Roles for Accessible Rich Internet Applications (WAI-ARIA Roles)

1.1 About This Draft

This section is informative.

This draft currently handles two aspects of roles—GUI functionality and structural relationships of the element. For more information see the Roadmap for Accessible Rich Internet Applications implementation examples [ARIA-ROADMAP, section 5.11] for the use of roles making dynamically generated content accessible.

This taxonomy is designed in-part to support the common roles found in platform accessibility API frameworks. Reference to roles found in this taxonomy by dynamic Web content may be used to support interoperability with assistive technologies.

The schema to support this standard has been designed to be extended so that custom roles can be created by extending base roles. This allows user agents to support at least the base role, and user agents that support the custom role can provide enhanced access. Note that much of this could be formalized in XML Schema [XSD]. However, being able to define similarities between roles, such as baseConcepts and more descriptive definitions would not be available in XSD.

At some point the working group intends to add roles for A, Adding concepts in the type of content for adaptation to the user scenario and B, Knowledge representation of Web content.

1.2 Terms and Definitions

This section is informative.

While some terms are defined in place, the following definitions are used throughout this document. Familiarity with W3C XHTML 1.1 Recommendation [XHTML] and the W3C XML 1.0 Recommendation [XML] is highly recommended to understand these definitions.

Accessibility API

Operating systems and other platforms provide a set of interfaces that expose information about objects and events to assistive technology. Assistive technology uses these interfaces to get information about and interact with those controls. Examples of this are the Java Accessibility API [JAPI], Microsoft Active Accessibility [MSAA], Apple Accessibility for COCOA [AAC], the Gnome Accessibility Toolkit (ATK) [GAP], and IAccessible2 [IA2].

Functionality

Processes and outcomes achievable through user action

User Agent

Any software that retrieves and renders Web content for users, such as Web browsers, media players, plug-ins, and other programs including assistive technologies that help retrieve and render Web content.

Assistive Technology

A user agent that:

1. 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).
2. Relies on services (such as retrieving Web content 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 APIs, especially Accessibility APIs.

Examples of assistive technologies that are important in the context of this document include the following:

• 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;
• Screen readers, which are used by people who are blind or have reading disabilities to read textual information through synthesized speech or braille displays;
• Voice recognition software, which may be used by people who have some physical disabilities;
• Alternative keyboards, which are used by people with certain physical disabilities to simulate the keyboard;
• Alternative pointing devices, which are used by people with certain physical disabilities to simulate mouse pointing and button activations.

Note: This definition is based on the definition in Web Content Accessibility Guidelines 2.0 [WCAG20, Appendix A].

2.1 Introduction to using roles

Complex user interfaces become inaccessible because adaptive technologies that provide alternative access, are often left guessing at the semantics behind portions of a document (see the Roadmap for Accessible Rich Internet Applications [ARIA-ROADMAP]). When you associate an element in your document to a role in this taxonomy you are associating all the information about that role that has been defined in this specification.

Roles in this specification are defined with RDF to build rich description of the expected behaviors of the role. For example:

• The roles taxonomy describes what states are supported for each role. For example, a checkbox supports being checked.
• The roles taxonomy describes what the context of a role. For example a tabpanel should be inside a tabcontainer, or a group would contain section.
• The role taxonomy describes the relationships between roles. For example a directory is a type of list.

Hence referencing a role from the role taxonomy to an element in your document gives assistive technology the information it needs to handle an element correctly.

xmlns:wairole="http://www.w3.org/2005/01/wai-rdf/GUIRoleTaxonomy#"

<html xmlns="http://www.w3.org/1999/xhtml"
    xmlns:wairole="http://www.w3.org/2005/01/wai-rdf/GUIRoleTaxonomy#"
    xmlns:aaa="http://www.w3.org/2005/07/aaa" >
  <head>...</head>
  <body>
    ...
    <span class="checkboxtristate" id="chbox1" role="wairole:checkboxtristate"  aaa:checked="mixed"
        onkeydown="return checkBoxEvent(event);" onclick="return checkBoxEvent(event);" tabindex="0" >
      A checkbox label
    </span>
    ...
  </body>
</html>

2.2 Building Accessible Applications with Roles

Editorial Note: the PFWG has begun development of a best practices document, to externalize some of the instruction about how to use ARIA from the technical specification. When that document is more mature, we will return to this section and reconsider it in context of available resources and optimal understandability of this document.

An application becomes accessible when:

1. Each element or widget has full and correct semantics that fully describes it's behavior (using element names or roles).
2. The relationships between elements and groups are known
3. States, properties, and relationships are valid for each elements behavior and are accessible via the Document Object Model [DOM].
4. There is an element having the correct input focus.

Roles make the different elements in the application semantically rich. User agents use the role semantics to understand how to handle each element. Roles can be used to build accessible applications by providing any missing information that the assistive technology needs to anticipate the behavior of the elements inside the application.

For example, to support accessibility the browser may create accessible objects of a Web page through the Accessibility API of the operating system. When the full semantics are provided and understood by the browser, the application will properly map the page to accessible objects of the operating system.

2.3 Example: building a tree view in XHTML 1.0

A basic tree view allows the user to select different list items and expand and collapse embedded lists. Arrow keys are used to navigate through a tree, including left/right to collapse/expand sub trees. Double clicking with the mouse also toggles expansion.

<div x2:role="wairole:tree" >
  <div role="wairole:treeitem" >Veggies
    <div role="wairole:group">
      <div role="wairole:treeitem">Green
        <div role="wairole:group">
          <div role="wairole:treeitem">Asparagus</div>
          <div role="wairole:treeitem">Kale</div>
          <div role="wairole:treeitem" >Leafy
            <div role="wairole:group">
              <div role="wairole:treeitem">Lettuce</div>
              <div role="wairole:treeitem">Kale</div>
              <div role="wairole:treeitem">Spinach</div>
              <div role="wairole:treeitem">Chard</div>
            </div>
          </div> ---close leafy
          <div role="wairole:treeitem">Green beans</div>
        </div>
      </div> ---close green
      <div role="wairole:treeitem">Legumes</div>
      <div role="wairole:treeitem" >Yellow
        <div role="wairole:group">
          <div role="wairole:treeitem">Bell peppers</div>
          <div role="wairole:treeitem">Squash</div>
        </div>
      </div> ---close yellow
    </div>
  </div> ---close veggies
</div> ---close tree

<div x2:role="wairole:treeitem" aaa:haschild="yellowtreegroup">Yellow<div>
…
<div id="yellowtreegroup" role="wairole:group">
<div role="wairole:treeitem">Bell peppers</div>
<div role="wairole:treeitem">Squash</div>
…
</div>

<div tabindex="-1" role="wairole:treeitem" aaa:expanded="true">Yellow</div>

<div role="wairole:tree" tabindex="-1"
  onfocus="return treeItemFocus(event);"
  onclick="return treeItemEvent(event);"
  ondblclick="return treeItemEvent(event);"
  onkeydown="return treeItemEvent(event);"
  onkeypress="return treeItemEvent(event);">

2.4 Applying roles to documents

This section is normative.

Roles are provided in XML-based languages using an attribute designated for the purpose. Roles from this ontology are indicated as values of that role attribute. In order to indicate that the roles are used as specified in this document, the document must use the following namespace in the attribute value: http://www.w3.org/2005/01/wai-rdf/GUIRoleTaxonomy#.

Generally this namespace is declared on the root element of the document as specified in XML Namespaces [XML-NAMES]. Examples in this document use the namespace prefix “wairole” to indicate this namespace.

Editorial Note: There is discussion about changing the suggested prefix to “ariarole”. There is not yet group consensus about this.

For example, the start tag of a root element that includes the appropriate namespace declaration might look like:

<html xmlns="http://www.w3.org/1999/xhtml"
    xml:lang="en"
    xmlns:wairole="http://www.w3.org/2005/01/wai-rdf/GUIRoleTaxonomy#"
> 

<html lang="en" xml:lang="en" xmlns="http://www.w3.org/1999/xhtml
"xmlns:wairole="http://www.w3.org/2005/01/wai-rdf/GUIRoleTaxonomy#"><body>

<table id="table1" role="wairole:grid">
...
</table>

</body></html>

<html lang="en" xml:lang="en" xmlns="http://www.w3.org/1999/xhtml"
xmlns:xhtml10="http://www.w3.org/1999/xhtml"
xmlns:wairole="http://www.w3.org/2005/01/wai-rdf/GUIRoleTaxonomy#"><body>

<table id="table1" xhtml10:role="wairole:grid">
...
</table>
</body></html>

<html xmlns="http://www.w3.org/1999/xhtml"
    xmlns:wairole="http://www.w3.org/2005/01/wai-rdf/GUIRoleTaxonomy#"
> 

3.1 Role Properties

Roles are defined and described by their properties. Properties define the structural function of a role, such as: What a role is, concepts behind it, what it can contain, what it must contain.

In the case of widgets this also includes how it interacts with the user agent based on mapping to HTML forms and XForms, allowed states and required states.

3.2 Relationships between concepts

The are three properties that describe the relationship between concepts. They are:

• Type and subclasses - (from RDF Schema [RDFS]) this implies inheritance, which means, among other things, the inheritance of limitations and properties. Other than well known stable specifications, inheritance may be restricted to items defined inside this specification so that items can not be changed and affect inherited classes.

  For example: Buttonundo is a subclass or type of a button. If we change the properties and expected behavior of a button then the properties and behavior of buttonundo will also change.

• relatedConcept - A relatedConcept is a similar or related idea from other specifications. Concepts that are related are not necessarily identical. relatedConcepts do not inherit properties from each other. Hence if the definition of a type changes, the properties, behavior and definition of a relatedConcept is not affected.

  For example: A grid is like a table. Therefore, a grid has a relatedConcept of a table as defined at http://www.w3.org/TR/html4/struct/tables.html#edef-TABLE. However if the definition of table is modified our definition of a grid will not be affected.

• baseConcept - A baseConcept is like a "borrowed" concept. BaseConcept is similar to type, but without inheritance of limitations and properties. baseConcepts are designed as a substitute for inheritance for external concepts. A baseConcept is like a relatedConcept except that baseConcepts are almost identical to each other.

  For example: the checkbox defined in this document has the same functionality and anticipated behavior as a checkbox defined in http://www.w3.org/MarkUp/HTML#checkbox.

  Therefore, a checkbox has a baseConcept of a checkbox as defined at http://www.w3.org/MarkUp/HTML#checkbox. However, if http://www.w3.org/MarkUp/HTML#checkbox is modified, the definition of a checkbox in this document will not be not affected.

The Roles Taxonomy supports the following additional properties:

3.3 Global States and Properties

Some states and properties are applicable to all roles, and most are applicable to all elements regardless of role. In addition to explicitly expressed supported states and properties, the following global states and properties are supported by roles as well. These include:

• atomic
• busy
• controls
• datatype
• describedby
• dropeffect
• flowto
• grab
• haspopup
• hidden
• invalid
• labelledby
• live
• owns
• relevant
• required
• tabindex

3.4 Roles

To support the current user scenario this specification defines roles that A, help define Widgets (For example, a tristate Checkbox) and B, help define page structure (for example, a section header).

Graph of the data model—Picture of the relationships described in the role data model (large)

Editorial Note: Is this image useful? Perhaps a manually generated one would be more helpful, one that's more UML-like.

Specific roles are enumerated below in Supported Roles.

<div designmode="on" role="wairole:textfield" aaa:readonly="false">
  type away
</div>

4.1 Example: Grid

This section is informative.

In this example, an XHTML table has been assigned the role of a grid or spreadsheet.

<table id="table1" role="wairole:grid" >
...
</table>

The role of "grid" maps this element to the appropriate feature in the platform accessibility infrastructure that enables it to be properly treated. In this case, the "grid" role means that the "multiselectable" state is supported and cells may be editable.

A full spreadsheet example is available online at http://www.mozilla.org/access/dhtml/spreadsheet

Roles can be embedded in any host language, e.g. XHTML 1.1 [XHTML]. In many case Roles will work well with other supporting technologies, such as States and Properties for Accessible Rich Internet Applications [ARIA-STATE] and XML Events [XML-EVENTS]

5.1 Document Conformance

Roles for Accessible Rich Internet Applications is not a stand-alone document type. It is intended to be integrated into other host languages such as XHTML [XHTML]. A conforming document requires only the facilities described as mandatory in this specification and the facilities described as mandatory in its host language. Such a document must meet all the following criteria:

1. The document must conform to the constraints expressed in Appendix A - RDF Schema combined with the constraints expressed in its host language implementation.

2. The document must contain an xmlns declaration for the role Namespace [XML-NAMES]. The namespace name for the roles defined here is

   http://www.w3.org/2005/01/wai-rdf/GUIRoleTaxonomy#

5.2 User Agent Conformance

User agents that conform to Roles for Accessible Rich Internet Applications expose role information provided by the author to assistive technologies, and if they are assistive technologies themselves, use role information to enhance the presentation. Conformance requirements:

1. User agents MUST make all roles provided by the author available in the DOM, using the attribute name, namespace, and values defined in this specification. This requirement parallels User Agent Accessibility Guidelines 1.0 Section 6.2: DOM access to HTML/XML content [UAAG, Section 6.2].

2. User agents SHOULD allow roles to be extended via RDF. When a role from a different specification extends or inherits from a role in this specification, then that role should also be supported, at least to the extent that the original role is supported.

3. User agents SHOULD expose role information provided by the author to the platform accessibility API. Refer to Mapping States and Properties to Accessibility APIs for guidance about how to expose this information. This requirement parallels User Agent Accessibility Guidelines 1.0 Section 6.3: Programmatic Access to non-HTML/XML Content [UAAG, Section 6.3], except that it applies even to HTML and XML content.

   Note: Not all platforms provide accessibility APIs, or provide interfaces that map to all the roles defined in this specification. User agents should expose those roles that are supported in order to support assistive technologies that work through the accessibility API. The remaining roles are available to assistive technologies via the DOM as per point 1 above, for those that provide explicit support for this specification.

4. User agents MUST override implicit roles of elements with roles provided by the author. This applies to elements that have particular default roles because of the semantics declared by the content technology. Processing and presentation must be appropriate to the declared role.

5. Assistive technologies that conform to this specification MUST use role information to present content to and support interaction with users in a manner appropriate to that role. The manner in which this is done is specific to each user agent but should be appropriate to the specified description of the role.

   Note: This does not specify how assistive technology obtains role information. Assistive technologies may obtain role information directly from content, through the DOM, or through the platform accessibility API. In the latter case, only incomplete role information may be available. This point only requires that assistive technology use the roles that are actually available to it to support the user.

6.1 Implementation

Note: This RDF is still in draft form and changes from last draft have not been validated. Some related concepts may be missing.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE rdf:RDF [
  <!ENTITY xsd "http://www.w3.org/2001/XMLSchema#">
  <!ENTITY dc "http://dublincore.org/2003/03/24/dces#">
  <!ENTITY owl "http://www.w3.org/2002/07/owl#">
  <!ENTITY rdfs "http://www.w3.org/2000/01/rdf-schema#">
  <!ENTITY rdf "http://www.w3.org/1999/02/22-rdf-syntax-ns#">
  <!ENTITY states "http://www.w3.org/2005/07/aaa#">
]>
<rdf:RDF 
  xmlns:dc="http://purl.org/dc/elements/1.1/#" 
  xmlns:html="http://www.w3.org/1999/xhtml" 
  xmlns:owl="http://www.w3.org/2002/07/owl#" 
  xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" 
  xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#" 
  xmlns:role="http://www.w3.org/2005/01/wai-rdf/GUIRoleTaxonomy#" 
  xmlns:states="http://www.w3.org/2005/07/aaa#" 
  xmlns:xsd="http://www.w3.org/2001/XMLSchema#" 
  xml:base="http://www.w3.org/2005/01/wai-rdf/GUIRoleTaxonomy"
>
  <!--==Objects==-->
  <owl:ObjectProperty rdf:ID="relatedConcept">
    <rdfs:comment xml:lang="en">The URI of similar/related types from
      other specifications (See SKOS)</rdfs:comment>
    <rdfs:range rdf:resource="&amp;xsd;anyURI" />
    <rdfs:domain rdf:resource="#roletype" />
  </owl:ObjectProperty>
  <owl:ObjectProperty rdf:ID="baseConcept">
    <rdfs:comment xml:lang="en">This is similar to type but without
      inheritance of limitations and properties. role:baseConcepts are designed as
      a substitute for inheritance for external concepts. </rdfs:comment>
    <rdfs:subpropertyOf rdf:resource="#relatedConcept" />
  </owl:ObjectProperty>
  <owl:ObjectProperty rdf:ID="supportedState">
    <rdfs:comment xml:lang="en">A state that can be supported for this a
      Role</rdfs:comment>
    <rdfs:domain rdf:resource="#widget" />
  </owl:ObjectProperty>
  <owl:ObjectProperty rdf:ID="scope">
    <rdfs:comment xml:lang="en">Context where this role is
      allowed</rdfs:comment>
    <rdfs:domain rdf:resource="#roletype" />
  </owl:ObjectProperty>
  <owl:ObjectProperty rdf:ID="mustContain">
    <rdfs:comment xml:lang="en">A child that must be contained by this
      role</rdfs:comment>
    <rdfs:subpropertyOf rdf:resource="#scope" />
  </owl:ObjectProperty>
  <owl:ObjectProperty rdf:ID="media">
    <rdfs:comment xml:lang="en">The media type, where the Role is
      allowed - a type of role:scope, simmilar to DC: Format or media
      type</rdfs:comment>
    <rdfs:subpropertyOf rdf:resource="#scope" />
  </owl:ObjectProperty>
  <owl:ObjectProperty rdf:ID="default">
    <rdfs:comment>Default value of a supported state in the context of
      this role</rdfs:comment>
  </owl:ObjectProperty>
  <owl:ObjectProperty rdf:ID="nameRef">
    <rdfs:comment>How a role type name is extracted and referenced
      inside a document. For example the DOM might reference a role by it's
      title.</rdfs:comment>
    <rdfs:domain rdf:resource="#widget" />
  </owl:ObjectProperty>
  <!--== Abstract and Base Classes==-->
  <owl:Class rdf:ID="roletype">
    <rdfs:subClassOf>
      <owl:Restriction>
        <owl:onProperty rdf:resource="http://dublincore.org/2003/03/24/dces#description" />
        <owl:cardinality rdf:datatype="http://www.w3.org/2001/XMLSchema#string">1</owl:cardinality>
      </owl:Restriction>
    </rdfs:subClassOf>
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#atomic" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#busy" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#controls" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#datatype" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#describedby" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#dropeffect" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#flowto" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#grab" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#haspopup" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#hidden" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#invalid" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#labelledby" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#live" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#owns" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#relevant" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#required" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#tabindex" />
    <dc:description xml:lang="en">Describes the structural and functional purpose of an element. A
      Role is also a concept.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="widget">
    <rdfs:subClassOf rdf:resource="#roletype" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#disabled" />
    <dc:description xml:lang="en">A component of a GUI (graphical user interface)</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="input">
    <rdfs:subClassOf rdf:resource="#widget" />
    <role:nameRef>Title</role:nameRef>
    <dc:description xml:lang="en">Generic type for widgets that can have a value</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="textbox">
    <rdfs:subClassOf rdf:resource="#input" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#readonly" />
    <role:nameRef>Title</role:nameRef>
    <dc:description xml:lang="en">Generic type for the inputs that allow free-form text as their
      value</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="select">
    <rdfs:subClassOf rdf:resource="#input" />
    <rdfs:subClassOf rdf:resource="#list" />
    <role:nameRef>Title</role:nameRef>
    <dc:description xml:lang="en">A form control that allows the user to make selections from a
      set of choices. A select must contain an option.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="range">
    <rdfs:subClassOf rdf:resource="#input" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#valuemax" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#valuemin" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#valuenow" />
    <role:nameRef>Title</role:nameRef>
    <dc:description xml:lang="en">Represents a range of values that can be set by the user.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="section">
    <rdfs:subClassOf rdf:resource="#roletype" />
    <role:nameRef>Child content or title attribute</role:nameRef>
    <dc:description xml:lang="en"> A base abstract class representing a renderable structural 
      containment unit found in a document or application. </dc:description>
  </owl:Class>
  <owl:Class rdf:ID="sectionhead">
    <rdfs:subClassOf rdf:resource="#roletype" />
    <role:nameRef>Child content </role:nameRef>
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">The section head labels or summarizes the topic of its related
      section</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="window">
    <rdfs:subClassOf rdf:resource="#roletype" />
    <role:nameRef>Child content</role:nameRef>
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">Browser or application window</dc:description>
  </owl:Class>
  <!--== Widget Roles==-->
  <owl:Class rdf:ID="link">
    <rdfs:subClassOf rdf:resource="#widget" />
    <role:nameRef>Child content</role:nameRef>
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">Interactive reference to a resource (note, that in [XHTML] 
      2.0 any element can have an href attribute and thus be a link)</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="combobox">
    <rdfs:subClassOf rdf:resource="#select" />
    <role:nameRef>Title</role:nameRef>
    <dc:description xml:lang="en">Combobox is a presentation of a select, where you can type to
      locate a selected item.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="listbox">
    <rdfs:subClassOf rdf:resource="#select" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#multiselectable" />
    <role:nameRef>Title</role:nameRef>
    <dc:description xml:lang="en">Todo: Created per Rich and Aaron's analysis/cleanup</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="option">
    <rdfs:subClassOf rdf:resource="#input" />
    <rdfs:subClassOf rdf:resource="#listitem" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#selected" />
    <role:nameRef>Child content</role:nameRef>
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">A selectable item in a list represented by a select. </dc:description>
  </owl:Class>
  <owl:Class rdf:ID="checkbox">
    <rdfs:subClassOf rdf:resource="#checkboxtristate" />
    <role:nameRef>Child content</role:nameRef>
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">A control that has two possible value states (an equivalent to a
      boolean).</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="checkboxtristate">
    <rdfs:subClassOf rdf:resource="#option" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#readonly" />
    <role:nameRef>Child content</role:nameRef>
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">A control that has three possible values, (1 0 -1). Often found
      in installer where an option has been partially installed.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="radio">
    <rdfs:subClassOf rdf:resource="#checkbox" />
    <role:nameRef>Child content</role:nameRef>
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">A radio is an option in single-select list. Only one radio
      control in a radiogroup can be selected at the same time.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="radiogroup">
    <rdfs:subClassOf rdf:resource="#select" />
    <role:nameRef>Title</role:nameRef>
    <dc:description xml:lang="en">A group of radio controls.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="button">
    <rdfs:subClassOf rdf:resource="#widget" />
    <rdfs:subClassOf rdf:resource="#link" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#pressed" />
    <role:nameRef>Child content</role:nameRef>
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">Allows for user-triggered actions. </dc:description>
  </owl:Class>
  <owl:Class rdf:ID="menuitemradio">
    <rdfs:subClassOf rdf:resource="#menuitem" />
    <rdfs:subClassOf rdf:resource="#radio" />
    <role:nameRef>Child content</role:nameRef>
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">Indicates that you have a menu item which is part of a group of
      menuitemradio roles.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="menuitemcheckbox">
    <rdfs:subClassOf rdf:resource="#menuitem" />
    <rdfs:subClassOf rdf:resource="#checkbox" />
    <role:nameRef>Child content</role:nameRef>
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">Defines a menuitem which is checkable (tri-state).</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="progressbar">
    <rdfs:subClassOf rdf:resource="#widget" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#valuenow" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#valuemin" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#valuemax" />
    <role:nameRef>Title</role:nameRef>
    <dc:description xml:lang="en">Used by applications for tasks that take a long time to execute,
      to show the execution progress.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="secret">
    <rdfs:subClassOf rdf:resource="#input" />
    <role:nameRef>Title</role:nameRef>
    <dc:description xml:lang="en">Provides the user with the ability to supply information to the
      system in a manner that makes it difficult for someone else (who may
      be watching) to discern the value that is being supplied.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="separator">
    <rdfs:subClassOf rdf:resource="#widget" />
    <role:nameRef>Title</role:nameRef>
    <dc:description xml:lang="en">A line or bar that separates and distinguishes sections of
      content. This is a visual separator between sections of content.
      Separators are found between lists of menu items in a menu.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="slider">
    <rdfs:subClassOf rdf:resource="#range" />
    <role:nameRef>Title</role:nameRef>
    <dc:description xml:lang="en">A user input where the user selects an input in a given range.
      This form of range expects an analog keyboard interface.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="spinbutton">
    <rdfs:subClassOf rdf:resource="#range" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#readonly" />
    <role:nameRef>Title</role:nameRef>
    <dc:description xml:lang="en">A form of Range that expects a user selecting from discrete
      choices.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="textarea">
    <rdfs:subClassOf rdf:resource="#textbox" />
    <role:nameRef>Title</role:nameRef>
    <dc:description xml:lang="en">This is a multi-line editable text box. For use when no standard
      form element exists with this functionality.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="textfield">
    <rdfs:subClassOf rdf:resource="#textbox" />
    <role:nameRef>Child content</role:nameRef>
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">Free-form data entry for short on-line content.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="tree">
    <rdfs:subClassOf rdf:resource="#select" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#multiselectable" />
    <role:nameRef>Child content</role:nameRef>
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">A form of  a list having groups
      inside groups, where sub trees can be collapsed and expanded.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="treeitem">
    <rdfs:subClassOf rdf:resource="#option" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#expanded" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#level" />
    <role:nameRef>Child content</role:nameRef>
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">An option item of a tree. This is an element within a tree that may
      be expanded or collapsed</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="status">
    <rdfs:subClassOf rdf:resource="#widget" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#activedescendent" />
    <dc:description xml:lang="en">This is a container for process
      advisory information to give feedback to the user. It must have a
      subtree. This object typically does not receive focus. </dc:description>
  </owl:Class>
  <owl:Class rdf:ID="alert">
    <rdfs:subClassOf rdf:resource="#status" />
    <role:nameRef>Title</role:nameRef>
    <dc:description xml:lang="en">A message with an alert or error information.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="alertdialog">
    <rdfs:subClassOf rdf:resource="#alert" />
    <rdfs:subClassOf rdf:resource="#dialog" />
    <role:nameRef>Title</role:nameRef>
    <dc:description xml:lang="en">A separate window with an alert or error information. 
    </dc:description>
  </owl:Class>
  <owl:Class rdf:ID="dialog">
    <rdfs:subClassOf rdf:resource="#window" />
    <role:nameRef>Title</role:nameRef>
    <dc:description xml:lang="en">A dialog is a small application window that sits above the
      application and is designed to interrupt the current processing of an
      application in order to prompt the user to enter information or
      require a response.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="marquee">
    <dc:description xml:lang="en">Todo: </dc:description>
  </owl:Class>
  <!--== Structural Roles==-->
  <owl:Class rdf:ID="application">
    <rdfs:subClassOf rdf:resource="#window" />
    <role:nameRef>title attribute</role:nameRef>
    <dc:description xml:lang="en">A software unit executing a set of tasks for its users
    </dc:description>
  </owl:Class>
  <owl:Class rdf:ID="document">
    <rdfs:subClassOf rdf:resource="#roletype" />
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">Content that contains related information, such as a book. The
      document role is used to tell the screen reader to use a document
      browsing mode, because screen readers use most of the keyboard navigation
      keys to provide its own keyboard user interface for this type of
      navigation.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="presentation">
    <rdfs:subClassOf rdf:resource="#roletype" />
    <dc:description xml:lang="en">An element whose role is presentational does not need to be
      mapped to the accessibility API.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="group">
    <rdfs:subClassOf rdf:resource="#section" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#expanded" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#activedescendent" />
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">A group is a section of user interface objects which would not 
      be included in a page summary or table of contents by an assistive technology. </dc:description>
  </owl:Class>
  <owl:Class rdf:ID="imggroup">
    <rdfs:subClassOf rdf:resource="#group" />

    <role:nameRef>title attribute</role:nameRef>
    <dc:description xml:lang="en">An imggroup is a container for a collection elements that form
      an image. </dc:description>
  </owl:Class>
  <owl:Class rdf:ID="directory">
    <rdfs:subClassOf rdf:resource="#list" />
    <role:nameRef>Child content</role:nameRef>
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">A list of references to members of a single group.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="region">
    <rdfs:subClassOf rdf:resource="#section" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#expanded" />
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en"> Region is a large perceivable section on your web page. </dc:description>
  </owl:Class>
  <owl:Class rdf:ID="log">
    <rdfs:subClassOf rdf:resource="#region" />
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">A region where new information is added and old information may
      disappear such as chat logs, messaging, game log or an error log.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="grid">
    <rdfs:subClassOf rdf:resource="#widget" />
    <role:mustContain rdf:resource="#gridcell" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#multiselectable" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#readonly" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#activedescendent" />
    <role:nameRef>title attribute</role:nameRef>
    <dc:description xml:lang="en">A grid is a table type that may be editable. </dc:description>
  </owl:Class>
  <owl:Class rdf:ID="gridcell">
    <rdfs:subClassOf rdf:resource="#td" />
    <rdfs:subClassOf rdf:resource="#textarea" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#selected" />
    <role:nameRef>Child content</role:nameRef>
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">A gridcell is a table cell in a grid. Gridcells may be active,
      editable, and selectable. Cells may have relationships such as controls to address the 
      application of functional relationships.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="tab">
    <rdfs:subClassOf rdf:resource="#sectionhead" />
    <rdfs:subClassOf rdf:resource="#widget" />
    <role:scope rdf:resource="#tabcontent" />
    <role:nameRef>Child content</role:nameRef>
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">A tab is a tabpanel header. Tab is used as a grouping label,
      providing a link for selecting the tabcontent to be rendered to the
      user.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="tabpanel">
    <rdfs:subClassOf rdf:resource="#region" />
    <role:scope rdf:resource="#tabcontainer" />
    <role:nameRef>title attribute</role:nameRef>
    <dc:description xml:lang="en">Tabpanel is a container for the resources associated with a tab.
    </dc:description>
  </owl:Class>
  <owl:Class rdf:ID="tablist">
    <rdfs:subClassOf rdf:resource="#directory" />
    <role:scope rdf:resource="#tabcontainer" />
    <role:nameRef>Child content</role:nameRef>
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">A list of references to tabpanels of a tabcontainer.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="table">
    <rdfs:subClassOf rdf:resource="#group" />
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">A table contains cells of tabular data arranged in rows and
      columns.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="td">
    <rdfs:subClassOf rdf:resource="#section" />
    <role:nameRef>Child content</role:nameRef>
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">A table cell containing data.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="th">
    <rdfs:subClassOf rdf:resource="#sectionhead" />
    <rdfs:subClassOf rdf:resource="#td" />
    <role:nameRef>Child content</role:nameRef>
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">A table cell containing header information.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="rowheader">
    <rdfs:subClassOf rdf:resource="#th" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#sort" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#readonly" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#selected" />
    <role:nameRef>Child content</role:nameRef>
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">A table cell containing header information for a row.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="columnheader">
    <rdfs:subClassOf rdf:resource="#th" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#sort" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#readonly" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#selected" />
    <role:nameRef>Child content</role:nameRef>
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">A table cell containing header information for a column.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="list">
    <rdfs:subClassOf rdf:resource="#group" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#readonly" />
    <role:nameRef>title attribute</role:nameRef>
    <dc:description xml:lang="en">Group of small items.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="listitem">
    <rdfs:subClassOf rdf:resource="#section" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#checked" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#disabled" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#posinset" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#setsize" />
    <role:nameRef>Child content</role:nameRef>
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">A single item in a list.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="menu">
    <rdfs:subClassOf rdf:resource="#widget" />
    <rdfs:subClassOf rdf:resource="#list" />
    <role:mustContain rdf:resource="#menuitem" />
    <role:nameRef>title attribute</role:nameRef>
    <dc:description xml:lang="en">Offers a list of choices to the user. A menu is often a list of
      links to important sections of a Document or a Site.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="toolbar">
    <rdfs:subClassOf rdf:resource="#menu" />
    <role:relatedConcept rdf:resource="#menubar" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#multiselectable" />
    <role:nameRef>title attribute</role:nameRef>
    <dc:description xml:lang="en">A toolbar is a collection of commonly used functions represented
      in compact visual form.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="menubar">
    <rdfs:subClassOf rdf:resource="#menu" />
    <role:relatedConcept rdf:resource="#toolbar" />
    <role:nameRef>title attribute</role:nameRef>
    <dc:description xml:lang="en">A menubar is a container of menu items. Each menu item may
      activate a new sub-menu. Navigation behavior should be similar to the
      typical menu bar graphical user interface.</dc:description>
  </owl:Class>
  <owl:Class rdf:ID="menuitem">
    <rdfs:subClassOf rdf:resource="#listitem" />
    <role:nameRef>Child content</role:nameRef>
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">A link in a menu. This is an option in a group of choices
      contained in a menu. </dc:description>
  </owl:Class>
  <owl:Class rdf:ID="breadcrumbs">
    <rdfs:subClassOf rdf:resource="#roletype" />
    <role:relatedConcept rdf:resource="#menu" />
    <role:mustContain rdf:resource="#link" />
    <role:supportedState rdf:resource="http://www.w3.org/2005/07/aaa#setsize" />
    <role:nameRef>Child content</role:nameRef>
    <role:nameRef> title attribute</role:nameRef>
    <dc:description xml:lang="en">Bread crumb navigation list. </dc:description>
  </owl:Class>
  <owl:Class rdf:ID="description">
    <rdfs:subClassOf rdf:resource="#section" />
    <dc:description xml:lang="en">Descriptive content for a page element which references this 
      element via describedby. </dc:description>
  </owl:Class>
  <owl:Class rdf:ID="tooltip">
    <rdfs:subClassOf rdf:resource="#description" />
    <dc:description xml:lang="en">A popup that displays a description for an element when a user 
      passes over or rests on that element. Supplement to the normal tooltip processing of the 
      user agent. </dc:description>
  </owl:Class>
</rdf:RDF>

6.2 References

[AAC]

Apple Accessibility for Cocoa™. Available at: http://developer.apple.com/documentation/Cocoa/Conceptual/Accessibility/index.html.

[ARIA-ROADMAP]

Roadmap for Accessible Rich Internet Applications (WAI-ARIA Roadmap), R. Schwerdtfeger, Editor. World Wide Web Consortium, 26 September 2006. This version of WAI-ARIA Roadmap is available at http://www.w3.org/TR/2006/WD-aria-roadmap-20060926/. The latest version of WAI-ARIA Roadmap is available at http://www.w3.org/TR/aria-roadmap/.

[ARIA-STATE]

States and Properties Module for Accessible Rich Internet Applications (WAI-ARIA States and Properties), L. Seeman, Editor. World Wide Web Consortium, 26 September 2006. This version of WAI-ARIA States and Properties is available at http://www.w3.org/TR/2006/WD-aria-state-20060926/. The latest version of WAI-ARIA States and Properties is available at http://www.w3.org/TR/aria-state/.

[CSS]

Cascading Style Sheets, level 2 (CSS2) Specification, I. Jacobs, B. Bos, H. Lie, C. Lilley, Editors, W3C Recommendation, 12 May 1998, http://www.w3.org/TR/1998/REC-CSS2-19980512/. Latest version available at http://www.w3.org/TR/REC-CSS2/.

[DI-GLOSS]

Glossary of Terms for Device Independence, R. Lewis, Editor, W3C Working Draft (work in progress), 18 January 2005, http://www.w3.org/TR/2005/WD-di-gloss-20050118/. Latest version available at http://www.w3.org/TR/di-gloss/.

[DOM]

Document Object Model (DOM) Level 2 Core Specification, L. Wood, G. Nicol, A. Le Hors, J. Robie, S. Byrne, P. Le Hégaret, M. Champion, Editors, W3C Recommendation, 13 November 2000, http://www.w3.org/TR/2000/REC-DOM-Level-2-Core-20001113/. Latest version available at http://www.w3.org/TR/DOM-Level-2-Core/.

[GAP]

Gnome Accessibility Project (GAP) State and StateSets. Available at: http://developer.gnome.org/projects/gap/tech-docs/at-spi-docs/at-spi-cspi-state-and-statesets.html.

[HTML]

HTML 4.01 Specification, I. Jacobs, A. Le Hors, D. Raggett, Editors, W3C Recommendation, 24 December 1999, http://www.w3.org/TR/1999/REC-html401-19991224/. Latest version available at http://www.w3.org/TR/html401/.

[IA2]

IAccessible2. Available at http://www.linux-foundation.org/en/Accessibility/IAccessible2.

[JAPI]

Java Accessibility API (JAPI). Available at: http://java.sun.com/products/jfc/accessibility/index.jsp.

[MSAA]

Microsoft Active Accessibility (MSAA). Available at: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/msaa/msaastart_9w2t.asp.

[OWL]

OWL Web Ontology Language Overview, D. L. McGuinness, F. van Harmelen, Editors, W3C Recommendation, 10 February 2004, http://www.w3.org/TR/2004/REC-owl-features-20040210/ . Latest version available at http://www.w3.org/TR/owl-features/ .

[RDF]

Resource Description Framework (RDF): Concepts and Abstract Syntax, G. Klyne, J. J. Carroll, Editors, W3C Recommendation, 10 February 2004, http://www.w3.org/TR/2004/REC-rdf-concepts-20040210/. Latest version available at http://www.w3.org/TR/rdf-concepts/.

[RDFS]

RDF Vocabulary Description Language 1.0: RDF Schema, D. Brickley, R. V. Guha, Editors, W3C Recommendation, 10 February 2004, http://www.w3.org/TR/2004/REC-rdf-schema-20040210/. Latest version available at http://www.w3.org/TR/rdf-schema/.

[RFC2119]

"Key words for use in RFCs to indicate requirement levels ", RFC 2119, S. Bradner, March 1997. Available at: http://www.rfc-editor.org/rfc/rfc2119.txt.

[SVG]

Scalable Vector Graphics (SVG) 1.1 Specification, D. Jackson, J. Ferraiolo, 藤沢, Editors, W3C Recommendation, 14 January 2003, http://www.w3.org/TR/2003/REC-SVG11-20030114/. Latest version available at http://www.w3.org/TR/SVG11/.

[UAAG]

User Agent Accessibility Guidelines 1.0, I. Jacobs, J. Gunderson, E. Hansen, Editors, W3C Recommendation, 17 December 2002, http://www.w3.org/TR/2002/REC-UAAG10-20021217/. Latest version available at http://www.w3.org/TR/UAAG10/.

[WCAG20]

Web Content Accessibility Guidelines 2.0, M. Cooper, B. Caldwell, G. Vanderheiden, L. Guarino Reid, Editors, W3C Working Draft (work in progress), 17 May 2007, http://www.w3.org/TR/2007/WD-WCAG20-20070517/. Latest version available at http://www.w3.org/TR/WCAG20/.

[XFORMS]

XForms 1.0 (Second Edition), R. Merrick, M. Dubinko, T. V. Raman, J. Boyer, D. Landwehr, L. L. Klotz, Editors, W3C Recommendation, 14 March 2006, http://www.w3.org/TR/2006/REC-xforms-20060314/. Latest version available at http://www.w3.org/TR/xforms/.

[XHTML]

XHTML™ 1.0 The Extensible HyperText Markup Language (Second Edition), S. Pemberton, Editor, W3C Recommendation, 1 August 2002, http://www.w3.org/TR/2002/REC-xhtml1-20020801/. Latest version available at http://www.w3.org/TR/xhtml1/.

[XHTMLMOD]

XHTML™ Modularization 1.1 , M. Altheim, F. Boumphrey, S. McCarron, S. Schnitzenbaumer, S. Dooley, T. Wugofski, Editors, W3C Working Draft (work in progress), 5 July 2006, http://www.w3.org/TR/2006/WD-xhtml-modularization-20060705/. Latest version available at http://www.w3.org/TR/xhtml-modularization/.

[XML]

Extensible Markup Language (XML) 1.0 (Fourth Edition) , T. Bray, J. Paoli, E. Maler, C. M. Sperberg-McQueen, F. Yergeau, Editors, W3C Recommendation, 16 August 2006, http://www.w3.org/TR/2006/REC-xml-20060816/. Latest version available at http://www.w3.org/TR/xml/.

[XML-EVENTS]

XML Events, S. McCarron, S. Pemberton, T. V. Raman, Editors, W3C Recommendation, 14 October 2003, http://www.w3.org/TR/2003/REC-xml-events-20031014/. Latest version available at http://www.w3.org/TR/xml-events/.

[XML-NAMES]

Namespaces in XML 1.0 (Second Edition) , D. Hollander, A. Layman, R. Tobin, T. Bray, Editors, W3C Recommendation, 16 August 2006, http://www.w3.org/TR/2006/REC-xml-names-20060816/. Latest version available at http://www.w3.org/TR/xml-names/.

[XHTML-ROLES]

XHTML Role Attribute Module, S. Pemberton, T. V. Raman, R. Schwerdtfeger, S. McCarron, M. Birbeck, Editors, W3C Working Draft (work in progress), 25 July 2006, http://www.w3.org/TR/2006/WD-xhtml-role-20060725/. Latest version available at http://www.w3.org/TR/xhtml-role/.

[XSD]

XML Schema Part 0: Primer Second Edition, D. C. Fallside, P. Walmsley, Editors, W3C Recommendation, 28 October 2004, http://www.w3.org/TR/2004/REC-xmlschema-0-20041028/. Latest version available at http://www.w3.org/TR/xmlschema-0/.

Editorial Note: The following references are included as important resources but are not referenced from the body of the document.

[SKOS]

SKOS is an area of work developing specifications and standards to support the use of knowledge organisation systems (KOS) such as thesauri, classification schemes, subject heading lists, taxonomies, terminologies, glossaries and other types of controlled vocabulary within the framework of the Semantic Web.

[DAISY]

DAISY denotes the Digital Accessible Information System

[NIMAS]

NIMAS the National Instructional Materials Accessibility Standard (NIMAS), is a voluntary standard to guide the production and electronic distribution of flexible digital instructional materials, such as textbooks, so that they can be more easily converted to Braille, text-to-speech, and other accessible formats.

[DTB]

The DigitalDigital Talking Book standard that defines the format and content of the electronic file set that comprises a digital talking book (DTB) and establishes a limited set of requirements for DTB playback devices.

6.3 Acknowledgments (Non-Normative)

This section is informative.

The following contributed to the development of this document.