[contents]
This document provides guidelines for designing user agents that lower barriers to Web
accessibility for people with disabilities. User agents include browsers and other types
of software that retrieve and render Web content. A user agent that
conforms 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 assistive technologies).
Furthermore, all users, not just users with disabilities, should find
conforming user agents to be more usable.
In addition to helping developers of browsers and media players, this
document will also 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
this document (e.g., technologies for braille rendering) will be essential to
ensuring Web access for some users with disabilities.
The "User Agent Accessibility Guidelines 2.0" (UAAG 2.0)
is part of a series of accessibility guidelines published by the W3C Web
Accessibility Initiative (WAI).
May be Superseded
This section describes the status of this document at the time of its
publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be
found in the W3C technical reports index at
http://www.w3.org/TR/.
Editor's Draft of UAAG 2.0
This document provides a major rewrite of section 4.1 addressing keyboard accessibility issues.
Comments on the draft should be sent to public-uaag2-comments@w3.org (Public Archive).
Should UAAG 2.0 become a W3C Recommendation, it will supersede UAAG 1.0. Until that time User Agent Accessibility Guidelines 1.0 (UAAG 1.0) [UAAG10] is
the stable, referenceable version. This Working Draft does not supersede
UAAG 1.0.
Web Accessibility Initiative
This document has been produced as part of the W3C Web
Accessibility Initiative (WAI). The goals of the User Agent Working Group (UAWG) are discussed
in the Working Group charter.
The UAWG is part of the WAI
Technical Activity.
No Endorsement
Publication as a Working Draft does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.
Patents
This document was produced by a group operating under the 5
February 2004 W3C Patent Policy. W3C maintains a public
list of any patent disclosures 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 Essential
Claim(s) must disclose the information in accordance with section
6 of the W3C Patent Policy.
Editing Styles:
- newly-approved-text: New changes to this draft
- text that is changed from the previous version
- proposed-text: Proposals that have not been accepted
- @@editor-notes@@: Notices from the editor(s).
This section is informative.
This document specifies requirements that, if satisfied by
user agent developers, will lower barriers
to accessibility.
A separate document, entitled "Implementation Techniques for User Agent Accessibility
Guidelines 2.0" (the "Techniques document" from here on) will be produced at a later date. It will provide
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 Techniques
document are informative examples only,
and other strategies may be used or required to satisfy the success criteria. The
UAWG expects to update the Techniques document more
frequently than the current guidelines. Developers, W3C Working Groups, users,
and others are encouraged to contribute techniques.
In this document, the term "user agent" is used in two
ways:
- The software and documentation components that together, conform to the requirements of this
document. This is the most common use of the term in this document and is the
usage in the guidelines.
- Any software that retrieves and renders Web content for users. This may
include Web browsers, browser extensions, media players, plug-ins,
and other programs — including assistive technologies —
that help in retrieving and rendering Web content.
Components of Web Accessibility
Web accessibility depends not only on accessible user agents, but also on the availability of accessible content, a factor that is greatly influenced by the accessibility of authoring tools. For an overview of how these components of Web development and interaction work together, see:
Levels of Conformance
User Agents may claim conformance
to UAAG 2.0 at one of three conformance levels. The level achieved depends
on the level of the success
criteria that have been satisfied. The conformance
levels are:
- UAAG 2.0 Conformance at Level "A"
The user agent satisfies all of
the Level A success criteria.
- UAAG 2.0 Conformance at Level "Double-A"
The user agent satisfies all of
the Level A and Level
AA success criteria.
- UAAG 2.0 Conformance at Level "Triple-A"
The user agent satisfies all of
the success criteria.
Other Issues
Installation@@Keep idea and check against SCs for mention...@@
Some of the requirements of this document may have security implications,
such as communication through APIs, and allowing programmatic read and write
access to content and user interface control. This
document assumes that features required by this document will be built on top
of an underlying security architecture. Consequently, unless permitted
explicitly in a success criterion, this document grants no conformance
exemptions based on security issues.
This document emphasizes the goal of ensuring that users, including users
with disabilities, have control over their environment for accessing the Web.
Key methods for achieving that goal include: optional self-pacing,
configurability, device-independence, interoperability, direct support for both
graphical and auditory output, and adherence to published conventions.@@Move to...@@
This document also acknowledges the importance of author preferences and the
proper implementation of specifications. However, this document includes
requirements to override certain author preferences when the user would not
otherwise be able to access that content.
This document includes requirements for users with a variety of
disabilities, in part because some users may have more than one disability. In
some cases, it may appear that two requirements contradict each other. For
instance, a user with a physical disability may prefer that the user agent
offer more automatic behavior (to reduce demand for physical effort) than a
user with a cognitive disability (for whom automatic behavior may cause
confusion). Thus, many of the requirements in this document involve
configuration as one way to ensure that a functionality designed to improve
accessibility for one user does not interfere with accessibility for another.
Also, since a default user agent setting may be useful for one user but
interfere with accessibility for another, this document prefers configuration
requirements to requirements for default settings. Finally, there may be some
cases where, for some content, a feature required by this document is
ineffective or causes content to be less accessible, making it imperative that
the user be able to turn off the feature.@@park the rest of this for an understanding document@@
To avoid overwhelming users with an abundance of configuration options, this
document includes requirements that promote ease of configuration and
documentation of accessibility features.
The UAWG expects that software which satisfies the requirements of this
document will be more flexible, manageable, extensible, and beneficial to all
users.@@in conceptual info, reworded@@
UAAG 2.0 Guidelines
Principle 1: Comply with applicable specifications and conventions
Guideline 1.1 Ensure that Web-based functionality is accessible.
1.1.1 Web-Based Accessible (Level A): Web-based user agent user interfaces conform to WCAG Level "A". (Level A)
1.1.2 Web-Based Accessible (Level AA): Web-based user agent user interfaces conform to WCAG Level "AA". (Level AA)
1.1.3 Web-Based Accessible (Level AAA): Web-based user agent user interfaces conform to WCAG Level "AAA". (Level AAA)
Applicability Notes:
This guideline does not apply to non-Web-based user agent user interfaces, but does includes any parts of non-Web-based user agents that are Web-based (e.g., help systems).
Guideline 1.2 Ensure that non-Web-based functionality is accessible.
1.2.1 Non-Web-Based Accessible (Level A): Non-Web-based user agent user interfaces comply with and cite the "Level A" requirements of standards and/or platform conventions that benefit accessibility. The "Level A" requirements are those that are functionally equivalent to WCAG Level A success criteria. (Level A)
1.2.2 Non-Web-Based Accessible (Level AA): Non-Web-based user agent user interfaces comply with and cite the "Level AA" requirements of standards and/or platform conventions that benefit accessibility. The "Level AA" requirements are those that are functionally equivalent to WCAG Level AA success criteria. (Level AA)
1.2.3 Non-Web-Based Accessible (Level AAA): Non-Web-based user agent user interfaces comply with and cite the "Level AAA" requirements of standards and/or platform conventions that benefit accessibility. The "Level AAA" requirements are those that are functionally equivalent to WCAG Level AAA success criteria. (Level AAA)
Applicability Notes:
This guideline does not apply to Web-based user agent user interfaces, but does includes any parts of Web-based user agents that are non-Web-based (e.g., client-side file uploaders).
Guideline 1.3 Support accessibility
features of technologies.
1.3.1 Accessibility Features: Implement and cite in the conformance claim the accessibility features of a technology specification. Accessibility features are those that are either (Level A):
- identified as such in the specification or
- allow authors to satisfy a requirement of WCAG.
Guideline 1.4 Render content according to
specification.
1.4.1 Follow Specifications: Render content according to the technology specification. This includes any accessibility features of the technology (see Guideline 1.3). (Level A) @@2.1 in UAAG10@@
1.4.2 Handle Unrendered Technologies: If the user agent does not render a technology, it allows the user to choose a way to handle content in that technology (e.g., by launching another application or by saving it to disk). (Level A)@@NEW@@
Applicability Note:
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.
PRINCIPLE 2. Facilitate programmatic access
by assistive technologies
Guideline 2.1 Facilitate programmatic access
by assistive technologies
2.1.1 Accessibility Platform Architecture: Support an accessibility platform architecture relevant to the platform.
2.1.2 Name, Role, State, Value, Description: For all user interface components including the user interface and rendered content, make available the name, role, state, value, and description via an accessibility platform architecture.
2.1.3 Accessible Alternative: If any functionality is not supported by the implemented accessibility platform architecture(s), then a separate accessible alternative for that functionality that is supported by the implemented accessibility platform architecture(s) is provided and a description of the inaccessible functionality appears in the conformance claim.
2.1.4 Programmatic Availability of DOMs: If the user agent implements one or more DOMs, they must be made programmatically available to assistive technologies.
2.1.5 Write Access: If the user can modify the state or value of a
piece of content through the user interface (e.g., by checking a
box or editing a text area), the same degree of write access is available programmatically.
2.1.6 Properties: If any of the following properties are supported by the accessibility platform architecture, they must be made available via the architecture:
- (a)
the bounding dimensions and coordinates of rendered graphical objects
- (b) font family of text
- (c) font size of text
- (d) foreground color of text
- (e) background color of text.
- (f) change state/value notifications @@(e.g. of DOMs)
2.1.7 Timely Communication: For APIs implemented to satisfy the requirements of this document, programmatic exchanges proceed in a timely manner (Level AA).
Applicability Note:
Non-Web-based user agent interfaces only.
PRINCIPLE 3: Perceivable - The user interface and rendered content must be presented to users in ways they can perceive
Guideline 3.1 Provide text alternatives for non-text components.
3.1.1 Non-Text Objects: Every non-text component (e.g., prompt, alert, or notification) has a text
equivalent. (Level A) @@1.3 in UAAG10@@
Guideline 3.12 Provide access to alternative content.
3.12.1 Notification of Alternative Content: Provide a global option for the user to be notified of alternatives to rendered content (e.g., short text alternatives, long descriptions, captions).
3.12.2 Configurable Default Rendering: The user has the global option to set preferences for which alternative(s) are rendered by default. (Level A) @@2.9 in UAAG10@@
3.12.3 Browse and Render: The user can browse the alternatives and render them according to the following (Level A):
- (a) text alternative:
- (b) captions
- (c) audio descriptions
- (d) sign language video
- (e) full text alternative
- to replace...
- (a) 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 @@Implied in 2.3 in UAAG10@@
- (b) non-synchronized alternatives (e.g., short text alternatives, long descriptions) can be rendered as replacements for the original rendered content. If the new item has different dimensions, then a user option controls whether the dimensions of the original content are used or the dimensions of the new content, which will cause the document to reflow accordingly. @@Implied in 2.3 in UAAG10@@
3.12.4 Available Programmatically: If an alternative is plain text (e.g., short text alternative), then it is available programmatically, even when not rendered. (Level A) @@Implied in 2.3 in UAAG10@@
3.12.4 Simultaneous Rendering: The user has the option to simultaneously render any and all items from the alternative content stack (which will cause the document to reflow accordingly) unless the user agent can recognize a mutual exclusion (e.g., conflicting soundtracks). (Level AA) @@NEW@@@@goes into 3.12.2 rewrite
@@New Technique 3.12.5=User agents should expose configuration choices in as highly visible a fashion as is practical such as on a menu entry or dialog settings devoted to accessibility@@.
Guideline 3.3 Provide access to relationship information. @@NEW 10.1@@
3.3.1 Relationships Available Programmatically: Make explicitly-defined relationships in the content (e.g., labeled_by, table_header_for, etc.) available programmatically. (Level A) @@Expanded 10.1 in UAAG10@@
3.3.2 Access Relationships: The user can access information from explicitly-defined relationships in the content (e.g., what is form control's label?, what is label's form control?, what is cell's table header?, etc.). (Level A) @@Expanded 10.1 in UAAG10@@
3.3.3 Location in Hierarchy: For content in a hierarchy (e.g., tree node, nested frame), the user can view the path of nodes leading from the root to the content. (Level AA)@@NEW@@
3.4.2 Repair Empty Alternatives: The user has the option of receiving generated repair text when the user agent recognizes that the author has provided empty alternative
content for an enabled element. (Level AA) @@2.8 in UAAG10@@
Guideline 3.5 Provide highlighting for selection, content
focus, enabled elements, visited links.
3.5.1 Highlighted items: The user has the option to highlight the following classes of information (Level A):
@@10.2 in UAAG10@@
- (a) selection,
- (b) content focus,
- (c) recognized enabled elements, and
- (d) recently visited links.@@Remove since so common?@@
3.5.2 Highlighting options: The highlighting options (with the same configurable range as the platform's conventional selection utilities) include at least (Level A):@@10.2 in UAAG10@@
- (a) foreground colors,
- (b) background colors, and
- (c) borders (with configurable color and width).
Guideline 3.6 Provide text configuration. @@4.1, 4.2, 4.3 in UAAG10@@
@@Rationale: applies to captions, alt etc.@@
3.6.1 Configure Text: The user can globally set the following characteristics of visually rendered text content, overriding any specified by
the author or user agent defaults (Level A):
- (a) text scale (i.e., the general size of text) ,@@4.1 in UAAG10@@
- (b) font family, and @@4.2 in UAAG10@@
- (c) text color (i.e., foreground and background).@@4.3 in UAAG10@@
3.6.2 Preserve Distinctions: When rendered text is rescaled, distinctions in the size of rendered text are preserved (e.g., headers continue to be larger than body text). (Level A)@@4.1 in UAAG10@@
3.6.3 Option Range: The range of options for each text characteristic includes at least (Level A):
- (a) the range offered by the conventional utility available in the operating environment, or
- (b) if no such utility is available, the range supported by the
conventional APIs of the
operating environment for drawing text.
3.6.4 Maintain contrast: The user has the option to constrain the configuration of the default text foreground color, background
color and highlighting colors, so that text contrast is maintained between them. (Level AAA) @@NEW@@
Guideline 3.7 Provide volume configuration.
3.7.1 Global Volume: The user can globally set the
volume of all rendered audio tracks (including a "mute" setting) through available operating environment mechanisms. (Level A) @@4.7 in UAAG10@@
3.7.2 Speech Volume: If speech and non-speech audio tracks can be recognized, then the user can set the volume of these two types of audio tracks independently. (Level A) @@NEW 4.8@@
Guideline 3.8 Provide synthesized speech configuration.
3.8.1 Speech Characteristics: The user can set both of the following synthesized speech characteristics, overriding any values specified by
the author (Level A):
@@4.9,4.10 in UAAG10@@
- (a) speech rate and
- (b) speech volume (independently of other sources of
audio).
3.8.2 Option Range: The user can set all of the speech characteristics offered by the speech synthesizer, according to the full range of values available, overriding any values specified by
the author. (Level A)
@@4.11 in UAAG10@@
3.8.3 Speech Characteristics: The user can set all of the following synthesized speech characteristics,
overriding any values specified by
the author (Level AA):
@@4.12 in UAAG10@@
- (a) pitch ("pitch" refers to the average frequency of the speaking voice),
- (b) pitch range ("pitch range" specifies a variation in average frequency), and
- (c) speech stress.
("speech stress" refers to the height of "local peaks" in the intonation contour of the
voice).@@richness deleted since not in CSS3 http://www.w3.org/TR/2004/WD-css3-speech-20041216/@@
3.8.4 Speech Features: The following speech features are provided (Level AA):
@@4.13 in UAAG10@@
- (a) user-defined extensions to the synthesized speech dictionary,
- (b) "spell-out", where text is spelled
one character at a time, or according to language-dependent pronunciation
rules,
- (c) at least two ways of speaking numerals: one
where numerals are spoken as individual digits, and one where full numbers are
spoken, and
- (d) at least two ways of speaking punctuation: one where punctuation is spoken literally, and one where punctuation is
rendered as natural pauses.
Guideline 3.9 Provide style sheets
configuration.
Guideline 3.10 Help user to use and orient within viewports.
3.10.1 Highlight Viewport: The viewport with the current focus is highlighted (including any frame that
takes current focus) using a highlight
mechanism that does not rely on rendered text foreground and background
colors alone (e.g., a thick outline). (Level A)@@10.6 in UAAG10@@
3.10.2 Move Viewport to Selection: When a viewport's selection changes, the viewport moves as necessary to ensure that the new selection is at least
partially in the viewport. (Level A)@@5.4 in UAAG10@@
3.10.3 Move Viewport to Focus: When a viewport's content focus changes, the viewport moves as necessary to ensure that the new content focus is at least
partially in the viewport. (Level A)@@5.4 in UAAG10@@
3.10.4 Resizable: The user has the option to make graphical viewports resizable, within the limits of the display, overriding any values specified by
the author. (Level A)@@NEW@@
3.10.5 Scrollbars: Graphical viewports include scrollbars if the rendered content (including after user preferences have been applied) extends beyond the viewport dimensions, overriding any values specified by
the author. (Level A)@@NEW@@
3.10.6 Viewport History: If the user agent maintains a viewport history mechanism (e.g., via the "back button") that stores previous "viable" states (i.e., that have not been negated by the content, user agent settings or user agent extensions), it maintains
information about the point of regard and it restores the saved values when the user returns to a state in the history. (Level A)@@9.4 in UAAG10@@
3.10.7 Open on Request: The user has the option of having "top-level" viewports (e.g., windows) only open
on explicit user request. In this mode, instead of opening a viewport automatically, alert the user and
allow the user to open it with an explicit request (e.g., by
confirming a prompt or following a link generated by the user agent). (Level AA)@@5.3 in UAAG10@@
3.10.8 Do Not Take Focus: When configured to allow "top-level" viewports to open without explicit user request, the user has the option that if a "top-level" viewport opens, neither
its content focus nor its user interface focus automatically becomes the current focus. (Level AA) @@5.1 in UAAG10@@
3.10.9 Stay on Top: The user has the option of having the viewport with the current focus remain "on top" of all
other viewports with which it overlaps. (Level AA) @@5.2 in UAAG10@@
3.10.10 Close Viewport: The user can close any "top-level" viewport. (Level AA) @@5.3 in UAAG10@@
3.10.11 Same UI: The user has the option of having all "top-level" viewports follow the same user interface configuration as the current or spawning viewport, including the same "chrome". (Level AA) @@NEW@@
3.10.12 Indicate Viewport Position: Indicate the viewport's position relative to rendered content (e.g., the proportion along an audio or video timeline, the
proportion of a Web page before the current position ). (Level AAA) @@10.7 in UAAG10@@
Guideline 3.12 Provide an effective focus mechanism.
3.11.1 Content Focus: At least one content focus is provided for each viewport (including frames), where enabled elements are part of the rendered
content. (Level A) @@ 9.1 in UAAG10@@
3.11.2 Current Focus: The user can make the content focus of
each viewport the current focus. (Level A) @@ 9.1 in UAAG10@@
3.11.3 User Interface Focus: A user interface
focus is provided. (Level A) @@from 9.2 in UAAG10@@
3.11.4 Extensions Focusable: The user interface focus can navigate within extensions to the user interface "chrome". (Level A) @@If it knows how to insert and render the extension in its chrome, then it should have good enough programmatic access and knowledge to properly give focus. - Tech XUL spec for FF@@
3.11.5 Hand-Off Focus: The user agent programmatically notifies any nested user agent(s) (e.g., plug-ins) when focus moves to them. (Level A) @@NEW@@
3.11.6 Retrieve Focus: At any time, the user agent is able to retrieve focus from a nested viewport (including nested viewports that are user agents). (Level A) @@NEW@@
3.11.7 Return Focus: Embedded user agents are responsible for notifying embedding user agent that focus should move back to it. (Level A) @@Embedded user agents must write to AccessAPI and HTML DOM if applicable@@
3.11.8 Bi-Directional: The user can move the content focus forward or backward to any enabled element in the viewport. (Level A) @@ 9.3, 9.7 in UAAG10@@
3.11.9 Sequential Navigation: If
the author has not specified a navigation order, the default is sequential
navigation, in document order. (Level A) @@ 9.3 in UAAG10@@
3.11.10 Only on User Request: The user has the option of having the content focus of
a viewport only change on explicit user request. (Level A) @@ 9.3 in UAAG10@@
3.11.11 On Focus: The user has the option of ensuring that moving the content focus to or from an enabled element does not cause the user agent to take any further action. (Level A) @@9.5 in UAAG10@@
3.12.2 Outline View: An "outline"
view of rendered content 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). Note: What constitutes a label is defined by each markup language specification.
For example, in HTML, a heading (H1-H6) is a label
for the section that follows it, a CAPTION is a label for a table,
and the title attribute is a label for its element. (Level AA) @@10.4 in UAAG10@@
3.12.3 Configure Set of Important Elements: The user has the option to configure the set of important
elements for the "outline" view, including by element type (e.g., headers). (Level AAA) @@9.10 in UAAG10@@
3.13.1 Basic Link Information: The following
information is provided for each link (Level A):
@@10.5 in UAAG10@@
- (a) link element content,
- (b) link title,
- (c) technology type: of the linked Web resource,
- (d) internal/external: whether the link is internal to the resource (e.g., the link is to a target
in the same Web page),
- (e) new viewport: whether the author has specified that the resource will open in a new viewport.
3.13.2 Extended Link Information: The following
information is provided for each link (Level AAA):
@@10.5 in UAAG10@@
- (a) visited: whether the user has visited the the linked Web resource recently,
- (c) size: the size of the linked Web resource,
- (c) language: natural language of linked Web resource.
PRINCIPLE 4. Ensure that the user interface is operable
Guideline 4.1 Ensure full keyboard access.
4.1.1 Keyboard Operation: All functionality can be operated via the keyboard using sequential and/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. (Level A)
4.1.2 Keystroke Precedence: The user has the option to specify that keystrokes be processed in the following order: user agent user interface, user agent extensions, content keystroke operations administered by the user agent (e.g., access keys), and executable content (e.g., key press events in scripts, etc.). (Level A)
4.1.3 No Keyboard Trap (Minimum): The user agent prevents keyboard traps as follows (Level A):
- (a) in the UI: 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)
- (b) in the rendered content: provides a documented direct keyboard command that will always restore keyboard focus to a known location (e.g., the address bar).
- (c) in the rendered content: provides a documented direct keyboard command that will always move keyboard focus to a subsequent focusable element
4.1.4 Separate Selection from Activation: The user has the option to have selection separate from activation
(e.g., navigating through the items in a dropdown menu without
activating any of the items). (Level A)
4.1.5 Discovery of Keyboard Commands: User has the option to have any *recognized* direct keyboard
commands displayed with their associated controls. (Level A)
4.1.6 Standard Text Area Navigation Conventions: Views that render text support the standard text area conventions for the platform including, but not necessarily limited to: 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, etc. (Level A)
4.1.7 Keyboard Navigation: The user can use the keyboard to navigate from group to group of focusable items and to traverse forwards and backwards all of the focusable items within each group. Groups include but are not limited to toolbars, panels, and user agent extensions. (Level AA)
4.1.8 Important Command Functions: Important command functions (e.g. related to navigation, display, content, information management, etc.) are available in a single keystroke. (Level AA)
4.1.9 Override of UI Keyboard Commands: The user can override any keyboard
shortcut binding for the user agent user interface except for
conventional bindings for the operating environment (e.g., for access to
help). The rebinding options must include single-key and key-plus-modifier keys if available in the operating environment. (Level A)
4.1.10 Specify preferred keystrokes: 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., for access to help)
4.1.11xx User Override of Accesskeys: The user can override any author supplied content keybinding (i.e. access key) that the user agent can *recognize*. The user must have an option to save the override of user interface keyboard shortcuts so that the rebinding persists beyond the current session. (Level AA)
4.1.11 Intergroup Navigation: Allow the user to navigate between and within groups of focusable controls (e.g., toolbars, dialogs, panels, etc.) (Level AAA)
Guideline 4.2 Provide access to event handlers.
4.2.1 All Available: The user can activate, through keyboard input alone, all
input device event handlers (including those for pointing devices, voice, etc.) that are
explicitly associated with the element designated by the content focus. (Level A) @@1.2 in UAAG10@@
4.2.2 Show All: For the element with content focus, the list
of input device event types for which there are
event handlers explicitly associated
with the element are provided. (Level A) @@9.6 in UAAG10@@
4.2.3 Activate All: The user can activate, as a group, all event
handlers of the same input device event type, for the same control. (Level A) @@1.2 in UAAG10@@
Guideline 4.3 Allow time-independent interaction.
4.3.1 Timing Adjustable: Where time limits for user input are recognized and controllable by the user agent, an option is provided to extend the time limit. (Level A) @@2.4 in UAAG10@@
Guideline 4.4 Help users avoid flashing that could cause seizures.
4.4.1 Below Threshold: The user interface "chrome" never violates the general flash or red flash thresholds. (Level A) @@NEW@@
4.4.2 Three Flashes: No part of the user interface "chrome" ever flashes more than three times in any one second period. (Level AAA) [WCAG 2.0] @@NEW@@
Guideline 4.5 Store preference settings.
4.5.1 Save Settings: User agent preference settings are stored between sessions. (Level A) @@NEW@@
4.5.2 User Profiles: The user can save and retrieve multiple sets of user agent preference settings. (Level AA) @@11.6 in UAAG10@@
4.5.3 Portable Profiles: Sets of preferences are stored as separate files (allowing them to be transmitted electronically). (Level AAA) @@NEW@@
4.5.4 Preferences Wizard: A "wizard" helps the user to configure (at least) the accessibility-related user agent preferences. (Level AAA) @@NEW@@
4.6.1 Search Rendered: The user can perform a search within rendered (e.g., not hidden with a style) content for text and text alternatives for a sequence
of characters from the document character set. (Level AA)@@9.8 in UAAG10@@
4.6.2 Bi-Directional: The user has the option of searching forward or backward (in document order) from any selected
or focused location in content. (Level AA)@@NEW@@
4.6.3 Match Found: When there is a match, both of the following are true (Level AA):
- (a) move: the viewport moves so that the matched text content is at least partially
within it, and@@9.8 in UAAG10@@
- (b) search again: the user can search for the next instance of the text from the
location of the match.@@9.8 in UAAG10@@
4.6.4 No Match: The user is alerted 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). (Level AA) @@9.8 in UAAG10@@
4.6.5 Case Insensitive: There is a case-insensitive search option. (Level AA) @@9.8 in UAAG10@@
Guideline 4.7 Provide structured navigation.
@@Video nav included@@
4.7.2 Configure Set of Important Elements: The user has the option to configure the set of important
elements for structured navigation, including by element type (e.g., headers). (Level AAA) @@9.10 in UAAG10@@
Note: For example, allow the user to navigate only
paragraphs, or only headings and paragraphs, or to suppress and restore
navigation bars, or to navigate within and among tables and table cells
Guideline 4.8 Provide tool bar configuration.
4.8.1 Configure Position: For graphical user agent user interfaces with tool bars, the user can add, remove and configure the position of user agent user interface
controls on those tool bars from a pre-defined set of controls. (Level AAA)@@11.7 in UAAG10@@
4.8.2 Restore Default: The user can restore the default tool
bar configuration. (Level AAA)@@11.7 in UAAG10@
Guideline 3.34.9 Provide control of content that may reduce accessibility.
3.3.A Change Rate of Time-Based Media: (@@MH)
3.3.B Track Enable/Disable of Time-Based Media: (@@KF)
3.3.C Visual Media Scaling (@@JR)
3.3.D Text Scaling (@@JR)
3.3.E Visual Media Brightness/Contrast (@@JA)
3.3.F Paused Time-Based Media (@@JS revealing state info, captions hotspots when paused)
3.3.1 Background Image Toggle: The user has the global option to hide/show background images. (Level A) @@3.1 in UAAG10@@
3.3.3 Time-Based Media Load-Only: The user has the option to load time-based media content @@DEFINE@@ such that the first frame is displayed (if video), but the content is not played until explicit user
request. (Level A) @@NEW@@
3.3.4 Execution Toggle: The user has the option to turn on/off the execution of executable content that would not normally be contained within a particular area (e.g., Javascript). (Level A)@@3.4 in UAAG10@@
3.3.5 Execution Placeholder: The user has the option to render a placeholder instead of executable content that would normally be contained within an on-screen area (e.g., Applet, Flash), until explicit user
request to execute. (Level A)@@NEW@@
3.3.6 Unavailable Content: If a resource is unavailable, render the next item on the alternative content stack, if any. Otherwise render a placeholder. (Level A)@@NEW@@
3.3.7 Retrieval Progress: Show the progress of content retrieval. (Level A) @@NEW@@
3.3.8 Slow Multimedia: The user can slow the presentation rate
of recognized prerecorded audio and animation content, such that all of the following are true (Level A):@@4.4 in UAAG10@@
- if only an audio track is present, provide at least one setting between 75% and 80% of the
original speed.
- if a visual track is present, provide at
least one setting between 40% and 60% of the original speed.
- when audio and video tracks are synchronized: above 75% of the original speed, maintain synchronization; below 75% the user agent is not required to render the audio track.
3.3.9 Stop/Pause/Resume Multimedia: The user can stop, pause, and resume
rendered audio and animation content (including
video and animated images) that last three or more seconds at their default
playback rate. (Level A)@@4.5 in UAAG10@@
3.3.10 Navigate Multimedia: The user can navigate efficiently
within rendered audio and animations (including video and animated
images) that last three or more seconds at their default playback
rate. (Level A)@@4.5 in UAAG10@@
Applicability Notes:
The guideline only applies to images, animations, video, audio, etc. that the user agent can recognize.
@@Tech=Provide the user with the ability to toggle whether the base user agent executes content that it is able to . - if cond. content exists reveal it (2.3)
@@Tech=Provide the user with the ability to toggle the loading of plugins that execute content the base browser is unable to execute - if cond. content exists reveal it (2.3)
Principle 5: Ensure that user interface is understandable
Guideline 5.1 Help users avoid unnecessary messages.
5.1.1 Option to Ignore: The user has the option to turn off rendering of non-essential or low priority text messages, based on priority properties defined by the author (e.g., ignoring messages marked "polite" using ARIA ). (Level AA) @@NEW@@
Guideline 5.2 Help users avoid and correct mistakes.
5.2.1 Form Submission: The user has the option to confirm (or cancel) any
form submission made while content focus is not on the submitting control (e.g., forms that submit when Enter is pressed). (Level AA) @@5.5 in UAAG10@@
Guideline 5.3 Document the user agent user interface
including all accessibility features.
5.3.1 Accessible Format: At least one
version of the documentation is either (Level A):
@@12.1 in UAAG10@@
- (a) "A" accessible: Web content and conforms to WCAG 2.0 Level "A" (although it is not necessary
for the documentation to be delivered on-line), or,
- (b) accessible platform format: not Web content and conforms to a published accessibility
benchmark that is identified in the conformance
claim (e.g.,
when platform-specific documentation systems are used).
5.3.2 Document Accessibility Features: All user agent
features that benefit accessibility @@DEFINE - as specified in the conformance claim@@ are documented. (Level A) @@12.2 in UAAG10@@
5.3.3 Changes Between Versions: Changes to features that benefit
accessibility since the
previous version of the user agent are documented. (Level AA) @@12.4 in UAAG10@@
5.3.4 Centralized View: There is a centralized view of all
features of the user agent that benefit accessibility, in a dedicated section
of the documentation. (Level AA)@@12.5 in UAAG10@@
5.3.5 Context Sensitive Help: There is context-sensitive help on all user agent features that benefit accessibility. (Level AAA) @@NEW@@
Conformance
@@Ed. This section is still under development@@
This glossary is normative.
- activate
- In the context of rendered content this means to execute or carry out one or more behaviors associated with an
enabled element.
In the context of the user interface "chrome", this means to execute or carry out one or more behaviors associated with a component of the
user agent user interface.
The effect of activation depends on the type of the
user interface control.
For instance, when a link is activated, the user agent generally retrieves the linked
Web resource.
When a form element is activated, it may change state (e.g., check boxes) or may take user input (e.g., a text entry field).
- accessibility platform architecture
- A programmatic interface that is specifically engineered to enhance communication between mainstream software applications and assistive technologies (e.g., MSAA and IAccessible2 for Windows 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 DOM.
- alert
- To make the user aware
of some event, without requiring acknowledgement. For example, the user agent
may alert the user that new content is available on the server by displaying a
text message in the user agent's status bar.
- alternative content
- Content that should be made available to the user only under certain conditions (e.g., based on user preferences or operating environment limitations). Some examples include:
- The
alt attribute of the IMG element in HTML 4 [HTML4].
OBJECT elements in HTML 4 [HTML4].- The
switch element and test attributes in SMIL 1.0 [SMIL].
- The
NOSCRIPT and NOFRAMES elements in HTML 4 [HTML4].
Note: Specifications vary in how completely they define how and when to render alternative content.
- alternative content stack:
- The set of alternative content items for a given position in content. 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).
- animation
- Content that, when rendered, creates a visual
movement effect automatically (i.e., without explicit user interaction). This
definition of animation includes video and animated images. Animation
techniques include:
- graphically displaying a sequence of snapshots within the same region
(e.g., as is done for video and animated images). The series of snapshots may
be provided by a single resource (e.g., an animated GIF image) or from distinct
resources (e.g., a series of images downloaded continuously by the user
agent).
- scrolling text (e.g., achieved through markup or style sheets).
- displacing graphical objects around the viewport (e.g., a picture of a ball
that is moved around the viewport giving the impression that it is bouncing off
of the viewport edges). For instance, the SMIL 2.0
[SMIL20] animation modules explain
how to create such animation effects in a declarative manner (i.e., not by
composition of successive snapshots).
- applet
- A program (generally written in the Java
programming language) that is part of content
and that the user agent executes.
- application
programming interface (API), conventional input/output/device
API
- An application programming interface
(API) defines how
communication may take place between applications.
Implementing APIs that are independent of a particular operating environment
(as are the W3C DOM Level 2 specifications) may reduce implementation costs for
multi-platform user agents and promote the development of multi-platform
assistive technologies. Implementing conventional APIs for a particular
operating environment may reduce implementation costs for assistive technology
developers who wish to interoperate with more than one piece of software
running on that operating environment.
A "device API" defines how communication may take place
with an input or output device such as a keyboard, mouse, or video card.
In this document, an "input/output API" defines how
applications or devices communicate with a user agent. As used in this
document, input and output APIs include, but are not limited to, device APIs.
Input and output APIs also include more abstract communication interfaces than
those specified by device APIs. A "conventional input/output API" is one that
is expected to be implemented by software running on a particular operating
environment. For example, the conventional input APIs of the
user agent are for the mouse and
keyboard. For touch screen devices or mobile devices, conventional input
APIs may include stylus, buttons, and voice. The graphical
display and sound card are considered conventional output devices for a
graphical desktop computer environment, and each has an associated
API.
- assistive technology
- In the context of this document, an assistive technology
is a user agent that:
- relies on services (such as retrieving Web
resources 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.
- 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).
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.
- Beyond this document, 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 [AT1998]:
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.
- audio
- Content that
encodes prerecorded sound.
- audio-only presentation
- Content consisting exclusively of one or more audio tracks presented concurrently or in series (e.g., musical performances, radio-style news broadcasts, narrations).
- audio track
- Content rendered as sound through an
audio viewport. 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).@@add mention of video@@
- audio description - also called described video, video description and descriptive narration
- An equivalent alternative that takes the form of narration added to the audio 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 extended audio description, the video is paused so that there is time to add additional description.
- authors
- The people who have worked either alone or collaboratively to create the content (includes content authors, designers, programmers, publishers, testers, etc.).
- author styles
- Style property values that come from content (e.g., style sheets within a document, that are associated with a document, or that are generated by a server).
- background images
- Images that are rendered on the base background.
- base background
- 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.).
- blinking text
- Text whose visual rendering alternates between visible and invisible at any rate of change.
- captions
- An equivalent alternative that takes the form of text presented and synchronized with synchronized 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. Open captions are captions that are always
rendered with a visual track; they cannot be turned off. Closed
captions are captions that may be turned on and off. The
captions requirements of this document assume that the user agent can recognize the captions as such.
Note: Other terms that include the word "caption" may have
different meanings in this document. For instance, a "table caption" is a title
for the table, often positioned graphically above or below the table. In this
document, the intended meaning of "caption" will be clear from
context.
- character encoding
- A mapping from a character set
definition to the actual code units used to represent the data. Refer to the
Unicode specification [UNICODE] for more information
about character encodings. Refer to "Character Model for the World Wide Web"
[CHARMOD] for additional
information about characters and character encodings.
- collated text
transcript
- A collated text transcript is a text
equivalent of a movie or other animation. More specifically, it is the
combination of the text transcript of the
audio track and the text equivalent of
the visual track. 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
text transcript and
audio description. Collated text
transcripts are essential for individuals who are deaf-blind.
- configure, control, user option
- In the context of this document, the verbs "to control"
and "to configure" share in common the idea of governance such as a user may
exercise over interface layout, user agent behavior, rendering style, and other
parameters required by this document. Generally, the difference in the terms
centers on the idea of persistence. When a user makes a change by
"controlling" a setting, that change usually does not persist beyond that user
session. On the other hand, when a user "configures" a setting, that setting
typically persists into later user sessions. Furthermore, the term "control"
typically means that the change can be made easily (such as through a keyboard
shortcut) and that the results of the change occur immediately. The term
"configure" typically means that making the change requires more time and
effort (such as making the change via a series of menus leading to a dialog
box, or via style sheets or scripts). The results of "configuration" might not
take effect immediately (e.g., due to time spent reinitializing the system,
initiating a new session, or rebooting the system).
In order to be able to configure and control the user agent, the user needs
to be able to "write" as well as "read" values for these parameters.
Configuration settings may be stored in a profile.
The range and granularity of the changes that can be controlled or configured
by the user may depend on limitations of the operating environment or
hardware.
Both configuration and control can apply at different "levels": across
Web resources (i.e., at the user agent
level, or inherited from the operating environment), to the
entirety of a Web resource, or to components of a Web resource (e.g., on a
per-element basis).
A global configuration is one
that applies across elements of the same Web resource, as well as across Web
resources.
User agents may allow users to choose configurations based on various
parameters, such as hardware capabilities or natural language preferences.@@POINT TO NEW GUIDELINE ON HOW TO SAVE SETTTINGS@@
Note: In this document, the noun "control" refers to a
user interface
control.
- content
- In this specification, the noun "content" is used in three
ways:
- It is used to mean the document object as a
whole or in parts.
- It is used to mean the content of an HTML or XML element, in the sense
employed by the XML 1.0 specification ([XML], section 3.1): "The text between
the start-tag and end-tag is called the element's content." Context should
indicate that the term content is being used in this sense.
- It is used in the terms non-text content and
text content.
empty
content (which may be alternative content) is either a
null value or an empty string (i.e., one that is zero characters long). For
instance, in HTML, alt="" sets the value of the alt
attribute to the empty string. In some markup languages, an element may have
empty content (e.g., the HR element in HTML).
- device-independence
- In this document, device-independence refers to the
desirable property that operation of a user agent feature is not bound to only
one input or output device.
- document object,
Document Object Model
(DOM)
- In general usage, the term "document object" refers to the
user agent's representation of data (e.g., a document). This data generally
comes from the document source, but
may also be generated (e.g., from style sheets, scripts, or transformations),
produced as a result of preferences set within the user agent, or added as the
result of a repair performed automatically by the user agent. Some data that is
part of the document object is routinely rendered (e.g., in HTML, what
appears between the start and end tags of elements and the values of attributes
such as
alt, title, and summary). Other
parts of the document object are generally processed by the user agent without
user awareness, such as
DTD- or schema-defined
names of element types and attributes, and other attribute values such as
href and id. Most of the requirements of this
document apply to the document object after its construction. However, a few
guidelines (e.g., @@) may affect the construction of the document
object.
- A "document object model" is the abstraction that governs
the construction of the user agent's document object. The document object model
employed by different user agents may vary in implementation and sometimes in
scope. This specification requires that user agents implement the
APIs defined
in Document Object Model (DOM) Level 2 specifications
([DOM2CORE] and
[DOM2STYLE]) for access to
HTML, XML, and CSS
content. These DOM APIs allow authors to access and modify the content via a
scripting language (e.g., JavaScript) in a consistent manner across different
scripting languages.
- document character set
- In this document, a document character set (a concept from
SGML) is a collection of abstract characters that a format specification allows
to appear in an instance of the format. A document character set consists of:
- A "repertoire": A set of abstract characters, such as the Latin letter "A,"
the Cyrillic letter "I," and the Chinese character meaning "water."
- Code positions: A set of integer references to characters in the
repertoire.
For instance, the character set required by the HTML 4 specification
[HTML4] is defined in the Unicode
specification [UNICODE]. Refer to "Character
Model for the World Wide Web" [CHARMOD] for more information
about document character sets.
- document source,
text
source
- In this document, the term "document source" refers to the
data that the user agent receives as the direct result of a request for a
Web resource (e.g., as the result of an
HTTP/1.1 [RFC2616] "GET", or as the result
of viewing a resource on the local file system). The document source generally
refers to the "payload" of the user agent's request, and does not generally
include information exchanged as part of the transfer protocol. The document
source is data that is prior to any repair by the user agent (e.g., prior to
repairing invalid markup). "Text source" refers to the text portion of
the document source.
- documentation
- Documentation refers to 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., some parts may be delivered on CD-ROM, others on the Web).
See guideline 5.3 for information about documentation requirements.
- element, element type
- This document uses the terms "element" and "element type"
primarily in the sense employed by the XML 1.0 specification
([XML], 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. The document
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).
- enabled element,
disabled
element
- An enabled element is a piece of content
with associated behaviors that can be activated through the user interface or
through an API. The set
of elements that a user agent enables is generally derived from, but is not
limited to, the set of interactive
elements defined by implemented markup languages.
Some elements may only be enabled elements for part of a user session. For
instance, an element may be disabled by a script as the result of user
interaction. Or, an element may only be enabled during a given time period
(e.g., during part of a SMIL 1.0 [SMIL] presentation). Or, the user
may be viewing content in "read-only" mode, which may disable some
elements.
A disabled element is a piece of content that is potentially an
enabled element, but is not in the current session. One example of a disabled
element is a menu item that is unavailable in the current session; it might be "grayed out" to show that it is disabled. Generally, disabled elements will be
interactive elements that are not
enabled in the current session. This document distinguishes disabled elements
(not currently enabled) from non-interactive elements
(never enabled).
For the requirements of this document, user
selection does not constitute user interaction with enabled elements. See
the definition of content focus.
Note: Enabled and disabled elements come from content; they
are not part of the user agent user
interface.
Note: The term "active element" is not used in this
document since it may suggest several different concepts, including:
interactive element, enabled element, an element "in the process of being
activated" (which is the meaning of :active in CSS2
[CSS2], for example).
- equivalent (for content)
- The term "equivalent" is used in this document as it is
used in the Web Content Accessibility Guidelines 1.0
[WCAG10]:
Content is "equivalent" to other content when both fulfill essentially the
same function or purpose upon presentation to the user. In the context of this
document, the equivalent must fulfill essentially the same function for the
person with a disability (at least insofar as is feasible, given the nature of
the disability and the state of technology), as the primary content does for
the person without any disability.
Equivalents include text equivalents
(e.g., text equivalents for images, text transcripts for audio tracks, or
collated text transcripts for a movie) and non-text equivalents (e.g., a
prerecorded audio description of a visual track of a movie, or a sign
language video rendition of a written text).
Each markup language defines its own mechanisms for specifying
alternative content, and these
mechanisms may be used by authors to provide text equivalents. For instance, in
HTML 4 [HTML4] or SMIL 1.0
[SMIL], authors may use the
alt attribute to specify a text equivalent for some elements. In
HTML 4, authors may provide equivalents and other alternative content in
attribute values (e.g., the summary attribute for the
TABLE element), in element content (e.g., OBJECT for
external content it specifies, NOFRAMES for frame equivalents, and
NOSCRIPT for script equivalents), and in prose. Please consult the
Web Content Accessibility Guidelines 1.0
[WCAG10] and its associated
Techniques document [WCAG10-TECHS] for more
information about equivalents.
- events and
scripting, event handler, event type
- User agents often perform a task when an event having a
particular "event type" occurs, including user interface events, changes to
content, loading of content, and requests from the operating environment. Some
markup languages allow authors to specify that a script, called an
event
handler, be executed when an event of a given type occurs. An
event handler is explicitly associated with an
element when the event handler is associated with that element
through markup or the DOM. The term "event bubbling" describes a
programming style where a single event handler dispatches events to more than
one element. In this case, the event handlers are not explicitly associated
with the elements receiving the events (except for the single element that
dispatches the events).
Note: The combination of HTML, style sheets, the Document
Object Model (DOM), and scripting is commonly referred to as "Dynamic HTML" or DHTML. However, as there is no W3C specification that
formally defines DHTML, this document only refers to event handlers and
scripts.
- explicit user request
- In this document, the term "explicit user request" refers
to any user interaction through the user agent user
interface (not through rendered content),
the focus, or the selection. User requests are made, for
example, through user agent user interface
controls and keyboard bindings.
- 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.
- Note: Users make mistakes. For example, a
user may inadvertently respond "yes" to a prompt instead of "no." In this
document, this type of mistake is still considered an explicit user
request.
- focus, content focus,
user interface
focus, current focus
- In this document, the term "content focus" refers to a user agent mechanism that has all of the following
properties:
- It designates zero or one element in content
that is either enabled or
disabled. In general, the focus
should only designate enabled elements, but it may also designate disabled
elements.
- It has state, i.e., it may be "set" on an enabled element, programmatically
or through the user interface. Some content specifications (e.g., HTML, CSS)
allow authors to associate behavior with focus set and unset
events.
- Once it has been set, it may be used to trigger other behaviors associated
with the enabled element (e.g., the user may activate a link or change the
state of a form control). These behaviors may be triggered programmatically or
through the user interface (e.g., through keyboard events).
User interface mechanisms may resemble content focus, but do not satisfy all
of the properties. For example, designers of word processing software often
implement a "caret" that indicates the current location of text input or
editing. The caret may have state and may respond to input device events, but
it does not enable users to activate the behaviors associated with enabled
elements.
The user interface focus shares the properties of the content focus except
that, rather than designating pieces of content, it designates zero or one
control of the
user agent user interface
that has associated behaviors (e.g., a radio button, text box, or menu).
On the screen, the user agent may highlight the content focus in a variety of
ways, including through colors, fonts, graphics, and magnification. The user
agent may also highlight the content focus when rendered as synthesized speech,
for example through changes in speech prosody. The
dimensions of the rendered content focus may
exceed those of the viewport.
In this document, each viewport is expected to have at most one content
focus and at most one user interface focus. This document includes requirements
for content focus only, for user interface focus only, and for both. When a
requirement refers to both, the term "focus" is used.
When several viewports coexist, at most one viewport's
content focus or user interface focus responds to input
events; this is called the current focus.
- graphical
- In this document, the term "graphical" refers to
information (including text, colors, graphics, images, and animations) rendered
for visual consumption.
- highlight
- In this document, "to highlight" means to emphasize
through the user interface. For example, user agents highlight which content is
selected or focused. Graphical highlight mechanisms include dotted boxes,
underlining, and reverse video. Synthesized speech highlight mechanisms include
alterations of voice pitch and volume ("speech prosody").
- image
- This document uses the term "image" to refer (as is
commonly the case) to pictorial content. However, in this
document, term image is limited to static (i.e., unmoving) visual information.
See also the definition of animation.
- important elements
- This specification intentionally does not identify which "important elements" must be navigable as 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 Techniques document [UAAG10-TECHS] for information about identifying and navigating important elements.
- input configuration
- An input configuration is the set of "bindings" between
user agent functionalities and user interface 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
accesskey attribute of HTML 4
[HTML4]).
- interactive element,
non-interactive
element,
- An interactive element is piece of content that, by specification or by programmatic enablement, may have associated behaviors to be executed or carried out as a result of user or programmatic interaction."
@@edit the rest@@For instance, the interactive
elements of HTML 4
[HTML4] include: links, image maps,
form elements, elements with a value for the longdesc attribute,
and elements with event handlers
explicitly associated with them (e.g., through the various "on" attributes).
The role of an element as an interactive element is subject to applicability. A non-interactive
element is an element that, by format specification, does not have associated
behaviors. The expectation of this document is that interactive elements become
enabled elements in some sessions,
and non-interactive elements never become enabled elements.
- natural language
- Natural language is spoken, written, or signed human
language such as French, Japanese, and American Sign Language. On the Web, the
natural language of content may be specified by markup or HTTP
headers. Some examples include the
lang attribute in HTML 4
([HTML4] section 8.1), the
xml:lang
attribute in XML 1.0
([XML], section 2.12), the
hreflang attribute for links in HTML 4
([HTML4], section 12.1.5), the HTTP
Content-Language header ([RFC2616], section 14.12) and the
Accept-Language request header ([RFC2616], section 14.4). See also
the definition of script.
- normative, informative [WCAG 2.0, ATAG 2.0]
- What is identified as "normative" is required for
conformance (noting that one may
conform in a variety of well-defined ways to this document). What is identified
as "informative" (sometimes, "non-normative") is never required for
conformance.
- operating environment
- 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.
- override
- In this document, the term "override" means that one
configuration or behavior preference prevails over another. Generally, the
requirements of this document 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).
- placeholder
- 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 repair content (e.g., when an image
cannot be found). Placeholders can be any type of content, including text,
images, and audio cues. Placeholders should identify the technology of the object of which it is holding the place. Placeholders will appear in the alternative content stack.
- plug-in [ATAG 2.0]
- A plug-in is a program that runs as part of the user agent
and that is not part of content. Users generally
choose to include or exclude plug-ins from their user agent.
- point of regard
- The point of regard is a position in
rendered content 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
dimensions of the viewport (see the
definition of rendered content 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, content focus, and
selection. The stability of the point of
regard is addressed by @@.
- profile
- 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
operating environments 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 platforms.
- prompt [ATAG 2.0]
- Any user agent initiated
request for a decision or piece of information from users.
- properties, values, and
defaults
- 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: on screen, on
paper, through loudspeakers, on a braille display, or on a mobile device. Style
information (e.g., fonts, colors, and 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 this
document, the term
"property"
has the meaning defined in CSS 2 ([CSS2], section 3). A reference to "styles" in this document means a set of style-related properties. The value
given to a property by a user agent at installation is called the property's
default value.
- recognize
- 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
H1
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 this document 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
conformance for more information
about applicability.
In practice, user agents will rely heavily on information that the author
has encoded in a markup language or style sheet language. On the other hand,
behaviors, style, meaning encoded in a script, and
markup in an unfamiliar XML namespace may not be recognized by the user agent
as easily or at all. The Techniques document
[UAAG10-TECHS] lists some
markup known to affect accessibility that user agents can recognize.
- rendered content,
rendered
text
- Rendered content is the part of content
that the user agent makes available to the user's senses of sight and hearing
(and only those senses for the purposes of this document). 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 anything else in content that, once processed, may be perceived through
sight and hearing.
- The term "rendered text" refers to text content
that is rendered in a way that communicates information about the characters
themselves, whether visually or as synthesized speech.@@add captions, etc.@@
- In the context of this document,
invisible
content is content that is not rendered but that may influence
the graphical rendering (e.g., layout) of other content. Similarly,
silent
content 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.
- repair content,
repair
text
- In this document, the term "repair content" refers to
content generated by the user agent in order to correct an error condition. "Repair text" refers to the text portion of repair content.
Some error conditions that may lead to the generation of repair content
include:
- Erroneous or incomplete content (e.g., ill-formed markup, invalid markup,
or missing alternative
content that is required by format specification);
- 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).
This document does not require user agents to include repair content in the
document object. Repair content
inserted in the document object should conform to the Web Content Accessibility
Guidelines 1.0 [WCAG10]. For more information
about repair techniques for Web content and software, refer to "Techniques for
Authoring Tool Accessibility Guidelines 1.0"
[ATAG10-TECHS].
- script
- In this document, 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
[UNICODE] to mean "A collection of
symbols used to represent textual information in one or more writing
systems."
- Information encoded in (programming) scripts may be
difficult for a user agent to recognize. 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).
- selection,
current
selection
- In this document, the term "selection" refers to a user
agent mechanism for identifying a (possibly empty) range of
content. Generally, user agents limit the
type of content that may be selected to text content (e.g., one or more
fragments of text). In some user agents, the value of the
selection is constrained by the structure
of the document tree.
On the screen, the selection may be highlighted in a variety of ways, including
through colors, fonts, graphics, and magnification. The selection may also be
highlighted when rendered as synthesized speech, for example through changes in
speech prosody. The dimensions of the rendered selection may exceed those of
the viewport.
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.
The selection has state, i.e., it may be "set," programmatically or through
the user interface.
In this document, each viewport is expected to have at most one selection.
When several viewports coexist, at most one viewport's
selection responds to input events; this is called the current selection.
Note: Some user agents may also implement a selection for
designating a range of information in the user agent user interface.
The current document only includes requirements for a content
selection mechanism.
- serial access,
sequential navigation
- In this document, the expression "serial access" refers to
one-dimensional 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.
The expression "sequential navigation" refers to navigation through an
ordered set of items (e.g., the enabled elements 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).
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.
- support, implement, conform
- In this document, the terms "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 API (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 and satisfies its conformance criteria.
- synchronize
- In this document, "to synchronize" refers to the act of
time-coordinating two or more presentation components (e.g., a
visual track 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 (slow reading speeds, large font sizes, high need
for review or repeat functions), and content that is sub-optimal in terms of
accessibility.
- technology (Web content) - or shortened to technology [WCAG 2.0, ATAG 2.0]
- A mechanism for encoding instructions to be rendered, played or executed by user agents. Web Content technologies may include markup languages, data formats, or programming languages that authors 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.
- text
- In this document, the term "text" used by itself refers to
a sequence of characters from a markup language's document character set. Refer
to the "Character Model for the World Wide Web"
[CHARMOD] for more information
about text and characters. Note: This document makes use of
other terms that include the word "text" that have highly specialized meanings:
collated text transcript,
non-text content,
text content, non-text element,
text element, text
equivalent, and text transcript.
- text content,
non-text
content, text element,
non-text
element, text
equivalent, non-text equivalent
- As used in this document a "text element" adds
text characters to either
content or the user interface. Both in the Web
Content Accessibility Guidelines 1.0 [WCAG10] and in this document, 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:
- visually-displayed text benefits users who are deaf and adept in reading
visually-displayed text;
- synthesized speech benefits users who are blind and adept in use of
synthesized speech;
- braille benefits users who are blind, and possibly deaf-blind, and adept at
reading braille.
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., JPEG).
"Text content" is content that is composed of one or more text elements. A "text equivalent" (whether in content or the user interface) is an
equivalent composed of one
or more text elements. Authors generally provide text equivalents for content
by using the alternative
content mechanisms of a specification.
A "non-text element" is an element (in content or the user interface) that
does not have the qualities of a text element. "Non-text content" is composed
of one or more non-text elements. A "non-text equivalent" (whether in content
or the user interface) is an equivalent
composed of one or more non-text elements.
- text decoration
- In this document, a "text decoration" is any stylistic
effect that the user agent may apply to visually rendered text 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.
- text format
- Any media object given an Internet media type of "text" (e.g., "text/plain", "text/html", or "text/*") as defined in RFC 2046 [RFC2046], section 4.1, or any media object identified by Internet media type to be an XML document
(as defined in [XML], section 2) or SGML application.
Refer, for example, to Internet media types defined in "XML Media Types" [RFC3023].
- text transcript
- A text transcript is a text equivalent of audio
information (e.g., an audio-only presentation or
the audio track of a movie or other
animation). It 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
captions and collated text
transcripts.
- user agent
- In this document, the term "user agent" is used in two
ways:
- The software and documentation components that together,
conform to the requirements of this
document. This is the most common use of the term in this document and is the
usage in the guidelines.
- Any software that retrieves and renders Web content for users. This may
include Web browsers, browser extensions, media players, plug-ins,
and other programs — including assistive technologies —
that help in retrieving and rendering Web content.
- user agent default styles
- User agent default styles are style property
values 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, XML 1.0
[XML] does not specify default styles
for XML documents. HTML 4
[HTML4] does not specify default
styles for HTML documents, but the CSS 2
[CSS2] specification suggests a
sample
default style sheet for HTML 4 based on current practice.
- user interface,
user interface
control
- For the purposes of this document, user interface includes
both:
- the user agent user
interface, 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
content.
- the "content user interface," i.e., the enabled elements that are part of
content, such as form controls, links, and applets.
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 @@.
The term "user interface control" refers to a component of the user agent
user interface or the content user interface, distinguished where
necessary.
- user styles
- User styles are style property
values that come from user interface settings, user style sheets, or other
user interactions.
- view, viewport
- The user agent renders content 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). User agent user interface
controls such as prompts, menus, and alerts are not viewports.
Graphical and tactile viewports have two spatial dimensions. 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.
When several viewports coexist, only one has the current focus at a given moment. This
viewport is highlighted to make it stand out.
User agents may render the same content in a variety of ways; each rendering
is called a view. 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.
"top-level" viewports are viewports that are not contained within other user agent viewports.
- visual-only
presentation
- A visual-only presentation is content consisting
exclusively of one or more visual tracks presented
concurrently or in series. A silent movie is an example of a visual-only
presentation.
- visual track
- A visual object is content rendered through a graphical
viewport. 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.
- voice browser
- From "Introduction and Overview of W3C Speech Interface
Framework" [VOICEBROWSER]: "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."
- web resource
- Anything that
can be identified by a Uniform Resource Identifier (URI).
Appendix B: How to refer to UAAG 2.0 from other documents
@@Ed. This section is still under development@@
Appendix C: References
This section is informative.
For the latest version of any W3C specification please consult the list of W3C Technical Reports at http://www.w3.org/TR/. Some documents listed below may have been superseded since the publication of this document.
Note: In this document, bracketed labels such as "[WCAG20]" link to the corresponding entries in this section. These labels are also identified as references through markup.
- [CSS1]
- "Cascading
Style Sheets (CSS1) Level 1 Specification," 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.
- [CSS2]
- "Cascading
Style Sheets, level 2 (CSS2) Specification," 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/.
- [DOM2CORE]
- "Document
Object Model (DOM) Level 2 Core Specification," 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/.
- [DOM2STYLE]
- "Document
Object Model (DOM) Level 2 Style Specification," 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/.
- [INFOSET]
- "XML
Information Set," J. Cowan and R. Tobin, eds., 24 October 2001. This
W3C Recommendation is http://www.w3.org/TR/2001/REC-xml-infoset-20011024/.
- [RFC2046]
- "Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types," N. Freed, N. Borenstein, November 1996.
- [WCAG10]
- "Web
Content Accessibility Guidelines 1.0," W. Chisholm, G. Vanderheiden,
and I. Jacobs, eds., 5 May 1999. This W3C Recommendation is
http://www.w3.org/TR/1999/WAI-WEBCONTENT-19990505/.
- [XML]
- "Extensible
Markup Language (XML) 1.0 (Second Edition)," 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.
- [AT1998]
- The Assistive
Technology Act of 1998.
- [ATAG10]
- "Authoring Tool Accessibility Guidelines 1.0," 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/.
- [ATAG10-TECHS]
- "Techniques
for Authoring Tool Accessibility Guidelines 1.0," J. Treviranus, C.
McCathieNevile, J. Richards, eds., 29 Oct 2002. This W3C Note is
http://www.w3.org/TR/2002/NOTE-ATAG10-TECHS-20021029/.
- [CHARMOD]
- "Character
Model for the World Wide Web," M. Dürst and F. Yergeau, eds., 30
April 2002. This W3C Working Draft is http://www.w3.org/TR/2002/WD-charmod-20020430/. The
latest version is available at
http://www.w3.org/TR/charmod/.
- [DOM2HTML]
- "Document
Object Model (DOM) Level 2 HTML Specification," 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
latest version is
available at http://www.w3.org/TR/DOM-Level-2-HTML/.
- [HTML4]
- "HTML 4.01
Recommendation," 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/.
- [RFC2616]
- "Hypertext Transfer
Protocol — HTTP/1.1," J. Gettys, J. Mogul, H. Frystyk, L.
Masinter, P. Leach, T. Berners-Lee, June 1999.
- [RFC3023]
- "XML Media
Types," M. Murata, S. St. Laurent, D. Kohn, January 2001.
- [SMIL]
- "Synchronized
Multimedia Integration Language (SMIL) 1.0 Specification," P.
Hoschka, ed., 15 June 1998. This W3C Recommendation is
http://www.w3.org/TR/1998/REC-smil-19980615/.
- [SMIL20]
- "Synchronized
Multimedia Integration Language (SMIL 2.0) Specification," J. Ayars,
et al., eds., 7 August 2001. This W3C Recommendation is
http://www.w3.org/TR/2001/REC-smil20-20010807/.
- [SVG]
- "Scalable
Vector Graphics (SVG) 1.0 Specification," J. Ferraiolo, ed., 4
September 2001. This W3C Recommendation is
http://www.w3.org/TR/2001/REC-SVG-20010904/.
- [UAAG10]
- "User Agent Accessibility Guidelines 1.0," 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/.
- [UAAG10-CHECKLIST]
- An appendix to this document lists all of the checkpoints, sorted by
priority. The checklist is available in either tabular
form or list
form.
- [UAAG10-ICONS]
- Information about UAAG
1.0 conformance icons and their usage is available at
http://www.w3.org/WAI/UAAG10-Conformance.
- [UAAG10-SUMMARY]
- An appendix to this document provides a
summary of the goals and structure of User Agent
Accessibility Guidelines 1.0.
- [UAAG10-TECHS]
- "Techniques for User
Agent Accessibility Guidelines 1.0," I. Jacobs, J. Gunderson, E.
Hansen, eds. The latest draft of the techniques document is available at
http://www.w3.org/TR/UAAG10-TECHS/.
- [UNICODE]
- "The Unicode
Standard, Version 3.2." This technical report of the
Unicode Consortium is available at
http://www.unicode.org/unicode/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
http://www.unicode.org/unicode/standard/versions/.
For information about character encodings, refer to
Unicode Technical Report
#17 "Character Encoding Model".
- [VOICEBROWSER]
- "Introduction
and Overview of W3C Speech Interface Framework," J. Larson, 4
December 2000. This W3C Working Draft is
http://www.w3.org/TR/2000/WD-voice-intro-20001204/. The
latest version is available at
http://www.w3.org/TR/voice-intro/. This document includes references to
additional W3C specifications about voice browser technology.
- [W3CPROCESS]
- "World Wide
Web Consortium Process Document," I. Jacobs ed. The 19 July 2001
version of the Process Document is
http://www.w3.org/Consortium/Process-20010719/. The
latest version is available
at http://www.w3.org/Consortium/Process/.
- [WCAG10-TECHS]
- "Techniques for Web
Content Accessibility Guidelines 1.0," W. Chisholm, G. Vanderheiden,
and I. Jacobs, eds., 6 November 2000. This W3C Note is
http://www.w3.org/TR/2000/NOTE-WCAG10-TECHS-20001106/. The
latest version is available at
http://www.w3.org/TR/WCAG10-TECHS/. Additional format-specific techniques
documents are available from this Note.
- [WEBCHAR]
- "Web
Characterization Terminology and Definitions Sheet," 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.
- [XAG10]
- "XML Accessibility Guidelines 1.0," 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 latest version is available at http://www.w3.org/TR/xag.
- [XHTML10]
- "XHTML[tm] 1.0: The Extensible HyperText Markup Language," S. Pemberton, et al., 26 January 2000. This W3C Recommendation is http://www.w3.org/TR/2000/REC-xhtml1-20000126/.
- [XMLDSIG]
- "XML-Signature Syntax and Processing," D. Eastlake, J. Reagle, D. Solo, eds., 12 February 2002. This W3C Recommendation is http://www.w3.org/TR/2002/REC-xmldsig-core-20020212/.
- [XMLENC]
- "XML Encryption Syntax and Processing," D. Eastlake, J. Reagle, eds., 10 December 2002. This W3C Recommendation is http://www.w3.org/TR/2002/REC-xmlenc-core-20021210/.
Appendix D: Acknowledgments
Participants active in the UAWG prior publication:
- Jim Allan (WG Chair, Texas School for the Blind and Visually Impaired)
- Judy Brewer (W3C)
- Kelly Ford (Microsoft)
- David Poehlman
- Jan Richards (Adaptive Technology Resource Centre, University of Toronto)
- Gregory Rosmaita
Other previously active UAWG participants and other contributors to UAAG 2.0:
- Cathy Laws (IBM)
- Peter Parente (IBM)
This document would not have been possible without the work of those who contributed to UAAG 1.0.
This publication has been funded in part with Federal funds from the U.S. Department of Education under contract number ED05CO0039. 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.
Appendix E: Checklist
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Appendix F: Comparison of UAAG 1.0 guidelines to UAAG 2.0
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