+
   |    Tech Street     |    Tech Street1    |     27    |      16     |
   +--------------------+--------------------+-----------+-------------+
   |    Tech Country    |    Tech Country    |     18    |      5      |
   +--------------------+--------------------+-----------+-------------+
   |    Tech Fax Ext    |    Tech Fax Ext    |     18    |      3      |
   +--------------------+--------------------+-----------+-------------+
   |  Tech Phone Ext.   |  Tech Phone Ext.   |     13    |      3      |
   +--------------------+--------------------+-----------+-------------+

                          Table 9.  Tech Contact

   Among all the data elements, there are no elements supported by more
   than one half of registries.  Those supported by more than one third
   of registries are: "Tech Email", "Tech ID", "Tech Name", "Tech Fax",
   "Tech Phone", and "Tech Country Code".

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5.2.2.4.  Billing Contact

   Table 10 shows all the information for a domain name billing contact.
   14 data elements are listed below.

   +--------------------+--------------------+-----------+-------------+
   |    Data Element    | Most Popular Label |   No. of  |    No. of   |
   |                    |                    |    TLDs   |    Labels   |
   +--------------------+--------------------+-----------+-------------+
   |    Billing Name    |        Name        |     47    |      5      |
   +--------------------+--------------------+-----------+-------------+
   |    Billing Fax     |        Fax         |     43    |      6      |
   +--------------------+--------------------+-----------+-------------+
   |   Billing Email    |   Email Address    |     42    |      7      |
   +--------------------+--------------------+-----------+-------------+
   |  Billing Country   |      Country       |     38    |      4      |
   |        Code        |                    |           |             |
   +--------------------+--------------------+-----------+-------------+
   |   Billing Phone    |    Phone Number    |     34    |      6      |
   +--------------------+--------------------+-----------+-------------+
   |     Billing ID     |     Billing ID     |     28    |      9      |
   +--------------------+--------------------+-----------+-------------+
   |    Billing City    |    Billing City    |     28    |      4      |
   +--------------------+--------------------+-----------+-------------+
   |      Billing       |      Billing       |     28    |      5      |
   |    Organization    |    Organization    |           |             |
   +--------------------+--------------------+-----------+-------------+
   |   Billing Postal   |   Billing Postal   |     27    |      4      |
   |        Code        |        Code        |           |             |
   +--------------------+--------------------+-----------+-------------+
   |      Billing       |      Billing       |     21    |      4      |
   |   State/Province   |   State/Province   |           |             |
   +--------------------+--------------------+-----------+-------------+
   |   Billing Street   |  Billing Street1   |     19    |      13     |
   +--------------------+--------------------+-----------+-------------+
   |  Billing Country   |  Billing Country   |     13    |      5      |
   +--------------------+--------------------+-----------+-------------+
   | Billing Phone Ext. | Billing Phone Ext. |     10    |      2      |
   +--------------------+--------------------+-----------+-------------+
   |  Billing Fax Ext   |  Billing Fax Ext   |     10    |      2      |
   +--------------------+--------------------+-----------+-------------+

                        Table 10.  Billing Contact

   Among all the data elements, there are no elements supported by more
   than one half of registries.  Those supported by more than one third
   of registries are "Billing Name", "Billing Fax", and "Billing Email".

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5.2.3.  WHOIS Data for Nameservers

   114 registries (about 92% of the 124 registries) have the
   "nameserver" data element in their WHOIS responses.  However, there
   are 63 different labels for this element, as shown in Table 11.  The
   top three labels for this element are "Name Server" (which is
   supported by 25% of the registries), "Name Servers" (which is
   supported by 16% of the registries), and "nserver" (which is
   supported by 12% of the registries).

    +--------------+--------------------+-------------+---------------+
    | Data Element | Most Popular Label | No. of TLDs | No. of Labels |
    +--------------+--------------------+-------------+---------------+
    |  NameServer  |    Name Server     |     114     |       63      |
    +--------------+--------------------+-------------+---------------+

                   Table 11.  WHOIS Data for Nameservers

   Some registries have nameserver elements such like "nameserver 1",
   "nameserver 2" till "nameserver n".  Thus, there are more labels than
   of other data elements.

5.2.4.  WHOIS Data for Registrars

   There are three data elements about registrar information.

   +-------------------+---------------------+-----------+-------------+
   |    Data Element   |  Most Popular Label |   No. of  |    No. of   |
   |                   |                     |    TLDs   |    Labels   |
   +-------------------+---------------------+-----------+-------------+
   |     Sponsoring    |      Registrar      |     84    |      6      |
   |     Registrar     |                     |           |             |
   +-------------------+---------------------+-----------+-------------+
   |     Created by    |      Created by     |     14    |      3      |
   |     Registrar     |                     |           |             |
   +-------------------+---------------------+-----------+-------------+
   |     Updated by    |   Last Updated by   |     11    |      3      |
   |     Registrar     |      Registrar      |           |             |
   +-------------------+---------------------+-----------+-------------+

                   Table 12.  WHOIS Data for Registrars

   67.7% of the registries have the "Sponsoring Registrar" data element.
   The elements "Created by Registrar" and "Updated by Registrar" are
   supported by 11.3% and 8.9% of the registries, respectively.

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5.3.  Other Objects

   So-called "other objects" are those data elements that are privately
   specified or are difficult to be classified.  There are 392 other
   objects altogether.  Table 13 lists the top 50 other objects found
   during data collection.

            +----------------------------------------+-------------+
            |              Data Element              | No. of TLDs |
            +----------------------------------------+-------------+
            |               Registrant               |      41     |
            +----------------------------------------+-------------+
            |                 Phone                  |      32     |
            +----------------------------------------+-------------+
            |           Technical contact            |      26     |
            +----------------------------------------+-------------+
            |         Administrative contact         |      15     |
            +----------------------------------------+-------------+
            |                 source                 |      14     |
            +----------------------------------------+-------------+
            |                 fax-no                 |      13     |
            +----------------------------------------+-------------+
            |                nic-hdl                 |      13     |
            +----------------------------------------+-------------+
            |            Billing Contact             |      12     |
            +----------------------------------------+-------------+
            |              referral url              |      11     |
            +----------------------------------------+-------------+
            |                 e-mail                 |      10     |
            +----------------------------------------+-------------+
            |              WHOIS server              |      9      |
            +----------------------------------------+-------------+
            |             Admin Contact              |      9      |
            +----------------------------------------+-------------+
            |                  Type                  |      9      |
            +----------------------------------------+-------------+
            |                Website                 |      9      |
            +----------------------------------------+-------------+
            |                 zone-c                 |      8      |
            +----------------------------------------+-------------+
            |                remarks                 |      7      |
            +----------------------------------------+-------------+
            |            Registration URL            |      6      |
            +----------------------------------------+-------------+
            |               anonymous                |      6      |
            +----------------------------------------+-------------+
            |              anniversary               |      6      |

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            +----------------------------------------+-------------+
            |                  hold                  |      6      |
            +----------------------------------------+-------------+
            |                 nsl-id                 |      6      |
            +----------------------------------------+-------------+
            |               obsoleted                |      6      |
            +----------------------------------------+-------------+
            |        Customer Service Contact        |      5      |
            +----------------------------------------+-------------+
            |         Customer Service Email         |      4      |
            +----------------------------------------+-------------+
            |              Registrar ID              |      4      |
            +----------------------------------------+-------------+
            |                  org                   |      4      |
            +----------------------------------------+-------------+
            |                 person                 |      4      |
            +----------------------------------------+-------------+
            |               Maintainer               |      4      |
            +----------------------------------------+-------------+
            |                 Nombre                 |      3      |
            +----------------------------------------+-------------+
            |      Sponsoring Registrar IANA ID      |      3      |
            +----------------------------------------+-------------+
            |            Trademark Number            |      3      |
            +----------------------------------------+-------------+
            |           Trademark Country            |      3      |
            +----------------------------------------+-------------+
            |                 descr                  |      3      |
            +----------------------------------------+-------------+
            |                  url                   |      3      |
            +----------------------------------------+-------------+
            |             Postal address             |      3      |
            +----------------------------------------+-------------+
            |             Registrar URL              |      3      |
            +----------------------------------------+-------------+
            |           International Name           |      3      |
            +----------------------------------------+-------------+
            |         International Address          |      3      |
            +----------------------------------------+-------------+
            |             Admin Contacts             |      2      |
            +----------------------------------------+-------------+
            |          Contractual Language          |      2      |
            +----------------------------------------+-------------+
            |       Date Trademark Registered        |      2      |
            +----------------------------------------+-------------+
            |       Date Trademark Applied For       |      2      |
            +----------------------------------------+-------------+
            |               IP Address               |      2      |

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            +----------------------------------------+-------------+
            |                  Keys                  |      2      |
            +----------------------------------------+-------------+
            |                Language                |      2      |
            +----------------------------------------+-------------+
            |               NIC handle               |      2      |
            +----------------------------------------+-------------+
            |          Record maintained by          |      2      |
            +----------------------------------------+-------------+
            |     Registration Service Provider      |      2      |
            +----------------------------------------+-------------+
            |    Registration Service Provided By    |      2      |
            +----------------------------------------+-------------+
            | Registrar URL (registration services)  |      2      |
            +----------------------------------------+-------------+

                    Table 13.  The Top 50 Other Objects

   Some registries returned things that looked like labels, but were
   not.  For example, in this reply:

         Registrant:
           Name:
           Email:
           ...

   "Name" and "Email" appeared to be data elements, but "Registrant" did
   not.  The inventory work proceeded on that assumption, i.e., there
   were two data elements to be recorded in this example.

   Some other data elements, like "Remarks", "anniversary", and
   "Customer service Contact", are designed particularly for their own
   purpose by different registries.

5.4.  Conclusion

5.4.1.  Preliminary Statistics

   Some preliminary conclusions could be drawn from the raw data.

   o  All of the 124 domain registries have the object names in their
      responses, although they are in various formats.

   o  Of the 118 WHOIS services contacted, 65 registries show their
      registrant contact.  About half of the registries (60 registries)
      support admin contact information.  There are 47 registries, which
      is about one third of the total number, that have technical and

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      billing contact information.  Only seven of the 124 registries
      give their abuse email in a "remarks" section.  No explicit abuse
      contact information is provided.

   o  There are mainly two presentation formats.  One is key-value; the
      other is data block format.  Example of key-value format:

   Domain Information
   Query: nic.example.com
   Status: Delegated
   Created: 17 Apr 2004
   Modified: 14 Nov 2010
   Expires: 31 Dec 9999
   Name Servers: ns.example.net
   ns1.na.example.net
   ns2.na.example.net
   ...

      Example of data block format:

  WHOIS database
  domain nic.example.org

  Domain Name nic.example.org
  Registered 1998-09-02
  Expiry 2012-09-02

  Resource Records

  a   198.51.100.1
  mx 10 test.example.net
  www a   198.51.100.10

  Contact details

  Registrant,
  Technical Contact,
  Billing Contact,
  Admin. Contact AdamsNames Reserved Domains (i)
  These domains are not available for registration
  United Kingdom
  Identifier: test123

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  Servidor WHOIS de NIC-Example

  Este servidor contiene informacion autoritativa exclusivamente de
  dominios nic.example.org Cualquier consulta sobre este servicio, puede
  hacerla al correo electronico whois@nic.example.org

  Titular:
  John (nic.example.org) john@nic.example.org
  NIC Example
  Av. Veracruz con calle Cali, Edif Aguila, Urb. Las Mercedes
  Caracas, Distrito Capital VE
  0212-1234567 (FAX) +582123456789

   o  11 registries give local script responses.  The WHOIS information
      of other registries are all represented in English.

5.4.2.  Data Element Analysis

   The top 10 data elements are listed in Table 14.

                     +----------------------+-------------+
                     |     Data Element     | No. of TLDs |
                     +----------------------+-------------+
                     |     Domain Name      |     118     |
                     +----------------------+-------------+
                     |     Name Server      |     114     |
                     +----------------------+-------------+
                     |    Creation Date     |     106     |
                     +----------------------+-------------+
                     |    Domain Status     |      95     |
                     +----------------------+-------------+
                     | Sponsoring Registrar |      84     |
                     +----------------------+-------------+
                     |   Expiration Date    |      81     |
                     +----------------------+-------------+
                     |     Updated Date     |      70     |
                     +----------------------+-------------+
                     |   Registrant Name    |      65     |
                     +----------------------+-------------+
                     |     Admin Street     |      64     |
                     +----------------------+-------------+
                     |      Admin Name      |      60     |
                     +----------------------+-------------+

                    Table 14.  The Top 10 Data Elements

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   Most of the domain-related WHOIS information is included in the top
   10 data elements.  Other information like name server and registrar
   name is also supported by most registries.

   A cumulative distribution analysis of all the data elements was done.

   (1)  About 5% of the data elements discovered by the inventory work
        are supported by 111 registries (i.e., 90%).

   (2)  About 30% of the data elements discovered by the inventory work
        are supported by 44 registries (i.e., 35%).

   (3)  About 60% of the data elements discovered by the inventory work
        are supported by 32 registries (i.e., 26%).

   (4)  About 90% of the data elements discovered by the inventory work
        are supported by 14 registries (i.e., 11%).

   From the above result, it is clear that only a few registries support
   all the public objects, most of the registries support just some of
   the objects.

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5.4.3.  Label Analysis

   The top 10 labels of different data elements are listed in Table 15.

                      +-------------------+---------------+
                      |       Labels      | No. of Labels |
                      +-------------------+---------------+
                      |    Name Server    |       63      |
                      +-------------------+---------------+
                      |   Creation Date   |       24      |
                      +-------------------+---------------+
                      |  Expiration Date  |       21      |
                      +-------------------+---------------+
                      |    Updated Date   |       20      |
                      +-------------------+---------------+
                      |    Admin Street   |       19      |
                      +-------------------+---------------+
                      |      Tech ID      |       18      |
                      +-------------------+---------------+
                      | Registrant Street |       16      |
                      +-------------------+---------------+
                      |      Admin ID     |       16      |
                      +-------------------+---------------+
                      |    Tech Street    |       16      |
                      +-------------------+---------------+
                      |   Billing Street  |       13      |
                      +-------------------+---------------+

                       Table 15.  The Top 10 Labels

   As explained above, the "Name Server" label is a unique example
   because many registries define the name server elements from
   "nameserver 1" through "nameserver n".  Thus, the count of labels for
   name servers is much higher than other elements.  Data elements
   representing dates and street addresses were also common.

   A cumulative distribution analysis of label numbers was done.  About
   90% of data elements have more than two labels.  It is therefore
   necessary to specify a standard and unified format for object names
   in a WHOIS response.

5.4.4.  Analysis of Other Objects

   The results indicate that there are 392 other data objects in total
   that are not easy to be classified or are privately defined by
   various registries.  The top 50 other objects are listed in Table 13
   in Section 5.3.  It is clear that various different objects are

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   designed for some particular purpose.  In order to ensure uniqueness
   of JSON names used in the RDAP service, establishment of an IANA
   registry is advised.

5.5.  Limitations

   This section lists the limitations of the survey and some assumptions
   that were made in the execution of this work.

   o  The input "nic.ccTLD" may not be a good choice, for the term "nic"
      is often specially used by the corresponding ccTLD, so the
      collected WHOIS data may be customized and different from the
      common data.

   o  Since the programming script queried the "nic.ccTLD" in an
      anonymous way, only the public WHOIS data from WHOIS servers
      having nic.ccTLD were collected.  So, the private WHOIS data were
      not covered by this document.

   o  11 registries did not provide responses in English.  The
      classification of data elements within their responses may not be
      accurate.

   o  The extension data elements are used randomly by different
      registries.  It is difficult to do statistical analysis.

   o  Sample sizes of contact, name server, and registrar queries are
      small.

      *  Only WHOIS queries for contact ID, nameserver, and registrar
         were used.

      *  Some registries may not support contact, name server, or
         registrar queries.

      *  Some may not support query contact by ID.

      *  Contact information of some registries may be protected.

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6.  Reference Extension Objects

   There are some objects that are included in the existing WHOIS system
   but not mentioned in [RFC7483].  This document is intended to give a
   list of reference extension objects for discussion.

6.1.  RIR Reference Extension Objects

   o  company - the company name registered by the registrant.

   o  maintainer - authentication information that identifies who can
      modify the contents of this object.

   o  list of resources - a list of IPv4 addresses, IPv6 addresses, and
      Autonomous System numbers.

   o  referral NOC contact - the Network Operations Center contact.

6.2.  DNR Reference Extension Objects

   The following objects are selected from the top 50 other objects in
   Section 5.3 that are supported by more than five registries.  These
   objects are considered as possible extension objects.

   o  zone-c - The identifier of a 'role' object with authority over a
      zone.

   o  maintainer - authentication information that identifies who can
      modify the contents of this object.

   o  Registration URL - typically the website address of a registry.

   o  anonymous - whether the registration information is anonymous or
      not.

   o  hold - whether the domain is "on hold" or not.

   o  nsl-id - nameserver list ID.

   o  obsoleted - whether a domain is obsoleted or not.

   o  Customer Service Contact - a kind of contact.

7.  Security Considerations

   This document does not provide any security services or introduce
   additional considerations to those discussed in [RFC7481].

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8.  Informative References

   [ICANN.AGB-201206]
              ICANN, "gTLD Applicant Guidebook", June 2012,
              <http://newgtlds.icann.org/en/applicants/agb/
              guidebook-full-04jun12-en.pdf>.

   [RFC2622]  Alaettinoglu, C., Villamizar, C., Gerich, E., Kessens, D.,
              Meyer, D., Bates, T., Karrenberg, D., and M. Terpstra,
              "Routing Policy Specification Language (RPSL)", RFC 2622,
              June 1999, <http://www.rfc-editor.org/info/rfc2622>.

   [RFC3912]  Daigle, L., "WHOIS Protocol Specification", RFC 3912,
              September 2004, <http://www.rfc-editor.org/info/rfc3912>.

   [RFC5730]  Hollenbeck, S., "Extensible Provisioning Protocol (EPP)",
              STD 69, RFC 5730, August 2009,
              <http://www.rfc-editor.org/info/rfc5730>.

   [RFC5731]  Hollenbeck, S., "Extensible Provisioning Protocol (EPP)
              Domain Name Mapping", STD 69, RFC 5731, August 2009,
              <http://www.rfc-editor.org/info/rfc5731>.

   [RFC5732]  Hollenbeck, S., "Extensible Provisioning Protocol (EPP)
              Host Mapping", STD 69, RFC 5732, August 2009,
              <http://www.rfc-editor.org/info/rfc5732>.

   [RFC5733]  Hollenbeck, S., "Extensible Provisioning Protocol (EPP)
              Contact Mapping", STD 69, RFC 5733, August 2009,
              <http://www.rfc-editor.org/info/rfc5733>.

   [RFC5890]  Klensin, J., "Internationalized Domain Names for
              Applications (IDNA): Definitions and Document Framework",
              RFC 5890, August 2010,
              <http://www.rfc-editor.org/info/rfc5890>.

   [RFC7480]  Newton, A., Ellacott, B., and N. Kong, "HTTP Usage in the
              Registration Data Access Protocol (RDAP)", RFC 7480, March
              2015, <http://www.rfc-editor.org/info/rfc7480>.

   [RFC7481]  Hollenbeck, S. and N. Kong, "Security Services for the
              Registration Data Access Protocol (RDAP)", RFC 7481, March
              2015, <http://www.rfc-editor.org/info/rfc7481>.

   [RFC7482]  Newton, A. and S. Hollenbeck, "Registration Data Access
              Protocol (RDAP) Query Format", RFC 7482, March 2015,
              <http://www.rfc-editor.org/info/rfc7482>.

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   [RFC7483]  Newton, A. and S. Hollenbeck, "JSON Responses for the
              Registration Data Access Protocol (RDAP)", RFC 7483, March
              2015, <http://www.rfc-editor.org/info/rfc7483>.

   [RFC7484]  Blanchet, M., "Finding the Authoritative Registration Data
              (RDAP) Service", RFC 7484, March 2015,
              <http://www.rfc-editor.org/info/rfc7484>.

Acknowledgements

   This document is the work product of the IETF's WEIRDS working group,
   of which Olaf Kolkman and Murray Kucherawy were chairs.

   The authors especially thank the following individuals who gave their
   suggestions and contributions to this document: Guangqing Deng,
   Frederico A C Neves, Ray Bellis, Edward Shryane, Kaveh Ranjbar,
   Murray Kucherawy, Edward Lewis, Pete Resnick, Juergen Schoenwaelder,
   Ben Campbell, and Claudio Allocchio.

Authors' Addresses

   Linlin Zhou
   CNNIC
   4 South 4th Street, Zhongguancun, Haidian District
   Beijing  100190
   China

   Phone: +86 10 5881 2677
   EMail: zhoulinlin@cnnic.cn

   Ning Kong
   CNNIC
   4 South 4th Street, Zhongguancun, Haidian District
   Beijing  100190
   China

   Phone: +86 10 5881 3147
   EMail: nkong@cnnic.cn

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   Sean Shen
   CNNIC
   4 South 4th Street, Zhongguancun, Haidian District
   Beijing  100190
   China

   Phone: +86 10 5881 3038
   EMail: shenshuo@cnnic.cn

   Steve Sheng
   ICANN
   12025 Waterfront Drive, Suite 300
   Los Angeles, CA  90094-2536
   United States

   Phone: +1 310 301 5800
   EMail: steve.sheng@icann.org

   Arturo Servin
   LACNIC
   Rambla Mexico 6125
   Montevideo  11400
   Uruguay

   Phone: +598-2604-2222
   EMail: arturo.servin@gmail.com

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