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Versions: 00                                                            
INTERNET DRAFT                                              Nicolas Popp
draft-popp-realname-hfn-00.txt                      Centraal Corporation
September 23, 1998                                        Larry Masinter
expires in six months                                  Xerox Corporation

         The RealName System: a Human Friendly Naming scheme

Status of this Memo

   This document is an Internet-Draft. Internet-Drafts are working
   documents of the Internet Engineering Task Force (IETF), its areas,
   and its working groups.  Note that other groups may also distribute
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Abstract

  The notion of a 'Human Friendly Naming scheme' (HFN) has been
  discussed in a variety of contexts, as an alternative to the use of
  URIs or URNs as a way of designating Internet resources (see [RFC
  2276], for example).

  This document introduces the RealName system, and its use as a
  HFN. It provides a mapping for RealNames into a URN namespace ('rn')
  as well as a URL scheme ('vnd.rn').

  This is a preliminary draft, intended to raise the discussion of
  HFNs and the uses of RealNames as an initial example in creating a
  standard for access and resolution.

1. Introduction

  It has been widely recognized that the URL syntax and structure has
  been unfriendly (frustrating and confusing) for non-technical
  Internet users, and that the URN naming system retains the
  'unfriendly' behavior. For example, from RFC 2276:

    In contrast to URNs, one can imagine a variety human-friendly
    naming (HFN) schemes supporting different suites of applications
    and user communities.  These will need to provide mappings to URNs
    in tighter or looser couplings, depending on the namespace.  It is
    these HFNs that will be mnemonic, content-full, and perhaps
    mutable, to track changes in use and semantics.  They may provide
    nicknaming and other aliasing, relative or short names, context
    sensitive names, descriptive names, etc.  Their definition is not
    part of this effort, but will clearly play an important role in
    the long run.

  URLs provide a powerful mechanism to resolve the location of
  resources on the Internet. For many applications, though, URLs are
  complex, totally unpredictable, and too lengthy to memorize.

  In order to facilitate the adoption of the Internet by the broad
  non-technical audience, it is desirable to simplify Internet
  navigation via a simpler, globally available, human friendly naming
  system.

  The RealName system has such user friendly naming as a goal. By
  simplifying navigation on the Internet, it aims at facilitating the
  adoption of the Internet by novice users. The RealName System
  primarily focuses on World Wide Web pages that can be associated
  with a trade name. Examples of trade names are brands
  (e.g. "Tylenol"), company names (e.g. "Apple Computer Inc"),
  trademarks (e.g. "Coca-Cola") and advertising slogans (e.g. Nike's
  "Just do it"). The RealName system offers a familiar interface to
  users: simple everyday words in their own language. Each year,
  commercial entities invest vast amount of marketing dollars in order
  to promote their brands and ensure that these names are known by
  millions of consumers all around the planet. Brand names are catchy,
  and mnemonic for commercial reasons and cross media advertising
  provides powerful means to guarantee that these names are
  universally known. For all these reasons, brand names are great
  candidates as HFNs.

  Another fundamental value of a RealName is that it is by nature a
  name and not an address. Unlike most URLs, a RealName does not
  contain any information about the location of the resource that it
  refers to. Hence, a RealName is a more persistent name than the
  traditional HTTP URL of a Web page. If a user has bookmarked an HTTP
  URL and it changes, the resource can no longer be found. In the
  RealName System, HTTP URLs can change without impacting
  navigation. This level of indirection has clear benefits for
  navigating on the Internet. It also requires a new piece of
  infrastructure: a name resolution service. The RealName resolver is
  a backend service that maps RealNames into URLs.

  In addition to increased robustness, name resolution services can
  provide benefits such as the ability to access metadata and discover
  resources characteristics prior to accessing it. The RealName
  resolution service provides simple query capabilities so that a user
  can search the namespace and discover new RealNames.

  The notions of location independence, persistence and name
  resolution service are core to the concept of URN as presented in
  RFC 2141 [1]. The RealName system also provides a URN namespace;
  Section 3 of this document defines a compliant URN syntax for
  RealNames and proposes the RealName System as a formal URN
  namespace; Section 4 of this document defines a compliant URL syntax
  for RealName locators using the (undated) form of the RealName URN.

  Human Friendly Names can be considered a new class of URI that are
  neither URNs nor URLs. The RealName system is proposed as an initial
  example of HFNs, and as the basis for future standardization of the
  general class.

2. The RealName system as a Human Friendly Name scheme

  A "RealName" is a name registered with Centraal Corporation.
  Centraal Corporation owns and manages the RealName repository
  database and is the sole assigning authority for RealNames.  Names
  are arbitrary strings, encoded in Unicode UTF-8. The Centraal
  realname resolution service offers a variety of different searching
  and matching mechanisms for looking up and searching the database of
  RealNames. The result of RealName resolution is a set of metadata
  about the resource, including available URLs and URNs.

3. Mapping the RealName System into a formal URN namespace

  The RealName system also forms the basis of a formal URN namespace.
  The URN namespace consists only of the canonical registered
  representation of a RealName. That is, while a RealName HFN might be
  part of a database to be searched, the RealName URN is used for
  canonical lookup.

  A specification template is submitted according to the guidelines
  defined in the IETF working draft on URN Namespace Definition
  Mechanisms [2].

2.1. The "rn" URN namespace Specification Template

  Namespace ID:
   "rn" requested.

  Declared registrant of the namespace:
    Nicolas Popp
    nico@centraal.com

  Relevant ancillary documentation:
    An introduction to the RealName System can be found on the
    Centraal Corporation Web site at http://company.realnames.com.
    Also note that an implementation of the RealName resolution
    service is available at http://www.realnames.com as well as from
    http://altavista.digital.com.

  Declaration of structure:
    The identifier structure is as follows:
      urn:rn:<NSS>

    The <NSS> being defined as:
      <NSS> ::= <prefix> "/" <realname>
      <prefix> ::= (hex-escaped opaque string)
      <realname> ::= (hex-escaped UTF-8 encoded Unicode string)

    Conceptually, the <prefix> organizes the namespace in distinct sub
    name spaces and gives the RealName URN a hierarchical
    structure. The <prefix> is automatically assigned by Centraal.

    The <realname> component of the NSS is the document's RealName
    expressed in the URN canonical form as specified in RFC 2141
    [1]. A RealName is a globally unique name that has a natural
    language structure.

  Identifier uniqueness considerations:
    The Centraal repository database enforces the uniqueness of URNs
    for all subscribed RealNames as an integrity constraint.  This
    guarantees that a RealName URN is unique across the entire name
    space.

    Centraal Corporation owns and manages the RealName repository
    database and is the sole assigning authority for RealNames.

  Identifier persistence considerations:
    A RealName will persist in the repository beyond the life of the
    Web page that it points to. Nevertheless, since commercial
    entities and their brands can be replaced, it is possible on
    occasion that a RealName be reassigned. For example, this would be
    the case if a corporation had ceased to exist and later, a new
    company was incorporated under the exact same name. In such
    instance, the new corporation could legitimately subscribe and be
    reassigned the defunct company's RealName.

    To ensure that a RealName URN always points to the same
    resource, the <prefix> for the RealName URN is changed
    each time a RealName is reassigned. This guarantees that the
    new RealName has a different URN than the old one.

    In the first implementation of the RealName System, the URN
    <prefix> is the calendar year of the subscribed RealName (note
    that the proposed syntax is more general to allow future
    evolution). Since RealNames are subscribed on a yearly basis, and
    Centraal guarantees that a RealName cannot be reassigned for at
    least one year, the RealName URN is therefore persistent.

  Process of identifier assignment:
    Organizations and Web site owners can subscribe to a RealName
    using an online subscription service. This service is available at
    https://customer.realnames.com. Centraal Corporation usually
    charges a yearly maintenance fee for each subscribed
    RealName. Unlike domain names that are registered on a first-come
    first-served basis, Centraal exercises management and adjudication
    processes to ensure that a RealName is assigned to the
    'appropriate' Web page. Centraal's terms and conditions require a
    subscriber to choose a RealName that represents 'appropriate use'
    for the specified Web page.  If Centraal judges that a subscribed
    RealName is not 'appropriate', it rejects it. To assess whether or
    not the RealName that has been chosen by the subscriber is
    'appropriate', Centraal has established a department of the
    company to make this determination.

    'Appropriate use' should be interpreted loosely as meaning: will
    the Internet user community anticipate coming to the aliased Web
    page when using the RealName for navigation.  Accordingly, common
    terms such as "books", "music" or "cars" are improper RealNames
    and cannot be subscribed because they are not unique to a single
    commercial Web page.

    Centraal Corporation is therefore the sole assigning and managing
    authority for the RealName System. However, in the future, it is
    conceivable that the <prefix> in the RealName URN could be used as
    a mechanism to partition the name space and delegate some of the
    administrative authority to a third party.

  Process for identifier resolution:
    Centraal operates a form-based Web resolution service at
    http://www.realnames.com. The RealName resolvers are built on
    indexing and clustering technology. Hence, they can handle large
    numbers of resolutions and can be distributed across the
    Internet. As of today, Centraal has deployed two clusters of
    resolvers, one on the East Coast and one on the West Coast of the
    United States. The current service resolves more than 5 millions
    RealNames a week while only operating at 20% of its current
    capacity. In the near future, some portions of the resolution
    service will be delegated to Centraal's partners all around the
    globe.

    Centraal will follow new registration guidelines and implement the
    mechanisms necessary to support emerging RDS standards. For
    instance, Centraal will subscribe to URN.NET and will maintain a
    list of active resolvers as NAPTR records in the DNS.

    Centraal has already prototyped an experimental URN resolver
    implementing the NAPTR Resolver Discovery Service as described in
    RFC 2168 [3].

    Centraal will support THTTP and implement the N2L, N2N and N2C
    resolution services as described in the Internet draft "URI
    Resolution Services Necessary for URN Resolutions" [4].

  Rules for Lexical Equivalence:
    RealNames are case insensitive. Characters with and without
    diacritics such as accent and vowel marks are distinguished.

    To give an example (using an ASCII representation of accented
    characters), the RealName 'la de'pe^che du midi' is not equivalent
    to the Realname 'la depeche du midi'. The internal representation
    of a RealName is Unicode 2.1.

    Hence, RealName URNs should be compared based on Unicode string
    equivalence as described in [5].  In particular, encoding
    artifacts invisible to the user should be accounted for when
    assessing the equivalence of two RealNames.

  Conformance with URN Syntax:
    There are no reserved characters in the RealName System. The
    reserved characters of the URN syntax will be escaped as specified
    in RFC 2141 [1] to ensure full conformance with that syntax. In
    particular, the <realname> component of the NSS is the
    hex-encoding of the UTF-8 for that RealName. For example, the
    RealName 'porsche boxster' becomes:

      urn:rn:1998/porsche%20boxster

  Validation mechanism:
    The RealName online subscription service available at
    https://customer.realnames.com provides a mechanism to check
    whether a RealName is already in use. Subscribers can also
    directly contact a name space management representative by email
    or telephone in order to assess what RealName is appropriate for
    their Web page.

  Scope:
    The RealName System introduced in this document does not aim to
    provide a RealName for every Web page on the Internet.  Rather, it
    focuses on the subset of Web pages that can be unambiguously
    associated with a commercial brand name, trademark or company
    name. RealNames will be available in all human languages.

    RealNames are globally unique and usable across the entire
    Internet. Therefore, the scope of a RealName URN is global.

2.2. Examples

  The following are examples of URNs that a RealName resolver can
  resolve:

      urn:rn:1998/bambi
      urn:rn:1998/bmw%20z3
      urn:rn:1998/tylenol

2.3. Security Considerations

  The primary security risk in the use of identifiers is that in some
  way the resource reached when following a reference will not
  correspond to the resource intended. The RealName system maintains a
  centralized scope of authority, but the reliability of the mapping
  depends on the security of the RealName mapping system.

3.  A Proposal for the RealName System as a URL scheme

  This section of the document proposes the RealName System as a new
  URL scheme in the vendor tree. A complete registration template is
  presented according to the guidelines defined in [6].

3.1 Registration Template:

  URL Scheme Name:
    "vnd.rn" requested.

  Scope:

    The RealName System focuses on the subset of Web pages that can be
    unambiguously associated with a commercial brand name, trademark
    or company name. RealNames may be in any human language. RealNames
    are globally unique and usable across the entire Internet; thus,
    the scope of a RealName URL is global.

  Conformance with URL Syntax and Character encoding considerations:

    A RealName URL reads
      vnd.rn:<realname>
    where
      <realname>  :: = (hex-escaped UTF-8 encoded UNICODE string)

    There are no reserved characters in the RealName System. The
    reserved characters of the URL syntax will be escaped as specified
    in RFC 2396 [7] to ensure full conformance with the URI
    Syntax. This means that the scheme specific part of the RealName
    URL is the hex-encoding of the UTF-8 for that RealName. For
    example, the RealName 'porsche boxster' becomes:

       url:vnd.rn:porsche%20boxster

  Security Considerations:

    As with RealName URNs, the primary security risk in the use of
    identifiers is that in some way the resource reached when
    following a reference will not correspond to the resource
    intended. The RealName system maintains a centralized scope of
    authority, but the reliability of the mapping depends on the
    security of the RealName mapping system.

  NameSpace Ownership:

    Centraal Corporation owns and manages the RealName repository
    database and is the sole assigning authority for RealNames. The
    RealNames are globally unique.

  Interoperability considerations:

    A RealName resolution service is provided on the internet at
    http://www.realnames.com. The resolvers implement an HTTP/XML API
    that can be used by a wide variety of clients to access resources
    on the internet using the RealName URL.

  Published specification:

    This document.

  Applications which use this URL scheme name:

    Typical web applications can use RealName URLs as a way of
    locating resources by their canonical RealName without invoking a
    search service.

  Additional information:

    Centraal's Web site at http://www.centraal.com give a
    comprehensive introduction of the RealName System.

  Contact:

    Nicolas Popp
    Centraal Corporation
    811 Hansen Way
    PO Box 50750
    Palo Alto CA 94303 0750
    U.S.A.
    Phone: (650)846-3615
    Fax: (650)858-0454
    Email: nico@centraal.com

  Intend usage:

    COMMON

  Author/Change controller:

    Nicolas Popp.
    Centraal Corporation

4. Acknowledgments

  Special thanks go to Yves Arrouye and Bill Washburn from Centraal
  Corporation for comments on earlier drafts of this document.

5. References:

  [1] Ryan Moats, "URN Syntax", RFC 2141, May 1997.

  [2] Leslie L. Daigle, "URN Namespace Definition Mechanisms",
      Internet Draft, August 1998.

  [3] Ron Daniel & Michael Mealling, "Resolution of Uniform Resource
      Identifiers using the Domain Name System", RFC 2168, June 1997.

  [4] Ron Daniel & Michael Mealling, Internet Draft, " URI Resolution
      Services Necessary for URN Resolution", RFC 2168, March 1998.

  [5] Martin J. Duerst, "Requirements for String Identity Matching and
      String Indexing",  World Wide Web Consortium Working Draft
      10-July-1998.

  [6] R. Petke, "Registration Procedures for URL Scheme Names",
      Internet Draft, August 1998.

  [7] T. Berners-Lee, "Uniform Resource Locators (URL)", RFC 1738,
      August 1998.

7. Authors Addresses:

   Nicolas Popp
   Centraal Corporation
   811 Hansen Way
   PO Box 50750
   Palo Alto CA 94303 0750
   U.S.A.
   Phone: (650)846-3615
   Fax: (650)858-0454
   Email: nico@centraal.com

   Larry Masinter
   Xerox Palo Alto Research Center
   3333 Coyote Hill Road
   Palo Alto, CA 94304
   Phone: (650)812-4365
   Fax: (650)812-4333
   Email: masinter@parc.xerox.com

8. Copyright

Copyright (C) The Internet Society, 1997. All Rights Reserved.

This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published and
distributed, in whole or in part, without restriction of any kind,
provided that the above copyright notice and this paragraph are
included on all such copies and derivative works.  However, this
document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of developing
Internet standards in which case the procedures for copyrights defined
in the Internet Standards process must be followed, or as required to
translate it into languages other than English.

The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns.

This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT
NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN
WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE."