UAAG 2.0 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, UAAG 2.0 will benefit developers of assistive technologies because it
explains what types of information and control an assistive technology may
expect from a conforming user agent. Technologies not addressed directly by
UAAG 2.0 (e.g. technologies for braille rendering) will be essential to
ensuring Web access for some users with disabilities.
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Superseded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 is the internal working draft used by the UAWG and is updated continuously and without notice. This document has no formal standing within W3C. Please consult the group's home page and the W3C technical reports index for information about the latest publications by this group.
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.
This section is informative.
A user agent is any software that retrieves and presents Web content for
end users. User agents include Web browsers, media players, @@ Editors' Note: virtual worlds?? @@ and plug-ins that help in retrieving, rendering
and interacting with Web content. UAAG 2.0 specifies requirements that,
if satisfied by user agent developers, will lower barriers
to accessibility.
Overview
Accessibility involves a wide range of disabilities. These include visual,
auditory, physical, speech, cognitive, language, learning, neurological
disabilities, and disabilities related to ageing. UAAG 2.0 emphasizes
the goal of ensuring that all users, including users with disabilities, have
control over their environment for accessing the Web. Key methods for
achieving that goal include:
- optional self-pacing
- configurability
- device independence
- interoperability
- direct support for both graphical and auditory output
- adherence to published conventions.
Some users have more than one disability, and the needs of different
disabilities may contradict. Thus, many of the requirements in UAAG 2.0
use configuration to ensure that a functionality designed to
improve accessibility for one user does not interfere with accessibility for
another. A default user agent setting may be useful for one user but
interfere with accessibility for another, therefore UAAG 2.0 prefers
configuration requirements rather than requirements for default settings. For
some content, a feature required by UAAG 2.0 may be ineffective or cause
content to be less accessible, making it imperative that the user be able to
turn off the feature. To avoid overwhelming users with an abundance of
configuration options, UAAG 2.0 includes requirements that promote documentation and ease
of configuration.
UAAG 2.0 acknowledges the importance of author preferences.
However, requirements are included to override certain author preferences
when the user would not otherwise be able to access that content.
Some UAAG 2.0 requirements may have security implications,
such as communication through APIs, or allowing programmatic read and write
access to content and user interface
control. UAAG 2.0 assumes that features required by UAAG 2.0
will be built on top of an underlying security architecture. Consequently,
unless permitted explicitly in a success criterion, UAAG 2.0 grants no
conformance exemptions based on security issues.
The UAWG expects that software that satisfies the requirements of UAAG 2.0 will be more flexible, manageable, extensible, and beneficial for all
users.
UAAG 2.0 Layers of Guidance
In order to meet the needs of different audiences using UAAG,
several layers of guidance are provided, including overall
principles, general guidelines, testable success
criteria, and a explanatory intent, examples and
resource links.
-
Principles - At the top are five principles that
provide the foundation for accessible user agents. Principles 1, 2, and 3 are congruent to Web Content Accessibility Guidelines (WCAG)
2.0: to make the user agent perceivable, operable, and understandable. Principles 4 and 5 are specific to user agents: facilitate programmatic access and comply with
specifications and conventions.
Guidelines - Under the principles are guidelines.
The guidelines provide the basic goals that authors should work toward in
order to make user agents more accessible to users with different
disabilities. The guidelines are not testable, but provide the framework
and overall objectives to help authors understand the success criteria
and better implement the techniques.
Success Criteria - For each guideline, testable
success criteria are provided to allow UAAG 2.0 to be used where
requirements and conformance testing are necessary such as in design
specification, purchasing, regulation, and contractual agreements. In
order to meet the needs of different groups and different situations,
three levels of conformance are defined: A (lowest), AA, and AAA
(highest). Additional information on UAAG levels can be found in the
section on Conformance.
The principles, guidelines, and success criteria work together to provide layers of guidance on
how to make user agents more accessible. Developers are encouraged to view
and apply all layers that they are able to order to best address the needs of the widest possible range
of users.
Note that even user agents that conform at the highest level (AAA) may
not be accessible to individuals with all types, degrees, or combinations of
disability, particularly in the cognitive, language, and learning areas.
Developers are encouraged to seek relevant advice about current
best practice to ensure that their user agent is accessible as
possible to this community.
UAAG 2.0 Supporting Documents
A separate document, entitled "Implementing User Agent
Accessibility Guidelines 2.0" (the "Implementing document" from here on) provides suggestions and
examples of how each success criteria might be satisfied. It also includes
references to other accessibility resources (such as platform-specific
software accessibility guidelines) that provide additional information on how
a user agent may satisfy each success criteria. The techniques in the
Implementing document are informative examples only.
Other strategies may be used or required to satisfy the success criteria.
The UAWG expects to update the Implementing document more
frequently than the current guidelines. Developers, W3C Working Groups,
users, and others are encouraged to contribute examples and resources.
Components of Web
Accessibility
Web accessibility depends on accessible user agents and accessible content. Accessible content availability is greatly influenced
by the accessibility of the authoring tool. For an overview of how these
components of Web development and interaction work together, see:
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 success criteria 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.
A user agent is any software that retrieves, renders and facilitates end-user interaction with Web content.
Relationship to the Authoring Tool Accessibility Guidelines (ATAG) 2.0
While it is convenient to think of user agents retrieving and rendering web content for one group of people (end-users) that was previously authored by another group (authors), user agents are frequently involved with the process of authoring content.
For these cases, it is important for user agent developers to consider the application of another W3C-WAI Recommendation, the Authoring Tool Accessibility Guidelines (ATAG). ATAG (currently 2.0 is in draft) provides guidance to the developers of tools regarding the accessibility of authoring interfaces to authors (ATAG 2.0 Part A) and ways in which all authors can be supported in producing accessible web content (ATAG 2.0 Part B).
UAAG 2.0 Guidelines
The success criteria and applicability notes in this section are normative. Guideline summaries are informative.
PRINCIPLE 1 - Perceivable
Ensure that the user interface
and rendered content are perceivable
Guideline 1.1 - Alternative Content
Provide access to alternative content. [Implementing
1.1]
Summary: The user can easily determine which pieces of content have alternatives such as alt text or longdesc (1.1.1) and interact with the text to see the available
alternatives (1.1.3). The user can also choose at least one alternative such as alt text to be always displayed (1.1.2), but it's recommended that users also be
able to specify a cascade (1.1.4), such as alt text if it's there, otherwise longdesc, otherwise filename, etc.
1.1.1 Configurable Default
Rendering:
The user can specify which types of alternative content to render by default. (Level A)
1.1.2 Browse and Render:
When a rendered element has alternative content, the user can render alternatives according to the following: (Level 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
- non-synchronized alternatives (e.g. short text alternatives, long descriptions) can be rendered as replacements for the original rendered content.
1.1.3 Identify Presence of Unrendered Alternative Content:
The user can specify that content be rendered with an adjacent indicator when unrendered alternative content is present (e.g. an icon to indicate an image has a short text alternative). (Level A)
1.1.4 Rendering Alternative
(Enhanced)
: The user can specify the cascade order in which to render alternative content. (Level AA)
Guideline 1.2 - Repair missing content. [Implementing
1.2]
Summary: The user can request useful alternative content when the author fails to provide it. For example, showing a filename in place of missing (1.2.1) or empty (1.2.2) alt text. The user can ask the browser to predict altertive content if it is missing (1.2.3) or notifiy the user if the content cannot be rendered (1.2.4).
1.2.1 Repair Missing
Alternatives:
The user can specify whether or not the user agent should generate and render repair text (e.g. file name) when it recognizes that the author has not provided alternative content. (Level A)
1.2.2 Repair Empty
Alternatives:
The user can specify whether or not the user agent should generate and render repair text (e.g. file name) when it recognizes that the author has provided empty alternative content. (Level AA)
1.2.3 Repair Missing Associations:
The user can specify whether or not the user agent should attempt to predict associations from author-specified presentation attributes (i.e. position and appearance). (Level AAA)
1.2.4 Broken Alternative Content:
The user can be notified when the user agent cannot render alternative content (e.g. when captions are broken).
(Level AAA)
Guideline 1.3 - Provide highlighting for
selection, keyboard focus, enabled elements, visited links.
[Implementing
1.3]
Summary: The user can visually distinguish selected, focused, and enabled items, and recently visited links (1.3.1), with a choice of highighting options that at least include foreground and background colors, and border color and thickness (1.3.2).
1.3.1 Highlighted Items:
The user can globally specify that the following be highlighted so that each class is uniquely distinguished. It is not the intention that all recognized enabled elements be uniquely distinguished, just that they be distinguished from disabled elements. (Level A)
- selection
- active keyboard focus (indicated by focus cursors and/or text cursors)
- active window
- active viewport
- recognized enabled elements
- presence of alternative content
- recently visited links
1.3.2 Highlighting Options:
When highlighting classes specified by 1.3.1 Highlighted Itemsand 1.3.3 Highlighted Input Controls, The user can specify highlighting options that include at least: (Level A)
- (a) foreground colors,
- (b) background colors, and
- (c) border (configurable color, style, and thickness)
1.3.3 Highlighted Input Controls:
The user can have the following highlighted when they are recognized:
(Level AA)
- (a) enabled controls that take input (e.g. push buttons, radio buttons, check boxes, and text input fields, but not groupings or static text and images) regardless of whether they are read-write or read-only, and
- (b) elements with scripted input handlers (e.g. images or text ranges that have onClick or onKeyPress events) regardless of whether the current state allows them to operate.
Guideline 1.4 - Provide text configuration.
[Implementing 1.4]
Summary: The user can control text font, color, and size (1.4.1), including whether all text should be the shown the same size (1.4.2).
1.4.1 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) ,
- (b) font family, and
- (c) text color (i.e. foreground and
background).
1.4.2 Preserving
Size Distinctions:
The user can specify whether or not distinctions in the size of rendered text are preserved when that text is rescaled (e.g. headers continue to be larger than body text). (Level A)
Guideline 1.5 - Provide volume configuration.
[Implementing 1.5]
Summary: The user can adjust the volume of each audio track relative to the global volume level (1.5.1).
1.5.1 Global Volume:
The user can independently
adjust the volume of all audio tracks, relative to the global volume level set
through operating environment mechanisms. However, the user agent may only override a global mute on explicit user request and if the user has been cautioned about the implication. (Level A)
Guideline 1.6 - Provide synthesized speech configuration.
[Implementing 1.6]
Summary: If synthesized speech is produced, the user can specify speech rate and volume (1.6.1), pitch and pitch range (1.6.2), and synthesizer speech characteristics like emphasis (1.6.3) and features like spelling (1.6.4).
1.6.1 Speech Rate and Volume:
If synthesized speech is produced, the user can specify the following: (Level A)
- speech rate and
- speech volume (independently of
other sources of audio).
1.6.2 Speech Pitch and Range:
The user can specify the following for synthesized speech: (Level AA) :
- (a) pitch ("pitch" refers to the
average frequency of the speaking voice), and
- (b) pitch range ("pitch range"
specifies a variation in average frequency),
1.6.3 Advanced Speech Characteristics:
The
user can specify all of the speech characteristics offered by the speech
synthesizer. (Level AAA)
1.6.4 Synthesized Speech Features:
For synthesized speech, the following features are provided: (Level AA)
- (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 punctuation (e.g. "one two zero three point five" for 1203.5 or "one comma two zero three point five" for 1,203.5), and
one where full numbers are spoken (e.g. "one thousand, two hundred
and three point five").
- (d) at least two ways of speaking
punctuation: one where punctuation is spoken literally, and one
where punctuation is rendered as natural pauses.
Guideline 1.7 - Provide style sheets configuration.
[Implementing 1.7]
Summary: The user can choose which if any author-supplied (1.7.1) and user-supplied (1.7.2) style sheets to use.
1.7.1 Author Style Sheets:
: The user can turn off the use of author style sheets, and for every author style sheet defined the user can choose whether or not it should be applied to: (Level A)
- (a) the current page, or
- (b) all pages for which it is defined.
1.7.2 User Style Sheets:
The user can turn off the use of user style
sheets, and for every user style sheet defined the user can choose whether or not it should be applied to: (Level A)
- (a) the current page, or
- (b) all pages on specified web sites, or
- (c) all pages.
1.7.3 Save copies of style sheets:
The user can save copies of the style sheets referenced by the current page, so that they can edit and load them as user style
sheets. (Level AA)
Guideline 1.8 - Help users to use viewports and orient within viewports.
[Implementing 1.8]
Summary: The user agent provides programmatic and visual cues to keep the user oriented. These include highlighting the viewport (1.8.1), keeping the focus within the viewport (1.8.2), resizing the viewport (1.8.3), providing scrollbar(s) that identify when content is outside the visible region (1.8.4) and which portion is visible (1.8.11), and restoring the the focus and point of regard when the user returns to a previously viewed page (1.8.5). Additionally, the user can specify that all view ports have the same user interface elements (1.8.10), if and how new viewports open (1.8.6), and whether the new window automatically gets focus (1.8.7). The user can also close any open window or tab (1.8.9).
1.8.1 Highlight Viewport:
The viewport with the input focus (including nested viewports and their containers) is highlighted, and the user can customize attributes of the highlighted mechanism, including, but not limited to, shape, size, stroke width, color, and blink rate (if any). (Level A)
1.8.2 Move Viewport to Selection and Focus:
When a viewport's selection or input focus changes, the viewport's content moves as necessary to ensure that the new selection or input focus location is at least partially in the visible portion of the viewport. (Level A)
1.8.3 Resizable:
The user can make graphical viewports
resizable, within the limits of the display, overriding any values
specified by the author. (Level A)
1.8.4 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)
1.8.5 Viewport History:
For user agents that implement a viewport history mechanism (e.g. "back" button), the user can return to any state in the viewport history, restoring the prior point of regard, input focus and selection.(Level A)
1.8.6 Open on Request:
The user can specify whether or not top-level viewports (e.g. windows or tabs) open only with an explicit user request or confirmation. (Level A)
1.8.7 Do Not Take Focus:
If new top-level viewports (e.g. windows or tabs) are configured to open without explicit user request, the user can specify whether or not top-level viewports take the active keyboard focus when they open. (Level AA)
1.8.9 Close Viewport:
The
user can close any top-level viewports (e.g. windows or tabs) . (Level AA)
1.8.10 Same UI:
The user can specify that all top-level viewports (e.g. windows or tabs) follow the current user interface configuration. (Level AA)
1.8.11 Indicate Viewport Position:
The user can determine the viewport's position relative to the full extent of the rendered
content. (Level AA)
Guideline 1.10 - Provide alternative views.
[Implementing 1.10]
Summary: The user can view the source of content (1.10.1), or an "outline" view (1.10.2), and may specify the elements to be used for the outline view (1.10.3).
1.10.1 Text View:
The user can view all text source that is available to the user agent. (Level AA)
1.10.2 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).
(Level AA)
Note: The outline constitutes the important structural elements for the user (See 1.10.3). A label is defined by each markup
language specification. For example, in HTML, a heading
(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.
1.10.3 Configure
Elements for Structural Navigation:
The user can configure the set of important elements for the hierarchical view, including by element type (e.g. headers). (Level AAA)
Guideline 1.11 - Provide element information.
[Implementing 1.11]
Summary:The user agent presents information about content relationships (e.g. form labels, table headers)(1.11.1), and extended link information (e.g. title, internal vs. external) (1.11.2)
1.11.1 Access Relationships:
The user can access explicitly-defined relationships based on the user's position in content (e.g. show form control's label, show label's form control, show a cell's table headers). (Level A) :
1.11.2 Extended Link
Information:
The user agent provides for each link:
(Level AAA) :
- link title
- technology type (of the linked Web resource)
- internal/external: (whether the link
is internal to the resource e.g. the link is to a target in the same
Web page)
PRINCIPLE 2. Ensure that the user interface is
operable
Summary: Users can operate all functions (2.1.1), and move focus (2.1.2, 2.1.3) using just the keyboard. Users can activate important or common features with shortcut keys, (2.1.8), override keyboard shortcuts in content and user interface (2.1.4), escape keyboard traps (2.1.5), specify that selecting an item in a dropdown list or menuoes not activate that item or move to that new web page (2.1.6) and use standard keys for that platform (2.1.7).
2.1.1 Keyboard Operation
: All
functionality can be operated via the keyboard using sequential or direct
keyboard commands that do not require specific timings for individual
keystrokes, except where the underlying function requires input that depends
on the path of the user's movement and not just the endpoints (e.g. free
hand drawing). This does not forbid and should not discourage providing mouse
input or other input methods in addition to keyboard operation. (Level A)
2.1.2 Keyboard Focus (former 1.9.1):
Every viewport
has an active or inactive keyboard focus at all times. (Level A)
2.1.3 Viewport Navigation (former 1.9.2 & 1.9.4):
The user can move the active keyboard focus to any viewport. (Level A)
2.1.4 Specify preferred keystrokes: (former 2.1.2)
: The user can override any keyboard shortcut including recognized author supplied shortcuts (e.g. accesskeys) and user interface controls, except for conventional bindings for the operating environment (e.g. arrow keys for navigating within menus). (Level A)
2.1.5 No Keyboard Trap (former 2.1.3)
: 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
2.1.6 Separate Selection from
Activation: (former 2.1.4)
The user can specify that selection is separate from activation (e.g. navigating through a set of radio buttons without changing
which is the active/selected option). (Level A)
2.1.7
Follow Text Keyboard Conventions (former 2.1.5)
: Views that render text support the standard text area
conventions for the operating environment, such as
character keys, Backspace/Delete, Insert, arrow key navigation (e.g.
caret browsing), Page Up/Page Down, navigate to start/end, navigate by
paragraph, shift-to-select mechanism. (Level A)
2.1.8
Make Important Command Functions Efficient (former 2.1.9)
: Important command functions (e.g. related to navigation, display, content, information management) are more efficient than sequential keyboard navigation. (Level AA)
2.1.9
Allow Override of User Interface Keyboard Commands (former 2.1.10):
The user can override any keyboard shortcut binding for the user agent user
interface except for conventional bindings for the operating environment
(e.g. access to help). The rebinding options must include single-key and
key-plus-modifier keys if available in the operating environment. (Level AA)
Guideline 2.2 - Provide sequential navigation [new, includes former 2.1.8 and 1.9.8, and a new SC] [Implementing 2.2]
Summary: Users can use the keyboard to navigate sequentially (2.2.3) to all the operable elements (2.2.1) in the viewport as well as between viewports (2.2.2). Users can optionally disable wrapping or request a signal when wrapping occurs (2.2.4).
2.2.1 Sequential Navigation Between Elements [replaces 1.9.8 Bi-Directional and 2.1.8 Keyboard Navigation]
The user can move the keyboard focus backwards and forwards through all recognized enabled elements in the current viewport. (Level A)
2.2.2 Sequential Navigation Between Viewports [new]:
The user can move the keyboard focus backwards and forwards between viewports, without having to sequentially navigate all the elements in a viewport. (Level A)
2.2.3 Default Navigation Order: (former 1.9.9)
If the author has not specified a navigation order, the default is
sequential navigation, in
document order. (Level A)
2.2.4 Options for Wrapping in Navigation: (new)
The user can have sequential navigation prevent wrapping or can receive feedback when wrapping. (Level AA)
Guideline 2.3 - Provide direct navigation and activation [includes former 2.1.6, 2.1.7, 2.1.11] [Implementing 2.3]
Summary: Users can navigate directly (e.g. keyboard shortcuts) to important elements (2.3.1) with the option of immediate activation of the operable elements (2.3.3). Display commands with the elements to make it easier for users to discover the commands (2.3.2 & 2.3.4). The user can remap the direct commands to their needs (2.3.5).
2.3.1 Direct Navigation to Important Elements: (former 2.7.4)
The user can navigate directly to important (structural and operable) elements in rendered content. (Level A)
2.3.2
Present Direct Commands in Rendered Content (former 2.1.6):
The user can have any recognized direct commands (e.g. accesskey) in rendered content be presented with their associated elements. (Level A)
2.3.3 Direct activation (former 2.7.6)
: The user can move directly to and activate any operable
elements in rendered content. (Level AA)
2.3.4 Present Direct Commands in User Interface (former 2.1.7):
The user can have any direct commands (e.g. keyboard shortcuts) in the user agent user interface be presented with their associated user interface controls (e.g. "Ctrl+S" displayed on the "Save" menu item and toolbar button). (Level AA)
2.3.5
Allow Override of Accesskeys (former 2.1.11)
: The
user can override any recognized author supplied content keybinding (i.e. access key). The user must have an option to save the
override of user interface keyboard shortcuts so that the rebinding persists
beyond the current session. (Level AA)
Summary: Users can search rendered content (2.4.1) forward or backward (2.4.2) and can have the matched content highlighted in the viewport (2.4.3). The user is notified if there is no match (2.4.4). Users can also search by case and for text alternatives (2.4.5).
2.4.1 Find:
The user can perform a search within rendered content (e.g. not hidden with a style), including text alternatives, for any sequence of characters from the document character set. (Level A)
2.4.2 Find Direction:
The user can search forward or backward from the focused location in content. The user is notified of changes in search direction. The user is notified when the search reaches the upper or lower extent of the content based on the search direction. (Level A)
2.4.3 Match Found:
When there is a match, the user is alerted and the viewport's content moves so that the matched text content is at least partially within it. The user can search for the next instance of the text from the location of the match.
(Level A)
2.4.4 Alert on No Match:
The user is
notified 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 A)
2.4.5 Advanced Find:
The user agent provides an accessible advanced
search facility, with a case-sensitive and case-insensitive search
option, and the ability for the user to perform a search within all
content (including hidden content and captioning) for text and text
alternatives, for any sequence of characters from the document character
set. (Level AA)
Summary: Users can customize user agent settings related to accessibility (2.7.1) with settings being saved between sessions (2.7.2) and restore settings to default values (2.7.3). Users can have multiple sets of preferences (2.7.4), have related settings restored to default as a group (2.7.5) and adjust preferences outside the user agent main user interface (2.7.6). Users can also transfer settings between devices (2.7.7) and are offered a wizard to assist in user customization (2.7.8).
2.5.1 Discover navigation and activation keystrokes
: The user can discover direct navigation and activation keystrokes both
programmatically and via perceivable labels. (Level A)
2.5.3 Location in
Hierarchy:
The user can view the path of nodes leading
from the root of any content hierarchy in which the structure and
semantics are implied by presentation, as opposed to an explicit logical
structure with defined semantics (such as the HTML5 Canvas Element), or
as a consequence of decentralized-extensibility (such as the HTML5 item
/ itemprop microdata elements), and only if the user agent keeps an
internal model of the hierarchy that it does not expose via the DOM or
some other accessibility mechanism. (Level A) .
2.5.5 Access to Relationships which Aid Navigation:
The user can access explicitly-defined relationships based on the user's position in content, and the path of nodes leading from the root of any content hierarchy to that position. (Level AA)
2.5.7 Configure Elements for Hierarchical Views:
The user has the option to
configure the set of important elements for structured navigation, including
by element type (e.g. headers, list items, images). (Level AAA) @@ Editor's
note: Review the definition of "important elements" @@
Summary:Users can interact with web content by mouse, keyboard, voice input, gesture, or a combination of input methods. Users can discover what event handlers (e.g. onmouseover) are available at the element (2.6.1) and activate an element's events individually (2.6.2) or [@@ Editor's Note: PLACEHOLDER @@] (2.6.3)
2.6.1
List event handlers:
The user can, through keyboard input alone, call up a list of input device event handlers explicitly associated with the keyboard focus element. (Level A)
2.6.2
Activate any event handler:
The
user can, through keyboard input alone, activate any
input device event handlers explicitly
associated with the
keyboard focus element. (Level A)
2.6.3
Activate all event handlers:
The user can, through keyboard input alone, simultaneously activate all input device event handlers explicitly associated with the
content focus element. (Level A)
Guideline
2.7 - Configure and store preference settings.
Summary: Users can configure and restore accessibility preference settings (2.7.1, 2.7.3), and accessibility settings persist between sessions (2.7.2). Users can manage multiple sets of preference settings and restore groups of settings to defaults (2.7.4, 2.7.5), and adjust preference setting outside the user interface so the current user interface does not prevent access (2.7.6). It's also recommended that groups of settings can be transported to compatible systems, and a wizard be available to help users configure their preferences (2.7.7, 2.7.8).
2.7.1
Change Preference Settings
The user can change settings that impact accessibility. (Level A)
2.7.2
Persistent Accessibility Settings
: User agent accessibility preference settings persist between sessions. (Level A)
2.7.3
Restore all to default:
The user can restore all preference settings to default values. (Level A)
2.7.4
Multiple Sets of Preference Settings:
The
user can save and retrieve multiple sets of user agent preference settings.
(Level AA)
2.7.5
Restore related preferences to default:
The user can restore groups of related preference settings to default values (e.g. reset keyboard shortcuts, reset colors and sizes of rendered content). (Level AA)
2.7.6
Change preference setting outside the UI:
The user can adjust preference settings from outside the user agent user interface. (Level AA)
2.7.7
Portable Preference Settings:
The user can transfer preference settings across locations onto a compatible system. (Level AAA)
2.7.8
Preferences Wizard:
A
wizard helps the user to configure the accessibility-related
user agent preferences (at least). (Level AAA)
Summary: It's recommended that users can add, remove and configure the position of graphical user agent controls (2.8.1) and restore them to their default settings (2.8.2).
2.8.1 Configure Position:
When graphical user agent user interfaces have toolbars, panels, inspectors, or similar, the user can add, remove and configure the position of user agent user interface
controls from a pre-defined set. (Level AAA)
2.8.2 Restore Default Toolbars:
The
user can restore the default toolbar, panel, or inspector configuration. (Level AAA)
Summary: Users can extend the time limit for user input when such limits are controllable by the user agent (2.9.1); by default, the user agent shows the progress of content in the process of downloading (2.9.2).
2.9.1
Timing Adjustable
:
Where time limits for user input are recognized
and controllable by the user agent, the user can extend the time
limit. (Level A)
2.9.2 Retrieval Progress:
By default, the user agent shows the progress of content retrieval. (Level A)
Guideline 2.10 (former 2.4) - Help users avoid flashing that could cause seizures. [Implementing 2.10]
Summary: @@ Editors' Note: To be written @@
2.10.1
Three Flashes or Below Threshold:
In its default configuration, the user agent does not display any user interface components or recognized content that flashes more than three times in any one-second period, unless the flash is below the general flash and red flash thresholds. (Level A)
2.10.2
Three Flashes:
In its default configuration, the user agent does not display any user interface components or recognized content that flashes more than three times in any one-second period (regardless of whether not the flash is below the general flash and red flash thresholds). (Level AAA) [WCAG 2.0]
Guideline 2.11 - Provide control of
content that may reduce accessibility. (former 2.9) [Implementing 2.11]
Summary: @@ Editors' Note: To be written @@
2.11.1 Background Image
Toggle:
The user has the global option to hide/show background images. (Level A)
2.11.2 Time-Based Media
Load-Only:
The user can
load time-based media content @@ Editors' Note: DEFINE@@
such that a placeholder is displayed, but the content is not
played until explicit user request. (Level A)
2.11.3 Execution
Placeholder:
The user can
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)
2.11.4 Execution Toggle:
The
user can turn on/off the execution
of executable content that would not normally be contained within a
particular area (e.g. Javascript). (Level A)
2.11.5 Playback Rate Adjustment for Prerecorded Content:
The user can adjust the playback rate of prerecorded time-based media content, such that all of the following are true: (Level A)
- The user can adjust the playback rate of the time-based media tracks to between 50% and 250% of real time.
- Speech whose playback rate has been adjusted by the user maintains pitch in order to limit degradation of the speech quality.
- Audio and video tracks remain synchronized across this required range of playback rates.
- The user agent provides a function that resets the playback rate to normal (100%).
2.11.6 Stop/Pause/Resume
Time-Based Media:
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)
2.11.7 Navigate Time-Based Media:
The user can navigate along the timebase using a continuous scale, and by relative time units within rendered audio and animations (including video and animated images) that last three or more seconds at their default playback rate. (Level A)
2.11.8 Semantic Navigation of Time-Based Media:
The user can navigate by semantic structure within the time-based media, such as by chapters or scenes present in the media (Level AA).
2.11.9 Track Enable/Disable of Time-Based Media:
During time-based media playback, the user can determine which tracks are available and select or deselect tracks. These selections may override global default settings for captions, audio descriptions, etc. (Level AA)
2.11.10 Sizing Playback Viewport:
The user can adjust the size of the time-based media up to the full height or width of the containing viewport. In doing so, the user can preserve aspect ratio and adjust the size of the playback viewport to avoid cropping, within the scaling limitations imposed by the media itself. (Level AA)
2.11.11 Scale and position alternative media tracks:
The user can scale and position alternative media tracks independent of base video. (Level AAA)
2.11.12 Adjust Playback Contrast and Brightness:
User can control the contrast and brightness of the content within the playback viewport.
Applicability Notes:
The guideline only applies to images, animations, video, audio, etc. that
the user agent can recognize.
@@ Editors' Note: If the browser is playing the video natively, there is only 1 user agent. In that case, it falls on the browser to meet the UAAG spec. @@
@@ Editors' Note: If an author uses windows media player inside the video element, the browser needs to map its native controls to the embedded wmp controls, and provide access to all the controls. @@
@@ Editors' Note: The user needs to be able to define rendering parameters of playback at render-time. @@
Principle 3: Ensure that the user interface is
understandable
Guideline 3.1 - Help users avoid
unnecessary messages. [Implementing 3.1]
Summary: Users can turn off non-essential messaes from the author or user-agent.
@@ Editors' Note: Add SC based on this note from IRC of 10 November 2010: We could consider adding to this section a recommendation that messages have a checkbox that lets the user avoid getting the message again. But I'm not sure how we could write it to have an appropriate scope, that is only apply to messages where it's appropriate. AND when you do have those check boxes, it's also useful to have something in the application's settings that allows the user to reset those to their default, thus making all the messages visible again.@@
3.1.2 Option to Ignore:
The
user can turn off rendering of
non-essential or low priority text messages or updating/changing information in the content based on priority properties
defined by the author or the user agent. (Level AA)
Summary: Users can choose to confirm form submissions. [@@ Editor's Note: Add SC for built-in spell checking@@]
3.2.1 Form Submission:
The user can specify whether or not recognized form submissions must be confirmed. (Level AA)
Guideline 3.3 - Document the user agent user
interface including all accessibility features.[Implementing 3.3]
Summary: User documentation is available in an accessible format (3.3.1), it includes accessibility features (3.3.2), delineates differences between versions (3.3.3), provides a centralized views of conformance UAAG2.0 (3.3.4), and is available as context sensitive help in the UA (3.3.5).
3.3.1 Accessible documentation:
The product documentation is available in a format that meets success criteria of WCAG 2.0 Level "A" or greater. (Level A)
3.3.2 Document Accessibility
Features:
All user agent features
that benefit accessibility are documented. (Level A) @@ Editors' Note: write a definition of "benefit accessibility" - as contributing to conforming to these guidelines or a feature specifically added to improve accessibility @@
3.3.3 Changes Between
Versions:
Changes to features that benefit accessibility since the previous user agent release are documented. @@Editors' Note: Link to the definition to benefit accessibility from previous 3.3.2 @@(Level AA)
3.3.4 Centralized View:
There is a dedicated section of the documentation that presents a view of all features of the user agent necessary to meet the requirements of User Agent Accessibility Guidelines 2.0. (Level AAA)
3.3.5 Context Sensitive
Help:
There is context-sensitive
help on all user agent features that benefit accessibility. (Level AAA)
Guideline 3.4 - The user agent must behave in a predictable fashion. [Implementing 3.4]
Summary: Moving the focus allows presentation of information (e.g. tooltips) but does not cause any other action (3.4.2). Users can prevent non-requested focus changes (3.4.1).
3.4.1 Avoid unpredictable focus [formerly 3.4.2, before that 5.4.2, and 1.9.10, broadened] :
The user can prevent focus changes that are not a result of explicit user request. (Level A)
3.4.2 Avoid Side Effects of Navigation [former 1.9.1, before that 3.11.11, changed]:
The user can move the keyboard focus without causing the user agent to take any further action, other than the presentation of information (e.g. scrolling or pop-ups that do not change the focus or selection). (Level A)
@@ Editors' Note: Missing: Greater ease in interpreting security messaging. Should be cross-referenced with the security working group. @@
PRINCIPLE 4: Facilitate programmatic access
Guideline 4.1 - Facilitate
programmatic access to assistive technology [Implementing 4.1]
Summary: Be compatible with assistive technologies by supporting platform standards (4.1.1), including providing information about all menus, buttons, dialogs, etc. (4.1.2, 4.1.6), access to DOMs (4.1.4), and access to structural relationships and meanings, such as what text or image labels a control or serves as a heading (4.1.5). Where something can't be made accessible, provide an accessible alternative version, such as a standard window in place of a customized window (4.1.3). Make sure that that programmatic exchanges are quick and responsive (4.1.7).
4.1.1 Platform Accessibility Architecture:
The user agent supports a platform accessibility architecture
relevant to the operating environment. (Level A)
4.1.2 Name, Role, State, Value,
Description:
For all user interface components including user interface, rendered content, generated content, and alternative content, the user agent makes available the name, role, state, value,
and description via a platform accessibility architecture. (Level A)
4.1.3 Accessible
Alternative:
If a component of the user agent user interface cannot be exposed through the platform accessibility architecture, then the user agent provides an equivalent alternative that is exposed through the platform accessibility architecture. (Level A)
4.1.4 Programmatic Availability of
DOMs:
If the user agent implements one or more DOMs, they must be
made programmatically available to assistive technologies. (Level A)
4.1.5 Write Access:
If the user agent keeps an internal representation of the user content in terms of element structure, relationships between elements, element meaning, or some combination thereof, it must expose this internal representation via an appropriate means (normally by using the platform accessibility architecture or a programmatically available DOM). (Level A)
4.1.6 Properties:
If any of
the following properties are supported by the accessibility platform
architecture, make the properties available to the accessibility platform
architecture: (Level A)
- the bounding dimensions and coordinates of onscreen elements
- font family of text
- font size of text
- foreground color of text
- background color of text.
- change state/value notifications
- selection
- highlighting
- input device focus
- direct keyboard commands
4.1.7 Timely Communication:
For APIs implemented to satisfy the requirements of UAAG 2.0, ensure that programmatic exchanges proceed at a rate such that users do not perceive a delay. (Level A)
Guideline 4.2 - Facilitate programmatic access to nested user agents [Implementing 4.2]
Summary: Input focus correctly transitions between nested user agents (4.2.1),users can retrieve input focus at any time (4.2.2) and input focus never gets stuck in any nested user agent (4.2.3).
4.2.1 Hand-Off Focus [former 1.9.5]:
The
user agent programmatically notifies any nested user agent(s) (e.g.
plug-ins) when active input focus moves to a nested agent. (Level A)
4.2.2 Retrieve Focus [former 1.9.6, before that 3.11.6]:
At any time, the user is able to retrieve input focus from a nested viewport (including a nested viewport that is a user agent).(Level A)
4.2.3 Return Focus [former 1.9.7, before that 3.11.7]:
At any time, the user agent can retrieve input focus from a nested viewport (including nested viewports that are user agents). (Level A)
PRINCIPLE 5: Comply with applicable
specifications and conventions
Guideline 5.1 - Ensure that non-Web-based
functionality is accessible.[Implementing 5.1]
Summary: The browser's own menus, buttons, dialogs, etc. need to meet any accessibility standards for the operating system.
5.1.1 Non-Web-Based Accessible
(Level A) :
Non-Web-based user agent user interfaces comply with and
cite the requirements of standards or operating environment conventions that
benefit accessibility. (Level A)
Applicability Notes:
This guideline does not apply to Web-based user agent user interfaces, but
does include any parts of Web-based user agents that are non-Web-based (e.g. client-side file uploaders).
Guideline 5.2 - Ensure that Web-based
functionality is accessible. [Implementing 5.2]
Summary: When the browser's menus, buttons, dialogs, etc. are authored in HTML or similar standards, they need to meet W3C's Web Content Accessibility Guidelines.
5.2.1 Web-Based Accessible (Level A) :
User agent user interfaces that are rendered using Web standard technologies conform to WCAG Level "A".
(Level A)
5.2.2 Web-Based Accessible (Level AA) :
User agent user interfaces that are rendered using Web standard technologies conform to WCAG Level
"AA". (Level AA)
5.2.3 Web-Based Accessible (Level AAA) :
User agent user interfaces that are rendered using Web standard technologies conform to WCAG Level
"AAA". (Level AAA)
Applicability Notes:
This guideline does not apply to non-Web-based user agent user interfaces,
but does include any parts of non-Web-based user agents that are
Web-based (e.g. help systems).
Summary: Implement the accessibility features of all the technologies you're using, such as supporting the platform's multitasking capabilities and HTML's alt attribute for images. Document your implementation.
5.3.1 Implement accessibility features of content specs:
Implement and cite in the conformance claim the accessibility
features of content
specifications. Accessibility features are those that are either (Level A) :
- identified as such in the specification or
- allow authors to satisfy a requirement of WCAG.
5.3.2 Implement Accessibility Features of platform:
Implement and cite in the conformance claim the accessibility
features of content and platform technology
specifications. Accessibility features are those that are either (Level A) :
- identified as such in the specification or
- allow authors to satisfy a requirement of WCAG.
[@@ Editor's Note: Suzanne proposed additional SC which are holding on action items. @@]]
Summary: Render content according to the technology specification, including accessibility features (5.4.1), and let users choose how content types are handled, such as opening embedded images, videos, or documents in separate applications or saving them to disk (5.4.2, 5.4.3).
5.4.1 Follow Specifications:
The user agent renders content according to the technology specification, except where it would actually harm overall accessibility.
(Level A)
5.4.2 Handle Unrendered
Technologies:
If the user agent does
not render a technology, the user can choose a way to handle content
in that technology (e.g. by launching another application or by saving it to
disk). (Level A)
5.4.3 Alternative content handlers:
The user can select content elements and have them rendered in alternative viewers. (Level AA)
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.
Conformance
This section is normative.
Conformance means that the user agent satisfies the success criteria
defined in the guidelines section. This conformance section describes
conformance and lists the conformance requirements.
Conformance Requirements
In order for a Web page to conform to UAAG 2.0, one of the following levels of conformance is met
in full.
- Level A: For Level A conformance (the minimum level of conformance), the
user agent satisfies all the Level A Success Criteria.
- Level AA: For Level AA conformance, the user agent satisfies all the
Level A and Level AA Success Criteria.
- Level AAA: For Level AAA conformance, the user agent satisfies all the
Level A, Level AA and Level AAA Success Criteria.
Note 1: Although conformance can only be achieved at the stated levels,
developers are encouraged to report (in their claim) any progress toward
meeting success criteria from all levels beyond the achieved level of
conformance.
Conformance Claims (Optional)
If a conformance claim is made, the conformance claim must meet the
following conditions and include the following information (user agents
can conform to UAAG 2.0 without making a claim):
Conditions on Conformance Claims
- At least one version of the conformance claim must be published on the
web as a document meeting level "A" of WCAG 2.0. A suggested metadata
description for this document is "UAAG 2.0 Conformance Claim".
- Whenever the claimed conformance level is published (e.g. product
information website), the URI for the on-line published version of the
conformance claim must be included.
- The existence of a conformance claim does not imply that the W3C has
reviewed the claim or assured its validity.
- Claimants may be anyone (e.g. user agent developers, journalists, other
third parties).
- Claimants are solely responsible for the accuracy of their claims
(including claims that include products for which they are not
responsible) and keeping claims up to date.
- Claimants are encouraged to claim conformance to the most recent version
of the User Agent Accessibility Guidelines Recommendation.
Required Components of an UAAG 2.0 Conformance Claim
- Claimant name and affiliation.
- Date of the claim.
- Conformance level satisfied.
- User agent information: The name of the user agent and sufficient
additional information to specify the version (e.g. vendor name,
version number (or version range), required patches or updates, human
language of the user interface or documentation).
Note: If the user agent is a collection of software components (e.g. a
browser and extentions or plugins), then the name and version information must be provided
separately for each component, although the conformance claim will treat
them as a whole. As stated above, the Claimant has sole responsibility
for the conformance claim, not the developer of any of the software
components.
- Included Technologies: A list of the web content technologies
(including version numbers) rendered by the user agent that the Claimant
is including in the conformance claim. By including a web content
technology, the Claimant is claiming that the user agent meets the
requirements of UAAG 2.0 during the rendering of web content using that
web content technology.
Note 1: Web content technologies may be a combination of constituent web
content technologies. For example, an image technology (e.g. PNG) might
be listed together with a markup technology (e.g. HTML) since web
content in the markup technology is used make web content in the image
technology accessible (e.g. a PNG graph is made accessible using an
HTML table).
- Excluded Technologies: A list of any web content technologies produced
by the the user agent that the Claimant is excluding from the
conformance claim. The user agent is not required to meet the
requirements of UAAG 2.0 during the production of the web content
technologies on this list.
- Declarations: For each success criterion:
A declaration of whether or not the success criterion has been
satisfied; or
A declaration that the success criterion is not applicable and a
rationale for why not.
- Platform(s): The platform(s) upon which the user agent was evaluated:
For user agent platform(s) (used to evaluate web-based user agent user
interfaces): provide the name and version information of the user agent(s).
For platforms that are not user agents (used to evaluate non-web-based
user agent user interfaces) provide: The name and version information of
the platform(s) (e.g. operating system, etc.) and the the name and
version of the platform accessibility architecture(s) employed.
Optional Components of an UAAG 2.0 Conformance Claim
A description of how the UAAG 2.0 success criteria were met where this
may not be obvious.
"Progress Towards Conformance" Statement
Developers of user agents that do not yet conform fully to a particular
UAAG 2.0 conformance level are encouraged to publish a statement on
progress towards conformance. The progress statement is the same as a
conformance claim except an UAAG 2.0
conformance level that is being progressed towards, rather than one
already satisfied, and report progress on success criteria not yet
met. Authors of "Progress Towards Conformance" Statement are solely
responsible for the accuracy of their statements. Developers are
encouraged to provide expected timelines for meeting outstanding success
criteria within the Statement.
Disclaimer
Neither W3C, WAI, nor UAWG take any responsibility for any aspect or
result of any UAAG 2.0 conformance claim that has not been published
under the authority of the W3C, WAI, or UAWG.
This glossary is normative.
- accelerator key
- see keyboard command
- activate
- To carry out the behaviors associated
with an enabled element in the rendered
content or a component of the user agent user
interface.
- active input focus
- see focus
- active selection
- see focus
- alternative content
- Content that can be used in place of default content that may not be universally accessible. Alternative content fulfills the same purpose as the original content. Examples include text alternatives for non-text content, captions for audio, audio descriptions for video, sign language for audio, media alternatives for time-based media. See WCAG for more information.
- alternative content
stack
- A set of alternative content items. The items may be mutually exclusive (e.g.
regular contrast graphic vs. high contrast graphic) or non-exclusive
(e.g. caption track that can play at the same time as a sound
track).
- animation
- Graphical content rendered to automatically change over time, giving the user a visual perception of movement. Examples include video, animated images, scrolling text, programmatic animation (e.g. moving or replacing rendered objects).
-
- application
programming interface (API), (conventional input/output/device
API)
- An application programming interface (API) defines how
communication may take place between applications.
- assistive technology
- An assistive
technology:
- 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 UAAG 2.0 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 are used by some people who have
physical disabilities to simulate the keyboard and mouse.
- alternative keyboards, which are used by some people with
physical disabilities to simulate the keyboard and mouse.
- alternative pointing devices, which are used by some people with
physical disabilities to simulate mouse pointing and button
activations.
- Beyond UAAG 2.0, assistive technologies consist
of software or hardware that has been specifically designed to assist
people with disabilities in carrying out daily activities. These
technologies include wheelchairs, reading machines, devices for
grasping, text telephones, and vibrating pagers. For example, the
following very general definition of "assistive technology device"
comes from the (U.S.) Assistive Technology Act of 1998 [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
- The technology of sound reproduction. Audio can be created synthetically (including speech synthesis), streamed from a live source (such as a radio broadcast), or recorded from real world sounds.
-
- audio description - (described video, video description or 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 (e.g. content authors, designers, programmers,
publishers, testers).
- author styles
- Style property
values that are set by the author as part of the content.
- 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 (caption)
- An equivalent alternative that takes the form of text presented and synchronized with time-based 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 UAAG 2.0 assume that the user agent
can recognize the captions as such.
Note: Other terms that include the word "caption" may
have different meanings in UAAG 2.0. For instance, a "table
caption" is a title for the table, often positioned graphically above
or below the table. In UAAG 2.0, the intended meaning of "caption"
will be clear from context.
- collated text
transcript
- A collated text transcript is a text equivalent of a movie or
other animation. 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 people who are deaf-blind.
-
-
- content (web content)
- Information and sensory experience to be communicated to the user by means of a user agent, including code or markup that defines the content's structure, presentation, and interactions [adapted from WCAG 2.0]
empty
content (which may be alternative content) is
either a null value or an empty string (e.g. 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).
- cursor
- see focus
- default
- see properties
- direct command, direct navigation command, direct activation command, linear navigation command
, spacial (directional) command, structural navigation command
- direct navigation commands move focus to a specified item regardless of which currently has the focus
- direct activation commands activate a specified item regardless of which currently has the focus; they may move the focus to the item before immediately activating it
- linear navigation commands (sometimes called logical or sequential navigation commands) move forwards and backwards through a list of items
- structural navigation commands move forwards, backwards, up and down a hierarchy
- spatial commands (sometimes called directional commands), require the user to be cognizant of the spatial arrangement of items on the screen:
- spatial navigation commands move from one item to another based on direction on the screen
- spatial manipulation commands resize or reposition an item on the screen
-
document character set
- The internal representation of data in the source content by a user agent.
-
document object, (Document Object Model, DOM)
- The Document Object Model is a platform- and language-neutral interface that allows programs and scripts to dynamically access and update the content, structure and style of documents. The document can be further processed and the results of that processing can be incorporated back into the presented page. This is an overview of DOM-related materials here at W3C and around the web:
http://www.w3.org/DOM/#what.
- document source, (text source)
- Text the user agent renders upon user request to view the source of specific viewport content (e.g. selected content, frame, page).
- documentation
- Any information that supports the use of a user agent. This information may be found, for example, in manuals, installation instructions, the help system, and tutorials. Documentation may be distributed (e.g. as files installed as part of the installation, some parts may be delivered on CD-ROM, others on the Web). See guideline 5.3 for information about
documentation.
- element, element type
- UAAG 2.0 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. UAAG 2.0 also uses the term "element" more generally
to mean a type of content (such as video or sound) or a logical
construct (such as a header or list).
- empty content
- see content
- enabled element, disabled
element
-
An element 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 elements defined by implemented markup languages. A disabled element is a potentially enabled element that is not currently available for activation (e.g. a "grayed out" menu item).
- equivalent alternative
- Acceptable substitute content that a user may not be able to access. An equivalent alternative fulfills essentially the same function or purpose as the original content upon presentation:
- text alternative: text that is available via the operating environment that is used in place of non-text content (e.g. text equivalents for images, text transcripts for audio tracks, or collated text transcripts for a movie). [from WCAG 2.0]
- full text alternative for synchronized media including any interaction: document including correctly sequenced text descriptions of all visual settings, actions, speakers, and non-speech sounds, and transcript of all dialogue combined with a means of achieving any outcomes that are achieved using interaction (if any) during the synchronized media. [from WCAG 2.0]
- synchronized alternatives: present essential audio information visually (i.e. captions) and essential video information in an auditory manner (i.e. audio descriptions).
[from ATAG 2.0]
- events and
scripting, event handler, event type
- User agents often perform a task when an event
having a particular "event type" occurs, including a user interface
event, a change to content, loading of content, or a request from the
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 through scripting, markup or the DOM.
- explicit user request
- An interaction by the user through the user
agent user interface, the focus, or the selection. User requests are made, for example, through user
agent user interface controls and keyboard commands. 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 can make errors when interacting with the user agent. For example, a user may inadvertently respond "yes" to a prompt instead of "no." This type of error is considered an explicit user request.
- focus (active input focus, active selection, cursor, focus cursor, focusable element, highlight, inactive input focus, inactive selection, input focus, keyboard focus, pointer, pointing device focus, selection, split focus, text cursor)
Hierarchical Summary of some focus terms
- Input Focus (active/inactive)
- Keyboard Focus (active/inactive)
- Cursor (active/inactive)
- Focus cursor (active/inactive)
- Text cursor (active/inactive)
- Pointing device focus (active/inactive)
- active input focus
- The input focus location in the active viewport. The active focus is in the active viewport, while the inactive input focus is the inactive viewport. The active input focus is usually visibly indicated. In UAAG 2.0 "active input focus" generally refers to the active keyboard input focus. @@ Editors' Note: this term is not used in the document other than the glossary.@@
- active selection
- The selection that will currently be affected by a user command, as opposed to selections in other viewports, called inactive selections, which would not currently be affected by a user command. @@ Editors' Note: this term is not used in the document other than the glossary.@@
- conform
- see support
- cursor
- Visual indicator showing where keyboard input will occur. There are two types of cursors: focus cursor (e.g. the dotted line around a button) and text cursor (e.g. the flashing vertical bar in a text field, also called a 'caret'). Cursors are active when in the active viewport, and inactive when in an inactive viewport.
- focus cursor
- Indicator that highlights a user interface element to show that it has keyboard focus, e.g. a dotted line around a button, or brightened title bar on a window. There are two types of cursors: focus cursor (e.g. the dotted line around a button) and text cursor (e.g. the flashing vertical bar in a text field).
- focusable element
- Any element capable of having input focus, e.g. link, text box, or menu item. In order to be accessible and fully usable, every focusable element should take keyboard focus, and ideally would also take pointer focus.
- highlight, highlighted, highlighting
- Emphasis indicated through the user interface. For example, user agents highlight content that is selected,focused, or matched by a search operation. Graphical highlight mechanisms include dotted boxes, changed colors or fonts, underlining, magnification, and reverse video. Synthesized speech highlight mechanisms include alterations of voice pitch and volume ("speech prosody"). User interface items may also be highlighted, for example a specific set of foreground and background colors for the title bar of the active window. Content that is highlighted may or may not be a selection.
- inactive input focus
- An input focus location in an inactive viewport such as a background window or pane. The inactive input focus location will become the active input focus location when input focus returns to that viewport. An inactive input focus may or may not be visibly indicated.
- inactive selection
- A selection that does not have the input focus and thus does not take input events.
- input focus
- The place where input will occur if a viewport is active. Examples include keyboard focus and pointing device focus. Input focus can also be active (in the active viewport) or inactive (in an inactive viewport).
- keyboard focus
- The screen location where keyboard input will occur if a viewport is active. Keyboard focus can be active (in the active viewport) or inactive (in an inactive viewport).
- pointer
- Visual indicator showing where pointing device input will occur. The indicator can be moved with a pointing device or emulator such as a mouse, pen tablet, keyboard-based mouse emulator, speech-based mouse commands, or 3-D wand. A pointing device click typically moves the input focus to the pointer location. The indicator may change to reflect different states.When touch screens are used, the "pointing device" is a combination of the touch screen and the user's finger or stylus. On most systems there is no pointer (on-screen visual indication) associated with this type of pointing device.
- pointing device focus
- The screen location where pointer input will occur if a viewport is active. There can be multiple pointing device foci for example when using a screen sharing utility there is typically one for the user's physical mouse and one for the remote mouse. @@ Editors' Note: this term is not used in the document other than the glossary.@@
- selection
- A user agent mechanism for identifying a (possibly empty) range of content that will be the implicit source or target for subsequent operations. The selection may be used for a variety of purposes, including for cut-and-paste operations, to designate a specific element in a document for the purposes of a query, and as an indication of point of regard (e.g. the matched results of a search may be automatically selected). The selection should be highlighted in a distinctive manner. On the screen, the selection may be highlighted in a variety of ways, including through colors, fonts, graphics, and magnification. When rendered using synthesized speech, the selection may be highlighted through changes in pitch, speed, or prosody.
- split focus
- A state when the user could be confused because the input focus is separated from something it is usually linked to, such as being at a different place than the selection or similar highlighting, or has been scrolled outside of the visible portion of the viewport. @@ Editors' Note: this term is not used in the document other than the glossary.@@
- text cursor
- Indicator showing where keyboard input will occur in text (e.g. the flashing vertical bar in a text field, also called a caret).
- @@ Editor's Note: Need to find the hrefs to these definitions and fix them. @@
- globally, global configuration
- @@ Editors' Note: Needs to be written@@
- graphical
- Information (e.g. text, colors, graphics, images, and animations)
rendered for visual consumption.
- highlight, highlighted, highlighting
- see focus
- image
- Pictorial content that is static (i.e. not moving or changing). See also the definition of animation.
- implement
- see support
- important elements
- This specification intentionally does not identify
which "important elements" must be navigable because this will vary by
specification. What constitutes "efficient navigation" may depend on a
number of factors as well, including the "shape" of content (e.g.
sequential navigation of long lists is not efficient) and desired
granularity (e.g. among tables, then among the cells of a given
table). Refer to the Implementing document [Implementing UAAG 2.0] for information
about identifying and navigating important elements. @@ Editors' Note: Update links
- inactive input focus
- see focus
- inactive selection
- see focus
- informative (non-normative)
- see normative
- input configuration
- 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]).
- input focus
- see focus
-
- keyboard command (keyboard binding,keyboard shortcuts or accelerator keys)
- Commands tied to particular UI controls or application functions, allowing the user to navigate-to or activate them without traversing any intervening controls (e.g. "ctrl"+"S" to save a document). It is sometimes useful to distinguish keyboard commands that are associated with controls that are rendered in the current context (e.g. "alt"+"D" to move focus to the address bar) from those that may be able to activate program functionality that is not associated with any currently rendered controls (e.g. "F1" to open the Help system). Keyboard commands help users accelerate their selections.
- keyboard focus
- see focus
- 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.
- non-text content (non-text element, non-text equivalent)
- see text
- normative, informative (non-normative) [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 UAAG 2.0). What is identified as
"informative" (or, "non-normative") is never required for
conformance.
- notify
- To make the user aware of events or status changes. Notifications can occur within the user agent user interface (e.g. a status bar) or within the content display. Notifications may be passive and not require user acknowledgment, or they may be presented in the form of a prompt requesting a user response (e.g. a confirmation dialog).
- 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 UAAG 2.0, the term "override" means that one
configuration or behavior preference prevails over another. Generally,
the requirements of UAAG 2.0 involve user preferences prevailing
over author preferences and user agent default settings and behaviors.
Preferences may be multi-valued in general (e.g. the user prefers blue
over red or yellow), and include the special case of two values (e.g.
turn on or off blinking text content).
- 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). A placeholder can be any type of content,
including text, images, and audio cues. A placeholder should identify
the technology of the replaced object.
Placeholders appear in the alternative content stack.
- platform accessibility
architecture
- A programmatic interface that is engineered to enhance
communication between mainstream software applications and assistive
technologies (e.g. MSAA, UI Automation, and IAccessible2 for Windows applications, AXAPI for MacOSX applications, Gnome Accessibility Toolkit API for Gnome applications, Java Access for Java applications). On some platforms it may be conventional to enhance
communication further via implementing a DOM.
- 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
agents.
- point of regard
- The point of regard is the 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, keyboard focus, and selection. The stability of the point
of regard is addressed by [@@ Editors' Note: Need reference here@@].
- pointer
- see focus
- pointing device focus
- see focus
- 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 devices.
- prompt [ATAG
2.0]
- Any user-agent-initiated request for a decision or piece of
information from a user.
- 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 (e.g. on screen, on paper, through loudspeakers, on a braille
display, on a mobile device). Style information (e.g. fonts, colors,
synthesized speech prosody) may come from the elements themselves
(e.g. certain font and phrase elements in HTML), from style sheets, or
from user agent settings. For the purposes of these guidelines, each
formatting or style option is governed by a property and each property
may take one value from a set of legal values. Generally in UAAG 2.0, the term "property"
has the meaning defined in CSS 2 ([CSS2], section 3). A
reference to "styles" in UAAG 2.0 means a set of style-related
properties. The value given to a property by a user agent at
installation is the property's 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 UAAG 2.0 depend on content roles, content
relationships, timing relationships, and other information supplied by
the author. These requirements only apply when the author has encoded
that information in a manner that the user agent can recognize. See the
section on conformance for more information
about applicability. User agents will rely heavily on information that the
author has encoded in a markup language or style sheet language. Behaviors, style, meaning encoded in a script, and markup in an unfamiliar XML
namespace may not be recognized by the user agent as easily or at all.
- 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 UAAG 2.0). Any content that causes an
effect that may be perceived through these senses constitutes rendered
content. This includes text characters, images, style sheets, scripts,
and any other content that, once processed, may be perceived
through sight and hearing.
- 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.
- In the context of UAAG 2.0, invisible
content is content that is not rendered but that may
influence the graphical rendering (i.e. 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
- Content generated by the user agent to correct an error
condition. "Repair text" refers to the text portion of repair
content. 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).
UAAG 2.0 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 UAAG 2.0, the term "script" almost always
refers to a scripting (programming) language used to create dynamic Web
content. However, in guidelines referring to the written (natural)
language of content, the term "script" is used as in Unicode [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
- see focus
- serial access, sequential navigation
- 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
- 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
- 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 (e.g. slow reading speeds, large font sizes,
high need for review or repeat functions), and content that is
sub-optimal in terms of accessibility.
- technology (web content 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 (text content, non-text
content,
text element, non-text
element, text
equivalent, non-text equivalent )
- 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: UAAG 2.0 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.
Atext element adds text
characters to either content or the user
interface. Both in the Web Content Accessibility Guidelines 2.0 [WCAG20] and in UAAG 2.0, text elements are presumed to produce text that can be
understood when rendered visually, as synthesized speech, or as
Braille. Such text elements benefit at least these three groups of
users:
- 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
- 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 equivalent of audio
information (e.g. an audio-only presentation
or the audio track of a movie or other
animation). A text transcript provides text for both spoken words and non-spoken
sounds such as sound effects. Text transcripts make audio information
accessible to people who have hearing disabilities and to people who
cannot play the audio. Text transcripts are usually created by hand but
may be generated on the fly (e.g. by voice-to-text converters). See
also the definitions of captions and collated text
transcripts.
- track (audio track or
visual 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). Also see definition of visual track
- user agent
- A user agent is any software that retrieves, renders
and facilitates end user interaction with 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 UAAG 2.0, 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.
- values
- see properties
- 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
This section is informative.
There are two recommended ways to refer to the "User Agent Accessibility
Guidelines 2.0" (and to W3C documents in general):
- References to a specific version of "User Agent Accessibility
Guidelines 2.0." For example, use the "this version" URI to
refer to the current document:
http://www.w3.org/TR/2010/WD-UAAG20-20100617/
- References to the latest version of "User Agent Accessibility
Guidelines 2.0." Use the "latest version" URI to refer to
the most recently published document in the series:
http://www.w3.org/TR/UAAG20/.
In almost all cases, references (either by name or by link) should be to
a specific version of the document. W3C will make every effort to make UAAG 2.0 indefinitely available at its original address in its original form.
The top of UAAG 2.0 includes the relevant catalog metadata for specific
references (including title, publication date, "this version" URI,
editors' names, and copyright information).
An XHTML 1.0 paragraph including a reference to this specific document
might be written:
<p>
<cite><a href="http://www.w3.org/TR/2010/WD-UAAG20-20100617/">
"User Agent Accessibility Guidelines 2.0,"</a></cite>
J. Allan, K. Ford, J. Spellman, eds.,
W3C Recommendation, http://www.w3.org/TR/ATAG20/.
The <a href="http://www.w3.org/TR/ATAG20/">latest version</a> of this document is available at http://www.w3.org/TR/ATAG20/.</p>
For very general references to this document (where stability of content
and anchors is not required), it may be appropriate to refer to the latest
version of this document. Other sections of this document explain how to build a conformance
claim.
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 UAAG 2.0.
Note: In UAAG 2.0, bracketed labels such as
"[WCAG20]" link to the corresponding entries in this section. These labels
are also identified as references through markup.
- [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 UAAG 2.0 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 UAAG 2.0 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/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/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/. UAAG 2.0 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/.
- [WCAG20]
- "Web Content Accessibility Guidelines (WCAG) 2.0" B. Caldwell, M. Cooper, L. Guarino Reid, G. Vanderheiden, eds., 8 December 2008. This W3C Recommendation is
http://www.w3.org/TR/2008/REC-WCAG20-20081211/. The latest version is
available at http://www.w3.org/TR/WCAG20/. Additional
format-specific techniques documents are available from this Recommendation.
- [WCAG20-TECHS]
- "Techniques for
Web Content Accessibility Guidelines 2.0," B. Caldwell, M. Cooper, L. Guarino Reid, G. Vanderheiden, eds., 8 December 2008. This W3C Note is
http://www.w3.org/TR/2010/NOTE-WCAG20-TECHS-20101014/. The latest version is
available at http://www.w3.org/TR/WCAG20-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 (Co-Chair, Texas School for the Blind and Visually
Impaired)
- Alan Cantor (Invited Expert)
- Bim Egan (Royal National Institute of Blind People)
- Kelly Ford (Co-Chair, Microsoft)
- Mark Hakkinen (Invited Expert)
- Simon Harper (University of Manchester)
- Patrick Lauke (Opera Software)
- Greg Lowney (Invited Expert)
- Kimberly Patch (Invited Expert)
- Jan Richards (Adaptive Technology Resource Centre, University of
Toronto)
- Jeanne Spellman (W3C Staff Contact)
Other
previously active UAWG participants and other contributors to UAAG 2.0:
- Judy Brewer (W3C)
- Sean Hayes (Microsoft)
- Dean Hudson (Apple)
- Cathy Laws (IBM)
- Peter Parente (IBM)
- David Poehlman (Invited Expert)
- Simon Pieters (Opera Software)
- Henny Swan (Opera Software)
- Gregory Rosmaita (Invited Expert)
- David Tseng (Apple)
UAAG 2.0 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, National Institute on Disability and Rehabilitation
Research (NIDRR) under contract number ED-OSE-10-C-0067. The content of this
publication does not necessarily reflect the views or policies of the U.S.
Department of Education, nor does mention of trade names, commercial
products, or organizations imply endorsement by the U.S. Government.
Appendix E: Checklist
@@ Editors' Note: This section is still under development@@
Appendix F:
Comparison of UAAG 1.0 guidelines to UAAG 2.0
@@ Editors' Note: This section is still under development@@