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<div class="gl-only">
<p align="center">[<a href="#toc">contents</a>] [<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/">implementing</a>]</p>
<div class="head">
<a href="http://www.w3.org/"><img height="48"
src="http://www.w3.org/Icons/w3c_home" width="72" alt="W3C" /></a>

<h1><a name="title" id="title"></a>User Agent Accessibility Guidelines (UAAG)
2.0</h1>

<h2><a name="w3c-doctype" id="w3c-doctype"></a>W3C Working Draft 19 July
2011</h2>
<dl>
  <dt>This version:</dt>
    <dd><a href="http://www.w3.org/TR/2011/WD-UAAG20-20110719/">http://www.w3.org/TR/2011/WD-UAAG20-20110719/</a></dd>
  <dt>Latest version:</dt>
    <dd><a
      href="http://www.w3.org/TR/UAAG20/">http://www.w3.org/TR/UAAG20/</a></dd>
  <dt>Previous version:</dt>
    <dd><a
      href="http://www.w3.org/TR/2010/WD-UAAG20-20100617/">http://www.w3.org/TR/2010/WD-UAAG20-20100617/</a></dd>
  <dt>Editors:</dt>
    <dd>James Allan, Texas School for the Blind and Visually Impaired</dd>
    <dd>Kelly Ford, Microsoft</dd>
    <dd>Jeanne Spellman, W3C/Web Accessibility Initiative </dd>
  <dt>Previous Editors:</dt>
    <dd>Jan Richards, Adaptive Technology Resource Centre, University of
      Toronto</dd>
</dl>

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<p class="copyright"><a
href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a>
© 2011 <a href="http://www.w3.org/"><acronym
title="World Wide Web Consortium">W3C</acronym></a><sup>®</sup> (<a
href="http://www.csail.mit.edu/"><acronym
title="Massachusetts Institute of Technology">MIT</acronym></a>, <a
href="http://www.ercim.eu/"><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
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<a
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and <a href="http://www.w3.org/Consortium/Legal/copyright-documents">document
use</a> rules apply.</p>
<hr />
</div>
<!-- gl-only --></div>


<div class="gl-only">
<h2 class="nonb"><a name="abstract" id="abstract">Abstract</a></h2>

<p>UAAG 2.0 provides guidelines for designing <a class="dfn-instance"
href="#def-user-agent" rel="glossary" title="definition: User agent">user
agents</a> that lower barriers to Web accessibility for people with
disabilities. User agents include browsers and other types of software that
retrieve and render <a class="dfn-instance" href="#def-content"
rel="glossary" title="definition: Content">Web content</a>. A user agent that
<a href="#conformance">conforms</a> to these guidelines will promote
accessibility through its own user interface and through other internal
facilities, including its ability to communicate with other technologies
(especially <a class="dfn-instance" href="#def-assistive-technology"
rel="glossary" title="definition: Assistive technology">assistive
technologies</a>). Furthermore, all users, not just users with disabilities,
should find conforming user agents to be more usable.</p>

<p>In addition to helping developers of browsers and media players, UAAG 2.0 will  benefit developers of assistive technologies because it
explains what types of information and control an assistive technology may
expect from a conforming user agent. Technologies not addressed directly by
UAAG 2.0 (e.g. technologies for braille rendering) will be essential to
ensuring Web access for some users with disabilities.</p>

<p>The "User Agent Accessibility Guidelines 2.0" (<acronym
title="Authoring Tool Accessibility Guidelines">UAAG</acronym> 2.0) is part
of a series of accessibility guidelines published by the <acronym
title="the World Wide Web Consortium">W3C</acronym> <a
href="http://www.w3.org/WAI/" title="Link to W3C-WAI">Web Accessibility
Initiative</a> (<acronym title="the Web Access Initiative">WAI</acronym>).</p>

<h2 class="nonb"><a name="status" id="status">Status of this document</a></h2>

<h3><a name="status-superseded" id="status-superseded"></a>May be
Superseded</h3>

<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
<acronym title="the World Wide Web Consortium">W3C</acronym> publications and
the latest revision of this technical report can be found in the <a
href="http://www.w3.org/TR/"><acronym
title="the World Wide Web Consortium">W3C</acronym> technical reports
index</a> at http://www.w3.org/TR/.</em></p>
<!-- COMMENT OUT FOR WORKING DRAFT -->
<!-- <h3><a name="status-status" id="status-status"></a>Editor's Draft of UAAG 2.0</h3>
<p><strong>This document is the internal working draft used by the <acronym title="User Agent Working Group">UAWG</acronym> and is updated continuously and without notice. This document has no formal standing within W3C. Please consult the <a href="http://www.w3.org/WAI/UA/">group's home page</a> and the <a href="http://www.w3.org/TR/">W3C technical reports index</a> for information about the latest publications by this group.</strong></p> -->
<!-- END COMMENT OUT FOR WORKING DRAFT -->
<!-- COMMENT OUT FOR EDITOR'S DRAFT -->

<h3><a name="status-status" id="status-status"></a>Working Draft of UAAG
2.0</h3>

<p>This is the W3C Working Draft of 19 July 2011. This draft includes   re-organization of the Guidelines and clarifications to the success criteria suggested from comments and from writing  the Implementation document. Substantial changes include: </p>
<ul>
  <li><strong>New organization</strong> – the  	order of the Principles has been changed to more closely reflect WCAG.
  </li>
  <li>
   <strong>Focus</strong> - the success criteria related to focus have been separated into more discrete, testable success criteria.
  Success criteria have been moved and consolidated for clarity and ease of testing. </li>
  <li>
  <strong>Media</strong> – the success criteria were removed that were best practices, but not required for accessibility. </li>
  <li><strong>Clarity</strong> - all success criteria were reviewed for clarity, consistency and ease of testing.</li>
</ul>
<p><a name="status-feedback" id="status-feedback"></a>The Working Group seeks feedback on  the following points for this draft: </p>

<ul>
  <li>Should  UAAG 2.0 include <a href="#gl-speech-config">guidance  	for self-voicing user agents</a> that provide their own audio  	interface? </li>
  <li>
    Is the  language for success  	criteria <a href="#gl-control-inaccessible-content">2.11.5 (playback rate adjustment for pre-recorded content)</a> clear and complete?
  </li>
  <li>
    Is the language clear in the new  	success criteria for speech input users? Are additional success  	criteria required? See <a href="#gl-device-independent-handlers">2.6  	Event handlers</a>, <a href="#gl-viewport-orient">1.8 Viewports</a>, <a href="#gl-focus-mechanism">1.9  	Focus mechanism</a>
  </li>
  <li>
    Are the levels (A, AA, AAA) correct for the new  	success criteria on resetting preferences? See: <a href="#gl-store-prefs">2.7  	Managing preferences</a>.
  </li>
  <li>
    More information is needed to refine success criteria <a href="#app-note-control-video">2.11.12 Adjust Playback Contrast and Brightness</a> range for video. What are the ranges of contrast and brightness that should be required to  	meet the needs of users with low vision?
  </li>
  <li>What suggestions do people have for partial conformance models that could appropriately apply to assistive technologies but not be applied inappropriately for non-assistive-technology  user agents? </li>
</ul>
<p>Comments on this draft should be sent to <a href="mailto:public-uaag2-comments@w3.org">public-uaag2-comments@w3.org</a> (<a href="http://lists.w3.org/Archives/Public/public-uaag2-comments/">Public  Archive</a>) <strong>by 19 August 2011</strong>.</p>
<p>UAAG 2.0 is not yet a Recommendation. The <a href="http://www.w3.org/WAI/UA/">User  Agent Working Group</a> (UAWG)  intends to publish UAAG 2.0 as a W3C Recommendation.  Until that time <a href="http://www.w3.org/TR/ATAG10/">User Agent Accessibility  Guidelines 1.0</a> (UAAG 1.0) <cite><a href="#ref-UAAG10">[UAAG10]</a></cite> is the stable, referenceable version. This Working Draft does not  supersede UAAG 1.0. </p>
<!-- END COMMENT OUT FOR EDITOR'S DRAFT -->

<h3><a name="status-wai" id="status-wai"></a>Web Accessibility Initiative</h3>

<p>This document has been produced as part of the <acronym
title="World Wide Web Consortium">W3C</acronym> <a
href="http://www.w3.org/WAI/">Web Accessibility Initiative</a> (WAI). The
goals of the User Agent Working Group (UAWG) are discussed in the <a
href="http://www.w3.org/WAI/UA/2010/uawg_charter.html">Working Group charter</a>. The
<acronym title="User Agent Working Group">UAWG</acronym> is part of the <a
href="http://www.w3.org/WAI/Technical/Activity">WAI Technical
Activity</a>.</p>

<h3><a name="status-no-endorsement" id="status-no-endorsement"></a>No
Endorsement</h3>

<p>Publication as a Working Draft does not imply endorsement by the <acronym
title="the World Wide Web Consortium">W3C</acronym> 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>

<h3><a name="status-patents" id="status-patents"></a>Patents</h3>

<p>This document was produced by a group operating under the <a
href="http://www.w3.org/Consortium/Patent-Policy-20040205/">5 February 2004
W3C Patent Policy</a>. W3C maintains a <a
href="http://www.w3.org/2004/01/pp-impl/36791/status">public list of any
patent disclosures</a> made in connection with the deliverables of the group;
that page also includes instructions for disclosing a patent. An individual
who has actual knowledge of a patent which the individual believes contains
<a
href="http://www.w3.org/Consortium/Patent-Policy-20040205/#def-essential">Essential
Claim(s)</a> must disclose the information in accordance with <a
href="http://www.w3.org/Consortium/Patent-Policy-20040205/#sec-Disclosure">section
6 of the W3C Patent Policy</a>.</p>
<hr />
</div>

<div class="toc">
<h2><a name="toc" id="toc">Table of Contents</a></h2>
<ul class="toc">
  <li><a href="#abstract">Abstract</a></li>
  <li><a href="#status">Status of this document</a></li>
  <li><a href="#introduction">Introduction</a>
    <ul class="toc">
      <li class="gl-only"><a href="#conceptual_overview">Overview</a></li>
      <li class="gl-only"><a href="#layers_guide">UAAG 2.0 Layers of Guidance</a></li>
      <li class="gl-only"><a href="#supporting_docs">UAAG 2.0 Supporting Documents</a></li>
      <li class="gl-only"><a href="#intro-components">Components of Web Accessibility</a></li>
      <li class="gl-only"><a href="#intro-conf-levels">Levels of Conformance</a></li>
      <li><a href="#intro-def-ua">Definition of User Agent </a></li>
      <li><a href="#intro-atag">Relationship with Authoring Tool Accessibility Guidelines 2.0 (ATAG)</a></li>
    </ul>
  </li>
  <li><a href="#Guidelines">UAAG 2.0 Guidelines</a>
    <ul class="toc">
      <li><a href="#principle-perceivable">PRINCIPLE 1</a>: <span class="principle">Perceivable</span>
        <ul class="toc">
         <li><a href="#gl-access-alternative-content">Guideline 1.1</a>: Alternative content</li>
         <li><a href="#gl-missing-alt">Guideline 1.2</a>: Missing content </li>
         <li><a href="#gl-interaction-highlight">Guideline 1.3</a>: Highlighting</li>
         <li><a href="#gl-text-config">Guideline 1.4</a>: Text configuration</li>
         <li><a href="#gl-volume-config">Guideline 1.5</a>: Volume configuration</li>
         <li><a href="#gl-speech-config">Guideline 1.6</a>: Synthesized speech configuration</li>
         <li><a href="#gl-style-sheets-config">Guideline 1.7</a>: Style sheets configuration</li>
         <li><a href="#gl-viewport-orient">Guideline 1.8</a>: Viewports</li>
         <li><a href="#gl-focus-mechanism">Guideline 1.9</a>: Focus</li>
         <li><a href="#gl-alternative-views">Guideline 1.10</a>: Source views</li>
         <li><a href="#gl-info-link">Guideline 1.11</a>: Element Information</li>
      </ul>
      </li>
      <li><a href="#principle-operable">PRINCIPLE 2</a>. Operable
        <ul class="toc">
          <li><a href="#gl-keyboard-access">Guideline 2.1</a>: Keyboard access</li>
          <li><a href="#gl-sequential-navigation">Guideline 2.2</a>: Sequential navigation</li>
          <li><a href="#gl-direct-navigation-and-activation">Guideline 2.3</a>: Direct navigation and activation</li>
          <li><a href="#gl-search-text">Guideline 2.4</a>: Search</li>
          <li><a href="#gl-nav-structure">Guideline 2.5</a>: Structured navigation</li>
          <li><a href="#gl-device-independent-handlers">Guideline 2.6</a>: Event handlers</li>
          <li><a href="#gl-store-prefs">Guideline 2.7</a>: Preference settings</li>
          <li><a href="#gl-configure-controls">Guideline 2.8</a>: Toolbar configuration</li>
          <li><a href="#gl-time-independent">Guideline 2.9</a>: Time-independence</li>
          <li><a href="#gl-prevent-flash">Guideline 2.10</a>: Flashing</li>
          <li><a href="#gl-control-inaccessible-content">Guideline 2.11</a>: Media </li>
        </ul>
      </li>
      <li><a href="#principle-understandable">PRINCIPLE 3</a>: Understandable
         <ul class="toc">
            <li><a href="#gl-avoid-unnecessary-messages">Guideline 3.1</a>: Unnecessary messages</li>
            <li><a href="#gl-avoid-mistakes">Guideline 3.2</a>: Mistakes </li>
            <li><a href="#gl-doc-access-features">Guideline 3.3</a>: Documentation</li>
            <li><a href="#gl-predictable-operation">Guideline 3.4</a>: Predictable</li>
         </ul>
      </li>
        <li><a href="#principle-AT-access">PRINCIPLE 4</a>. Programmatic access
          <ul class="toc">
        <li><a href="#gl-AT-access">Guideline 4.1</a>: Assistive technology </li>
              <li><a href="#gl-AT-access">Guideline 4.2</a>: Nested user agents </li>
           </ul>
        </li>
        <li><a href="#principle-follow-specs">PRINCIPLE 5. Specifications and conventions</a>
           <ul class="toc">
              <li><a href="#gl-desktop-access">Guideline 5.1: Desktop apps</a></li>
              <li><a href="#gl-obs-env-conventions">Guideline 5.2: Web &amp; web apps</a></li>
              <li><a href="#gl-implement-access-features">Guideline 5.3: Accessibility features</a></li>
              <li><a href="#gl-render-to-spec">Guideline 5.4: Follow specifications</a></li>
           </ul>
        </li>
    </ul>
  </li>
  <li><a href="#conformance">Conformance</a></li>
  <li>Appendix A: <a href="#glossary">Glossary</a></li>
  <li>Appendix B: <a href="#ref-this-doc">How to refer to UAAG 2.0 from other
    documents</a></li>
  <li>Appendix C: <a href="#references">References</a></li>
  <li>Appendix D: <a href="#acknowledgments">Acknowledgements</a> </li>
  <li>Appendix E: Checklist </li>
  <li>Appendix F: Comparison of UAAG 1.0 guidelines to UAAG 2.0</li>

</ul>
</div>
<hr />
<h2><a name="introduction" id="introduction">Introduction</a></h2>
<div class="gl-only">
<p>This section is <a href="#def-informative">informative</a>.</p>

<p>A user agent is any software that retrieves and presents Web content for
end users. User agents include Web browsers, media players, <span class="editor-notes">@@ Editors' Note: virtual worlds?? @@</span> and plug-ins that help in retrieving, rendering
and interacting with Web content. UAAG 2.0 specifies requirements that,
if satisfied by <a class="dfn-instance" href="#def-user-agent" rel="glossary"
title="definition: User agent">user agent</a> developers, will lower barriers
to accessibility.</p>

<h3 id="conceptual_overview">Overview</h3>

<p>Accessibility involves a wide range of disabilities. These include visual,
auditory, physical, speech, cognitive, language, learning, neurological
disabilities, and disabilities related to ageing. UAAG 2.0 emphasizes
the goal of ensuring that all users, including users with disabilities, have
control over their environment for accessing the Web. Key methods for
achieving that goal include: </p>
<ul>
  <li>optional self-pacing</li>
  <li>configurability</li>
  <li>device independence</li>
  <li>interoperability</li>
  <li>direct support for both graphical and auditory output</li>
  <li>adherence to published conventions.</li>
</ul>

<p>Some users  have more than one disability, and the needs of different
disabilities may contradict. Thus, many of the requirements in UAAG 2.0
use configuration  to ensure that a functionality designed to
improve accessibility for one user does not interfere with accessibility for
another. A default user agent setting may be useful for one user but
interfere with accessibility for another, therefore UAAG 2.0 prefers
configuration requirements rather than requirements for default settings. For
some content, a feature required by UAAG 2.0 may be ineffective or cause
content to be less accessible, making it imperative that the user be able to
turn off the feature. To avoid overwhelming users with an abundance of
configuration options, UAAG 2.0 includes requirements that promote documentation and ease
of configuration. </p>

<p>UAAG 2.0  acknowledges the importance of author preferences.
However, requirements are included to override certain author preferences
when the user would not otherwise be able to access that content. </p>

<p>Some  UAAG 2.0 requirements  may have security implications,
such as communication through APIs, or allowing programmatic read and write
access to content and <a class="dfn-instance" href="#def-ui-control"
rel="glossary" title="definition: user interface control">user interface
control</a>. UAAG 2.0 assumes that features required by UAAG 2.0
will be built on top of an underlying security architecture. Consequently,
unless permitted explicitly in a success criterion, UAAG 2.0 grants no
conformance exemptions based on security issues.</p>

<p>The UAWG expects that software that satisfies the requirements of UAAG 2.0 will be more flexible, manageable, extensible, and beneficial for all
users. </p>

<h3 id="layers_guide">UAAG 2.0 Layers of Guidance</h3>

<p>In order to meet the  needs of  different audiences using UAAG,
several layers of guidance are provided, including overall
<em>principles</em>, general <em>guidelines</em>, testable <em>success
criteria</em>, and a explanatory intent, examples <em></em> and
resource links.</p>
<ul>
  <li>
    <p><strong>Principles</strong> - At the top are five principles that
    provide the foundation for accessible user agents. Principles 1, 2, and 3 are congruent to Web Content Accessibility Guidelines (WCAG)
    2.0: <em>to make the user agent perceivable, operable, and understandable</em>. Principles 4 and 5 are specific to user agents: <em>facilitate programmatic access</em> and <em>comply with
    specifications and conventions</em>. </p>
  </li>
  <li><p><strong>Guidelines</strong> - Under the principles are guidelines.
    The guidelines provide the basic goals that authors should work toward in
    order to make user agents more accessible to users with different
    disabilities. The guidelines are not testable, but provide the framework
    and overall objectives to help authors understand the success criteria
    and better implement the techniques.</p>
  </li>
  <li><p><strong>Success Criteria</strong> - For each guideline, testable
    success criteria are provided to allow UAAG 2.0 to be used where
    requirements and conformance testing are necessary such as in design
    specification, purchasing, regulation, and contractual agreements. In
    order to meet the needs of different groups and different situations,
    three levels of conformance are defined: A (lowest), AA, and AAA
    (highest). Additional information on UAAG levels can be found in the
    section on <a href="#conformance">Conformance</a>.</p>
  </li>
</ul>

<p>The principles, guidelines, and success criteria work together to provide layers of guidance on
how to make user agents more accessible. Developers are encouraged to view
and apply all layers that they are able to order to best address the needs of the widest possible range
of users.</p>

<p>Note that even user agents that conform at the highest level (AAA) may
not be accessible to individuals with all types, degrees, or combinations of
disability, particularly in the cognitive, language, and learning areas.
Developers are encouraged to seek relevant advice about current
best practice to ensure that their user agent is accessible as
possible to this community. </p>

<h3 id="supporting_docs">UAAG 2.0 Supporting Documents</h3>

<p><strong>A separate document, entitled "Implementing  User Agent
Accessibility Guidelines 2.0" (the "Implementing document" from here on) </strong>provides suggestions and
examples of how each success criteria might be satisfied. It also includes
references to other accessibility resources (such as platform-specific
software accessibility guidelines) that provide additional information on how
a user agent may satisfy each success criteria. The techniques in the
Implementing document are <a class="dfn-instance" href="#def-informative"
rel="glossary" title="definition: informative">informative</a> examples only.
Other strategies may be used or required to satisfy the success criteria.
The <acronym>UAWG</acronym> expects to update the Implementing document more
frequently than the current guidelines. Developers, W3C Working Groups,
users, and others are encouraged to contribute examples and resources.</p>

<h3><a name="intro-components" id="intro-components"></a>Components of Web
Accessibility</h3>

<p>Web accessibility depends on accessible user agents and accessible content. Accessible content availability is greatly influenced
by the accessibility of the authoring tool. For an overview of how these
components of Web development and interaction work together, see:</p>
<ul>
  <li><strong><a href="http://www.w3.org/WAI/intro/components">Essential
    Components of Web Accessibility</a></strong></li>
  <li><strong><a href="http://www.w3.org/WAI/intro/wcag.php">Web Content
    Accessibility Guidelines (WCAG) Overview</a></strong></li>
  <li><strong><a href="http://www.w3.org/WAI/intro/atag.php">Authoring Tool
    Accessibility Guidelines (ATAG) Overview</a></strong></li>
</ul>

<h3><a name="intro-conf-levels" id="intro-conf-levels"></a>Levels of
Conformance</h3>

<p>User Agents may claim conformance to UAAG 2.0 at one of three conformance
levels. The level achieved depends on the level of  success criteria satisfied. The conformance levels are: </p>
<ol>
  <li><strong>UAAG 2.0 Conformance at Level "A" </strong><br />
    The user agent satisfies <em>all</em> of the Level A success
  criteria.</li>
  <li><strong>UAAG 2.0 Conformance at Level "Double-A" </strong><br />
    The user agent satisfies <em>all</em> of the Level A and Level AA success
    criteria.</li>
  <li><strong>UAAG 2.0 Conformance at Level "Triple-A"</strong> <br />
    The user agent satisfies <em>all</em> of the success criteria.</li>
</ol>
</div>
<div>
<h3><a id="intro-def-ua" name="intro-def-ua">Definition of <dfn>User Agent
</dfn></a></h3>

<p>A user agent is any software that retrieves, renders and facilitates end-user interaction with Web content. </p>
</div>

<h3><a name="intro-atag" id="intro-atag"></a>Relationship to the Authoring Tool Accessibility Guidelines (ATAG) 2.0</h3>
<p>While it is convenient to think of user agents retrieving and rendering web content for one group of people (end-users) that was previously authored by another group (authors), user agents are frequently involved with the process of authoring content.</p>
<p>
For these cases, it is important for user agent developers to consider the application of another W3C-WAI Recommendation, the Authoring Tool Accessibility Guidelines (ATAG). ATAG (currently 2.0 is in draft) provides guidance to the developers of tools regarding the accessibility of authoring interfaces to authors (ATAG 2.0 Part A) and ways in which all authors can be supported in producing accessible web content (ATAG 2.0 Part B).
</p>
<div class="gl-only">
<p>Additional information on the role of user agents in web authoring is included in <a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#intro-atag-role">Implementing UAAG 2.0</a></p>
</div>


<h2><a name="Guidelines" id="Guidelines"></a>UAAG 2.0 Guidelines</h2>
<p>The success criteria and applicability notes in this section are <a class="dfn-instance" href="#def-normative"
title="definition: Normative">normative</a>. Guideline summaries are informative. </p>

<div class="principle">
<h2 class="pr-title"><a name="principle-perceivable"
id="principle-perceivable"></a>PRINCIPLE 1 - Perceivable</h2>
<p class="pr-text">Ensure that the user interface
and rendered content are perceivable</p>
</div>
<div class="guideline">
<h3 class="gl-title">
<a name="gl-access-alternative-content" id="gl-access-alternative-content"></a>

Guideline 1.1 - Alternative Content</h3>
 <p class="gl-text">Provide access to alternative content. <span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-access-alternative-content">Implementing

1.1</a>] </span></p>
<p class="summary" id="summary11"><strong>Summary</strong>: The user can easily determine which pieces of content have alternatives such as  alt text or longdesc (1.1.1) and interact with the text to see the available
alternatives (1.1.3). The user can also choose at least one alternative such as alt text to be always displayed (1.1.2), but it's recommended that users also be
able to specify a cascade (1.1.4), such as alt text if it's there, otherwise longdesc, otherwise filename, etc.
</p>
</div>
<div class="sc-level">
<h4 class="sc-title" id="sc-111">1.1.1 Configurable Default
Rendering: </h4>
<p class="sc-text"> The user can  specify which types of <a class="dfn-instance"
href="#def-conditional-content"
title="definition: Conditional content">alternative content</a> to render by default. <span class="level"><span class="level">(Level A)</span> </span> </p><br clear="all" class="sc-close" />

<h4 class="sc-title" id="sc-112">1.1.2 Browse and Render:</h4><p class="sc-text">
 When a rendered element has <a class="dfn-instance"
href="#def-conditional-content"
title="definition: Conditional content">alternative content</a>, the user can render alternatives according to the following: <span class="level"><span class="level">(Level A)</span> </span> </p>
<ul>
  <li>synchronized      alternatives for time-based media (e.g. captions, audio      descriptions, sign language) can be rendered at the same time      as their associated audio tracks and visual tracks, and</li>
  <li>non-synchronized alternatives (e.g. short text alternatives, long descriptions) can be rendered as replacements for the original rendered content.</li>
  </ul>


<h4 class="sc-title" id="sc-113">1.1.3 Identify Presence of Unrendered Alternative Content: </h4><p class="sc-text">The user can specify that content be rendered with an adjacent indicator when unrendered <a class="dfn-instance"
href="#def-conditional-content"
title="definition: Conditional content">alternative content</a> is present (e.g. an icon to indicate an image has a short text alternative). <span class="level"><span class="level">(Level A)</span> </span> </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-114">1.1.4 Rendering Alternative
(Enhanced)</h4>
<p class="sc-text">: The user can specify the cascade order in which to render <a class="dfn-instance"
href="#def-conditional-content"
title="definition: Conditional content">alternative content</a>. <span class="level">(Level AA)</span> </p>
<br clear="all" class="sc-close" />

</div>

<h3 class="guideline">
<a name="gl-missing-alt" id="gl-missing-alt"></a>

Guideline 1.2 - Repair missing content. <span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-missing-alt">Implementing
1.2</a>] </span></h3>
<p class="summary" id="summary12"><strong>Summary</strong>: The user can request useful alternative content when the author fails to provide it. For example,  showing a filename in place of missing (1.2.1) or empty (1.2.2) alt text.</p>
<div class="sc-level">
<h4 class="sc-title" id="sc-121">1.2.1 Repair Missing
Alternatives:</h4>
<p class="sc-text"> The user can specify whether or not the user agent should generate and render <a class="dfn-instance" href="#def-repair-text"
title="definition: repair text">repair text</a> (e.g. file name) when it <a class="dfn-instance" href="#def-recognize"
title="definition: Recognize">recognizes</a> that the author has not provided <a class="dfn-instance"
href="#def-conditional-content"
title="definition: Conditional content">alternative content</a>. <span class="level"><span class="level">(Level A)</span> </span></p>
<br clear="all" class="sc-close" />

</div>

<div class="sc-level">
<h4 class="sc-title" id="sc-122">1.2.2 Repair Empty
Alternatives:</h4><p class="sc-text"> The user can specify whether or not the user agent should generate and render repair text (e.g. file name) when it recognizes that the author has provided <a class="dfn-instance" href="#def-empty-content"
title="definition: Empty content">empty</a> alternative content. <span class="level">(Level AA)</span></p>
<br clear="all" class="sc-close" />

</div>
<div class="sc-level">
<h4 class="sc-title" id="sc-123">1.2.3 Repair Missing Associations:</h4><p class="sc-text"> The user can specify whether or not the user agent should attempt to predict associations from author-specified presentation attributes (i.e. position and appearance). <span class="level">(Level AAA)</span> </p><br clear="all" class="sc-close" />

  <h4 class="sc-title" id="sc-124">1.2.4 Broken Alternative Content: </h4>
  <p class="sc-text">The user can be notified when the user agent cannot render alternative content (e.g. when captions are broken).</p> <span class="level">(Level AAA)</span>

</div>

<h3 class="guideline">
<a name="gl-interaction-highlight" id="gl-interaction-highlight"></a>

Guideline 1.3 - Provide highlighting for
selection, keyboard focus, enabled elements, visited links.
<span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-interaction-highlight">Implementing
1.3</a>] </span></h3>
<p class="summary" id="summary13"><strong>Summary</strong>: The user can visually distinguish selected, focused, and enabled items, and recently visited links (1.3.1), with a choice of highlighting options that at least include foreground and background colors, and border color and thickness (1.3.2).</p>
<div class="sc-level">
<h4 class="sc-title" id="sc-131">1.3.1 Highlighted Items:</h4>
<p class="sc-text">The user can globally specify that the following be highlighted so that each class is uniquely distinguished. It is not the intention that all recognized enabled elements be uniquely distinguished, just that they be distinguished from disabled elements.  <span class="level">(Level A)</span></p>
<ol type="a">
<li>selection </li>
<li>active keyboard focus (indicated by focus cursors and/or text cursors) </li>
<li>active window </li>
<li>active viewport </li>
<li>recognized enabled elements </li>
<li>presence of alternative content </li>
<li>recently visited links </li>
</ol>


<h4 class="sc-title" id="sc-132">1.3.2 Highlighting Options:</h4>
<p class="sc-text">
 When highlighting classes specified by <a href="#sc-131">1.3.1 Highlighted Items</a> and <a href="#sc-131">1.3.3 Highlighted Input Controls</a>, The user can specify highlighting options that include at least: <span class="level"><span class="level">(Level A)</span> </span></p>
<ul>
  <li><strong class="handle">(a) foreground colors</strong>, </li>
  <li><strong class="handle">(b) background colors</strong>, and </li>
  <li><strong class="handle">(c) border</strong> (configurable color, style, and thickness)</li>
</ul>

<h4 class="sc-title" id="sc-133">1.3.3 Highlighted Input Controls:</h4>
<p class="sc-text">The user can have the following highlighted when they are recognized:
<span class="level">(Level AA)</span> </p>
<ul>
  <li>(a) enabled controls that take input (e.g. push buttons, radio buttons, check boxes, and text input fields, but not groupings or static text and images) regardless of whether they are read-write or read-only, and </li>
  <li>(b) elements with scripted input handlers (e.g. images or text ranges that have onClick or onKeyPress events) regardless of whether the current state allows them to operate.</li>
</ul>

</div>

<h3 class="guideline">
<a name="gl-text-config" id="gl-text-config"></a>

Guideline 1.4 - Provide text configuration.
<span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-text-config">Implementing 1.4</a>] </span></h3>
<p class="summary" id="summary14"><strong>Summary</strong>: The user can control text font, color, and size (1.4.1), including whether all text should be the shown the same size (1.4.2).</p>
<div class="sc-level">
<h4 class="sc-title" id="sc-141">1.4.1 Configure Text: </h4><p class="sc-text"> The
user can globally set the following
characteristics of visually <a class="dfn-instance" href="#def-rendered-text"
title="definition: rendered text">rendered text</a> content, <a
class="dfn-instance" href="#def-override"
title="definition: Override">overriding</a> any specified by the <a
href="#def-author">author</a> or user agent defaults: <span class="level"><span class="level">(Level A)</span> </span> </p>
<ul>
  <li><strong class="handle">(a) text scale</strong> (i.e. the general size
    of text) ,</li>
  <li><strong class="handle">(b) font family</strong>, and</li>
  <li><strong class="handle">(c) text color</strong> (i.e. foreground and
    background).</li>
  </ul>


<h4 class="sc-title" id="sc-142">1.4.2 Preserving
Size Distinctions:</h4><p class="sc-text"> The user can specify whether or not distinctions in the size of <a class="dfn-instance" href="#def-rendered-text"
title="definition: rendered text">rendered text</a> are preserved when that text is rescaled (e.g. headers continue to be larger than body text). <span class="level"><span class="level">(Level A)</span> </span>  </p><br clear="all" class="sc-close" />

</div>
<h3 class="guideline">
<a name="gl-volume-config" id="gl-volume-config"></a>

Guideline 1.5 - Provide volume configuration.
<span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-volume-config">Implementing 1.5</a>] </span></h3>
<p class="summary" id="summary15"><strong>Summary</strong>: The user can adjust the volume of each audio track relative to the global volume level (1.5.1).</p>
<div class="sc-level">
<h4 class="sc-title" id="sc-151">1.5.1 Global Volume:</h4><p class="sc-text">
The user can independently
adjust the volume of all <a class="dfn-instance" href="#def-audio-track"
title="definition: Audio track">audio tracks</a>, relative to the global volume level set
through <a class="dfn-instance" href="#def-operating-environment"
title="definition: Operating environment">operating environment</a> mechanisms. However, the user agent may only override a global mute on explicit user request and if the user has been cautioned about the implication.  <span class="level">(Level A)</span></p><br clear="all" class="sc-close" />


<br clear="all" class="sc-close" />
</div>
<h3 class="guideline">
<a name="gl-speech-config" id="gl-speech-config"></a>

Guideline 1.6 - Provide synthesized speech configuration.
<span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-speech-config">Implementing 1.6</a>] </span></h3>
<p class="summary" id="summary16"><strong>Summary</strong>: <span class="editor-notes">@@ Editors' Note: To be written @@</span></p>
<div class="sc-level">
<h4 class="sc-title" id="sc-161">1.6.1 Speech Rate and Volume: </h4>
<p class="sc-text">If synthesized speech is produced, the user can specify the following: <span class="level"><span class="level">(Level A)</span> </span> </p>
<ul>
  <li><strong class="handle">speech rate</strong> and </li>
  <li><strong class="handle">speech volume</strong> (independently of
    other sources of <a class="dfn-instance" href="#def-audio"
    title="definition: Audio">audio</a>).</li>
</ul>

<h4 class="sc-title" id="sc-162">1.6.2 Speech Pitch and Range:</h4><p class="sc-text"> The user can specify the following for synthesized speech: <span class="level">(Level AA)</span> :</p>
<ul>
  <li><strong class="handle">(a) pitch</strong> ("pitch" refers to the
    average frequency of the speaking voice),  and </li>
  <li><strong class="handle">(b) pitch range</strong> ("pitch range"
    specifies a variation in average frequency),</li>
</ul>
<h4 class="sc-title" id="sc-163">1.6.3 Advanced Speech Characteristics:</h4><p class="sc-text"> The
  user can specify all of the speech characteristics offered by the speech
  synthesizer. <span class="level">(Level AAA)</span> </p><br clear="all" class="sc-close" />


  <h4 class="sc-title" id="sc-164">1.6.4 Synthesized Speech Features:</h4><p class="sc-text"> For synthesized speech, the following features are provided: <span class="level">(Level AA)</span> </p>
  <ul>
  <li><strong class="handle">(a) user-defined extensions</strong> to the
    synthesized speech dictionary,</li>
  <li><strong class="handle">(b) "spell-out"</strong>, where text is spelled
    one character at a time, or according to language-dependent pronunciation
    rules,</li>
  <li><strong class="handle">(c) at least two ways of speaking numerals:
    </strong>one where numerals are spoken as individual digits and punctuation (e.g. &quot;one two zero three point five&quot; for 1203.5 or &quot;one comma two zero three point five&quot; for 1,203.5), and
 one where full numbers are spoken (e.g. &quot;one thousand, two hundred
and three point five").</li>
  <li><strong class="handle">(d) at least two ways of speaking
    punctuation:</strong> one where punctuation is spoken literally, and one
    where punctuation is rendered as natural pauses.</li>
</ul>

</div>

<h3 class="guideline">
<a name="gl-style-sheets-config" id="gl-style-sheets-config"></a>

Guideline 1.7 - Provide style sheets configuration.
<span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-style-sheets-config">Implementing 1.7</a>] </span></h3>
<p class="summary" id="summary17"><strong>Summary</strong>: <span class="editor-notes">@@ Editors' Note: To be written @@</span></p>

<div class="sc-level">
<h4 class="sc-title" id="sc-171">1.7.1 Author Style Sheets:</h4><p class="sc-text">
If one or more <a class="dfn-instance" href="#def-author-styles"
title="definition: Author styles">author  style
sheets</a> are defined, the user has the following options: <span class="level"><span class="level">(Level A)</span> </span> </p>
<ul>
  <li><strong class="handle">(a)</strong> select  and apply one or more author style sheets, or  </li>
  <li><strong class="handle">(b)</strong> turn off  author style sheets.</li>
</ul>

<h4 class="sc-title" id="sc-172">1.7.2 User Style Sheets:</h4><p class="sc-text"> If
one or more  <a href="#def-user-styles">user style
sheets</a> are defined, the user has the following options: <span class="level"><span class="level">(Level A)</span> </span> </p>
<ul>
  <li><strong class="handle">(a)</strong> select and apply one or more user style sheets, or  </li>
  <li><strong class="handle">(b)</strong> turn off  user style sheets.</li>
</ul>

</div>

<h3 class="guideline">
<a name="gl-viewport-orient" id="gl-viewport-orient"></a>

Guideline 1.8 - Help users to use viewports and orient within viewports.
<span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-viewport-orient">Implementing 1.8</a>] </span></h3>
<p class="summary" id="summary18"><strong>Summary</strong>: <span class="editor-notes">@@ Editors' Note: To be written @@</span></p>

<div class="sc-level">
<h4 class="sc-title" id="sc-181">1.8.1 Highlight Viewport:</h4>
<p class="sc-text">The <a class="dfn-instance" href="#def-viewport"
title="definition: viewport">viewport</a> with the <a class="dfn-instance"
href="#def-input-focus" title="definition: input focus">input focus</a> (including nested viewports and their containers) is highlighted, and the user can customize attributes of the <a class="dfn-instance" href="#def-highlight"
title="definition: Highlight">highlighted</a> mechanism, including, but not limited to, shape, size, stroke width, color, and blink rate (if any). <span class="level"><span class="level">(Level A)</span> </span> </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-182">1.8.2 Move Viewport to Selection and Focus: </h4>
<p class="sc-text"> When a viewport's <a class="dfn-instance" href="#def-selection"
title="definition: Selection">selection</a> or <a class="dfn-instance"
href="#def-input-focus" title="definition: input focus">input focus</a> changes, the <a
class="dfn-instance" href="#def-viewport"
title="definition: viewport">viewport</a>'s content moves as necessary to ensure that the new selection or input focus location is at least partially in the visible portion of the viewport. <span class="level">(Level A)</span> </p>
<br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-183">1.8.3 Resizable: </h4>
<p class="sc-text">The user can make graphical viewports
resizable, within the limits of the display, <a class="dfn-instance"
href="#def-override" title="definition: Override">overriding</a> any values
specified by the <a href="#def-author">author</a>. <span class="level"><span class="level">(Level A)</span> </span> </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-184">1.8.4 Scrollbars:</h4><p class="sc-text">Graphical viewports include scrollbars if the rendered content
(including after user preferences have been applied) extends beyond the
viewport dimensions, <a class="dfn-instance" href="#def-override"
title="definition: Override">overriding</a> any values specified by the
author. <span class="level"><span class="level">(Level A)</span> </span> </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-185">1.8.5 Viewport History:</h4><p class="sc-text">  For user agents that implement a viewport history mechanism (e.g. &quot;back&quot; button), the user can return to any state in the viewport history, restoring the prior point of regard, input focus and selection.<span class="level">(Level A)</span></p>
<br clear="all" class="sc-close" />
<h4 class="sc-title" id="sc-186">1.8.6 Open on Request: </h4><p class="sc-text">The user can specify whether or not  <a
href="#def-viewport-toplevel">top-level</a> <a
href="#def-viewport-toplevel">viewports</a> (e.g. windows or tabs) open only with an explicit user request or confirmation.  (Level A)</p>
<br clear="all" class="sc-close" />

<h4 class="sc-title" id="sc-187">1.8.7 Do Not Take Focus:</h4><p class="sc-text">If new <a
href="#def-viewport-toplevel">top-level viewports</a> (e.g. windows or tabs) are configured to open without explicit user request, the user can specify whether or not top-level viewports take the active <a class="dfn-instance" href="#def-keyboard-focus"
title="definition: keyboard focus">keyboard focus</a> when they open.  <span class="level">(Level AA)</span> </p>
<br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-189">1.8.9 Close Viewport: </h4><p class="sc-text">The
user can close any <a
href="#def-viewport-toplevel">top-level viewports</a> (e.g. windows or tabs) . <span class="level">(Level AA)</span> </p>
<br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-1810">1.8.10 Same UI:</h4><p class="sc-text">  The user can specify that all <a
href="#def-viewport-toplevel">top-level viewports</a> (e.g. windows or tabs) follow the current user interface configuration.  <span class="level">(Level AA)</span> </p>
<br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-1811">1.8.11 Indicate Viewport Position:</h4><p class="sc-text"> The user can determine the viewport's position relative to the full extent of the <a class="dfn-instance"
href="#def-rendered-content" title="definition: Rendered content">rendered
content</a>. <span class="level">(Level AA)</span></p>
<br clear="all" class="sc-close" />

</div>

<h3 class="guideline"><a name="gl-focus-mechanism"
id="gl-focus-mechanism"></a>Guideline 1.9 - Provide an effective focus
mechanism.
<span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-focus-mechanism">Implementing 1.9</a>] </span></h3>
<p class="summary" id="summary19"><strong>Summary</strong>:
Understanding and controlling focus is key to successful interaction with a user agent and its content. The overall purpose of Guideline 1.9 is to ensure that the user can reliably identify the focus location. Additional guidance on focus can be found in Guidelines 2.1, 2.2, 2.3, 2.5, 3.4, 4.1 and 4.2.</p>

<div class="sc-level">

<h4 class="sc-title" id="sc-191">1.9.1 User Interface Focus:</h4><p class="sc-text">An <a class="dfn-instance" href="#def-active-input-focus"
title="definition: active input focus">active input focus</a> is
provided. <span class="level"><span class="level">(Level A)</span> </span> </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-192">1.9.2 Extensions Focusable:</h4><p class="sc-text">The <a class="dfn-instance" href="#def-keyboard-focus"
title="definition: keyboard focus">keyboard focus</a> can navigate within extensions to the user
interface. <span class="level">(Level A)</span>  </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-193">1.9.3 Retrieve Focus: </h4>
<p class="sc-text"> At
any time, the user agent can retrieve <a class="dfn-instance" href="#def-input-focus"
title="definition: input focus">input focus</a> from a nested viewport
(including nested viewports that are user agents). <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-194">1.9.4 Return Focus:</h4>
<p class="sc-text">Embedded user agents must support a mechanism for returning <a class="dfn-instance" href="#def-active-input-focus"
title="definition: active input focus">active input focus</a> to the base user agent. <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />

</div>

<h3 class="guideline"><a name="gl-alternative-views" id="gl-alternative-views"></a>

Guideline 1.10 - Provide alternative views.
<span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-alternative-views">Implementing 1.10</a>] </span></h3>
<p class="summary" id="summary110"><strong>Summary</strong>: <span class="editor-notes">@@ Editors' Note: To be written @@</span></p>

<div class="sc-level">
<h4 class="sc-title" id="sc-1101">1.10.1 Text View:</h4><p class="sc-text"> The user can view all <a
class="dfn-instance" href="#def-text-source"
title="definition: text source">text source</a> that is available to the user agent.  <span class="level">(Level AA)</span> </p>
<br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-1102">1.10.2 Outline View:</h4><p class="sc-text"> An
"outline" view of <a class="dfn-instance" href="#def-rendered-content"
title="definition: Rendered content">rendered content</a> is provided,
composed of labels for important structural elements (e.g. heading text,
table titles, form titles, and other labels that are part of the content).
<span class="level">(Level AA)</span> </p>
<p class="sc-note" id="note-1102"><strong>Note:</strong> The outline  constitutes the important structural elements for the user (See 1.10.3). A label is defined by each markup
language specification. For example, in HTML, a heading
(<code>H1</code>-<code>H6</code>) is a label for the section that follows it,
a <code>CAPTION</code> is a label for a table, and the <code>title</code> attribute is a label for its element. </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-1103">1.10.3 Configure Set of Important
Elements:</h4><p class="sc-text"> The user can configure the set of important elements for the hierarchical view, including by element type  (e.g. headers). <span class="level">(Level AAA)</span></p>
<br clear="all" class="sc-close" />

</div>

<h3 class="guideline"><a name="gl-info-link" id="gl-info-link"></a>

Guideline 1.11 - Provide element information.
<span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-info-link">Implementing 1.11</a>] </span></h3>
<p class="summary" id="summary111"><strong>Summary</strong>: <span class="editor-notes">@@ Editors' Note: To be written @@</span></p>

<div class="sc-level">
  <h4 class="sc-title" id="sc-1111">1.11.1 Access Relationships:</h4>
<p class="sc-text"> The user can access explicitly-defined relationships based on the user's position in content (e.g. show form control's label, show label's form control, show a cell's table headers). <span class="level">(Level A)</span> :</p>


  <h4 class="sc-title" id="sc-1112">1.11.2 Extended Link
  Information:</h4>
  <p class="sc-text"> The user agent provides for each link:
<span class="level">(Level AAA)</span> :</p>
<ul class="d">
  <li><strong class="handle">link title</strong></li>
  <li><strong class="handle">technology type</strong> (of the linked <a
    class="dfn-instance" href="#def-web-resource"
    title="definition: Web resource">Web resource</a>)</li>
  <li><strong class="handle">internal/external: </strong> (whether the link
    is internal to the resource e.g. the link is to a target in the same
    Web page)</li>
  </ul>

</div>

<h2 class="principle"><a name="principle-operable"
id="principle-operable"></a>PRINCIPLE 2<a name="gl-keyboard-access"
id="gl-keyboard-access2"></a>. Ensure that the user interface is
operable</h2>

<h3 class="guideline"><a name="gl-keyboard-access"
id="gl-keyboard-access">Guideline 2.1</a> - Ensure full keyboard access. <span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-keyboard-access">Implementing 2.1</a>] </span>
	  </h3>
<p class="summary" id="summary21"><strong>Summary</strong>: <span class="editor-notes">@@ Editors' Note: To be written @@</span></p>

<div class="sc-level">
<h4 class="sc-title" id="sc-211">2.1.1 Keyboard Operation</h4><p class="sc-text">: All
functionality can be operated via the keyboard using sequential or direct
keyboard commands that do not require specific timings for individual
keystrokes, except where the underlying function requires input that depends
on the path of the user's movement and not just the endpoints (e.g. free
hand drawing). This does not forbid and should not discourage providing mouse
input or other input methods in addition to keyboard operation. <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-212">2.1.2 Keyboard Focus<span class="diff-renumber"> (former 1.9.1)</span>: </h4>
<p class="sc-text">Every <a class="dfn-instance" href="#def-viewport" title="definition: viewport">viewport</a>
has an active or inactive <a class="dfn-instance" href="#def-keyboard-focus" title="definition: keyboard focus">keyboard focus</a> at all times. <span class="level"><span class="level">(Level A)</span> </span>  </p>
<br clear="all" class="sc-close" />


  <h4 class="sc-title" id="sc-213">2.1.3 Viewport Navigation<span class="diff-renumber"> (former 1.9.2 &amp; 1.9.4)</span>: </h4>
  <p class="sc-text">The user can move the active <a class="dfn-instance" href="#def-keyboard-focus"
title="definition: keyboard focus">keyboard focus</a> to any <a class="dfn-instance" href="#def-viewport" title="definition: viewport">viewport</a>. <span class="level">(Level A)</span> </p>
  <br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-214">2.1.4 Specify preferred keystrokes:<span class="diff-renumber"> (former 2.1.2)</span></h4>
<p class="sc-text">: The user can override any keyboard shortcut including recognized author supplied shortcuts (e.g. accesskeys) and user interface controls, except for conventional bindings for the operating environment (e.g. arrow keys for navigating within menus). <span class="level">(Level A)</span> </p>
<br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-215">2.1.5 No Keyboard Trap<span class="diff-renumber"> (former 2.1.3)</span></h4>
<p class="sc-text">: The user
agent prevents keyboard traps as follows: <span class="level">(Level A)</span></p>
<ul>
  <li><strong class="handle">(a) in the UI</strong>: if keyboard focus can be
    moved to a component using the keyboard, then focus can be moved away
    from that component using standard sequential keyboard commands (e.g.
    TAB key) </li>
  <li><strong class="handle">(b) in the rendered content</strong>: provides a
    documented direct keyboard command that will always restore keyboard
    focus to a known location (e.g. the address bar). </li>
  <li><strong class="handle">(c) in the rendered content:</strong> provides a
    documented direct keyboard command that will always move keyboard focus
    to a subsequent focusable element</li>
</ul>


<h4 class="sc-title" id="sc-216">2.1.6 Separate Selection from
Activation:<span class="diff-renumber"> (former 2.1.4)</span></h4><p class="sc-text"> The user can specify that selection is separate from activation (e.g. navigating through a set of radio buttons without changing
which is the active/selected option). <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />

<h4 class="sc-title" id="sc-217">2.1.7

 Follow Text Keyboard Conventions<span class="diff-renumber"> (former 2.1.5)</span></h4>
<p class="sc-text">: Views that render text support the standard text area
conventions for the <a class="termdef" href="#def-operating-environment" title="definition: operating environment">operating environment</a>, such as
character keys, Backspace/Delete, Insert, arrow key navigation (e.g.
caret browsing), Page Up/Page Down, navigate to start/end, navigate by
paragraph, shift-to-select mechanism. <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-218">2.1.8

 Make Important Command Functions Efficient<span class="diff-renumber"> (former 2.1.9)</span></h4>
<p class="sc-text">:  Important command functions (e.g. related to navigation, display,   content, information management) are more efficient than sequential   keyboard navigation.  <span class="level">(Level AA)</span></p>


<h4 class="sc-title" id="sc-219">2.1.9

 Allow Override of User Interface Keyboard Commands<span class="diff-renumber"> (former 2.1.10)</span>:</h4>
<p class="sc-text">
The user can override any keyboard shortcut binding for the user agent user
interface except for conventional bindings for the operating environment
(e.g. access to help). The rebinding options must include single-key and
key-plus-modifier keys if available in the operating environment. <span class="level">(Level AA)</span> </p><br clear="all" class="sc-close" />

</div>
<h3 class="guideline"><a name="gl-sequential-navigation"
id="gl-sequential-navigation"></a>Guideline 2.2 - Provide sequential navigation <span class="diff-renumber">[new, includes former 2.1.8 and 1.9.8, and a new SC]</span>  <span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-sequential-navigation">Implementing 2.2</a>] </span>
	  </h3>

<p class="summary" id="summary22"><strong>Summary</strong>: <span class="editor-notes">@@ Editors' Note: To be written @@</span></p>

<h4 class="sc-title" id="sc-221">2.2.1 Sequential Navigation Between  Elements <span class="diff-renumber">[replaces 1.9.8 Bi-Directional and 2.1.8 Keyboard Navigation] </span></h4>
<p class="sc-text">The user can move the keyboard focus backwards and forwards through all recognized enabled elements in the current viewport. (Level A) </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-222">2.2.2 Sequential Navigation Between Viewports<span class="diff-renumber"> [new]</span>:</h4>
<p class="sc-text">The user can move the keyboard focus backwards and forwards between viewports, without having to sequentially navigate all the elements in a viewport. <span class="level">(Level A)</span>  </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-223">2.2.3 Default Navigation Order:<span class="diff-renumber"> (former 1.9.9) </span></h4>
<p class="sc-text">If the author has not specified a navigation order, the default is
<a class="dfn-instance" href="#def-sequential-navigation"
title="definition: sequential navigation">sequential navigation</a>, in
document order. <span class="level">(Level A)</span>  </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-224">2.2.4 Options for Wrapping in Navigation:<span class="diff-renumber"> (new) </span></h4>
<p class="sc-text">The user can have sequential navigation prevent wrapping or can receive feedback when wrapping.  <span class="level">(Level AA)</span>  </p><br clear="all" class="sc-close" />

<h3 class="guideline"><a name="gl-direct-navigation-and-activation"
id="gl-direct-navigation-and-activation"></a>Guideline 2.3 - Provide direct navigation and activation<span class="diff-renumber"> [includes former 2.1.6, 2.1.7, 2.1.11]</span> <span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-direct-navigation-and-activation">Implementing 2.3</a>]</span>
	  </h3>
<p class="summary" id="summary23"><strong>Summary</strong>: <span class="editor-notes">@@ Editors' Note: To be written @@</span></p>

<h4 class="sc-title" id="sc-231">2.3.1 Direct Navigation to Important Elements:<span class="diff-renumber"> (former 2.7.4)</span></h4>
<p class="sc-text">The user can navigate directly to important (structural and operable) elements in rendered content.  <span class="level">(Level A)</span> </p>
<br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-232">2.3.2

Present Direct Commands in Rendered Content<span class="diff-renumber"> (former 2.1.6)</span>:</h4>
<p class="sc-text"> The user can have any      recognized direct commands (e.g. accesskey) in rendered content      be presented with their associated elements. <span class="level">(Level A)</span>  </p>
<br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-233">2.3.3  Direct activation<span class="diff-renumber"> (former 2.7.6)</span></h4>
<p class="sc-text">: The user can move directly to and activate  any operable
elements in rendered content. <span class="level">(Level AA)</span> </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-234">2.3.4 Present Direct Commands in User Interface<span class="diff-renumber"> (former 2.1.7)</span>:</h4>
<p class="sc-text"> The user can have any direct commands (e.g. keyboard shortcuts) in the user agent user interface be      presented with their associated user interface controls (e.g. &quot;Ctrl+S&quot; displayed on the &quot;Save&quot; menu item and toolbar button).      <span class="level">(Level AA)</span> </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-235">2.3.5

 Allow Override of Accesskeys<span class="diff-renumber"> (former 2.1.11)</span></h4><p class="sc-text">: The
user can override any  recognized author supplied content keybinding (i.e. access key). The user must have an option to save the
override of user interface keyboard shortcuts so that the rebinding persists
beyond the current session. <span class="level">(Level AA)</span> </p><br clear="all" class="sc-close" />


<h3 class="guideline"><a name="gl-search-text" id="gl-search-text">Guideline 2.4 <span class="diff-renumber">(former 2.6)</span></a> - Provide text search. <span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-search-text">Implementing </a>] </span>
	  </h3>
<p class="summary" id="summary24"><strong>Summary</strong>: <span class="editor-notes">@@ Editors' Note: To be written @@</span></p>

<div class="sc-level">
<h4 class="sc-title" id="sc-241">2.4.1  Find:</h4><p class="sc-text"> The user can perform a search within rendered content (e.g. not hidden with a style), including text alternatives, for any sequence of characters from the <a class="dfn-instance" href="#def-doc-char-set"
title="definition: Document character set">document character set</a>. <span class="level">(Level A)</span>  </p><br clear="all" class="sc-close" />

<h4 class="sc-title" id="sc-242">2.4.2  Find Direction:</h4><p class="sc-text"> The user can search forward or backward from the focused location in content. The user is  notified of changes in search direction. The user is notified when the search reaches the upper or lower extent of the content based on the search direction. <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-243">2.4.3  Match Found:</h4>
<p class="sc-text"> When there is a match, the user is alerted and the viewport's content moves so that the matched text content is at least partially within it. The user can search for the next instance of the text from the location of the match.

<span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-244">2.4.4  Alert on No Match: </h4><p class="sc-text">The user is
<a href="#def-alert">notified</a> when there is no match or after the last match in content (i.e.
prior to starting the search over from the beginning of content). <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-245">2.4.5  Advanced Find:</h4><p class="sc-text"> The user agent provides an accessible advanced
search facility, with a case-sensitive and case-insensitive search
option, and the ability for the user to perform a search within all
content (including hidden content and captioning) for text and text
alternatives, for any sequence of characters from the document character
set. <span class="level">(Level AA)</span> </p><br clear="all" class="sc-close" />

</div>

<h3 class="guideline"><a name="gl-nav-structure"
id="gl-nav-structure">Guideline 2.5 </a><span class="diff-renumber"> (former 2.7)</span> - Provide structural navigation. <span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-nav-structure">Implementing 2.5</a>] </span>
	  </h3>
<p class="summary" id="summary25"><strong>Summary</strong>: <span class="editor-notes">@@ Editors' Note: To be written @@</span></p>

<h4 class="sc-title" id="sc-251">2.5.1  Discover navigation and activation keystrokes</h4><p class="sc-text">: The user can discover direct navigation and activation keystrokes both
programmatically and via perceivable labels. <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-252">2.5.2  Access Relationships: </h4><p class="sc-text">The user can access  explicitly-defined relationships based on the
user's position in content (e.g. show form control's label, show label's
form control, show a cell's table headers). <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-253">2.5.3  Location in
Hierarchy:</h4><p class="sc-text"> The user can view the path of nodes leading
from the root of any content hierarchy in which the structure and
semantics are implied by presentation, as opposed to an explicit logical
structure with defined semantics (such as the HTML5 Canvas Element), or
as a consequence of decentralized-extensibility (such as the HTML5 item
/ itemprop microdata elements), and only if the user agent keeps an
internal model of the hierarchy that it does not expose via the <a class="dfn-instance"
      href="#def-dom" title="definition: Document Object Model">DOM</a> or
some other accessibility mechanism. <span class="level">(Level A)</span> .</p>
<br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-255">2.5.5  Access to Relationships which Aid Navigation:</h4><p class="sc-text"> The user can access  explicitly-defined relationships based on the user's position in content, and the path of nodes leading from the root of any content hierarchy to that position. <span class="level">(Level AA)</span> </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-257">2.5.7  Configure Set of Important Elements:</h4><p class="sc-text"> The user has the option to
configure the set of <a href="#def-important-elements">important elements</a> for structured navigation, including
by element type (e.g. headers, list items, images). <span class="level">(Level AAA)</span> <span class="editor-notes">@@ Editor's
note: Review the definition of "important elements" @@</span></p><br clear="all" class="sc-close" />


<h3 class="guideline"><a name="gl-device-independent-handlers"
id="gl-device-independent-handlers">Guideline 2.6

</a> <span class="diff-renumber">(former 2.2)</span> - Provide access to event
<span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-device-independent-handlers">Implementing 2.2</a>] </span>
	  </h3>

<p class="summary" id="summary26"><strong>Summary</strong>: <span class="editor-notes">@@ Editors' Note: To be written @@</span></p>

<div class="sc-level">
<h4 class="sc-title" id="sc-261">2.6.1

 List event handlers:</h4><p class="sc-text"> The user can, through keyboard input alone, call up a list of input device <a class="dfn-instance" href="#def-event-handler"
title="definition: event handler">event handlers</a> explicitly associated with the <a class="dfn-instance" href="#def-keyboard-focus"
title="definition: keyboard focus">keyboard focus</a> element. <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />

<h4 class="sc-title" id="sc-262">2.6.2

 Activate any event handler:</h4><p class="sc-text">  The
  user can, through keyboard input alone, <a class="dfn-instance" href="#def-activate"
title="definition: Activate">activate</a> any
  input device <a class="dfn-instance" href="#def-event-handler"
title="definition: event handler">event handlers</a> explicitly
    associated with the
<a class="dfn-instance" href="#def-keyboard-focus"
title="definition: keyboard focus">keyboard focus</a> element. <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />

<h4 class="sc-title" id="sc-263">2.6.3

 Activate all event handlers:</h4><p class="sc-text"> The user can, through keyboard input alone, simultaneously <a class="dfn-instance" href="#def-activate" title="definition: Activate">activate</a> all input device <a class="dfn-instance" href="#def-event-handler" title="definition: event handler">event handlers</a> explicitly associated with the
<a class="dfn-instance" href="#def-content-focus" title="definition: content focus">content focus</a> element. <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />

</div>


<h3 class="guideline"><a name="gl-store-prefs" id="gl-store-prefs">Guideline
2.7 - </a>Configure and store preference settings.</h3>
<p class="summary" id="summary27"><strong>Summary</strong>: <span class="editor-notes">@@ Editors' Note: To be written @@</span></p>

<div class="sc-level">
<h4 class="sc-title" id="sc-271">2.7.1

 Change Preference Settings</h4><p class="sc-text"> The user can change settings that impact accessibility. <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />
<h4 class="sc-title" id="sc-272">2.7.2

 Persistent Accessibility Settings</h4><p class="sc-text">: User agent accessibility preference settings persist between sessions. <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />

 <h4 class="sc-title" id="sc-273">2.7.3

 Restore all to default:</h4><p class="sc-text"> The user can restore all preference settings to  default values. <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />
<h4 class="sc-title" id="sc-274">2.7.4

 Multiple Sets of Preference Settings:</h4><p class="sc-text"> The
user can save and retrieve multiple sets of user agent preference settings.
<span class="level">(Level AA)</span> </p><br clear="all" class="sc-close" />

<h4 class="sc-title" id="sc-275">2.7.5

 Restore related   preferences to default:</h4><p class="sc-text"> The user can restore groups of related   preference settings to  default values (e.g. reset keyboard   shortcuts, reset colors and sizes of rendered content). <span class="level">(Level AA)</span> </p><br clear="all" class="sc-close" />
    <h4 class="sc-title" id="sc-276">2.7.6

 Change preference setting outside the UI:</h4><p class="sc-text"> The user can adjust preference settings from outside the user agent user interface. <span class="level">(Level AA)</span> </p><br clear="all" class="sc-close" />

 <h4 class="sc-title" id="sc-277">2.7.7

 Portable Preference Settings:</h4><p class="sc-text">The user can transfer preference settings across locations onto a compatible system. <span class="level">(Level AAA)</span> </p><br clear="all" class="sc-close" />

 <h4 class="sc-title" id="sc-278">2.7.8

 Preferences Wizard:</h4><p class="sc-text"> A
wizard helps the user to configure the accessibility-related
user agent preferences (at least). <span class="level">(Level AAA)</span> </p><br clear="all" class="sc-close" />

</div>
<h3 class="guideline"><a name="gl-configure-controls"
id="gl-configure-controls">Guideline 2.8 - </a> Provide toolbar
  configuration. <span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-configure-controls">Implementing 2.8</a>] </span>
  </h3>
<p class="summary" id="summary28"><strong>Summary</strong>: <span class="editor-notes">@@ Editors' Note: To be written @@</span></p>

<div class="sc-level">
<h4 class="sc-title" id="sc-281">2.8.1  Configure Position:</h4>
  <p class="sc-text"> When graphical <a class="dfn-instance" href="#def-ua-ui"
title="definition: user agent user interface">user agent user interfaces</a> have toolbars, panels, inspectors, or similar, the user can add, remove and configure the position of <a class="dfn-instance" href="#def-ui-control"
title="definition: user interface control">user agent user interface
      controls</a> from a pre-defined set.  <span class="level">(Level AAA)</span> </p>

<br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-282">2.8.2  Restore Default Toolbars: </h4><p class="sc-text">The
user can restore the default toolbar, panel, or inspector configuration. <span class="level">(Level AAA)</span> </p><br clear="all" class="sc-close" />

</div>

<h3 class="guideline"><a name="gl-time-independent"
id="gl-time-independent">Guideline 2.9</a><span class="diff-renumber"> (former 2.3)</span> - Allow time-independent
interaction. <span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-time-independent">Implementing 2.9</a>] </span>
	  </h3>
<p class="summary" id="summary29"><strong>Summary</strong>: <span class="editor-notes">@@ Editors' Note: To be written @@</span></p>

<div class="sc-level">
<h4 class="sc-title" id="sc-291">2.9.1

 Timing Adjustable</h4><p class="sc-text">:
Where time limits for user input are <a href="#def-recognize">recognized</a>
and controllable by the user agent, the user can extend the time
limit. <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />

</div>
<h4 class="sc-title" id="sc-292">2.9.2   Retrieval Progress:</h4>
<p class="sc-text">
The user agent shows the progress of content retrieval. <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />


<h3 class="guideline"><a name="gl-prevent-flash"
id="gl-prevent-flash"></a>Guideline 2.10<span class="diff-renumber"> (former 2.4)</span> - Help users avoid flashing that could cause seizures. <span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-prevent-flash">Implementing 2.10</a>]</span>
	  </h3>
<p class="summary" id="summary210"><strong>Summary</strong>: <span class="editor-notes">@@ Editors' Note: To be written @@</span></p>

<div class="sc-level">
<h4 class="sc-title" id="sc-2101">2.10.1

 Three Flashes or Below Threshold:</h4><p class="sc-text"> In its default configuration, the user agent does not display any user interface components or recognized content that flashes more than three times in any one-second period, unless the flash is below the general flash and red flash thresholds. <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />

</div>

<div class="sc-level">
<h4 class="sc-title" id="sc-2102">2.10.2

 Three Flashes:</h4><p class="sc-text"> In its default configuration, the user agent does not display any user interface components or recognized content that flashes more than three times in any one-second period (regardless of whether not the flash is below the general flash and red flash thresholds). <span class="level">(Level AAA)</span> [<a
href="http://www.w3.org/TR/WCAG20/#glossary">WCAG 2.0</a>]</p><br clear="all" class="sc-close" />

</div>


<h3 class="guideline"><a name="gl-control-inaccessible-content"
id="gl-control-inaccessible-content">Guideline 2.11 - </a> Provide control of
content that may reduce accessibility. <span class="diff-renumber">(former 2.9)</span> <span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-control-inaccessible-content">Implementing 2.11</a>] </span>
	  </h3>

<p class="summary" id="summary211"><strong>Summary</strong>: <span class="editor-notes">@@ Editors' Note: To be written @@</span></p>

<h4 class="sc-title" id="sc-2111">2.11.1  Background Image
Toggle:</h4><p class="sc-text"> The user has the global option to hide/show <a href="#def-background-images">background images</a>. <span class="level">(Level A)</span> </p>
<br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-2112">2.11.2  Time-Based Media
Load-Only:</h4>
<p class="sc-text"> The user can
load time-based media content <span class="editor-notes">@@ Editors' Note: DEFINE@@</span>
such that a placeholder is displayed, but the content is not
played until <a class="dfn-instance" href="#def-user-request"
title="definition: Explicit user request">explicit user request</a>. <span class="level">(Level A)</span> </p>
<br clear="all" class="sc-close" />

<h4 class="sc-title" id="sc-2113">2.11.3  Execution
Placeholder:</h4><p class="sc-text"> The user can
render a <a href="#def-placeholder">placeholder</a> instead of executable
content that would normally be contained within an on-screen area (e.g.
Applet, Flash), until <a class="dfn-instance" href="#def-user-request"
title="definition: Explicit user request">explicit user request</a> to
execute. <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />
<h4 class="sc-title" id="sc-2114">2.11.4  Execution Toggle:</h4><p class="sc-text"> The
 user can turn on/off the execution
  of executable content that would not normally be contained within a
  particular area (e.g. Javascript). <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />
<h4 class="sc-title" id="sc-2115">2.11.5  Playback Rate Adjustment for Prerecorded Content:</h4>
<p class="sc-text"> The user can adjust the playback rate of prerecorded time-based media  content, such that all of the following are true: <span class="level">(Level A)</span> </p>
<ul>
<li>The user can adjust the playback rate of the <span class="sc-txt">time-based media</span>  tracks to between 50% and 250% of real time. </li>
<li>Speech whose playback rate has been adjusted by the user maintains pitch in order to limit degradation of the speech quality.</li>
<li>Audio and video tracks remain synchronized across this required range of playback rates.</li>
<li>The user agent provides a function that resets the playback rate to normal (100%).</li>
</ul>

<h4 class="sc-title" id="sc-2116">2.11.6  Stop/Pause/Resume
Time-Based Media:</h4><p class="sc-text"> The user can stop, pause, and resume rendered audio and
<a class="dfn-instance" href="#def-animation"
title="definition: Animation">animation</a> content (including video and
animated images) that last three or more seconds at their default playback
rate. <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />

<h4 class="sc-title" id="sc-2117">2.11.7  Navigate Time-Based Media:</h4><p class="sc-text"> The user can navigate along the timebase using a continuous scale, and by relative time units within rendered audio and animations (including video and animated images) that last three or more seconds at their default playback rate. <span class="level">(Level A)</span>
</p><br clear="all" class="sc-close" />

<h4 class="sc-title" id="sc-2118">2.11.8 Semantic Navigation of Time-Based Media:</h4><p class="sc-text"> The user can navigate by semantic structure within the time-based media, such as by chapters or scenes present in the media <span class="level">(Level AA)</span>.</p><br clear="all" class="sc-close" />

<h4 class="sc-title" id="sc-2119">2.11.9 Track Enable/Disable of Time-Based Media:</h4><p class="sc-text"> During time-based media playback, the user can determine which tracks are available and select or deselect tracks. These selections may override global default settings for captions, audio descriptions, etc. <span class="level">(Level AA)</span></p><br clear="all" class="sc-close" />

<h4 class="sc-title" id="sc-21110">2.11.10 Sizing Playback Viewport: </h4>
<p class="sc-text"> The user can adjust the size of the time-based media up to the full height or width of the containing viewport. In doing so, the user can preserve aspect ratio and  adjust the size of the playback viewport to avoid cropping, within the  scaling limitations imposed by the media itself. <span class="level">(Level AA)</span> </p><br clear="all" class="sc-close" />

 <h4 class="sc-title" id="sc-21111">2.11.11  Scale and position alternative media tracks:</h4>
<p class="sc-text"> The user can scale and position alternative media tracks independent of base video. <span class="level">(Level AAA)</span> </p><br clear="all" class="sc-close" />

<h4 class="sc-title" id="sc-21112">2.11.12  Adjust Playback Contrast and Brightness: </h4><p class="sc-text"> User can control the contrast and brightness of the content within the playback viewport. </p><br clear="all" class="sc-close" />


<div class="applic-notes">
<h4 id="app-note-control-video">Applicability Notes:</h4>

<p>The guideline only applies to images, animations, video, audio, etc. that
the user agent can <a href="#def-recognize">recognize</a>. </p>
<p>&nbsp;</p>
<p class="editor-notes">@@ Editors' Note: If the browser is playing the video natively,  there is only 1 user agent. In that case, it falls on the browser to meet the UAAG spec. @@</p>
<p>&nbsp;</p>
<p class="editor-notes">@@ Editors' Note: If an author uses windows media player inside the video element, the browser needs to map its native controls to the embedded wmp controls, and provide access to all the controls. @@</p>
<p>&nbsp;</p>
<p class="editor-notes">@@ Editors' Note: The user needs to be able to define rendering parameters of playback at render-time. @@</p>
</div>

<h2 class="principle"><a name="principle-understandable"
id="principle-understandable"></a>Principle 3: Ensure that the user interface is
understandable</h2>

<h3 class="guideline"><a name="gl-avoid-unnecessary-messages"
id="gl-avoid-unnecessary-messages"></a>Guideline 3.1 - Help users avoid
unnecessary messages. <span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-avoid-unnecessary-messages">Implementing 3.1</a>] </span>
	  </h3>

<p class="summary" id="summary31"><strong>Summary</strong>: <span class="editor-notes">@@ Editors' Note: To be written @@</span></p>

<div class="sc-level">

<p class="editor-notes">@@ Editors' Note: Add SC based on this note from IRC of 10 November 2010: We could consider adding to this section a recommendation that messages have a checkbox that lets the user avoid getting the message again. But I'm not sure how we could write it to have an appropriate scope, that is only apply to messages where it's appropriate. AND when you do have those check boxes, it's also useful to have something in the application's settings that allows the user to reset those to their default, thus making all the messages visible again.@@</p>

<h4 class="sc-title" id="sc-312">3.1.2   Option to Ignore:</h4>
<p class="sc-text"> The
user can turn off rendering of
non-essential or low priority text messages or updating/changing information in the content based on priority properties
defined by the <a href="#def-author">author</a> or the user agent. <span class="level">(Level AA)</span> </p><br clear="all" class="sc-close" />

</div>

<h3 class="guideline"><a name="gl-avoid-mistakes"
id="gl-avoid-mistakes">Guideline 3.2 - </a> Help users avoid and correct
mistakes. <span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-avoid-mistakes">Implementing 3.2</a>] </span>
	  </h3>
<blockquote>
  <p class="summary" id="summary32"><strong>Summary</strong>: <span class="editor-notes">@@ Editors' Note: To be written @@</span></p>
</blockquote>

<div class="sc-level">
  <h4 class="sc-title" id="sc-321">3.2.1   Form Submission:</h4><p class="sc-text"> The user can specify whether or not recognized form submissions must be confirmed. <span class="level">(Level AA)</span> </p>
<br clear="all" class="sc-close" />

</div>

<h3 class="guideline"><a name="gl-doc-access-features"
id="gl-doc-access-features">Guideline 3.3 - </a> Document the user agent user
interface including all accessibility features.<span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-doc-access-features">Implementing 3.3</a>] </span>
	  </h3>
<p class="summary" id="summary33"><strong>Summary</strong>: <span class="editor-notes">@@ Editors' Note: To be written @@</span></p>

<div class="sc-level">
<h4 class="sc-title" id="sc-331">3.3.1   Accessible documentation:</h4>
<p class="sc-text"> The product <a class="termdef" href="#def-documentation" title="definition: documentation">documentation</a> is available in a format that meets success criteria of WCAG 2.0 Level "A" or greater. <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-332">3.3.2   Document Accessibility
Features: </h4><p class="sc-text"> All user agent features
that benefit accessibility  are documented. <span class="level">(Level A)</span> <span class="editor-notes"> @@ Editors' Note: write a definition of &quot;benefit accessibility&quot; - as contributing to conforming to these guidelines or a feature specifically added to improve accessibility @@</span></p><br clear="all" class="sc-close" />

</div>

<div class="sc-level">
<h4 class="sc-title" id="sc-333">3.3.3   Changes Between
Versions: </h4><p class="sc-text"> Changes to features that benefit accessibility since the previous user agent release are documented. <span class="editor-notes">@@Editors' Note: Link to the definition to benefit accessibility from previous 3.3.2 @@</span><span class="level">(Level AA)</span> </p>
<br clear="all" class="sc-close" />

<h4 class="sc-title" id="sc-334">3.3.4 Centralized View: </h4> <p class="sc-text">There is a dedicated section of the documentation that presents a view of all features of the user agent necessary to meet the requirements of User Agent Accessibility Guidelines 2.0. <span class="level">(Level AAA)</span></p>
<br clear="all" class="sc-close" />

<h4 class="sc-title" id="sc-335">3.3.5   Context Sensitive
Help: </h4><p class="sc-text"> There is context-sensitive
help on all user agent features that benefit accessibility. <span class="level">(Level AAA)</span> </p><br clear="all" class="sc-close" />

</div>
<div class="sc-level">
<h3 class="guideline"><a name="gl-predictable-operation" id="gl-predictable-operation"></a>Guideline 3.4 - The user agent must behave in a predictable fashion. <span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-predictable-operation">Implementing 3.4</a>] </span>
	  </h3>
<p class="summary" id="summary34"><strong>Summary</strong>: <span class="editor-notes">@@ Editors' Note: To be written @@</span></p>

<h4 class="sc-title" id="sc-341">3.4.1 Avoid unpredictable focus <span class="diff-renumber">[formerly 3.4.2, before that 5.4.2, and 1.9.10, broadened] </span>:</h4><p class="sc-text"> The user can prevent focus changes that are not a result of explicit user request. <span class="level">(Level A)</span></p><br clear="all" class="sc-close" />

<h4 class="sc-title" id="sc-342">3.4.2   Avoid Side Effects of Navigation<span class="diff-renumber"> [former 1.9.1, before that 3.11.11, changed]</span>:</h4><p class="sc-text"> The user can move the keyboard focus without causing the user agent to take any further action, other than the presentation of information (e.g. scrolling or pop-ups that do not change the focus or selection). <span class="level">(Level A)</span></p>
 <br clear="all" class="sc-close" />

<p class="editor-notes">@@ Editors' Note: Missing: Greater ease in interpreting security messaging. Should be cross-referenced with the security working group. @@</p>
</div>


<h2 class="principle"><a name="principle-AT-access"
id="principle-AT-access"></a>PRINCIPLE 4: Facilitate programmatic access</h2>

<h3 class="guideline"><a name="gl-AT-access" id="gl-AT-access"></a>Guideline 4.1 - <span class="principle">Facilitate
programmatic access to assistive technology </span> <span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-AT-access">Implementing 4.1</a>] </span>
	  </h3>
<p class="summary" id="summary41"><strong>Summary</strong>: Be compatible with assistive technologies by supporting platform standards (4.1.1), including providing information about all menus, buttons, dialogs, etc. (4.1.2, 4.1.6), access to DOMs (4.1.4), and access to structural relationships and meanings, such as what text or image labels a control or serves as a heading (4.1.5). Where something can't be made accessible, provide an accessible alternative version, such as a standard window in place of a customized window (4.1.3). Make sure that that programmatic exchanges are quick and responsive (4.1.7).</p>
<h4 class="sc-title" id="sc-411">4.1.1   Platform Accessibility Architecture:</h4>
<p class="sc-text"> The user agent supports a <a class="termdef"
href="#def-access-platform-arch">platform accessibility architecture</a>
relevant to the <a class="termdef" href="#def-operating-environment" title="definition: operating environment">operating environment</a>. <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-412">4.1.2   Name, Role, State, Value,
Description: </h4>
<p class="sc-text">For all user interface components including  user interface, rendered content, generated content, and alternative content, the user agent makes available the name, role, state, value,
and description via a <a class="termdef"
href="#def-access-platform-arch">platform accessibility architecture</a>. <span class="level">(Level A)</span> </p>
<br clear="all" class="sc-close" />

<h4 class="sc-title" id="sc-413">4.1.3   Accessible
Alternative:</h4>
<p class="sc-text"> If a component of the user agent user interface      cannot be exposed through the platform accessibility      architecture, then the user agent provides an equivalent alternative that is      exposed through the platform accessibility architecture. <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />

<h4 class="sc-title" id="sc-414">4.1.4   Programmatic Availability of
DOMs:</h4><p class="sc-text"> If the user agent implements one or more <a class="dfn-instance"
      href="#def-dom" title="definition: Document Object Model">DOMs</a>, they must be
made programmatically available to assistive technologies. <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-415">4.1.5   Write Access:</h4>
<p class="sc-text"> If the user agent keeps an internal representation of the user content in terms of element structure, relationships between elements, element meaning, or some combination thereof, it must expose this internal representation via an appropriate means (normally by using the platform accessibility architecture or a programmatically available DOM). <span class="level">(Level A)</span></p> <br clear="all" class="sc-close" />

<h4 class="sc-title" id="sc-416">4.1.6   Properties:</h4><p class="sc-text"> If any of
the following properties are supported by the accessibility platform
architecture, make the properties available to the accessibility platform
architecture: <span class="level">(Level A)</span>
</p><ol type="a">
  <li>the bounding dimensions and coordinates of rendered graphical
    objects</li>
  <li>font family of text </li>
  <li>font size of text </li>
  <li>foreground color of text </li>
  <li>background color of text.</li>
  <li>change state/value notifications</li>
  <li>selection</li>
  <li>highlighting</li>
  <li>input device focus</li>
</ol>

<h4 class="sc-title" id="sc-417">4.1.7   Timely Communication:</h4><p class="sc-text">
For APIs implemented to satisfy the requirements      of UAAG 2.0, ensure that programmatic exchanges proceed at      a rate such that users do not perceive a delay. <span class="level">(Level A)</span>  </p><br clear="all" class="sc-close" />


<h3 class="guideline"><a name="gl-nested-UA" id="gl-nested-UA"></a>Guideline 4.2 - <span class="principle">Facilitate programmatic access to nested user agents </span> <span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-nested-UA">Implementing 4.2</a>] </span>
	  </h3>
<p class="summary" id="summary42"><strong>Summary</strong>: <span class="editor-notes">@@ Editors' Note: To be written @@</span></p>

<h4 class="sc-title" id="sc-421">4.2.1 Hand-Off Focus<span class="diff-renumber"> [former 1.9.5]</span>: </h4>
<p class="sc-text">The
user agent programmatically notifies any nested user agent(s) (e.g.
plug-ins) when <a class="dfn-instance" href="#def-active-input-focus"
title="definition: active input focus">active input focus</a> moves to a nested agent. <span class="level">(Level A)</span>  </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-422">4.2.2 Retrieve Focus<span class="diff-renumber"> [former 1.9.6, before that 3.11.6]</span>: </h4>
<p class="sc-text">The
user agent programmatically notifies any nested user agent(s) (e.g.
plug-ins) when <a class="dfn-instance" href="#def-active-input-focus"
title="definition: active input focus">active input focus</a> moves to a nested agent. <span class="level">(Level A)</span>  </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-423">4.2.3 Return Focus<span class="diff-renumber"> [former 1.9.7, before that 3.11.7]</span>: </h4>
<p class="sc-text">At any time, the user agent can retrieve input focus from a   nested viewport (including nested viewports that are user agents). <span class="level">(Level A)</span>  </p>
<br clear="all" class="sc-close" />


<h2 class="principle"><a name="principle-follow-specs"
id="principle-follow-specs"></a>PRINCIPLE 5: Comply with applicable
specifications and conventions</h2>

<h3 class="guideline"><a name="gl-desktop-access"
id="gl-desktop-access"></a> Guideline 5.1 - Ensure that non-Web-based
functionality is accessible.<span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-desktop-access">Implementing 5.1</a>] </span>
	  </h3>
      <p class="summary" id="summary51"><strong>Summary</strong>: The browser's own menus, buttons, dialogs, etc. need to meet any accessibility standards for the operating system.</p>

<div class="sc-level">
<h4 class="sc-title" id="sc-511">5.1.1 Non-Web-Based Accessible
<span class="level">(Level A)</span> : </h4>
<p class="sc-text">Non-Web-based user agent user interfaces comply with and
cite the requirements of standards or <a class="termdef" href="#def-operating-environment" title="definition: operating environment">operating environment</a> conventions that
benefit accessibility. <span class="level">(Level A)</span>  </p>
<br clear="all" class="sc-close" />

</div>

<div class="applic-notes">
<h4 id="app-note-desktop-access">Applicability Notes:</h4>

<p>This guideline does not apply to Web-based user agent user interfaces, but
does include any parts of Web-based user agents that are non-Web-based  (e.g. client-side file uploaders).</p>
</div>

<h3 class="guideline"><a name="gl-obs-env-conventions"
id="gl-obs-env-conventions"></a>Guideline 5.2 - Ensure that Web-based
functionality is accessible. <span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-obs-env-conventions">Implementing 5.2</a>] </span>
	  </h3>
<p class="summary" id="summary52"><strong>Summary</strong>: When the browser's menus, buttons, dialogs, etc. are authored in HTML or similar standards, they need to meet W3C's Web Content Accessibility Guidelines.</p>
<div class="sc-level">
<h4 class="sc-title" id="sc-521">5.2.1 Web-Based Accessible <span class="level">(Level A)</span> : </h4><p class="sc-text">User agent user interfaces that are rendered using Web standard technologies conform to  WCAG Level "A".
<span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />
</div>

<div class="sc-level">
<h4 class="sc-title" id="sc-522">5.2.2 Web-Based Accessible <span class="level">(Level AA)</span> :</h4><p class="sc-text"> User agent user interfaces that are rendered using Web standard technologies conform to WCAG Level
"AA". <span class="level">(Level AA)</span> </p><br clear="all" class="sc-close" />
</div>

<div class="sc-level">
<h4 class="sc-title" id="sc-523">5.2.3 Web-Based Accessible <span class="level">(Level AAA)</span> :</h4><p class="sc-text"> User agent user interfaces that are rendered using Web standard technologies conform to  WCAG Level
"AAA". <span class="level">(Level AAA)</span> </p><br clear="all" class="sc-close" />

</div>

<div class="applic-notes">
<h4 id="app-note-web-access">Applicability Notes:</h4>

<p>This guideline does not apply to non-Web-based user agent user interfaces,
but does include any parts of non-Web-based user agents that are
Web-based (e.g. help systems).</p>
</div>

<h3 class="guideline"><a name="gl-implement-access-features"
class="guideline" id="gl-implement-access-features">Guideline 5.3</a> - Support
accessibility features of technologies. <span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-implement-access-features">Implementing 5.3</a>] </span>
	  </h3>
<p class="summary" id="summary53"><strong>Summary</strong>: Implement the accessibility features of all the technologies you're using, such as supporting the platform's multitasking capabilities and HTML's alt attribute for images. Document your implementation.</p>
<div class="sc-level">
<h4 class="sc-title" id="sc-531">5.3.1 Implement accessibility features of content specs:</h4>
<p class="sc-text">Implement and cite in the conformance claim the accessibility
features of content
specifications. Accessibility features are those that are either <span class="level">(Level A)</span> :</p>
<ul>
  <li>identified as such in the specification or</li>
  <li>allow authors to satisfy a requirement of WCAG.</li>
</ul>

</div>
<div class="sc-level">
<h4 class="sc-title" id="sc-532">5.3.2 Implement Accessibility Features of platform: </h4><p class="sc-text">Implement and cite in the conformance claim the accessibility
features of content and platform <a href="#def-Web-Content-Technology">technology</a>
specifications. Accessibility features are those that are either <span class="level">(Level A)</span> :</p>
<ul>
  <li>identified as such in the specification or</li>
  <li>allow authors to satisfy a requirement of WCAG.</li>
</ul>

</div>
<p class="editor-notes">[@@ Editor's Note: <a href="http://lists.w3.org/Archives/Public/public-uaag2-comments/2011May/0000.html">Suzanne proposed additional SC</a> which are holding on <a href="http://www.w3.org/2011/06/02-ua-minutes.html">action items</a>.  @@]]
</p>
<h3 class="guideline"><a name="gl-render-to-spec"
id="gl-render-to-spec">Guideline 5.4</a> - Render content according to
  specification. <span class="gl-only">[<a href="http://www.w3.org/TR/2011/WD-IMPLEMENTING-UAAG20-20110719/#gl-render-to-spec">Implementing 5.4</a>] </span>
  </h3>
<p class="summary" id="summary54"><strong>Summary</strong>: Render content according to the technology specification, including accessibility features (5.4.1), and let users choose how content types are handled, such as opening embedded images, videos, or documents in separate applications or saving them to disk (5.4.2, 5.4.3).</p>
<div class="sc-level">
<h4 class="sc-title"  id="sc-541">5.4.1 Follow Specifications:</h4>
<p class="sc-text"> The user agent renders <a class="dfn-instance" href="#def-content"
title="definition: Content">content</a> according to the <a
href="#def-Web-Content-Technology">technology</a> specification, except where it would actually harm overall accessibility.

<span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-542">5.4.2 Handle Unrendered
Technologies:</h4>
<p class="sc-text"> If the <a href="#def-user-agent">user agent</a> does
not render a technology, the user can choose a way to handle content
in that technology (e.g. by launching another application or by saving it to
disk). <span class="level">(Level A)</span> </p><br clear="all" class="sc-close" />


<h4 class="sc-title" id="sc-543">5.4.3 Alternative content handlers: </h4>
<p class="sc-text"> The user can select content elements and have them rendered in alternative viewers. <span class="level">(Level AA)</span> </p><br clear="all" class="sc-close" />

</div>

<div class="applic-notes">
<h4 id="app-note-render-to-spec">Applicability Note:</h4>

<p>When a rendering requirement of another specification contradicts a
requirement of UAAG 2.0, the user agent may disregard the rendering
requirement of the other specification and still satisfy this guideline.</p>
</div>

<h2><a name="conformance" id="conformance"></a>Conformance</h2>

<p>This section is normative.</p>
<p>Conformance means that the user agent satisfies the success criteria
defined in the guidelines section. This conformance section describes
conformance and lists the conformance requirements.</p>
<h3><a name="conformance-require" id="conformance-require"></a>Conformance Requirements</h3>
<p>  In order for a Web page to conform to UAAG 2.0, one of the following levels of conformance is met
  in full.</p>
 <ul>
  <li>Level A: For Level A conformance (the minimum level of conformance), the
  user agent satisfies all the Level A Success Criteria.</li>
  <li>Level AA: For Level AA conformance, the user agent satisfies all the
  Level A and Level AA Success Criteria.</li>
  <li>Level AAA: For Level AAA conformance, the user agent satisfies all the
  Level A, Level AA and Level AAA Success Criteria.</li>
</ul>
<p>  Note 1: Although conformance can only be achieved at the stated levels,
  developers are encouraged to report (in their claim) any progress toward
  meeting success criteria from all levels beyond the achieved level of
  conformance. </p>
 <h3><a name="conformance-claims" id="conformance-claims"></a>Conformance Claims (Optional)</h3>
<p>If a conformance claim is made,  the conformance claim must meet the
following conditions and include the following information (user agents
can conform to UAAG 2.0 without making a claim):</p>
<h3><a name="conformance-conditions" id="conformance-conditions"></a>Conditions on Conformance Claims</h3>
<ul>
<li>At least one version of the conformance claim must be published on the
web as a document meeting level "A" of WCAG 2.0. A suggested metadata
description for this document is "UAAG 2.0 Conformance Claim".</li>
<li>Whenever the claimed conformance level is published (e.g. product
information website), the URI for the on-line published version of the
conformance claim must be included. </li>
<li>The existence of a conformance claim does not imply that the W3C has
reviewed the claim or assured its validity. </li>
<li>Claimants may be anyone (e.g. user agent developers, journalists, other
third parties).</li>
<li>Claimants are solely responsible for the accuracy of their claims
(including claims that include products for which they are not
responsible) and keeping claims up to date.</li>
<li>Claimants are encouraged to claim conformance to the most recent version
of the User Agent Accessibility Guidelines Recommendation. </li>
</ul>
<h3><a name="conformance-req-components" id="conformance-req-components"></a>Required Components of an UAAG 2.0 Conformance Claim</h3>
<ol>
<li>Claimant name and affiliation.</li>
<li>Date of the claim. </li>
<li>Conformance level satisfied.</li>
<li>User agent information: The name of the user agent and sufficient
additional information to specify the version (e.g. vendor name,
version number (or version range), required patches or updates, human
language of the user interface or documentation). <br />

Note: If the user agent is a collection of software components (e.g. a
browser and extentions or plugins), then the name and version information   must be provided
separately for each component, although the conformance claim will treat
them as a whole. As stated above, the Claimant has sole responsibility
for the conformance claim, not the developer of any of the software
components.</li>
<li>Included Technologies: A list of the web content technologies
(including version numbers) rendered by the user agent that the Claimant
is including in the conformance claim. By including a web content
technology, the Claimant is claiming that the user agent meets the
requirements of UAAG 2.0 during the rendering of web content using that
web content technology. <br />
Note 1: Web content technologies may be a combination of constituent web
content technologies. For example, an image technology (e.g. PNG) might
be listed together with a markup technology (e.g. HTML) since web
content in the markup technology is used make web content in the image
technology accessible (e.g. a PNG graph is made accessible using an
HTML table).</li>
<li>Excluded Technologies: A list of any web content technologies produced
by the the user agent that the Claimant is excluding from the
conformance claim. The user agent is not required to meet the
requirements of UAAG 2.0 during the production of the web content
technologies on this list.</li>
<li>Declarations: For each success criterion:
A declaration of whether or not the success criterion has been
satisfied; or <br />
A declaration that the success criterion is not applicable and a
rationale for why not.</li>
<li>Platform(s): The platform(s) upon which the user agent was evaluated:
For user agent platform(s) (used to evaluate web-based user agent user
interfaces): provide the name and version information of the user agent(s).
For platforms that are not user agents (used to evaluate non-web-based
user agent user interfaces) provide: The name and version information of
the platform(s) (e.g. operating system, etc.) and the the name and
version of the platform accessibility architecture(s) employed.</li>
</ol>
<h3><a name="conformance-opt-components" id="conformance-opt-conponents"></a>Optional Components of an UAAG 2.0 Conformance Claim</h3>
<p>A description of how the UAAG 2.0 success criteria were met where this
may not be obvious. </p>
<h3><a name="conformance-progress" id="conformance-progress"></a>"Progress Towards Conformance" Statement</h3>
<p>Developers of user agents that do not yet conform fully to a particular
UAAG 2.0 conformance level are encouraged to publish a statement on
progress towards conformance. The progress statement is the same as a
conformance claim except an UAAG 2.0
conformance level that is being progressed towards, rather than one
already satisfied, and report  progress on success criteria not yet
met. Authors of  "Progress Towards Conformance" Statement are solely
responsible for the accuracy of their statements. Developers are
encouraged to provide expected timelines for meeting outstanding success
criteria within the Statement. </p>
<h3><a name="conformance-disclaimer" id="conformance-disclaimer"></a>Disclaimer</h3>
<p>Neither W3C, WAI, nor UAWG take any responsibility for any aspect or
result of any UAAG 2.0 conformance claim that has not been published
under the authority of the W3C, WAI, or UAWG. </p>


<h2><a name="glossary" id="glossary">Appendix A: Glossary</a></h2>

<p>This glossary is <a class="dfn-instance" href="#def-normative"
title="definition: Normative">normative</a>.</p>

<div class="noprint">
<map name="navbar-glossary" class="navbar" id="navbar-glossary">
  <p><a href="#a">a</a> · b · <a href="#c">c</a> · <a href="#d">d</a> ·
  <a href="#e">e</a> · <a href="#f">f</a> · <a href="#g">g</a> · <a
  href="#h">h</a> · <a href="#i">i</a> · j · k · l · m · <a
  href="#n">n</a> · <a href="#o">o</a> · <a href="#p">p</a> · q · <a
  href="#r">r</a> · <a href="#s">s</a> · <a href="#t">t</a> · <a
  href="#u">u</a> · <a href="#v">v</a> · <a href="#w">w</a> · x · y ·
  z</p>
</map>
</div>
<dl id="term-list">
  <dt><a name="a" id="a"></a><dfn>accelerator key</dfn></dt>
  <dd>see <a href="#def-accelerator-key"><dfn>keyboard command</dfn></a></dd>
  <dt class="glossary"><a name="def-activate"
  id="def-activate"><dfn>activate</dfn></a></dt>
  <dd class="glossary">To carry out the behaviors associated
      with an <a class="dfn-instance" href="#def-enabled-element"
      title="definition: Enabled element">enabled element</a> in the rendered
      content or a component of the <a class="dfn-instance" href="#def-ua-ui"
      title="definition: user agent user interface">user agent user
      interface</a>.</dd>
  <dt><dfn>active input focus</dfn></dt>
  <dd>see <a href="#def-focus"><dfn>focus</dfn></a></dd>
  <dt><dfn>active selection</dfn></dt>
  <dd>see <a href="#def-focus"><dfn>focus</dfn></a></dd>
  <dt class="glossary"><a name="def-conditional-content"
  id="def-conditional-content"><dfn>alternative content</dfn></a></dt>
    <dd><a href="#def-content"
      title="definition: Content">Content</a> that can be used in place of default content that may not be universally accessible. Alternative content fulfills  the same purpose as the original content. Examples include text alternatives for non-text content, captions for audio, audio descriptions for video, sign language for audio, media alternatives for time-based media. See <a href="http://www.w3.org/TR/WCAG20/">WCAG</a> for more information. </dd>
  <dt class="glossary"><a name="def-conditional-content-stack"
  id="def-conditional-content-stack"></a><dfn>alternative content
  stack</dfn></dt>
  <dd class="glossary">A set of <a
      href="#def-conditional-content">alternative content</a> items. The items may be mutually exclusive (e.g.
      regular contrast graphic vs. high contrast graphic) or non-exclusive
      (e.g. caption track that can play at the same time as a sound
    track).</dd>
  <dt class="glossary"><a name="def-animation"
  id="def-animation"><dfn>animation</dfn></a></dt>
    <dd class="glossary">Graphical <a href="#def-content"
      title="definition: Content">content</a> rendered to automatically change over time,  giving the user a visual perception of movement. Examples include video, animated images, scrolling text, programmatic animation (e.g. moving or replacing rendered objects). </dd>
  <dt class="glossary">&nbsp;</dt>
  <dt class="glossary"><a name="def-api" id="def-api"><dfn>application
  programming interface (API)</dfn></a>, <a name="def-conventional-io-api"
  id="def-conventional-io-api"><dfn>(conventional input/output/device
  <acronym>API</acronym></dfn></a>)</dt>
    <dd class="glossary">An application programming interface (<acronym
      title="application programming interface">API</acronym>) defines how
    communication may take place between applications.</dd>
  <dt class="glossary"><a name="def-assistive-technology"
  id="def-assistive-technology"><dfn>assistive technology</dfn></a></dt>
    <dd class="glossary">An assistive
      technology:
      <ol>
        <li>relies on services (such as retrieving <a class="dfn-instance"
          href="#def-web-resource" title="definition: Web resource">Web
          resources</a> and parsing markup) provided by one or more other
          "host" user agents. Assistive technologies communicate data and
          messages with host user agents by using and monitoring <a
          class="dfn-instance" href="#def-api"
          title="definition: Application Programming Interface (API)">APIs</a>.</li>
        <li>provides services beyond those offered by the host user agents to
          meet the requirements of users with disabilities. Additional
          services include alternative renderings (e.g. as synthesized
          speech or magnified content), alternative input methods (e.g.
          voice), additional navigation or orientation mechanisms, and
          content transformations (e.g. to make tables more accessible).</li>
      </ol>
      <p>Examples of assistive technologies that are important in the context
      of UAAG 2.0 include the following:</p>
      <ul>
        <li>screen magnifiers, which are used by people with visual
          disabilities to enlarge and change colors on the screen to improve
          the visual readability of rendered text and images.</li>
        <li>screen readers, which are used by people who are blind or have
          reading disabilities to read textual information through
          synthesized speech or braille displays.</li>
        <li>voice recognition software, which are used by some people who have
          physical disabilities to simulate the keyboard and mouse.</li>
        <li>alternative keyboards, which are used by some people with
          physical disabilities to simulate the keyboard and mouse.</li>
        <li>alternative pointing devices, which are used by some people with
           physical disabilities to simulate mouse pointing and button
          activations.</li>
      </ul>
    </dd>
  <dd class="glossary">Beyond UAAG 2.0, assistive technologies consist
      of software or hardware that has been specifically designed to assist
      people with disabilities in carrying out daily activities. These
      technologies include wheelchairs, reading machines, devices for
      grasping, text telephones, and vibrating pagers. For example, the
      following very general definition of "assistive technology device"
      comes from the (U.S.) Assistive Technology Act of 1998 <cite><a
      href="#ref-AT1998"
      title="Link to reference AT1998">[AT1998]</a></cite>:

      <blockquote>
        <p>Any item, piece of equipment, or product system, whether acquired
        commercially, modified, or customized, that is used to increase,
        maintain, or improve functional capabilities of individuals with
        disabilities.</p>
      </blockquote>
  </dd>
  <dt class="glossary"><a name="def-audio"
  id="def-audio"><dfn>audio</dfn></a></dt>
    <dd class="glossary">The technology of sound reproduction. Audio can be created synthetically (including speech synthesis), streamed from a live source (such as a radio broadcast), or recorded from real world sounds.</dd>
  <dt class="glossary">&nbsp;</dt>
  <dt class="glossary"><a name="def-audio-description"
  id="def-audio-description"><dfn>audio description</dfn></a> - (described video, video description or descriptive narration)</dt>
    <dd>An equivalent alternative that takes the form of narration added to
      the <a href="#def-audio">audio</a> to describe important visual details
      that cannot be understood from the main soundtrack alone. Audio
      description of video provides information about actions, characters,
      scene changes, on-screen text, and other visual content. In standard
      audio description, narration is added during existing pauses in
      dialogue. In <a id="def-Auditory-Description-Extended"
      name="def-Auditory-Description-Extended"><dfn>extended audio
      description</dfn>, </a>the video is paused so that there is time to add
      additional description.</dd>
  <dt><dfn><a id="def-author" name="def-author"></a>authors</dfn></dt>
    <dd>The people who have worked either alone or collaboratively to create
      the content (e.g. content authors, designers, programmers,
      publishers, testers).</dd>
  <dt><a name="def-author-styles" id="def-author-styles"
  class="glossary"><dfn>author styles</dfn></a></dt>
    <dd class="glossary"><a class="dfn-instance"
      href="#def-Properties-and-Values"
      title="definition: Properties, values, and defaults">Style property
      values</a> that are set by the author as part of the <a href="#def-content"
      title="definition: Content">content</a>. </dd>
  <dt><a name="def-background-images"
  id="def-background-images"></a>background images</dt>
    <dd class="sc-txt">Images that are rendered on the <a
      class="dfn-instance" href="#def-base-background"
      title="definition: Base Background">base background</a>.</dd>
  <dt><a name="def-base-background" id="def-base-background"></a><dfn>base
  background</dfn></dt>
    <dd>The background of the content as a whole, such that
      no content may be layered behind it. In graphics applications, the base
      background is often referred to as the canvas.).</dd>
  <dt><a name="def-blinking-text" id="def-blinking-text"></a><dfn>blinking
  text</dfn></dt>
    <dd>Text whose visual rendering alternates between visible and invisible
      at any rate of change.</dd>
  <dt class="glossary"><a name="c" id="c"></a><a name="def-captions"
  id="def-captions"><dfn>captions</dfn></a> (caption)</dt>
    <dd>An equivalent alternative that takes the form of text presented and synchronized with <em>time-based</em> media to provide not only the speech, but also non-speech information  conveyed through sound, including meaningful sound effects and  identification of speakers. In some
      countries, the term "subtitle" is used to refer to dialogue only and
      "captions" is used as the term for dialogue plus sounds and speaker
      identification. In other countries, "subtitle" (or its translation) is
      used to refer to both. <dfn>Open captions</dfn> are captions that are
      always rendered with a visual track; they cannot be turned off.
      <dfn>Closed captions</dfn> are captions that may be turned on and off.
      The captions requirements of UAAG 2.0 assume that the user agent
      can <a class="dfn-instance" href="#def-recognize"
      title="definition: Recognize">recognize</a> the captions as such.<br />
      <strong>Note:</strong> Other terms that include the word "caption" may
      have different meanings in UAAG 2.0. For instance, a "table
      caption" is a title for the table, often positioned graphically above
      or below the table. In UAAG 2.0, the intended meaning of "caption"
      will be clear from context.</dd>
  <dt class="glossary"><a name="def-collated-text-transcript"
  id="def-collated-text-transcript"><dfn>collated text
  transcript</dfn></a></dt>
    <dd class="glossary">A collated text transcript is a <a
      class="dfn-instance" href="#def-text-eq"
      title="definition: text equivalent">text equivalent</a> of a movie or
      other animation. It is the combination of the <a
      class="dfn-instance" href="#def-text-transcript"
      title="definition: Text transcript">text transcript</a> of the <a
      class="dfn-instance" href="#def-audio-track"
      title="definition: Audio track">audio track</a> and the text equivalent
      of the <a class="dfn-instance" href="#def-visual-track"
      title="definition: Visual track">visual track</a>. For example, a
      collated text transcript typically includes segments of spoken dialogue
      interspersed with text descriptions of the key visual elements of a
      presentation (actions, body language, graphics, and scene changes). See
      also the definitions of <a class="dfn-instance"
      href="#def-text-transcript" title="definition: Text transcript">text
      transcript</a> and <a class="dfn-instance"
      href="#def-audio-description"
      title="definition: Audio description">audio description</a>. Collated
      text transcripts are essential for people who are deaf-blind.</dd>
  <dt class="glossary">&nbsp;</dt>
    <dd class="glossary">&nbsp;</dd>
  <dt class="glossary"><a name="def-content"
  id="def-content"><dfn>content (web content)</dfn></a></dt>
    <dd class="glossary">Information and sensory experience to be communicated to the user by means of a user agent, including code or markup that defines the content's structure, presentation, and interactions [adapted from <a href="http://www.w3.org/TR/WCAG20/">WCAG 2.0</a>]
<p><a name="def-empty-content" id="def-empty-content"><dfn>empty
      content</dfn></a> (which may be <a class="dfn-instance"
      href="#def-conditional-content"
      title="definition: Conditional content">alternative content</a>) is
      either a null value or an empty string (e.g. one that is zero
      characters long). For instance, in HTML, <code>alt=""</code> sets the
      value of the <code>alt</code> attribute to the empty string. In some
      markup languages, an element may have empty content (e.g. the
      <code>HR</code> element in HTML).</p>
  </dd>
  <dt><dfn>cursor</dfn></dt>
  <dd>see <a href="#def-focus"><dfn>focus</dfn></a></dd>
<dt><a name="d" id="d"></a><dfn>default</dfn></dt>
  <dd>see <a href="#def-Properties-and-Values"><dfn>properties</dfn></a></dd>
   <dt class="glossary"><a name="def-direct-command" id="def-direct-command"></a><dfn>direct command</dfn>, <a name="def-direct-navigation" id="def-direct-navigation"></a><dfn>direct navigation command</dfn>, <a name="def-direct-activation" id="def-direct-activation"></a><dfn>direct activation command</dfn>, <a name="def-linear-navigation" id="def-linear-navigation"></a><dfn>linear navigation command</dfn>
   , <a name="def-spacial-command" id="def-spacial-command"></a><dfn>spacial (directional) command</dfn>, <a name="def-structural-navigation" id="def-structural-navigation"></a><dfn>structural navigation command</dfn></dt>
   <dd>direct navigation commands move focus to a specified item regardless of which currently has the focus</dd>
   <dd>direct activation commands activate a specified item regardless of which currently has the focus; they may move the focus to the item before immediately activating it</dd>
   <dd>linear navigation commands (sometimes called logical or sequential navigation commands) move forwards and backwards through a list of items</dd>
   <dd>structural navigation commands move forwards, backwards, up and down a hierarchy</dd>
   <dd>spatial commands (sometimes called directional commands), require the user to be cognizant of the spatial arrangement of items on the screen:
      <ul><li>spatial navigation commands move from one item to another based on direction on the screen</li>
          <li>spatial manipulation commands resize or reposition an item on the screen</li></ul></dd>
<dt class="glossary">
  <a name="def-doc-char-set" id="def-doc-char-set"><dfn>document character set</dfn></a></dt>
  <dd class="glossary">The internal representation of data in the source content by a user agent.</dd>
  <dt class="glossary">
  <a name="def-document-object"
  id="def-document-object"><dfn>document object</dfn></a>, <a name="def-dom"
  id="def-dom"><dfn>(Document Object Model</dfn></a>, <acronym title="Document Object Model">DOM</acronym>)</dt>
  <dd class="glossary">The Document Object Model is a platform- and language-neutral interface that allows programs and scripts to dynamically access and update the content, structure and style of documents. The document can be further processed and the results of that processing can be incorporated back into the presented page. This is an overview of DOM-related materials here at W3C and around the web:
      <a href="http://www.w3.org/DOM/#what">http://www.w3.org/DOM/#what</a>.</dd>
  <dt class="glossary"><a name="def-document-source"
  id="def-document-source"><dfn>document source</dfn></a>, <a
  name="def-text-source" id="def-text-source"><dfn>(text source)</dfn></a></dt>
    <dd class="glossary">Text the user agent renders upon user request to view the source of  specific viewport content (e.g. selected content, frame, page).</dd>
  <dt class="glossary"><a name="def-documentation"
  id="def-documentation"><dfn>documentation</dfn></a></dt>
    <dd class="glossary">Any information that supports the use of a user agent. This information  may be found, for example, in manuals, installation instructions, the  help system, and tutorials. Documentation may be distributed (e.g. as  files installed as part of the installation, some parts may be  delivered on CD-ROM, others on the Web). See <a
      href="#gl-doc-access-features">guideline 5.3</a> for information about
      documentation.</dd>
  <dt class="glossary"><a name="e" id="e"></a><a name="def-element"
  id="def-element"><dfn>element</dfn></a>, <a name="def-element-type"
  id="def-element-type"><dfn>element type</dfn></a></dt>
    <dd class="glossary">UAAG 2.0 uses the terms "element" and "element
      type" primarily in the sense employed by the XML 1.0 specification
      (<cite><a href="#ref-XML"
      title="Link to reference XML">[XML]</a></cite>, section 3): an element
      type is a syntactic construct of a document type definition (DTD) for
      its application. This sense is also relevant to structures defined by
      XML schemas. UAAG 2.0 also uses the term "element" more generally
      to mean a type of content (such as video or sound) or a logical
      construct (such as a header or list).</dd>
  <dt><dfn>empty content </dfn></dt>
  <dd>see <a href="#def-content"><dfn>content</dfn></a></dd>
  <dt class="glossary"><a name="def-enabled-element"
  id="def-enabled-element"><dfn>enabled element</dfn></a>, <a
  name="def-disabled-element" id="def-disabled-element"><dfn>disabled
  element</dfn></a></dt>
    <dd class="glossary">
    An <a href="#def-element">element</a> with associated behaviors that can be activated through the user interface or through an <a
      class="dfn-instance" href="#def-api"
      title="definition: Application Programming Interface (API)">API</a>. The set of elements that a user agent enables is generally derived from, but is not limited to, the set of <a class="dfn-instance"
      href="#def-element"
      title="definition: Interactive element">elements</a>  defined by implemented markup languages. A disabled element is a potentially enabled element that is not currently available for activation (e.g. a "grayed out" menu item).</dd>
  <dt class="glossary"><a name="def-equivalent"
  id="def-equivalent"><dfn>equivalent alternative</dfn></a></dt>
  <dd class="glossary">Acceptable substitute content that a user may not be able to access. An equivalent alternative fulfills essentially the same function or purpose as the original content upon presentation:
    <ul>
    <li>text alternative: text that is available via the <a class="termdef" href="#def-operating-environment" title="definition: operating environment">operating environment</a> that is used in place of non-text content (e.g. text equivalents for images, text transcripts for audio tracks, or collated text transcripts for a movie). [from <a href="http://www.w3.org/TR/WCAG20/">WCAG 2.0</a>]</li>
    <li>full text alternative for synchronized media including any interaction: document including correctly sequenced text descriptions of all visual settings, actions, speakers, and non-speech sounds, and transcript of all dialogue combined with a means of achieving any outcomes that are achieved using interaction (if any) during the synchronized media. [from <a href="http://www.w3.org/TR/WCAG20/">WCAG 2.0</a>]</li>
    <li>synchronized alternatives: present essential audio information visually (i.e. captions) and essential video information in an auditory manner (i.e. audio descriptions).
    [from <a href="http://www.w3.org/TR/ATAG20/">ATAG 2.0</a>] </li>
    </ul>
  </dd>
  <dt class="glossary"><a name="def-event" id="def-event"><dfn>events and
  scripting, event handler, event type</dfn></a></dt>
    <dd class="glossary">User agents often perform a task when an event
      having a particular "event type" occurs, including a user interface
      event, a change to content, loading of content, or a request from the
      <a class="dfn-instance" href="#def-operating-environment"
      title="definition: Operating environment">operating environment</a>.
      Some markup languages allow authors to specify that a script, called an
      <a name="def-event-handler" id="def-event-handler"><dfn>event
      handler</dfn></a>, be executed when an event of a given type occurs. An
      event handler is <a name="def-explicit-handler"
      id="def-explicit-handler"><dfn>explicitly associated with an
    element</dfn></a> through scripting, markup or the <a href="#def-dom"
 ><acronym title="Document Object Model">DOM</acronym></a>. </dd>
    <dt class="glossary"><a name="def-user-request"
  id="def-user-request"><dfn>explicit user request</dfn></a></dt>
    <dd class="glossary">An interaction by the user through the <a class="dfn-instance"
      href="#def-ua-ui" title="definition: user agent user interface">user
      agent user interface</a>, the <a
      class="dfn-instance" href="#def-focus"
      title="definition: Focus">focus</a>, or the <a class="dfn-instance"
      href="#def-selection" title="definition: Selection">selection</a>. User requests are made, for example, through <a class="dfn-instance"
      href="#def-ui-control" title="definition: user interface control">user
  agent user interface controls</a> and <a href="#def-keyboard-command" title="definition: keyboard command">keyboard commands</a>. Some examples of explicit user requests include when the user selects "New viewport," responds "yes" to a prompt in the user agent's user interface, configures the user agent to behave in a certain way, or changes the selection or focus with the keyboard or pointing device. <strong>Note:</strong> Users can make errors when interacting with the user agent. For example, a user may inadvertently respond "yes" to a prompt instead of "no." This type of error is  considered an explicit user request. </dd>
    <dt class="glossary"><a name="f" id="f"></a><a name="def-current-focus" id="def-current-focus"></a><a name="def-content-focus" id="def-content-focus"></a><a name="def-focus"
  id="def-focus"><dfn>focus</dfn></a> (active input focus, active selection, cursor, focus cursor, focusable element, highlight, inactive input focus, inactive selection, input focus, keyboard focus, pointer, pointing device focus, selection, split focus, text cursor)  </dt>
</dl>
<p class="handle"><strong>Hierarchical Summary of some focus terms</strong></p>
<ul><li>Input Focus (active/inactive)
     <ul><li>Keyboard Focus (active/inactive)
         <ul><li> Cursor (active/inactive)
             <ul><li>Focus cursor (active/inactive)</li>
                 <li>Text cursor (active/inactive)</li></ul>
             </li></ul>
         </li>
     <li>Pointing device focus (active/inactive)
     <ul><li>Pointer</li></ul>
     </li>
     </ul>
  </li>
  </ul>
<dl>
  <dt class="glossary"><a name="def-active-input-focus" id="def-active-input-focus"><dfn>active input focus</dfn></a></dt>
  <dd>The <a href="#def-input-focus">input focus</a> location in the active <a href="#def-viewport">viewport</a>. The active focus is in the active viewport, while the inactive input focus  is   the inactive viewport. The <a href="#def-active-input-focus">active input focus</a> is usually visibly indicated. In UAAG 2.0 "active input focus" generally refers to the active keyboard input focus. <span class="editor-notes">@@ Editors' Note: this term is not used in the document other than the glossary.@@</span></dd>
  <dt class="glossary"><a name="def-active-selection" id="def-active-selection"></a><dfn>active selection</dfn></dt>
  <dd>The selection that will currently be affected by a user command, as opposed to selections in other viewports, called inactive selections, which would not currently be affected by a user command. <span class="editor-notes">@@ Editors' Note: this term is not used in the document other than the glossary.@@</span></dd>
  <dt><dfn>conform</dfn></dt>
  <dd>see <a href="#def-support"><dfn>support</dfn></a></dd>
  <dt class="glossary"><a name="def-cursor" id="def-cursor"></a><dfn>cursor</dfn></dt>
  <dd>Visual indicator showing where keyboard input will occur. There are two types of cursors: <a href="#def-focus-cursor">focus cursor</a> (e.g. the dotted line around a button) and <a href="#def-text-cursor">text cursor</a> (e.g. the flashing vertical bar in a text field, also called a 'caret'). Cursors are active when in the active viewport, and inactive when in an inactive viewport. </dd>

 <dt class="glossary"><a name="def-focus-cursor" id="def-focus-cursor"></a><dfn>focus cursor</dfn></dt>
  <dd>Indicator that <a href="#def-highlight">highlights</a> a user interface element to show that it has <a href="#def-keyboard-focus">keyboard focus</a>, e.g. a dotted line around a button, or brightened title bar on a window. There are two types of cursors: focus cursor (e.g. the dotted line around a button) and <a href="">text cursor</a> (e.g. the flashing vertical bar in a text field).</dd>
  <dt class="glossary"><a name="def-focusable-element" id="def-focusable-element"></a><dfn>focusable element</dfn></dt>
  <dd>Any element capable of having <a href="#def-input-focus">input focus</a>, e.g. link, text box, or menu item. In order to be accessible and fully usable, every focusable element should take <a href="#def-keyboard-focus">keyboard focus</a>, and ideally would also take <a href="#def-pointing-device-focus">pointer focus</a>.</dd>
  <dt class="glossary"><a name="def-highlight-focus" id="def-highlight-focus"></a><a name="def-highlight" id="def-highlight"></a><dfn>highlight, highlighted, highlighting</dfn></dt>
  <dd>Emphasis indicated through the user interface. For example, user agents highlight content that is selected,focused, or matched by a search operation. Graphical highlight mechanisms include dotted boxes, changed colors or fonts, underlining, magnification, and reverse video. Synthesized speech highlight mechanisms include alterations of voice pitch and volume (&quot;speech      prosody&quot;). User interface items may also be highlighted, for      example a specific set of foreground and background colors for      the title bar of the active window. Content that is      highlighted may or may not be a <a href="#def-selection">selection</a>.</dd>
  <dt class="glossary"><a name="def-inactive-input-focus" id="def-inactive-input-focus"></a><dfn>inactive input focus</dfn></dt>
  <dd>An input focus location in an inactive viewport such as a background window or pane. The inactive input focus location will become the active input focus location when input focus returns to that viewport. An inactive input focus may or may not be visibly indicated. </dd>
  <dt class="glossary"><a name="def-inactive-selection" id="def-inactive-selection"></a><dfn>inactive selection</dfn></dt>
  <dd>A selection that does not have the <a href="#def-input-focus">input focus</a> and thus does not take input events.</dd>
  <dt class="glossary"><a name="def-input-focus" id="def-input-focus"></a><dfn>input focus</dfn></dt>
  <dd>The place where input will occur if a viewport is active. Examples include keyboard focus and pointing device focus. Input focus can also be active (in the active viewport) or inactive (in an inactive viewport). </dd>
  <dt class="glossary"><a name="def-keyboard-focus" id="def-keyboard-focus"></a><dfn>keyboard focus</dfn></dt>
  <dd>The screen location where keyboard input will occur if a viewport is active. Keyboard focus can be active (in the active viewport) or inactive (in an inactive viewport). </dd>
  <dt class="glossary"><a name="def-pointer" id="def-pointer"></a><dfn>pointer</dfn></dt>
  <dd>Visual indicator showing where pointing device input will occur. The indicator can be moved with a pointing device or emulator such as a mouse, pen tablet, keyboard-based mouse emulator, speech-based mouse commands, or 3-D wand. A pointing device click typically moves the <a href="#def-input-focus">input focus</a> to the pointer location. The indicator may change to reflect different states.When touch screens are used, the "pointing device" is a combination of the touch screen and the user's finger or stylus. On most systems there is no pointer (on-screen visual indication) associated with this type of pointing device. </dd>
  <dt class="glossary"><a name="def-pointing-device-focus" id="def-pointing-device-focus"></a><dfn>pointing device focus</dfn></dt>
  <dd>The screen location where pointer input will occur if a viewport is active. There can be multiple pointing device foci for example when using a screen sharing utility there is typically one for the user's physical mouse and one for the remote mouse. <span class="editor-notes">@@ Editors' Note: this term is not used in the document other than the glossary.@@</span></dd>
  <dt class="glossary"><a name="def-selection" id="def-selection"></a><dfn>selection</dfn></dt>
  <dd>A user agent mechanism for identifying a (possibly empty) range of content that will be the implicit source or target for subsequent operations. The selection may be used for a variety of purposes, including for cut-and-paste operations, to designate a specific element in a document for the purposes of a query, and as an indication of point of regard (e.g. the matched results of a search may be automatically selected). The selection should be <a href="#def-highlight">highlighted</a> in a distinctive manner. On the screen, the selection may be highlighted in a variety of ways, including through colors, fonts, graphics, and magnification. When rendered using synthesized speech, the selection may be highlighted through changes in pitch, speed, or prosody. </dd>
  <dt class="glossary"><a name="def-split-focus" id="def-split-focus"></a><dfn>split focus</dfn></dt>
  <dd>A state when the user could be confused because the input focus is separated from something it is usually linked to, such as being at a different place than the selection or similar highlighting, or has been scrolled outside of the visible portion of the viewport. <span class="editor-notes">@@ Editors' Note: this term is not used in the document other than the glossary.@@</span></dd>
  <dt class="glossary"><a name="def-text-cursor" id="def-text-cursor"></a><dfn>text cursor</dfn></dt>
  <dd>Indicator showing where keyboard input will occur in text (e.g. the flashing vertical bar in a text field, also called a caret).</dd>
  <dt class="glossary"><span class="editor-notes">@@ Editor's Note: Need to find the hrefs to these definitions and fix them. @@</span> </dt>
  <dt class="glossary"><a name="g" id="g"></a><a name="def-global-configuration"></a><dfn>globally, global configuration</dfn></dt>
  	<dd class="editor-notes">@@ Editors' Note: Needs to be written@@</dd>
  <dt class="glossary"><a name="def-graphical"
  id="def-graphical"><dfn>graphical</dfn></a></dt>
    <dd class="glossary">Information (e.g. text, colors, graphics, images, and animations)
      rendered for visual consumption.</dd>
  <dt class="glossary"><a name="h" id="h"></a><dfn>highlight, highlighted, highlighting</dfn></dt>
  <dd>see <a href="#def-highlight-focus"><dfn>focus</dfn></a></dd>
  <dt class="glossary"><a name="i" id="i"></a><a name="def-image"
  id="def-image"><dfn>image</dfn></a></dt>
    <dd class="glossary">Pictorial content that is static (i.e. not moving or changing). See also the definition of <a class="dfn-instance"
      href="#def-animation" title="definition: Animation">animation</a>.</dd>
  <dt><dfn>implement</dfn></dt>
  <dd>see <a href="#def-support"><dfn>support</dfn></a></dd>
  <dt class="glossary"><a name="def-important-elements"
  id="def-important-elements"><dfn>important elements</dfn></a></dt>
    <dd class="glossary">This specification intentionally does not identify
      which "important elements" must be navigable because this will vary by
      specification. What constitutes "efficient navigation" may depend on a
      number of factors as well, including the "shape" of content (e.g.
      sequential navigation of long lists is not efficient) and desired
      granularity (e.g. among tables, then among the cells of a given
      table). Refer to the Implementing document [Implementing UAAG 2.0] for information
      about identifying and navigating important elements. <span class="editor-notes">@@ Editors' Note: Update links</span></dd>
  <dt><dfn>inactive input focus</dfn></dt>
  <dd>see <a href="#def-inactive-input-focus"><dfn>focus</dfn></a></dd>
  <dt><dfn>inactive selection</dfn></dt>
  <dd>see <a href="#def-inactive-selection"><dfn>focus</dfn></a></dd>
  <dt><dfn>informative (non-normative)</dfn></dt>
  <dd>see <a href="#def-informative"><dfn>normative</dfn></a></dd>
  <dt class="glossary"><a name="def-input-configuration"
  id="def-input-configuration"><dfn>input configuration</dfn></a></dt>
    <dd class="glossary">The set of bindings
      between user agent functionalities and <a class="dfn-instance"
      href="#def-user-interface" title="definition: User interface">user
      interface</a> input mechanisms (e.g. menus, buttons, keyboard keys,
      and voice commands). The default input configuration is the set of
      bindings the user finds after installation of the software. Input
      configurations may be affected by author-specified bindings (e.g.
      through the <code>accesskey</code> attribute of HTML 4 <cite><a
      href="#ref-HTML4"
    title="Link to reference HTML4">[HTML4]</a></cite>).</dd>

  <dt><dfn>input focus</dfn></dt>
    <dd>see <a href="#def-input-focus"><dfn>focus</dfn></a></dd>
  <dt class="glossary">&nbsp;</dt>
  <dt class="glossary"><a name="k" id="k"></a><a
  name="def-keyboard-command"
  id="def-keyboard-command"><dfn>keyboard command</dfn></a> (<a
  name="def-keyboard-binding"
  id="def-keyboard-binding"><dfn>keyboard binding</dfn></a>,<a
  name="def-keyboard-shortcut"
  id="def-keyboard-shortcut"><dfn>keyboard shortcuts</dfn></a> or <a
  name="def-accelerator-key"
  id="def-accelerator-key"><dfn>accelerator keys</dfn></a>)</dt>
    <dd>Commands  tied to particular UI controls or application functions, allowing the user to navigate-to or activate them without traversing any intervening controls (e.g. "ctrl"+"S" to save a document). It is sometimes useful to distinguish keyboard commands that are associated with controls that are rendered in the current context (e.g. "alt"+"D" to move focus to the address bar) from those that may be able to activate program functionality that is not associated with any currently rendered controls (e.g. "F1" to open the Help system). Keyboard commands help users accelerate their selections. </dd>
    <dt><dfn>keyboard focus</dfn></dt>
  <dd>see <a href="#def-keyboard-focus"><dfn>focus</dfn></a></dd>
  <dt class="glossary"><a name="n" id="n"></a><a name="def-natural-language"
  id="def-natural-language"><dfn>natural language</dfn></a></dt>
    <dd class="glossary">Natural language is spoken, written, or signed human
      language such as French, Japanese, and American Sign Language. On the
      Web, the natural language of <a class="dfn-instance"
      href="#def-content" title="definition: Content">content</a> may be
      specified by markup or HTTP headers. Some examples include the <a
      href="http://www.w3.org/TR/1999/REC-html401-19991224/struct/dirlang.html#adef-lang"><code>lang</code>
      attribute in <acronym>HTML</acronym> 4</a> (<cite><a href="#ref-HTML4"
      title="Link to reference HTML4">[HTML4]</a></cite> section 8.1), the <a
      href="http://www.w3.org/TR/1998/REC-xml-19980210#sec-lang-tag"><code>xml:lang</code>
      attribute in <acronym>XML</acronym> 1.0</a> (<cite><a href="#ref-XML"
      title="Link to reference XML">[XML]</a></cite>, section 2.12), the <a
      href="http://www.w3.org/TR/1999/REC-html401-19991224/struct/links.html#adef-hreflang"><code>hreflang</code>
      attribute</a> for links in <acronym>HTML</acronym> 4 (<cite><a
      href="#ref-HTML4" title="Link to reference HTML4">[HTML4]</a></cite>,
      section 12.1.5), the HTTP Content-Language header (<cite><a
      href="#ref-RFC2616"
      title="Link to reference RFC2616">[RFC2616]</a></cite>, section 14.12)
      and the Accept-Language request header (<cite><a href="#ref-RFC2616"
      title="Link to reference RFC2616">[RFC2616]</a></cite>, section 14.4).
      See also the definition of <a class="dfn-instance" href="#def-script"
      title="definition: Script">script</a>.</dd>
  <dt><dfn>non-text content (non-text element, non-text equivalent)</dfn></dt>
  <dd>see <a href="#def-text"><dfn>text</dfn></a></dd>
  <dt class="glossary"><a name="def-normative"
  id="def-normative"><dfn>normative</dfn></a>, <a name="def-informative"
  id="def-informative"><dfn>informative (non-normative)</dfn></a> <span
  class="glossary-adapted">[<a
  href="http://www.w3.org/TR/WCAG20/#glossary">WCAG 2.0</a>, ATAG
  2.0]</span></dt>
    <dd class="glossary">What is identified as "normative" is required for <a
      href="#conformance">conformance</a> (noting that one may conform in a
      variety of well-defined ways to UAAG 2.0). What is identified as
      "informative" (or, "non-normative") is never required for
      conformance.</dd>
    <dt class="glossary"><a name="def-alert"
  id="def-alert"><dfn>notify</dfn></a></dt>
    <dd class="glossary">To make the user aware of events or status changes. Notifications can occur within the user agent user interface (e.g. a status bar) or within the content display. Notifications may be passive and not require user acknowledgment, or they may be presented in the form of a prompt requesting a user response (e.g. a confirmation dialog).</dd>
  <dt class="glossary"><a name="o" id="o"></a><a
  name="def-operating-environment"
  id="def-operating-environment"><dfn>operating environment</dfn></a></dt>
    <dd class="glossary">The term "operating environment" refers to the
      environment that governs the user agent's operation, whether it is an
      operating system or a programming language environment such as
    Java.</dd>
  <dt class="glossary"><a name="def-override"
  id="def-override"><dfn>override</dfn></a></dt>
    <dd class="glossary">In UAAG 2.0, the term "override" means that one
      configuration or behavior preference prevails over another. Generally,
      the requirements of UAAG 2.0 involve user preferences prevailing
      over author preferences and user agent default settings and behaviors.
      Preferences may be multi-valued in general (e.g. the user prefers blue
      over red or yellow), and include the special case of two values (e.g.
      turn on or off blinking text content).</dd>
  <dt class="glossary"><a name="p" id="p"></a><a name="def-placeholder"
  id="def-placeholder"><dfn>placeholder</dfn></a></dt>
    <dd class="glossary">A placeholder is content generated by the user agent
      to replace author-supplied content. A placeholder may be generated as
      the result of a user preference (e.g. to not render images) or as <a
      class="dfn-instance" href="#def-repair-content"
      title="definition: Repair content">repair content</a> (e.g. when an
      image cannot be found). A placeholder can be any type of content,
      including text, images, and audio cues. A placeholder should identify
      the technology of the replaced object.
      Placeholders  appear in the alternative content stack. </dd>
  <dt class="glossary"><a name="def-access-platform-arch"
  id="def-access-platform-arch"><dfn>platform accessibility
  architecture</dfn></a></dt>
  <dd>A programmatic interface that is  engineered to enhance
      communication between mainstream software applications and assistive
      technologies (e.g. MSAA, UI Automation, and IAccessible2 for Windows applications,  AXAPI for MacOSX applications, Gnome Accessibility Toolkit API for  Gnome applications, Java Access for Java applications). On some platforms it may be conventional to enhance
      communication further via implementing a <a class="dfn-instance"
      href="#def-dom" title="definition: Document Object Model">DOM</a>.</dd>
  <dt class="glossary"><a name="def-plug-in"
  id="def-plug-in"><dfn>plug-in</dfn></a> <span
  class="glossary-adapted">[ATAG 2.0]</span></dt>
    <dd class="glossary">A plug-in is a program that runs as part of the user
      agent and that is <em>not</em> part of <a class="dfn-instance"
      href="#def-content" title="definition: Content">content</a>. Users
      generally choose to include or exclude plug-ins from their user
    agents.</dd>
  <dt class="glossary"><a name="def-point-of-regard"
  id="def-point-of-regard"><dfn>point of regard</dfn></a></dt>
    <dd class="glossary">The point of regard is the position in <a
      class="dfn-instance" href="#def-rendered-content"
      title="definition: Rendered content">rendered content</a> that the user
      is presumed to be viewing. The dimensions of the point of regard may
      vary. For example, it may be a point (e.g. a moment during an audio
      rendering or a cursor position in a graphical rendering), or a range of
      text (e.g. focused text), or a two-dimensional area (e.g. content
      rendered through a two-dimensional graphical viewport). The point of
      regard is almost always within the viewport, but it may exceed the
      spatial or temporal <a href="#viewport-dimension">dimensions</a> of the
      viewport (see the definition of <a class="dfn-instance"
      href="#def-rendered-content"
      title="definition: Rendered content">rendered content</a> for more
      information about viewport dimensions). The point of regard may also
      refer to a particular moment in time for content that changes over time
      (e.g. an audio-only
      presentation). User agents may determine the point of regard in a
      number of ways, including based on viewport position in content, <a
      class="dfn-instance" href="#def-content-focus"
      title="definition: content focus">keyboard focus</a>, and <a
      class="dfn-instance" href="#def-selection"
      title="definition: Selection">selection</a>. The stability of the point
      of regard is addressed by <span class="editor-notes">[@@ Editors' Note: Need reference here@@].</span></dd>
      <dt><dfn>pointer</dfn></dt>
  <dd>see <a href="#def-pointer"><dfn>focus</dfn></a></dd>
  <dt><dfn>pointing device focus</dfn></dt>
  <dd>see <a href="#def-pointing-device-focus"><dfn>focus</dfn></a></dd>
  <dt class="glossary"><a name="def-profile"
  id="def-profile"><dfn>profile</dfn></a></dt>
    <dd class="glossary">A profile is a named and persistent representation
      of user preferences that may be used to configure a user agent.
      Preferences include input configurations, style preferences, and
      natural language preferences. In <a class="dfn-instance"
      href="#def-operating-environment"
      title="definition: Operating environment">operating environments</a>
      with distinct user accounts, profiles enable users to reconfigure
      software quickly when they log on. Users may share their profiles with
      one another.Platform-independent profiles are useful      for those who use the same user agent on different devices.  </dd>
  <dt class="glossary"><a name="def-prompt"
  id="def-prompt"><dfn>prompt</dfn></a> <span class="glossary-adapted">[ATAG
  2.0]</span></dt>
    <dd>Any user-agent-initiated request for a decision or piece of
      information from a user.</dd>
  <dt class="glossary"><a name="def-Properties-and-Values"
  id="def-Properties-and-Values"><dfn>properties, values, and
  defaults</dfn></a></dt>
    <dd class="glossary">A user agent renders a document by applying
      formatting algorithms and style information to the document's elements.
      Formatting depends on a number of factors, including where the document
      is rendered (e.g. on screen, on paper, through loudspeakers, on a braille
      display,  on a mobile device). Style information (e.g. fonts, colors,
       synthesized speech prosody) may come from the elements themselves
      (e.g. certain font and phrase elements in HTML), from style sheets, or
      from user agent settings. For the purposes of these guidelines, each
      formatting or style option is governed by a property and each property
      may take one value from a set of legal values. Generally in UAAG 2.0, the term "<a
      href="http://www.w3.org/TR/1998/REC-CSS2-19980512/conform.html">property</a>"
      has the meaning defined in CSS 2 (<cite><a href="#ref-CSS2"
      title="Link to reference CSS2">[CSS2]</a></cite>, section 3). A
      reference to "styles" in UAAG 2.0 means a set of style-related
      properties. The value given to a property by a user agent at
      installation is  the property's <a name="default-value"
      id="default-value">default value</a>.</dd>
  <dt class="glossary"><a name="r" id="r"></a><a name="def-recognize"
  id="def-recognize"><dfn>recognize</dfn></a></dt>
    <dd class="glossary">Authors encode information in many ways, including
      in markup languages, style sheet languages, scripting languages, and
      protocols. When the information is encoded in a manner that allows the
      user agent to process it with certainty, the user agent can "recognize"
      the information. For instance, HTML allows authors to specify a heading
      with the <code>H1</code> element, so a user agent that implements HTML
      can recognize that content as a heading. If the author creates a
      heading using a visual effect alone (e.g. just by increasing the font
      size), then the author has encoded the heading in a manner that does
      not allow the user agent to recognize it as a heading. Some requirements of UAAG 2.0 depend on content roles, content
      relationships, timing relationships, and other information supplied by
      the author. These requirements only apply when the author has encoded
      that information in a manner that the user agent can recognize. See the
      section on <a href="#conformance">conformance</a> for more information
      about applicability. User agents will rely heavily on information that the
      author has encoded in a markup language or style sheet language. Behaviors, style, meaning encoded in a <a
      class="dfn-instance" href="#def-script"
      title="definition: Script">script</a>, and markup in an unfamiliar XML
      namespace may not be recognized by the user agent as easily or at all.  </dd>
  <dt class="glossary"><a name="def-rendered-content"
  id="def-rendered-content"><dfn>rendered content</dfn></a>, <a
  name="def-rendered-text" id="def-rendered-text"><dfn>rendered
  text</dfn></a></dt>
    <dd class="glossary">Rendered content is the part of <a
      class="dfn-instance" href="#def-content"
      title="definition: Content">content</a> that the user agent makes
      available to the user's senses of sight and hearing (and only those
      senses for the purposes of UAAG 2.0). Any content that causes an
      effect that may be perceived through these senses constitutes rendered
      content. This includes text characters, images, style sheets, scripts,
      and any other content that, once processed, may be perceived
      through sight and hearing.</dd>
    <dd class="glossary">The term "rendered text" refers to <a
      class="dfn-instance" href="#def-text" title="definition: Text">text</a>
      content that is rendered in a way that communicates information about
      the characters themselves, whether visually or as synthesized
    speech.</dd>
    <dd class="glossary">In the context of UAAG 2.0, <a
      name="def-invisible-content" id="def-invisible-content"><dfn>invisible
      content</dfn></a> is content that is not rendered but that may
      influence the graphical rendering (i.e. layout) of other content.
      Similarly, <a name="def-silent-content"
      id="def-silent-content"><dfn>silent content</dfn></a> is content that
      is not rendered but that may influence the audio rendering of other
      content. Neither invisible nor silent content is considered rendered
      content.</dd>
  <dt class="glossary"><a name="def-repair-content"
  id="def-repair-content"><dfn>repair content</dfn></a>, <a
  name="def-repair-text" id="def-repair-text"><dfn>repair text</dfn></a></dt>
    <dd class="glossary">Content generated by the user agent  to correct an error
      condition. "Repair text" refers to the <a class="dfn-instance"
      href="#def-text" title="definition: Text">text</a> portion of repair
      content. Error conditions that may lead to the generation of
      repair content include:
      <ul>
        <li>Erroneous or incomplete content (e.g. ill-formed markup, invalid
          markup, or missing <a class="dfn-instance"
          href="#def-conditional-content"
          title="definition: Conditional content">alternative content</a>
          that is required by format specification);</li>
        <li>Missing resources for handling or rendering content (e.g. the
          user agent lacks a font family to display some characters, or the
          user agent does not implement a particular scripting language).</li>
      </ul>
      <p>UAAG 2.0 does not require user agents to include repair content
      in the <a class="dfn-instance" href="#def-document-object"
      title="definition: Document object">document object</a>. Repair content
      inserted in the document object should conform to the Web Content
      Accessibility Guidelines 1.0 <cite><a href="#ref-WCAG10"
      title="Link to reference WCAG10">[WCAG10]</a></cite>. For more
      information about repair techniques for Web content and software, refer
      to "Techniques for Authoring Tool Accessibility Guidelines 1.0"
      <cite><a href="#ref-ATAG10-TECHS"
      title="Link to reference ATAG10-TECHS">[ATAG10-TECHS]</a></cite>.</p>
    </dd>
  <dt class="glossary"><a name="s" id="s"></a><a name="def-script"
  id="def-script"><dfn>script</dfn></a></dt>
    <dd class="glossary">In UAAG 2.0, the term "script" almost always
      refers to a scripting (programming) language used to create dynamic Web
      content. However, in guidelines referring to the written (natural)
      language of content, the term "script" is used as in Unicode <cite><a
      href="#ref-UNICODE"
      title="Link to reference UNICODE">[UNICODE]</a></cite> to mean "A
      collection of symbols used to represent textual information in one or
      more writing systems."</dd>
    <dd class="glossary">Information encoded in (programming) scripts may be
      difficult for a user agent to <a class="dfn-instance"
      href="#def-recognize" title="definition: Recognize">recognize</a>. For
      instance, a user agent is not expected to recognize that, when
      executed, a script will calculate a factorial. The user agent will be
      able to recognize some information in a script by virtue of
      implementing the scripting language or a known program library (e.g.
      the user agent is expected to recognize when a script will open a
      viewport or retrieve a resource from the Web).</dd>
  <dt class="glossary"><a name="def-selection-focus"
  id="def-selection-focus"><dfn>selection</dfn></a>, <a
  name="def-current-selection" id="def-current-selection"><dfn>current
  selection</dfn></a></dt>

<dd>see <a href="#def-selection"><dfn>focus</dfn></a></dd>
  <dt class="glossary"><a name="def-serial-access"
  id="def-serial-access"><dfn>serial access</dfn></a>, <a
  name="def-sequential-navigation"
  id="def-sequential-navigation"><dfn>sequential navigation</dfn></a></dt>
    <dd class="glossary"><a href="#viewport-dimension">One-dimensional</a> access to
      rendered content. Some examples of serial access include listening to
      an audio stream or watching a video (both of which involve one temporal
      dimension), or reading a series of lines of braille one line at a time
      (one spatial dimension). Many users with blindness have serial access
      to content rendered as audio, synthesized speech, or lines of braille.
      <p>The expression "sequential navigation" refers to navigation through
      an ordered set of items (e.g. the <a class="dfn-instance"
      href="#def-enabled-element" title="definition: Enabled element">enabled
      elements</a> in a document, a sequence of lines or pages, or a sequence
      of menu options). Sequential navigation implies that the user cannot
      skip directly from one member of the set to another, in contrast to
      direct or structured navigation. Users with blindness or some users
      with a physical disability may navigate content sequentially (e.g. by
      navigating through links, one by one, in a graphical viewport with or
      without the aid of an assistive technology). Sequential navigation is
      important to users who cannot scan rendered content visually for
      context and also benefits users unfamiliar with content. The increments
      of sequential navigation may be determined by a number of factors,
      including element type (e.g. links only), content structure (e.g.
      navigation from heading to heading), and the current navigation context
      (e.g. having navigated to a table, allow navigation among the table
      cells).</p>
      <p>Users with serial access to content or who navigate sequentially may
      require more time to access content than users who use direct or
      structured navigation.</p>
    </dd>
  <dt class="glossary"><a name="def-support"
  id="def-support"><dfn>support</dfn></a>, <a name="def-implement"
  id="def-implement"><dfn>implement</dfn></a>, <a name="def-conform"
  id="def-conform"><dfn>conform</dfn></a></dt>
    <dd class="GLOSSARY">Support, implement,
      and conform all refer to what a developer has designed a user agent
      to do, but they represent different degrees of specificity. A user
      agent "supports" general classes of objects, such as "images" or
      "Japanese." A user agent "implements" a specification (e.g. the PNG
      and SVG image format specifications or a particular scripting
      language), or an <a class="dfn-instance" href="#def-api"
      title="definition: Application Programming Interface (API)">API</a>
      (e.g. the DOM API) when it has been programmed to follow all or part
      of a specification. A user agent "conforms to" a specification when it
      implements the specification <em>and</em> satisfies its conformance
      criteria.</dd>
  <dt class="glossary"><a name="def-synchronize"
  id="def-synchronize"><dfn>synchronize</dfn></a></dt>
    <dd class="GLOSSARY">The act
      of time-coordinating two or more presentation components (e.g. a <a
      class="dfn-instance" href="#def-visual-track"
      title="definition: Visual track">visual track</a> with captions, or
      several tracks in a multimedia presentation). For Web content
      developers, the requirement to synchronize means to provide the data
      that will permit sensible time-coordinated rendering by a user agent.
      For example, Web content developers can ensure that the segments of
      caption text are neither too long nor too short, and that they map to
      segments of the visual track that are appropriate in length. For user
      agent developers, the requirement to synchronize means to present the
      content in a sensible time-coordinated fashion under a wide range of
      circumstances including technology constraints (e.g. small text-only
      displays), user limitations (e.g. slow reading speeds, large font sizes,
      high need for review or repeat functions), and content that is
      sub-optimal in terms of accessibility.</dd>
  <dt><a name="t" id="t"></a><a id="def-Web-Content-Technology"
  name="def-Web-Content-Technology"><dfn>technology (web content technology)</dfn></a> <span class="glossary-adapted">[<a
  href="http://www.w3.org/TR/WCAG20/#glossary">WCAG 2.0</a>, ATAG
  2.0]</span></dt>
  <dd>A mechanism for encoding instructions to be rendered, played or
      executed by <a href="#def-user-agent">user agents</a>. Web Content
      technologies may include markup languages, data formats, or programming
      languages that <a href="#def-author">authors</a> may use alone or in
      combination to create end-user experiences that range from static Web
      pages to multimedia presentations to dynamic Web applications. Some
      common examples of Web content technologies include HTML, CSS, SVG,
      PNG, PDF, Flash, and JavaScript.</dd>
  <dt><a name="def-text" id="def-text"><dfn>text</dfn></a> (<dfn>text content</dfn>, <dfn>non-text
  content</dfn>,
  <dfn>text element</dfn>, <dfn>non-text
  element</dfn>, <dfn>text
  equivalent</dfn>, <dfn>non-text equivalent </dfn>)</dt>
    <dd class="glossary">Text used by itself
      refers to a sequence of characters from a markup language's <a
      class="dfn-instance" href="#def-doc-char-set"
      title="definition: Document character set">document character set</a>.
      Refer to the "Character Model for the World Wide Web" <cite><a
      href="#ref-CHARMOD"
      title="Link to reference CHARMOD">[CHARMOD]</a></cite> for more
      information about text and characters. <strong>Note:</strong> UAAG 2.0 makes use of other terms that include the word "text" that
      have highly specialized meanings: <a class="dfn-instance"
      href="#def-collated-text-transcript"
      title="definition: Collated text transcript">collated text
      transcript</a>, <a class="dfn-instance" href="#def-non-text-content"
      title="definition: non-text content">non-text content</a>, <a
      class="dfn-instance" href="#def-text-content"
      title="definition: Text content">text content</a>, <a
      class="dfn-instance" href="#def-non-text-element"
      title="definition: non-text element">non-text element</a>, <a
      class="dfn-instance" href="#def-text-element"
      title="definition: text element">text element</a>, <a
      class="dfn-instance" href="#def-text-eq"
      title="definition: text equivalent">text equivalent</a>, and <a
      class="dfn-instance" href="#def-text-transcript"
      title="definition: Text transcript">text transcript</a>.
  <p>A<a name="def-text-element"
  id="def-text-element"><dfn>text element</dfn></a> adds <a
      class="dfn-instance" href="#def-text" title="definition: Text">text
      characters</a> to either <a class="dfn-instance" href="#def-content"
      title="definition: Content">content</a> or the <a class="dfn-instance"
      href="#def-user-interface" title="definition: User interface">user
        interface</a>. Both in the Web Content Accessibility Guidelines 2.0 <cite><a href="#ref-WCAG20"
      title="Link to reference WCAG20">[WCAG20]</a></cite> and in UAAG 2.0, text elements are presumed to produce text that can be
      understood when rendered visually, as synthesized speech, or as
      Braille. Such text elements benefit at least these three groups of
      users: </p>
      <ol>
        <li>visually-displayed text benefits users who are deaf and adept in
          reading visually-displayed text;</li>
        <li>synthesized speech benefits users who are blind and adept in use
          of synthesized speech;</li>
        <li>braille benefits users who are blind, and possibly deaf-blind,
          and adept at reading braille.</li>
      </ol>
      <p>A text element may consist of both text and non-text data. For
        instance, a text element may contain markup for style (e.g. font size
        or color), structure (e.g. heading levels), and other semantics. The
        essential function of the text element should be retained even if style
      information happens to be lost in rendering. A user agent may have to process a text element in order to have
        access to the text characters. For instance, a text element may consist
        of markup, it may be encrypted or compressed, or it may include
      embedded text in a binary format (e.g. <acronym>JPEG</acronym>).</p>
      <p><a name="def-text-content"
  id="def-text-content"><dfn>Text content</dfn></a> is content that is composed of one or more text
        elements. A <a name="def-text-eq" id="def-text-eq"><dfn>text
  equivalent</dfn></a> (whether in content or the user
        interface) is an <a class="dfn-instance" href="#def-equivalent"
      title="definition: Equivalent (for content)">equivalent</a> composed of
        one or more text elements. Authors generally provide text equivalents
        for content by using the <a class="dfn-instance"
      href="#def-conditional-content"
      title="definition: Conditional content">alternative content</a>
      mechanisms of a specification.</p>
      <p>A <a
  name="def-non-text-element" id="def-non-text-element"><dfn>non-text
  element</dfn></a> is an element (in content or the user
        interface) that does not have the qualities of a text element.
        <a
  name="def-non-text-content" id="def-non-text-content"><dfn>Non-text
  content</dfn></a> is composed of one or more non-text elements. A
        <a name="def-non-text-eq"
  id="def-non-text-eq"><dfn>non-text equivalent</dfn></a> (whether in content or the user interface) is an
        <a class="dfn-instance" href="#def-equivalent"
      title="definition: Equivalent (for content)">equivalent</a> composed of
      one or more non-text elements.</p>
    </dd>
  <dt class="glossary"><a name="def-text-decoration"
  id="def-text-decoration"><dfn>text decoration</dfn></a></dt>
    <dd class="glossary">Any
      stylistic effect that the user agent may apply to visually <a
      class="dfn-instance" href="#def-rendered-text"
      title="definition: rendered text">rendered text</a> that does not
      affect the layout of the document (i.e. does not require reformatting
      when applied or removed). Text decoration mechanisms include underline,
      overline, and strike-through.</dd>
  <dt class="glossary"><a name="def-text-format"
  id="def-text-format"><dfn>text format</dfn></a></dt>
    <dd class="glossary">Any media object given an Internet media type of
      "text" (e.g. "text/plain", "text/html", or "text/*") as defined in RFC
      2046 <cite class="normref"><a href="#ref-RFC2046"
      title="Link to reference RFC2046">[RFC2046]</a></cite>, section 4.1, or
      any media object identified by Internet media type to be an XML
      document (as defined in <cite class="normref"><a href="#ref-XML"
      title="Link to reference XML">[XML]</a></cite>, section 2) or SGML
      application. Refer, for example, to Internet media types defined in
      "XML Media Types" <cite><a href="#ref-RFC3023"
      title="Link to reference RFC3023">[RFC3023]</a></cite>.</dd>
  <dt class="glossary"><a name="def-text-transcript"
  id="def-text-transcript"><dfn>text transcript</dfn></a></dt>
    <dd class="glossary">A  text equivalent of audio
      information (e.g. an audio-only presentation
      or the <a class="dfn-instance" href="#def-audio-track"
      title="definition: Audio track">audio track</a> of a movie or other
      animation). A text transcript provides text for both spoken words and non-spoken
      sounds such as sound effects. Text transcripts make audio information
      accessible to people who have hearing disabilities and to people who
      cannot play the audio. Text transcripts are usually created by hand but
      may be generated on the fly (e.g. by voice-to-text converters). See
      also the definitions of <a class="dfn-instance" href="#def-captions"
      title="definition: Captions">captions</a> and <a class="dfn-instance"
      href="#def-collated-text-transcript"
      title="definition: Collated text transcript">collated text
  transcripts</a>.</dd>

  <dt class="glossary"><a name="def-audio-track"
  id="def-audio-track"><dfn>track</dfn></a> (<dfn>audio track</dfn> or <a href="#def-visual-track">
  visual track</a>)</dt>
    <dd class="glossary"><a href="#def-content"
      title="definition: Content">Content</a> rendered as sound through an
      audio <a class="dfn-instance" href="#def-viewport"
      title="definition: viewport">viewport</a>. The audio track may be all
      or part of the audio portion presentation (e.g. each instrument may
      have a track, or each stereo channel may have a track). Also see definition of <a href="#def-visual-track">visual track</a></dd>
  <dt class="glossary"><a name="u" id="u"></a><a name="def-user-agent"
  id="def-user-agent"><dfn>user agent</dfn></a></dt>
    <dd class="GLOSSARY">A user agent is any software that retrieves, renders
      and facilitates end user interaction with Web content. </dd>
  <dt class="glossary"><a name="def-default-styles"
  id="def-default-styles"><dfn>user agent default styles</dfn></a></dt>
    <dd class="glossary">User agent default styles are <a
      class="dfn-instance" href="#def-Properties-and-Values"
      title="definition: Properties, values, and defaults">style property
      values</a> applied in the absence of any author or user styles. Some
      markup languages specify a default rendering for content in that markup
      language; others do not. For example, <acronym>XML</acronym> 1.0
      <cite><a href="#ref-XML" title="Link to reference XML">[XML]</a></cite>
      does not specify default styles for XML documents.
      <acronym>HTML</acronym> 4 <cite><a href="#ref-HTML4"
      title="Link to reference HTML4">[HTML4]</a></cite> does not specify
      default styles for HTML documents, but the CSS 2 <cite><a
      href="#ref-CSS2" title="Link to reference CSS2">[CSS2]</a></cite>
      specification suggests a <a
      href="http://www.w3.org/TR/1998/REC-CSS2-19980512/sample.html">sample
      default style sheet for HTML 4</a> based on current practice.</dd>
  <dt class="glossary"><a name="def-user-interface"
  id="def-user-interface"><dfn>user interface</dfn></a>, <a
  name="def-ui-control" id="def-ui-control"><dfn>user interface
  control</dfn></a></dt>
    <dd class="glossary">For the purposes of UAAG 2.0, user interface
      includes both:
      <ol>
        <li>the <a name="def-ua-ui" id="def-ua-ui"><dfn>user agent user
          interface</dfn></a>, i.e. the controls (e.g. menus, buttons,
          prompts, and other components for input and output) and mechanisms
          (e.g. selection and focus) provided by the user agent ("out of the
          box") that are not created by <a class="dfn-instance"
          href="#def-content" title="definition: Content">content</a>.</li>
        <li>the "content user interface," i.e. the <a class="dfn-instance"
          href="#def-enabled-element"
          title="definition: Enabled element">enabled elements</a> that are
          part of content, such as form controls, links, and applets.</li>
      </ol>
      The document distinguishes them only where required for clarity. For
      more information, see the section on requirements for content, for user
      agent features, or both @@.
      <p>The term "user interface control" refers to a component of the user
      agent user interface or the content user interface, distinguished where
      necessary.</p>
    </dd>
  <dt class="glossary"><a name="def-user-styles"
  id="def-user-styles"><dfn>user styles</dfn></a></dt>
    <dd class="glossary">User styles are <a class="dfn-instance"
      href="#def-Properties-and-Values"
      title="definition: Properties, values, and defaults">style property
      values</a> that come from user interface settings, user style sheets,
      or other user interactions.</dd>

<dt><a name="v" id="v"></a><dfn>values</dfn></dt>
  <dd>see <a href="#def-Properties-and-Values"><dfn>properties</dfn></a></dd>
  <dt class="glossary"><a name="def-view"
  id="def-view"><dfn>view</dfn></a>, <a name="def-viewport"
  id="def-viewport"><dfn>viewport</dfn></a></dt>
    <dd class="glossary">The user agent <a class="dfn-instance"
      href="#def-rendered-content"
      title="definition: Rendered content">renders content</a> through one or
      more viewports. Viewports include windows, frames, pieces of paper,
      loudspeakers, and virtual magnifying glasses. A viewport may contain
      another viewport (e.g. nested frames). <a class="dfn-instance"
      href="#def-ui-control" title="definition: user interface control">User
      agent user interface controls</a> such as prompts, menus, and alerts
      are not viewports.
      <p>Graphical and tactile viewports have two spatial <a
      name="viewport-dimension"
      id="viewport-dimension"><dfn>dimensions</dfn></a>. A viewport may also
      have temporal dimensions, for instance when audio, speech, animations,
      and movies are rendered. When the dimensions (spatial or temporal) of
      rendered content exceed the dimensions of the viewport, the user agent
      provides mechanisms such as scroll bars and advance and rewind controls
      so that the user can access the rendered content "outside" the
      viewport. Examples include: when the user can only view a portion of a
      large document through a small graphical viewport, or when audio
      content has already been played.</p>
      <p>When several viewports coexist, only one has the <a
      class="dfn-instance" href="#def-current-focus"
      title="definition: current focus">current focus</a> at a given moment.
      This viewport is <a class="dfn-instance" href="#def-highlight"
      title="definition: Highlight">highlighted</a> to make it stand out.</p>
      <p>User agents may render the same content in a variety of ways; each
      rendering is called a <em>view</em>. For instance, a user agent may
      allow users to view an entire document or just a list of the document's
      headers. These are two different views of the document.<br />
      <br />
      <dfn><a name="def-viewport-toplevel"
      id="def-viewport-toplevel"></a>top-level viewports</dfn> are
      viewports that are not contained within other user agent viewports.</p>
    </dd>
  <dt class="glossary"><a name="def-visual-only-presentation"
  id="def-visual-only-presentation"><dfn>visual-only
  presentation</dfn></a></dt>
    <dd class="glossary">A visual-only presentation is content consisting
      exclusively of one or more <a class="dfn-instance"
      href="#def-visual-track" title="definition: Visual track">visual
      tracks</a> presented concurrently or in series. A silent movie is an
      example of a visual-only presentation.</dd>
  <dt class="glossary"><a name="def-visual-track"
  id="def-visual-track"><dfn>visual track</dfn></a></dt>
    <dd class="glossary">A visual object is content rendered through a
      graphical <a class="dfn-instance" href="#def-viewport"
      title="definition: viewport">viewport</a>. Visual objects include
      graphics, text, and visual portions of movies and other animations. A
      visual track is a visual object that is intended as a whole or partial
      presentation. A visual track does not necessarily correspond to a
      single physical object or software object.</dd>
  <dt class="glossary"><a name="def-voice-browser"
  id="def-voice-browser"><dfn>voice browser</dfn></a></dt>
    <dd class="glossary">From "Introduction and Overview of W3C Speech
      Interface Framework" <cite><a href="#ref-VOICEBROWSER"
      title="Link to reference VOICEBROWSER">[VOICEBROWSER]</a></cite>: "A
      voice browser is a device (hardware and software) that interprets voice
      markup languages to generate voice output, interpret voice input, and
      possibly accept and produce other modalities of input and output."</dd>
  <dt class="glossary"><a name="w" id="w"></a><a name="def-web-resource"
  id="def-web-resource"><dfn>web resource</dfn></a></dt>
    <dd>Anything that can be identified by a Uniform Resource Identifier
      (<acronym>URI</acronym>).</dd>
</dl>
<hr />
<div id="sect-this-doc-ref">
<h2><a name="ref-this-doc" id="ref-this-doc"></a>Appendix B: How to refer to
UAAG 2.0 from other documents</h2>
  <p>This section is <a href="#def-informative" title="definition: informative" class="termdef">informative</a>. </p>
  <p>There are two recommended ways to refer to the &quot;User Agent Accessibility
    Guidelines 2.0&quot; (and to W3C documents in general):</p>
  <ol>
    <li>References to a specific version of &quot;User Agent Accessibility
      Guidelines 2.0.&quot; For example, use the &quot;this version&quot; <acronym>URI</acronym> to
      refer to the current document:<br />
      <a href="http://www.w3.org/TR/2010/WD-UAAG20-20100617/">http://www.w3.org/TR/2010/WD-UAAG20-20100617/</a></li>
    <li>References to the latest version of &quot;User Agent Accessibility
      Guidelines 2.0.&quot; Use the &quot;latest version&quot; URI to refer to
      the most recently published document in the series: <br />
      <a href="http://www.w3.org/TR/UAAG20/">http://www.w3.org/TR/UAAG20/</a>.</li>
  </ol>
  <p>In almost all cases, references (either by name or by link) should be to
    a specific version of the document. W3C will make every effort to make UAAG 2.0 indefinitely available at its original address in its original form.
    The top of UAAG 2.0 includes the relevant catalog metadata for specific
    references (including title, publication date, &quot;this version&quot; <acronym>URI</acronym>,
    editors' names, and copyright information).</p>
  <div id="example">
    <p>An XHTML 1.0 paragraph including a reference to this specific document
      might be written: </p>
    <blockquote>
      <p><code>&lt;p&gt;<br />
        &lt;cite&gt;&lt;a href=&quot;http://www.w3.org/TR/2010/WD-UAAG20-20100617/&quot;&gt;<br />
        &quot;User Agent Accessibility Guidelines 2.0,&quot;&lt;/a&gt;&lt;/cite&gt;<br />
        J. Allan, K. Ford, J. Spellman, eds.,<br />
        W3C Recommendation, http://www.w3.org/TR/ATAG20/.<br />
        The &lt;a href=&quot;http://www.w3.org/TR/ATAG20/&quot;&gt;latest version&lt;/a&gt; of this document is available at http://www.w3.org/TR/ATAG20/.&lt;/p&gt; </code></p>
    </blockquote>
  </div> <!-- example -->

  <p>For very general references to this document (where stability of content
    and anchors is not required), it may be appropriate to refer to the latest
    version of this document. Other sections of this document explain how to build a <a href="#conformance">conformance
    claim</a>.</p>
  <hr />
</div> <!-- sect-this-doc-ref -->

<h2><a name="references" id="references"></a>Appendix C: References</h2>

<p>This section is <a href="#def-informative">informative</a>.</p>

<p>For the <strong>latest version</strong> of any <acronym
title="the World Wide Web Consortium">W3C</acronym> specification please
consult the list of <a href="http://www.w3.org/TR/"><acronym
title="the World Wide Web Consortium">W3C</acronym> Technical Reports</a> at
http://www.w3.org/TR/. Some documents listed below may have been superseded
since the publication of UAAG 2.0.</p>

<p><strong>Note:</strong> In UAAG 2.0, bracketed labels such as
"[WCAG20]" link to the corresponding entries in this section. These labels
are also identified as references through markup.</p>
<dl>
  <dt><a name="ref-CSS1" id="ref-CSS1">[CSS1]</a></dt>
    <dd><cite><a
      href="http://www.w3.org/TR/1999/REC-CSS1-19990111">"Cascading Style
      Sheets (CSS1) Level 1 Specification,"</a></cite> B. Bos, H. Wium Lie,
      eds., 17 December 1996, revised 11 January 1999. This W3C
      Recommendation is http://www.w3.org/TR/1999/REC-CSS1-19990111.</dd>
  <dt><a name="ref-CSS2" id="ref-CSS2">[CSS2]</a></dt>
    <dd><cite><a
      href="http://www.w3.org/TR/1998/REC-CSS2-19980512/">"Cascading Style
      Sheets, level 2 (CSS2) Specification,"</a></cite> B. Bos, H. Wium Lie,
      C. Lilley, and I. Jacobs, eds., 12 May 1998. This W3C Recommendation is
      http://www.w3.org/TR/1998/REC-CSS2-19980512/.</dd>
  <dt><a name="ref-DOM2CORE" id="ref-DOM2CORE">[DOM2CORE]</a></dt>
    <dd><cite><a
      href="http://www.w3.org/TR/2000/REC-DOM-Level-2-Core-20001113/">"Document
      Object Model (DOM) Level 2 Core Specification,"</a></cite> A. Le Hors,
      P. Le Hégaret, L. Wood, G. Nicol, J. Robie, M. Champion, S. Byrne,
      eds., 13 November 2000. This W3C Recommendation is
      http://www.w3.org/TR/2000/REC-DOM-Level-2-Core-20001113/.</dd>
  <dt><a name="ref-DOM2STYLE" id="ref-DOM2STYLE">[DOM2STYLE]</a></dt>
    <dd><cite><a
      href="http://www.w3.org/TR/2000/REC-DOM-Level-2-Style-20001113/">"Document
      Object Model (DOM) Level 2 Style Specification,"</a></cite> V. Apparao,
      P. Le Hégaret, C. Wilson, eds., 13 November 2000. This W3C
      Recommendation is
      http://www.w3.org/TR/2000/REC-DOM-Level-2-Style-20001113/.</dd>
  <dt><a name="ref-INFOSET" id="ref-INFOSET">[INFOSET]</a></dt>
    <dd><cite><a
      href="http://www.w3.org/TR/2001/REC-xml-infoset-20011024/">"XML
      Information Set,"</a></cite> J. Cowan and R. Tobin, eds., 24 October
      2001. This W3C Recommendation is
      http://www.w3.org/TR/2001/REC-xml-infoset-20011024/.</dd>
  <dt><a name="ref-RFC2046" id="ref-RFC2046">[RFC2046]</a></dt>
    <dd><cite><a href="http://www.ietf.org/rfc/rfc2046.txt">"Multipurpose
      Internet Mail Extensions (MIME) Part Two: Media Types,"</a></cite> N.
      Freed, N. Borenstein, November 1996.</dd>
  <dt><a name="ref-WCAG10" id="ref-WCAG10">[WCAG10]</a></dt>
    <dd><cite><a
      href="http://www.w3.org/TR/1999/WAI-WEBCONTENT-19990505/">"Web Content
      Accessibility Guidelines 1.0,"</a></cite> W. Chisholm, G. Vanderheiden,
      and I. Jacobs, eds., 5 May 1999. This W3C Recommendation is
      http://www.w3.org/TR/1999/WAI-WEBCONTENT-19990505/.</dd>
  <dt><a name="ref-XML" id="ref-XML">[XML]</a></dt>
    <dd><cite><a
      href="http://www.w3.org/TR/1998/REC-xml-19980210">"Extensible Markup
      Language (XML) 1.0 (Second Edition),"</a></cite> T. Bray, J. Paoli,
      C.M. Sperberg-McQueen, eds., 6 October 2000. This W3C Recommendation is
      http://www.w3.org/TR/2000/REC-xml-20001006.</dd>
</dl>
<dl>
  <dt><a name="ref-AT1998" id="ref-AT1998">[AT1998]</a></dt>
    <dd>The <cite><a
      href="http://www.section508.gov/508Awareness/html/at1998.html">Assistive Technology
      Act of 1998</a></cite>.</dd>
  <dt><a name="ref-ATAG10" id="ref-ATAG10">[ATAG10]</a></dt>
    <dd><cite><a
      href="http://www.w3.org/TR/2000/REC-ATAG10-20000203/">"Authoring Tool
      Accessibility Guidelines 1.0,"</a></cite> J. Treviranus, C.
      McCathieNevile, I. Jacobs, and J. Richards, eds., 3 February 2000. This
      W3C Recommendation is
    http://www.w3.org/TR/2000/REC-ATAG10-20000203/.</dd>
  <dt><a name="ref-ATAG10-TECHS" id="ref-ATAG10-TECHS">[ATAG10-TECHS]</a></dt>
    <dd><cite><a
      href="http://www.w3.org/TR/2002/NOTE-ATAG10-TECHS-20021029/">"Techniques
      for Authoring Tool Accessibility Guidelines 1.0,"</a></cite> J.
      Treviranus, C. McCathieNevile, J. Richards, eds., 29 Oct 2002. This W3C
      Note is http://www.w3.org/TR/2002/NOTE-ATAG10-TECHS-20021029/.</dd>
  <dt><a name="ref-CHARMOD" id="ref-CHARMOD">[CHARMOD]</a></dt>
    <dd><cite><a
      href="http://www.w3.org/TR/2002/WD-charmod-20020430/">"Character Model
      for the World Wide Web,"</a></cite> M. Dürst and F. Yergeau, eds., 30
      April 2002. This W3C Working Draft is
      http://www.w3.org/TR/2002/WD-charmod-20020430/. The <a
      href="http://www.w3.org/TR/charmod/">latest version</a> is available at
      http://www.w3.org/TR/charmod/.</dd>
  <dt><a name="ref-DOM2HTML" id="ref-DOM2HTML">[DOM2HTML]</a></dt>
    <dd><cite><a
      href="http://www.w3.org/TR/2002/PR-DOM-Level-2-HTML-20021108/">"Document
      Object Model (DOM) Level 2 HTML Specification,"</a></cite> J. Stenback,
      P. Le Hégaret, A. Le Hors, eds., 8 November 2002. This W3C Proposed
      Recommendation is
      http://www.w3.org/TR/2002/PR-DOM-Level-2-HTML-20021108/. The <a
      href="http://www.w3.org/TR/DOM-Level-2-HTML/">latest version</a> is
      available at http://www.w3.org/TR/DOM-Level-2-HTML/.</dd>
  <dt><a name="ref-HTML4" id="ref-HTML4">[HTML4]</a></dt>
    <dd><cite><a href="http://www.w3.org/TR/1999/REC-html401-19991224/">"HTML
      4.01 Recommendation,"</a></cite> D. Raggett, A. Le Hors, and I. Jacobs,
      eds., 24 December 1999. This W3C Recommendation is
      http://www.w3.org/TR/1999/REC-html401-19991224/.</dd>
  <dt><a name="ref-RFC2616" id="ref-RFC2616">[RFC2616]</a></dt>
    <dd><cite><a href="http://www.ietf.org/rfc/rfc2616.txt">"Hypertext
      Transfer Protocol — HTTP/1.1,"</a></cite> J. Gettys, J. Mogul, H.
      Frystyk, L. Masinter, P. Leach, T. Berners-Lee, June 1999.</dd>
  <dt><a name="ref-RFC3023" id="ref-RFC3023">[RFC3023]</a></dt>
    <dd><cite><a href="http://www.ietf.org/rfc/rfc3023.txt">"XML Media
      Types,"</a></cite> M. Murata, S. St. Laurent, D. Kohn, January
    2001.</dd>
  <dt><a name="ref-SMIL" id="ref-SMIL">[SMIL]</a></dt>
    <dd><cite><a
      href="http://www.w3.org/TR/1998/REC-smil-19980615/">"Synchronized
      Multimedia Integration Language (SMIL) 1.0 Specification,"</a></cite>
      P. Hoschka, ed., 15 June 1998. This W3C Recommendation is
      http://www.w3.org/TR/1998/REC-smil-19980615/.</dd>
  <dt><a name="ref-SMIL20" id="ref-SMIL20">[SMIL20]</a></dt>
    <dd><cite><a
      href="http://www.w3.org/TR/2001/REC-smil20-20010807/">"Synchronized
      Multimedia Integration Language (SMIL 2.0) Specification,"</a></cite>
      J. Ayars, et al., eds., 7 August 2001. This W3C Recommendation is
      http://www.w3.org/TR/2001/REC-smil20-20010807/.</dd>
  <dt><a name="ref-SVG" id="ref-SVG">[SVG]</a></dt>
    <dd><cite><a href="http://www.w3.org/TR/2001/REC-SVG-20010904/">"Scalable
      Vector Graphics (SVG) 1.0 Specification,"</a></cite> J. Ferraiolo, ed.,
      4 September 2001. This W3C Recommendation is
      http://www.w3.org/TR/2001/REC-SVG-20010904/.</dd>
  <dt><a name="ref-UAAG10" id="ref-UAAG10"><strong>[UAAG10]</strong></a></dt>
    <dd>"<a href="http://www.w3.org/TR/2002/REC-UAAG10-20021217/">User Agent
      Accessibility Guidelines 1.0</a>," I. Jacobs, J. Gunderson, E. Hansen,
      eds.17 December 2002. This W3C Recommendation is available at
      http://www.w3.org/TR/2002/REC-UAAG10-20021217/. </dd>
  <dt><a name="ref-UAAG10-CHECKLIST"
  id="ref-UAAG10-CHECKLIST">[UAAG10-CHECKLIST]</a></dt>
    <dd>An appendix to UAAG 2.0 lists all of the checkpoints, sorted by
      priority. The checklist is available in either <a rel="Appendix"
      title="Tabular form of AUGL Checklist"
      href="http://www.w3.org/TR/2002/REC-UAAG10-20021217/uaag10-chktable">tabular
      form</a> or <a rel="Appendix" title="List form of AUGL Checklist"
      href="http://www.w3.org/TR/2002/REC-UAAG10-20021217/uaag10-chklist">list
      form</a>.</dd>
  <dt><a name="ref-UAAG10-ICONS" id="ref-UAAG10-ICONS">[UAAG10-ICONS]</a></dt>
    <dd>Information about <a
      href="http://www.w3.org/WAI/UAAG10-Conformance">UAAG 1.0 conformance
      icons</a> and their usage is available at
      http://www.w3.org/WAI/UAAG10-Conformance.</dd>
  <dt><a name="ref-UAAG10-SUMMARY"
  id="ref-UAAG10-SUMMARY">[UAAG10-SUMMARY]</a></dt>
    <dd>An appendix to UAAG 2.0 provides a <a
      href="http://www.w3.org/TR/2002/REC-UAAG10-20021217/uaag10-summary"
      rel="Appendix">summary</a> of the goals and structure of User Agent
      Accessibility Guidelines 1.0.</dd>
  <dt><a name="ref-UAAG10-TECHS" id="ref-UAAG10-TECHS">[UAAG10-TECHS]</a></dt>
    <dd><cite><a href="http://www.w3.org/TR/UAAG10-TECHS/">"Techniques for
      User Agent Accessibility Guidelines 1.0,"</a></cite> I. Jacobs, J.
      Gunderson, E. Hansen, eds. The latest draft of the techniques document
      is available at http://www.w3.org/TR/UAAG10-TECHS/.</dd>
  <dt><a name="ref-UNICODE" id="ref-UNICODE">[UNICODE]</a></dt>
    <dd><cite><a href="http://www.unicode.org/reports/tr28/">"The
      Unicode Standard, Version 3.2."</a></cite> This technical report of the
      <a href="http://www.unicode.org/">Unicode Consortium</a> is available
      at http://www.unicode.org/reports/tr28/. This is a revision of
      "The Unicode Standard, Version 3.0," The Unicode Consortium,
      Addison-Wesley Developers Press, 2000. ISBN 0-201-61633-5. Refer also
      to <a
      href="http://www.unicode.org/standard/versions/">http://www.unicode.org/standard/versions/</a>.
      For information about character encodings, refer
      to <a href="http://www.unicode.org/reports/tr17/">Unicode
      Technical Report #17 "Character Encoding Model"</a>.</dd>
  <dt><a name="ref-VOICEBROWSER" id="ref-VOICEBROWSER">[VOICEBROWSER]</a></dt>
    <dd><cite><a
      href="http://www.w3.org/TR/2000/WD-voice-intro-20001204/">"Introduction
      and Overview of W3C Speech Interface Framework,"</a></cite> J. Larson,
      4 December 2000. This W3C Working Draft is
      http://www.w3.org/TR/2000/WD-voice-intro-20001204/. The <a
      href="http://www.w3.org/TR/voice-intro/">latest version</a> is
      available at http://www.w3.org/TR/voice-intro/. UAAG 2.0 includes
      references to additional W3C specifications about voice browser
      technology.</dd>
  <dt><a name="ref-W3CPROCESS" id="ref-W3CPROCESS">[W3CPROCESS]</a></dt>
    <dd><cite><a href="http://www.w3.org/Consortium/Process-20010719/">"World
      Wide Web Consortium Process Document,"</a></cite> I. Jacobs ed. The 19
      July 2001 version of the Process Document is
      http://www.w3.org/Consortium/Process-20010719/. The <a
      href="http://www.w3.org/Consortium/Process/">latest version</a> is
      available at http://www.w3.org/Consortium/Process/.</dd>
  <dt><a name="ref-WCAG20" id="ref-WCAG20">[WCAG20]</a></dt>
    <dd><cite><a href="http://www.w3.org/TR/WCAG20/">"Web Content Accessibility Guidelines (WCAG) 2.0"</a></cite> B. Caldwell, M. Cooper, L. Guarino Reid, G. Vanderheiden, eds., 8 December 2008. This W3C Recommendation is
      http://www.w3.org/TR/2008/REC-WCAG20-20081211/. The <a
      href="http://www.w3.org/TR/WCAG20/">latest version</a> is
      available at http://www.w3.org/TR/WCAG20/. Additional
      format-specific techniques documents are available from this Recommendation.</dd>
  <dt><a name="ref-WCAG10-TECHS" id="ref-WCAG10-TECHS">[WCAG20-TECHS]</a></dt>
    <dd><cite><a href="http://www.w3.org/TR/WCAG10-TECHS/">"Techniques for
      Web Content Accessibility Guidelines 2.0,"</a></cite> B. Caldwell, M. Cooper, L. Guarino Reid, G. Vanderheiden, eds., 8 December 2008.  This W3C Note is
      http://www.w3.org/TR/2010/NOTE-WCAG20-TECHS-20101014/. The <a
      href="http://www.w3.org/TR/WCAG20-TECHS/">latest version</a> is
      available at http://www.w3.org/TR/WCAG20-TECHS/. Additional
      format-specific techniques documents are available from this Note.</dd>
  <dt><a name="ref-WEBCHAR" id="ref-WEBCHAR">[WEBCHAR]</a></dt>
    <dd><cite><a href="http://www.w3.org/1999/05/WCA-terms/01">"Web
      Characterization Terminology and Definitions Sheet,"</a></cite> B.
      Lavoie, H. F. Nielsen, eds., 24 May 1999. This is a W3C Working Draft
      that defines some terms to establish a common understanding about key
      Web concepts. This W3C Working Draft is
      http://www.w3.org/1999/05/WCA-terms/01.</dd>
  <dt><a name="ref-XAG10" id="ref-XAG10">[XAG10]</a></dt>
    <dd><cite><a href="http://www.w3.org/TR/2002/WD-xag-20021003">"XML
      Accessibility Guidelines 1.0,"</a></cite> D. Dardailler, S. Palmer, C.
      McCathieNevile, eds., 3 October 2001. This W3C Working Draft is
      http://www.w3.org/TR/2002/WD-xag-20021003. The <a
      href="http://www.w3.org/TR/xag">latest version</a> is available at
      http://www.w3.org/TR/xag.</dd>
  <dt><a name="ref-XHTML10" id="ref-XHTML10">[XHTML10]</a></dt>
    <dd><cite><a
      href="http://www.w3.org/TR/2000/REC-xhtml1-20000126/">"XHTML[tm] 1.0:
      The Extensible HyperText Markup Language,"</a></cite> S. Pemberton, et
      al., 26 January 2000. This W3C Recommendation is
      http://www.w3.org/TR/2000/REC-xhtml1-20000126/.</dd>
  <dt><a name="ref-XMLDSIG" id="ref-XMLDSIG">[XMLDSIG]</a></dt>
    <dd><cite><a
      href="http://www.w3.org/TR/2002/REC-xmldsig-core-20020212/">"XML-Signature
      Syntax and Processing,"</a></cite> D. Eastlake, J. Reagle, D. Solo,
      eds., 12 February 2002. This W3C Recommendation is
      http://www.w3.org/TR/2002/REC-xmldsig-core-20020212/.</dd>
  <dt><a name="ref-XMLENC" id="ref-XMLENC">[XMLENC]</a></dt>
    <dd><cite><a
      href="http://www.w3.org/TR/2002/REC-xmlenc-core-20021210/">"XML
      Encryption Syntax and Processing,"</a></cite> D. Eastlake, J. Reagle,
      eds., 10 December 2002. This W3C Recommendation is
      http://www.w3.org/TR/2002/REC-xmlenc-core-20021210/.</dd>
</dl>
<hr />

<h2><a id="acknowledgments" name="acknowledgments"></a>Appendix D:
Acknowledgments</h2>

<h3><a name="active-participants" id="active-participants"></a>Participants
active in the UAWG prior publication:</h3>
<ul>
  <li>Jim Allan (Co-Chair, Texas School for the Blind and Visually
  Impaired)</li>
  <li>Alan Cantor (Invited Expert)</li>
  <li>Bim Egan (Royal National Institute of Blind People)</li>
  <li>Kelly Ford (Co-Chair, Microsoft)</li>
  <li>Mark Hakkinen (Invited Expert)</li>
  <li>Simon Harper (University of Manchester)</li>
  <li>Patrick Lauke (Opera Software)</li>
  <li>Greg Lowney (Invited Expert)</li>
  <li>Kimberly Patch (Invited Expert)</li>
  <li>Jan Richards (Adaptive Technology Resource Centre, University of
    Toronto)</li>
  <li>Jeanne Spellman (W3C Staff Contact)</li>
</ul>

<h3><a name="previous-participants" id="previous-participants"></a>Other
previously active UAWG participants and other contributors to UAAG 2.0:</h3>
<ul>
  <li>Judy Brewer (W3C)</li>
  <li>Sean Hayes (Microsoft)</li>
  <li>Dean Hudson (Apple)</li>
  <li>Cathy Laws (IBM)</li>
  <li>Peter Parente (IBM)</li>
  <li>David Poehlman (Invited Expert)</li>
  <li>Simon Pieters (Opera Software)</li>
  <li>Henny Swan (Opera Software)</li>
  <li>Gregory Rosmaita (Invited Expert)</li>
  <li>David Tseng (Apple) </li>
</ul>

<p>UAAG 2.0 would not have been possible without the work of <a
href="http://www.w3.org/TR/WAI-USERAGENT/acks.html#Acknowledgments">those who
contributed to UAAG 1.0</a>.</p>

<p>This publication has been funded in part with Federal funds from the U.S.
Department of Education, National Institute on Disability and Rehabilitation
Research (NIDRR) under contract number ED-OSE-10-C-0067. The content of this
publication does not necessarily reflect the views or policies of the U.S.
Department of Education, nor does mention of trade names, commercial
products, or organizations imply endorsement by the U.S. Government. </p>
<hr />

<h2><a name="checklist" id="checklist"></a>Appendix E: Checklist </h2>

<p class="editor-notes">@@ Editors' Note: This section is still under development@@ </p>
<hr />

<h2><a name="version-comparison" id="version-comparison"></a>Appendix F:
Comparison of UAAG 1.0 guidelines to UAAG 2.0</h2>

<p class="editor-notes">@@ Editors' Note: This section is still under development@@ </p>

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