index.html 36 KB

Raw Blame History Permalink

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html lang="en" xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
	<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <link rel="stylesheet" type="text/css" href="http://www.w3.org/StyleSheets/TR/W3C-WG-NOTE"/>
  <title>Scope of Mobile Web Best Practices</title>
</head>

<body>
  <div class="head">
    <a href="http://www.w3.org/"><img height="48" alt="W3C" src="http://www.w3.org/Icons/w3c_home"
    width="72" /></a>

    <h1 id="title">Scope of Mobile Web Best Practices</h1>

    <h2 id="subtitle">W3C Working Group Note 20 December 2005</h2>

    <dl>
      <dt>This version:</dt>

      <dd><a href="http://www.w3.org/TR/2005/NOTE-mobile-bp-scope-20051220/">http://www.w3.org/TR/2005/NOTE-mobile-bp-scope-20051220/</a></dd>

      <dt>Latest version:</dt>

      <dd><a href="http://www.w3.org/TR/mobile-bp-scope/">http://www.w3.org/TR/mobile-bp-scope/</a></dd>

      <dt>Previous version:</dt>

      <dd><a href="http://www.w3.org/TR/2005/WD-mobile-bp-scope-20051103/">http://www.w3.org/TR/2005/WD-mobile-bp-scope-20051103/</a></dd>

      <dt>Editors:</dt>

      <dd><a href="http://www.icra.org/people/philarcher/">Phil Archer</a>, ICRA</dd>

      <dd>Ed Mitukiewicz, France Telecom.</dd>
    </dl>

    <p class="copyright"><a href=
    "http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a>
    &copy; 2005 <a href="http://www.w3.org/"><acronym title=
    " World Wide Web Consortium">W3C</acronym></a><sup>&reg;</sup>
    (<a href="http://www.csail.mit.edu/"><acronym title=
    "Massachusetts Institute of Technology">MIT</acronym></a>,
    <a href="http://www.ercim.org/"><acronym title=
    " European Research Consortium for Informatics and Mathematics">
    ERCIM</acronym></a>, <a href=
    "http://www.keio.ac.jp/">Keio</a>), All Rights Reserved. W3C
    <a href=
    "http://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">
    liability</a>, <a href=
    "http://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark</a>,
    <a href=
    "http://www.w3.org/Consortium/Legal/copyright-documents">document
    use</a> rules apply.</p>
    <hr title="Separator for header" />
  </div>

  <h2 class="notoc" id="abstract">Abstract</h2>

  <p>Web access from mobile devices suffers from problems that make
  the Web unattractive for most mobile users. W3C's Mobile Web
  Initiative (<a href="http://www.w3.org/2005/MWI/">MWI</a> )
  proposes to address these issues through a concerted effort of
  key players in the mobile value chain, including authoring tool
  vendors, content providers, handset manufacturers, browser
  vendors and mobile operators.</p>

  <p>To help frame the development of "best practices" for the
  mobile Web this document - created by the members of the Mobile
  Web Initiative Best Practices Working Group (<a href=
  "http://www.w3.org/2005/MWI/BPWG/"><abbr title="Mobile Web Best Practices Working Group">
  BPWG</abbr></a>) as an elaboration of its <a href=
  "http://www.w3.org/2005/01/BPWGCharter/Overview.html">charter</a>
  - identifies the nature of problems to be solved, outlines the
  scope of work to be undertaken and specifies the assumptions
  regarding the target audience and the anticipated deliverables.
  The <abbr title=
  "Mobile Web Best Practices Working Group">BPWG</abbr> has
  recently published the first public working draft of its initial
  Mobile Web Best Practices recommendations [<a href="#bp">BP</a>].</p>

  <h2 id="status">Status of this Document</h2>

  <p><em>This section describes the status of this document at the
  time of its publication. Other documents may supersede this
  document. A list of current W3C publications and the latest
  revision of this technical report can be found in the <a href=
  "http://www.w3.org/TR/">W3C technical reports index</a> at
  http://www.w3.org/TR/.</em></p>


<p>Publication as a Working Group Note does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.</p>

  <p>This third publication of the document as a Working Group Note by the
  <a href="http://www.w3.org/2005/MWI/BPWG/">Mobile Web Best
  Practices Working Group</a> addresses comments generated by the
  <a href=
  "http://www.w3.org/TR/2005/WD-mobile-bp-scope-20051103/">previous Working Draft</a> and marks that the Working Group believes its work on the Scope document is ready. The Working Group may publish an updated version if comments on this document make it necessary.</p>

  <p>To send comments, please use the
  public mailing list (<a href=
  "mailto:public-bpwg-comments@w3.org">public-bpwg-comments@w3.org</a>), an <a href=
  "http://lists.w3.org/Archives/Public/public-bpwg-comments/">archived
  mailing list</a>. See <a href="http://www.w3.org/Mail/">W3C
  mailing list and archive usage guidelines</a>.</p>

  <p>This document has been produced as part of the <a href=
  "http://www.w3.org/2005/MWI/Activity">W3C Mobile Web Initiative</a>,
  following the procedures set out for the <a href=
  "http://www.w3.org/Consortium/Process/">W3C Process</a>.</p>

  <p>As of this publication, the Working Group does not expect this
  document to become a W3C Recommendation, and therefore it has no
  associated W3C Patent Policy licensing obligations. If this
  expectation changes, the Working Group will have an opportunity
  to fulfill the associated patent policy requirements with respect
  to a future draft.</p>

  <h2 class="notoc" id="contents"><a id="toc" name="toc">Table of
  Contents</a></h2>

  <ul>
    <li class="tocline"><a href=
    "#s0">
    Vision for the Future</a></li>

    <li class="tocline">1. <a href=
    "#s1">
    Introduction</a></li>

    <li class="tocline">2. <a href=
    "#s2">
    Best Practice Dimensions and Scope</a></li>

    <li class="tocline">3. <a href=
    "#s3">
    Assumptions</a></li>

    <li class="tocline">4. <a href=
    "#s4">
    Internal and External Liaisons</a></li>

    <li class="tocline">5. <a href=
    "#s5">
    Resources</a></li>

    <li class="tocline">6. <a href=
    "#s6">
    References</a></li>

    <li class="tocline">7. <a href=
    "#s7">
    Acknowledgements</a></li>
  </ul>

  <h2 id="s0">Vision for the Future</h2>

  <p>The Mobile Web Best Practices Working Group is committed to a
  vision of making the Web an omnipresent service platform
  completely transparent to its users.</p>

  <p>This would require fully integrating the Web into our everyday
  lives - in a manner similar to cars, running water, central
  heating and telephones - so that our awareness of certain usage
  constraints and/or the limitations of the underlying technologies
  can gradually disappear.</p>

  <p>In order to realize its full potential the Web has to be
  accessible via any browser enabled device anywhere and at any
  time. Today many of the web services and content available via
  desktop computers are not easily accessible through mobile
  devices.</p>

  <p>An increasing variety of mobile device form factors,
  connectivity options and browsing constraints continues to slow
  down the growth of the mobile web. In order to cope with highly
  differentiated capabilities and limitations of mobile devices,
  content authors and service developers are often forced to deploy
  multiple versions of their offerings and/or rely on widespread
  use of adaptation techniques.</p>

  <p><em>&quot;One Web&quot;</em> vision of a seamlessly integrated Internet
  remains the long-term objective of the Mobile Web Initiative.
  Members of the Mobile Web Best Practices Working Group (BPWG) are
  well aware of the challenges and complexities stemming from
  diversity of mobile devices. However, we do not aim to address
  all the related issues - including many legacy problems. Our
  immediate goal is to define a set of forward looking Best
  Practices guidelines that - when followed by authors and
  developers - are likely to make their content accessible with
  equal ease to users of desktop and mobile devices of certain
  assumed capabilities. It is expected that this will ensure a positive user experience
  in both environments - within the constrains of an appropriate delivery context.</p>

  <h2 id="s1">1. Introduction</h2>

  <p>As a result of widespread use of World Wide Web technologies
  over the Internet, a variety of content and services are now
  easily accessible from desktop and notebook computing platforms.
  Web technologies have the potential to play the same role for
  mobile devices. However, mobile Internet today suffers from many
  problems that make the Web unattractive to use for most
  subscribers.</p>

  <p>The intention of the <a href="http://www.w3.org/2005/MWI/">W3C
  Mobile Web Initiative</a> is to make <q>Web access from a mobile
  device as simple, easy and convenient as Web access from a
  desktop device</q> and to facilitate advancement towards the
  ultimate goal of <em>"One Web"</em>. In many respects the mobile
  web provides a new medium with new and exciting
  possibilities.</p>

  <p>Aside from representing a further delivery channel for
  existing Web users, it could represent the only, or primary,
  delivery channel to end users who do not have access to any other
  Web enabled devices. Extending the reach of the Web to such
  people contributes to a primary W3C goal of bringing the benefits
  of the Web to all people. [see <em>"One Web"</em> statements in
  section 3.2 below]</p>

  <p>Members of the Mobile Web Initiative believe that it is in the
  interests of all the mobile value chain participants, from
  content author to end user, to minimize the impact of any fixed
  vs. mobile differences and maximize the benefits of all the
  similarities.</p>

  <p>The mission of the Mobile Web Initiative Best Practices
  Working Group <a href=
  "http://www.w3.org/2005/MWI/Overview.html">(BPWG)</a> is to
  enable the reach of the Web to be easily extended onto mobile
  devices. It intends to specify and publish a set of technical
  best practices and develop a <em>mobileOK</em> trustmark for Web
  pages that support such practices and provide an appropriate user
  experience on mobile devices. The best practice guidelines
  are intended to improve the delivery and display of content to mobile and other
  portable small screen-devices. For each guideline in the recommendations document [<a href="#bp">BP</a>]
  there is a corresponding &quot;How to do it&quot; statement discussing related
  content development techniques. These will be elaborated further in a companion
  <em>Techniques</em> document. In addition, every guideline is accompanied by an
  appropriate &quot;What to test&quot; statement discussing the related testing issues
  and applicable testability criteria.</p>

  <p>This document establishes the framework for the Best Practices
  guidelines, as an elaboration of the scope presented within the
  BPWG Charter [<a href=
  "#ref_CHARTER">
  CHARTER</a>].</p>

  <p>The <abbr title=
  "Mobile Web Best Practices Working Group">BPWG</abbr> does not
  intend to force content authors to limit the scope of their
  content delivery only to those mechanisms which are currently
  available on mobile devices. Rather, the guidelines produced are
  meant to enable content to be displayed as correctly as possible
  on a range of devices - either directly or, if and where
  necessary, assisted by some server, client or third-party
  adaptation mechanism which is transparent to the end user.</p>

  <p>There is no intention of developing new technology, such as
  markup languages. However if, during the life of the working
  group the need for new technologies is identified, the group may
  raise requirements with other W3C groups or groups within other
  standards organizations.</p>

  <h2 id="s2">2. Best Practice Dimensions and Scope</h2>

  <p>As the Mobile Web Initiative is primarily concerned with
  accessing content that would currently be rendered in a desktop
  or laptop browser, the <abbr title=
  "Mobile Web Best Practices Working Group">BPWG</abbr>'s focus
  is currently on best practices that are most pertinent to
  &quot;traditional&quot; browsing. However, in future phases, the group may broaden
  the scope of its work in order to take into account other content
  presentation options that may be available on mobile devices -
  e.g., using the emerging multimodal technologies.</p>

  <p>Also, whilst many mobile applications - such as Multimedia
  Messaging (MMS), ringtones or podcasting - remain beyond the
  scope of the Mobile Web Initiative scope, the <abbr title=
  "Mobile Web Best Practices Working Group">BPWG</abbr> should take
  account of the underlying service or device features, as mobile
  users are not likely to differentiate between similar types of
  content and services.</p>

  <p>The <abbr title=
  "Mobile Web Best Practices Working Group">BPWG</abbr> is also
  striving to address issues related to internationalisation and
  localisation of content on mobile devices - e.g., supporting
  translations, enabling right to left scripts, selecting
  appropriate character encodings, etc.</p>

  <p>The &quot;Mobile Web Best Practices&quot; recommendations [<a href="#bp">BP</a>]
  draw on applicable experiences from all the mobile web stakeholders
  and other W3C activities such as the W3C Web Accessibility Initiative [<a href="#wai">WAI</a>].</p>


  <h2 id="s2.1">2.1 Expected outcomes</h2>

 <p>Members of the Mobile Web Initiative expect the following results of the
  <abbr title=
  "Mobile Web Best Practices Working Group">BPWG</abbr> work:</p>

  <ul>
    <li>Authors who currently assume a desktop presentation, for
    example a screen size of at least 640 x 480 and the absence of
    the other mobile limitations, will create more mobile-friendly
    content</li>

    <li>Authors who currently target their material to mobile devices,
    for example by providing small page sizes and tiny graphics, will
    create more desktop-friendly content</li>
  </ul>

  <p>In both cases authors will do this either by producing simple sites
  that have a basic presentation effective in both desktop and
  mobile environments; or by adapting their content to suit the
  characteristics of a range of devices.</p>

  <h2 id="s3">3. Assumptions</h2>

  <h3 id="s3.1">3.1 Mobile User Experience Considerations</h3>

  <p>Most of the fixed vs. mobile user experience differences stem
  from</p>

  <ul>
    <li>the types of <b>content</b> involved</li>

    <li>the <b>capabilities of the devices and access networks</b>
    used (e.g., a small-screen mobile device vs. a desktop PC)</li>

    <li>the <b>context</b> in which the content is received by the
    user (e.g., sitting at a desk vs. sitting on a bus).</li>
  </ul>

  <p>An example of <b>content</b> issues involved is a large bitmap
  which contains a sports photo. The bitmap may be unsuitable for
  use on a mobile device and it would need to be resized or
  cropped, while maintaining the relevant information, such as the
  position of the ball.</p>

  <p>Examples of <b>device and access network capabilities</b> that
  need to be considered because of possible technical, ergonomic or
  economic implications for a mobile user include:</p>

  <dl>
    <dt class="label">bandwidth</dt>

    <dd>Basic cellular radio access often offers lower bandwidth
    than a fixed connection</dd>

    <dt class="label">battery</dt>

    <dd>Battery capacity is very constrained in mobile devices -
    certain activities tend to increase power consumption and
    shorten battery life</dd>

    <dt class="label">capabilities</dt>

    <dd>Predominantly proprietary platforms from multiple vendors -
    based on highly integrated hardware and relatively
    differentiated software (e.g., operating systems) - increase
    capability divergences between mobile devices. Consequently,
    alignment of browsing capabilities becomes quite difficult,
    especially when transcending the existing Open Mobile Alliance
    (<a href="http://www.openmobilealliance.org/">OMA</a>) Browsing
    baselines.</dd>

    <dt class="label">cost</dt>

    <dd>Cellular network connectivity is commonly charged per data
    volume</dd>

    <dt class="label">input</dt>

    <dd>Mobile device input capabilities tend to differ, but are
    usually more constrained than in desktop terminals - four-way
    navigation and softkeys are most common, but touchscreen-,
    stylus- and keyboard-based capabilities are improving. While
    many mobile devices offer predictive text input, data input
    tends to be relatively slow and cumbersome. Many mobile devices
    also do not offer as wide a character repertoire as desktop
    devices.</dd>

    <dt class="label">memory</dt>

    <dd>Significantly less working memory and storage is available
    on mobile devices than in desktop terminals</dd>

    <dt class="label">processing power</dt>

    <dd>Significantly less processing power is available on mobile
    devices than in desktop terminals - hence stringent efficiency
    and optimization requirements that often lead to highly
    integrated and differentiated solutions</dd>

    <dt class="label">screen</dt>

    <dd>Small screen is a major constraint for mobile devices. Furthermore,
    screen widths, heights, resolution, pixel densities, aspect ratios, color
    characteristics and actual performance under certain viewing
    conditions (e.g., in sunlight) tend to vary a lot - thus introducing
    additional content presentation and navigation complexities.
    Also, as currently only a few mobile devices are capable of
    multi-tasking, screen is typically "owned" by one application
    at a time and the user interface does not support multiple
    windows that are common on a desktop.</dd>

    <dt class="label">text</dt>

    <dd>Text input tends to be very slow and cumbersome on a mobile
    device</dd>

    <dt class="label">voice and multimodality</dt>

    <dd>Voice and multimodal technologies might supplement or
    enhance mobile device input and output capabilities, but
    currently multimodality is not commonly supported and should be
    viewed as an emerging technology.</dd>

    <dt class="label">usability</dt>

    <dd>Given highly differentiated capabilities and constraints of
    various mobile devices, making the user interface reasonably
    standardized, simple and efficient remains the main
    challenge.</dd>
  </dl>

  <p>Similarly, illustrative <b>context</b> characteristics that
  need to be considered because of possible usage implications
  include:</p>

  <dl>
    <dt class="label">partial attention</dt>

    <dd>Mobile devices are often used in situations when the users
    are unable to give their full attention to the content. A user
    will typically be distracted within a few seconds. If there is
    no activity on their mobile browser for longer than that
    seconds, they will be lost as a user. They will often be easily
    distracted from what happens to be displayed at a time on their
    screens. Information must be concise and easily
    accessible.</dd>

    <dt class="label">social situation or physical environment</dt>

    <dd>In direct contrast to a desktop user typically sitting
    alone at a desk in the office or at home, a mobile user might
    often be in a number of very different situations and
    environments - e.g., indoor or outdoor, at a party, in a
    meeting, on a beach, on a train etc.</dd>

    <dt class="label">connectivity</dt>

    <dd>The connection between a mobile device and the internet may
    involve a public mobile network. Such connection may drop out
    from time to time as the user moves into a poor reception area.
    Connections may also involve non-cellular networks and other
    wireless technologies - e.g., Wi-Fi, Bluetooth, etc.</dd>

    <dt class="label">availability</dt>

    <dd>Globally there are already more Web enabled mobile devices
    than computers in use. For many people mobile devices may be
    the only available way of accessing the Web and some of them
    may not even have any prior desktop or notebook Web
    experience.</dd>
  </dl>

  <p>In the light of the above, assumptions made by content authors
  about mobile users, their devices and usage contexts have to
  reflect some awareness of possible constraints and their
  technical, ergonomic, economic and environmental
  implications.</p>

  <h3 id="s3.2">3.2 "One Web"</h3>

  <p>The W3C has already made several statements relevant to the
  definition of "one web."</p>

  <blockquote cite="#ref_W3C">
    <p>The social value of the Web is that it enables human
    communication, commerce, and opportunities to share knowledge.
    One of W3C's primary goals is to make these benefits available
    to all people, whatever their hardware, software, network
    infrastructure, native language, culture, geographical
    location, or physical or mental ability.</p>

    <address>
      -from <cite>About the World Wide Web Consortium</cite>
      [<a href=
      "#ref_W3C">
      W3C</a>]
    </address>
  </blockquote>

  <blockquote cite="#ref_WEBARCH">
    <p>A URI owner SHOULD NOT associate arbitrarily different URIs
    with the same resource.</p>

    <address>
      -from <cite>Architecture of the Word Wide Web, Volume
      One</cite> [<a href=
      "#ref_WEBARCH">
      WEBARCH</a>]
    </address>
  </blockquote>

  <p>The number and nature of devices through which the Web may be
  accessed continues to grow. At one extreme, web content may be
  displayed on enormous plasma screens in public places with
  stadium-filling sound systems. However, the Mobile Web Initiative
  is primarily concerned with the opposite end of the spectrum -
  i.e., small, mobile devices. Given their proliferation and
  increasing diversity, making any general assumptions about
  specific device capabilities and/or particular circumstances of
  their use is, at best, unwise. In particular, the assumption that
  access to the web is primarily by means of a desktop or notebook
  browser and that this is the default web experience is very much
  open to challenge.</p>

  <p>One recent model suggests that within three years the number
  of web-capable mobile devices worldwide will exceed
  notebook/desktop PCs sixfold. [<a href=
  "#ref_WOE">
  WOE</a>]</p>

  <p>Other models suggest that while the number of PCs in use by
  2010 is likely to be over 1.3 billion, mobile subscriptions are
  expected to be on the order of 2.5 billion. [<a href=
  "#ref_STATS">
  STATS</a>]</p>

  <p>However, it is also noteworthy that 96.2% of an estimated 14.5
  million wireless internet users in Korea also use the wired
  internet. [<a href=
  "#ref_KOREA">
  KOREA</a>]</p>

  <p>The number of Japanese mobile-only Internet users has been
  declining recently in both absolute and relative terms. This is
  probably not because fewer people are using mobile access as
  applications such as e-mail and the download of ringtones
  continue to be immensely popular. Recent research suggests that
  if the mobile web experience is compelling, users may be more
  inclined to use fixed access as well. [<a href=
  "#ref_JAPAN">
  JAPAN</a>]</p>

  <p>It is often in the commercial interests of content providers
  to maximize the reach of their materials. Achieving this in the
  light of the trends referred to above means that the use of
  standard communication and formatting mechanisms is likely to be
  increasingly important. For content to be widely accessible it
  must not depend upon a particular implementation of standards or
  the end-user's choice of terminal device and browser.</p>

  <p>That said, content providers may wish to target particular
  classes of user or to provide material and services that are
  tailored to particular situations.</p>

  <p>This leads us to characterize &quot;One Web&quot; by postulating
  that:</p>

  <ul>
    <li>The representations of a resource identified by a given URI
    should provide thematically similar information targeted and
    formatted appropriately for their context. Such targeting and
    formatting may take place anywhere in the delivery chain
    between source and end user.</li>

    <li>Access to a URI from different devices or different
    locations should result in thematically similar information but
    may result in both the appearance and the specific content
    being different</li>

    <li>The user should have the choice of accessing the
    same information whatever the device used in whatever
    environment. This point is elaborated in the Best Practice recommendations [<a href="#bp">BP</a>].</li>
  </ul>

  <p>The Best Practices Working Group notes that these concepts
  will need further refinement when considering multimedia content
  and certain types of devices - e.g., voice browser enabled
  terminal devices without a screen. These issues will be addressed
  in Phase 2.</p>

  <h3 id="s3.3">3.3 Adaptation Layer</h3>

  <p>Due to increasing diversity of terminal devices the
  <abbr title=
  "Mobile Web Best Practices Working Group">BPWG</abbr>'s working
  assumption is that multiple versions of content representation or
  adaptation of content to a particular set of device capabilities
  will be commonly used for the foreseeable future. For example,
  adherence to XHTML-MP can lead to different results on different
  devices running the same browser software. The context in which a
  web resource is to be displayed must therefore be addressed and
  hence the concept of an "adaptation layer".</p>

  <p>As discussed above, "One Web" does not mean that precisely the
  same information must always be available in precisely the same
  way from a given URI. The context in which a web resource is to
  be displayed must therefore be addressed - hence the concept of
  an "adaptation layer" becomes an integral, if transparent,
  element of the Web.</p>

  <p>In order for the adaptation layer to do its job, content must
  be created in a way that makes adaptation relatively simple and,
  critically, makes the results predictable.</p>

  <p>The <abbr title=
  "Mobile Web Best Practices Working Group">BPWG</abbr> therefore strives to demonstrate:</p>

  <ul>
    <li>when and how best to create content that renders across fixed and mobile devices</li>

    <li>how to structure and mark-up content to ease adaptation</li>

    <li>the limits of adaptation and situations in which adaptation via the
  selection of alternative content with thematically similar information
  might be the only practical approach to ensure its rendering across
  fixed and mobile devices</li>

    <li>why the creation of thematically different content - for mobile only or
fixed only users - at the same URI strongly contradicts best practice.</li>
  </ul>

  <h3 id="s3.4">3.4 <em>mobileOK</em> Trustmark and Best Practices</h3>

  <p>Development of a <em>mobileOK</em> trustmark is a key
  objective of the Mobile Web Initiative - as described in the
  Mobile Web Best Practices Working Group <a href=
  "http://www.w3.org/2005/01/BPWGCharter/Overview.html">charter</a>.
  The intention is to establish a set of validation tests to which
  content resources can be subjected. If passed - possibly subject
  to some content adaptation - a particular resource will be deemed
  to be &quot;mobileOK&quot;. It is anticipated that this information will be
  presented in a visual form by means of a logo and in a machine
  processable form - e.g., for use by content aggregators.</p>

  <p>The <em>mobileOK</em> trustmark is intended not only to help
  authors to create content that will render correctly on mobile
  devices, but also encourage software manufacturers to develop a
  range of compatible tools, including authoring tools and clients.
  The <em>mobileOK</em> trustmark is envisaged to have relevance
  across the entire content production chain.</p>

  <p>The development of a <em>mobileOK</em> trustmark implies two
  work areas for the <abbr title=
  "Mobile Web Best Practices Working Group">BPWG</abbr>: defining
  the criteria a resource must meet to be <em>mobileOK</em> and defining the process and platform
  through which the trustmark is to be delivered.</p>

  <p>The idea of <em>mobileOK</em> requires further elaboration and will be discussed in more
  detail in a separate <em>mobileOK</em> document. Best practice guidelines and the
  corresponding testability statements in the recommendations document [<a href="#bp">BP</a>]
  are intended to provide a basis for establishing <em>mobileOK</em> technical requirements and
  conformance criteria.</p>

  <p>Levels of <em>mobileOK</em> conformance in relation to different dimensions of the
specified best practices - as applicable in certain delivery contexts - will be addressed in
the <em>mobileOK</em> document. The <abbr title=
  "Mobile Web Best Practices Working Group">BPWG</abbr> remains open minded on how this will
be achieved.</p>

  <p>For example, different sets of <em>mobileOK</em> conformance
  requirements could be applicable to different categories of
  browsers - e.g., "traditional" browsers, voice-enabled browsers,
  etc</p>

  <p>Also, specifications of <em>mobileOK</em> conformance criteria
  could be based on the "state of the art" practices prevailing at
  a particular point in time - e.g., MobileOK2005, MobileOK2007,
  etc.</p>

  <p>Another option could be to specify some "backward compatible"
  levels of <em>mobileOK</em> conformance criteria - e.g.,
  MobileOK, MobileGood, MobileExcellent - based on meeting a number
  of increasingly stringent best practices or their subsets or
  supersets.</p>

  <p>Yet another option would be to consider different content
  profiles - e.g., MobileOK HTML/CSS/PNG or MobileOK
  XHTML/CSS/SVG/ECMAscript - or some similar compound document
  profile variations.</p>

  <p>As some of these options are not mutually exclusive in nature,
  certain combinations of <em>mobileOK</em> conformance criteria
  might also be considered.</p>

  <h3 id="s3.5">3.5 Open Issues</h3>

  <p>The <abbr title=
  "Mobile Web Best Practices Working Group">BPWG</abbr> recognizes
  that it is necessary to structure the work on the Best
  Practice Recommendations into two or more phases, with the
  initial focus on best practices that are most pertinent to
  &quot;traditional&quot; browsing.</p>

  <p>The scope of Phase 2 work remains an open issue that
  will be addressed by a separate Phase 2 Scope document.</p>

  <h2 id="s4">4. Internal and External Liaisons</h2>

  <p>The principles developed by the W3C Device Independence
  Working Group (<a href=
  "http://www.w3.org/2001/di/">DIWG</a>) are recognized as
  being highly relevant to the Mobile Web Initiative. In particular
  concepts such as authoring units, delivery units and display
  units are important. The <abbr title=
  "Mobile Web Best Practices Working Group">BPWG</abbr> may have to
  extend this into a broader conceptual architecture, including for example, delivery
  context, device properties and geographical location. It is worth noting that the Best
  Practice guidelines include conditional statements in the form &quot;if
  feature X is supported by the target device then a delivery unit
  must/should be used in this way (else in some other way).&quot;</p>

  <p>The <abbr title=
  "Mobile Web Best Practices Working Group">BPWG</abbr> will
  coordinate their work with the related efforts within the W3C,
  including:</p>

  <ul>
    <li>Web Accessibility Initiative (<a href=
    "http://www.w3.org/WAI/">WAI</a>)</li>

    <li>Device Independence Working Group (<a href=
    "http://www.w3.org/2001/di/">DIWG</a>)</li>

    <li><abbr title="Mobile Web Initiative">MWI</abbr> Device
    Description Working Group (<a href=
    "http://www.w3.org/2005/MWI/DDWG/">DDWG</a>)</li>
  </ul>

  <p>The <abbr title=
  "Mobile Web Best Practices Working Group">BPWG</abbr> will also
  establish working relationships - based on formal
  liaisons, if and where appropriate - with certain organizations
  outside of the W3C, whose activities might impact the Mobile Web
  Initiative and/or be influenced by it, including:</p>

  <ul>
    <li>GSM Association (<a href=
    "http://www.gsmworld.com/">GSMA</a>)</li>

    <li>Open Mobile Alliance (<a href=
    "http://www.openmobilealliance.org/">OMA</a>)</li>

    <li>Wireless Universal Resource File (<a href=
    "http://wurfl.sourceforge.net/">WURFL</a>)</li>

    <li>Mobile Platform Special Subcommittee of the Korea Wireless
    Internet Standardization Forum (KWISF) - responsible for the
    Wireless Internet Platform for Interoperability (<a href=
    "http://wipi.or.kr/English/">WIPI</a>) specifications.</li>
  </ul>

  <h2 id="s5">5. Resources</h2>

  <p>The <abbr title=
  "Mobile Web Best Practices Working Group">BPWG</abbr> recognizes
  the existence of many resources that represent a considerable
  amount of work already done in this area. The Web Accessibility
  Initiative (<a href="#wai">WAI</a>) guidelines
  provide an important starting point for the work to be done, for
  example. Further material will be fully referenced in the Best
  Practices document.</p>

  <h2 id="s6">6. References</h2>

  <dl>

	<dt><a class="ref" id="bp" name="bp">[BP]</a></dt><dd>&quot;<cite><a href="http://www.w3.org/TR/mobile-bp/">Mobile Web Best Practices</a></cite>&quot;, see: http://www.w3.org/TR/mobile-bp/</dd>

    <dt><a class="ref" id="ref_CHARTER" name="ref_CHARTER">[CHARTER]</a></dt>

    <dd>"<cite><a href=
    "http://www.w3.org/2005/01/BPWGCharter/Overview.html">
    BPWG Charter</a></cite>", see:
    http://www.w3.org/2005/01/BPWGCharter/Overview.html</dd>

    <dt><a class="ref" id="ref_JAPAN" name=
    "ref_JAPAN">[JAPAN]</a></dt>

    <dd>"<cite><a href=
    "http://www.poweredcom.net/mailmag/front/01/03.html">Aug. 2005
    Poweredcom article with a bar chart of Internet users in Japan
    (mobile-only access users shown in light-grey)</a></cite>",
    see: http://www.poweredcom.net/mailmag/front/01/03.html</dd>

    <dt><a class="ref" id="ref_KOREA" name=
    "ref_KOREA">[KOREA]</a></dt>

    <dd>"<cite><a href=
    "http://isis.nic.or.kr/report_DD_View/upload/mobile200412_eng[1].pdf">
    2004 Survey on the Wireless Internet Use - National Internet
    Development Agency of Korea</a></cite>", see:
    http://isis.nic.or.kr/report_DD_View/upload/mobile200412_eng[1].pdf</dd>

    <dt><a class="ref" id="ref_STATS" name=
    "ref_STATS">[STATS]</a></dt>

    <dd>"<cite><a href="http://www.c-i-a.com/pr0605.htm">Computer
    Industry Almanac, June 2005 and Strategy Analytics, August
    2005</a></cite>", see: http://www.c-i-a.com/pr0605.htm</dd>

    <dt><a class="ref" id="ref_W3C" name="ref_W3C">[W3C]</a></dt>

    <dd>"<cite><a href=
    "http://www.w3.org/Consortium/about-w3c.html#universal-access1">
    About the World Wide Web Consortium</a></cite>", see:
    http://www.w3.org/Consortium/about-w3c.html#universal-access1</dd>

    <dt><a class="ref" id="ref_WEBARCH" name=
    "ref_WEBARCH">[WEBARCH]</a></dt>

    <dd>"<cite><a href=
    "http://www.w3.org/TR/2004/REC-webarch-20041215/#uri-aliases">Architecture
    of the Word Wide Web,Volume One</a></cite>", see:
    http://www.w3.org/TR/2004/REC-webarch-20041215/#uri-aliases</dd>

    <dt><a class="ref" id="ref_WOE" name="ref_WOE">[WOE]</a></dt>

    <dd>"<cite><a href=
    "http://www.w3.org/2004/Talks/w3c10-WebOnEverything/?n=15">T-Mobile
    - Global Mobile Capex Handbook, August 2004 - modeled on Credit
    Suisse First Boston, Mobile Data 2004, Pyramid
    Research</a></cite> ", see:
    http://www.w3.org/2004/Talks/w3c10-WebOnEverything/?n=15</dd>

    <dt><a class="ref" id="wai" name="wai">[WAI]</a></dt>

    <dd>&quot;<cite><a href="http://www.w3.org/WAI/">WAI</a></cite> &quot;, see: http://www.w3.org/WAI/</dd>
  </dl>


  <h2 id="s7">7. Acknowledgements</h2>

  <p>The editors would like to recognize the contributions of the
  following members of the W3C Mobile Web Initiative Best Practices
  Working Group <em>(listed in alphabetical order)</em>:</p>

  <ul>
    <li>Daniel Appelquist, Vodafone</li>

    <li>Jyri Hagman, Nokia</li>

    <li>Dominique Haza&euml;l-Massieux, W3C</li>

    <li>Charles McCathieNevile, Opera</li>

    <li>Giles Payne, NTT DoCoMo</li>

    <li>Jo Rabin, mTLD Consortium</li>

    <li>Kai-Dietrich Scheppe, T-Online</li>

    <li>Paul Walsh, Segala M Test</li>
  </ul>
</body>
</html>