WD-WAI-UA-BROWSER-19980602
WAI Accessibility Guidelines:
Browser User Interface
W3C Working Draft 02-June-1998
- This version:
- http://www.w3.org/WAI/UA/Group/1998/06/WD-WAI-UA-BROWSER-19980602
- Latest version:
- http://www.w3.org/WAI/UA/Group/1998/06/WD-WAI-UA-BROWSER-19980602
- Previous version:
- http://www.w3.org/WAI/UA/WD-WAI-UA-BROWSER-0529.html
- Editors:
- Jon Gunderson, University of Illinois at Urbana/Champaign <jongund@uiuc.edu>
- Ian Jacobs <ij@w3.org>
Please see the Acknowledgments for
a complete list of contributors.
Abstract
This document provides guidelines to browser designers (and to user
agent designers in general) designers on how to make their products more
accessible to persons with disabilities. Following the guidelines,
developers will find a helpful checklist for identifying and prioritizing
accessibility features.
This document is part of a series of accessibility documents published
by the Web Accessibility Initiative.
Status of this document
This is [not yet] a W3C Working Draft for review by W3C
members and other interested parties. It is a draft document and may be
updated, replaced or obsoleted by other documents at any time. It is
inappropriate to use W3C Working Drafts as reference material or to cite
them as other than "work in progress". This is work in progress
and does not imply endorsement by, or the consensus of, either W3C or
members of the WAI User Agent (UA) working group.
This document has been produced as part of the
W3C WAI Activity, and is intended as
a draft of a Proposed Recommendation for how to improve browser
accessibility. The goals of the WAI-UA Working
Group are discussed in the WAI
charter. A list of
the current Working
Group members is available.
Available formats
This document is available in the following formats:
- HTML:
- http://www.w3.org/WAI/UA/Group/1998/06/WD-WAI-UA-BROWSER-19980602
- A plain text file:
- http://www.w3.org/WAI/UA/Group/1998/06/WD-WAI-UA-BROWSER-19980602/wai-ua-browser.txt,
- HTML as a gzip'ed tar file:
- http://www.w3.org/WAI/UA/Group/1998/06/WD-WAI-UA-BROWSER-19980602/wai-ua-browser.tgz,
- HTML as a zip file (this is a '.zip' file not an '.exe'):
- http://www.w3.org/WAI/UA/Group/1998/06/WD-WAI-UA-BROWSER-19980602/wai-ua-browser.zip,
- A gzip'ed PostScript file:
- http://www.w3.org/WAI/UA/Group/1998/06/WD-WAI-UA-BROWSER-19980602/wai-ua-browser.ps.gz,
- A PDF file:
- http://www.w3.org/WAI/UA/Group/1998/06/WD-WAI-UA-BROWSER-19980602/wai-ua-browser.pdf.
In case of a discrepancy between the various formats of the
specification, http://www.w3.org/WAI/UA/Group/1998/06/WD-WAI-UA-BROWSER-19980602 is considered
the definitive version.
Comments
Please send detailed comments on this document to
w3c-wai-ua@w3.org. Public comments
about these guidelines may also be sent to this mailing list.
Each guideline is classified according to the following rating system:
- [Priority 1]
- This guideline must be implemented by a browser, or
one or more groups of
users will find it impossible to access information in the
document. This feature will significantly improve access to WWW
documents.
- [Priority 2]
- This guideline should be implemented by a browser,
or one or more groups of
users will find it difficult to access information in the
document. This feature will improve access to WWW documents.
- [Priority 3]
- This guideline should be implemented by a browser
to make it easier for one
or more groups of users to access information in the document.
This feature is not critical to accessibility, however.
The guidelines in this document have been organized around the following
general principles of accessible browser design:
- Allow the user to customize the presentation of documents to meet
special needs (e.g., large fonts, certain color combinations, etc.).
- Allow users to override author-specified and browser default styles.
- Provide access to alternate representations of information ("alt"
text of images, transcripts of video, etc.)
- Provide tools to navigate the document: from link to link, form
control to form control, frame to frame, etc. Allow navigation with the
keyboard at all times.
- Provide tools to improve orientation within the document so the user
can quickly grasp content and context.
- Render a page so that other software -- generically called "third-party
assistive technology" -- may interpret the rendered page in a
manner useful to the user. A screen reader is one example of such
technology; it synthesizes rendered lines of text in succession as
speech.
This document does not specify how browsers should implement the
guidelines based on these principles. It does assume that a browser can
implement the guidelines based on the characteristics, defined here.
A document is a series of elements
that are defined by a language (e.g., HTML 4.0, an XML application). Each
element consists of a name that identifies the type of element, optionally
a number of attributes, and a
(possibly empty) content. Attributes take values, and some of these values
are integral to document accessibility (e.g., the "alt", "title",
and "longdesc" attributes in HTML).
The rendered content is
that which an element actually causes to be rendered by the user agent.
This may differ from the element's content as defined above. For example,
some elements cause external data to be rendered (e.g., the IMG element in
HTML), and in some cases, browsers may render the value of an attribute
(e.g., "alt", "title") in place of the element's
content.
The presentation of a document is described by properties
(e.g., font face, font sizes for different headers, paragraph
justification, text color, etc.).
Each property has a current value
at any moment (e.g., "Helvetica" for font face, "12 point"
for font size, "black" for text color, etc.) The current value
comes from one of the following sources: browser, document, or user.
The value given to a property when the browser is first "turned on"
is called the default value.
Browsers may allow users to change default values through a variety of
mechanisms, including the user interface, style sheets, and initialization
files.
A property may receive its current value from the document itself,
through style sheets associated with the document, presentation attributes
of an element, a server, etc. These values are called
author styles.
Finally, the user may set the current value through user style sheets or
the user interface; these are called user
styles. Setting the current value of a property does not
change the default value.
Browsers allow users to interact with the rendered document through
several mechanisms.
- Selection
- Selection is a set of elements that the user has identified for a
particular operation (typically cut, copy and paste operations). The
selection may be rendered in a manner which distinguishes selected
elements from unselected elements. Typically selected elements are
highlighted visually. Highlighted text is often used by third party
assistive technologies to indicate through speech or Braille output what
the user wants read. Most screen readers are sensitive to highlight
colors.
- Activation
- Activation is the user commanding the browser to perform a particular
operation on the selection or focus.
- Focus
- The focus is a control element (link, form, DHTML events, etc.) that
indicates which control is currently active. A document can only have
one focus at a time.
- Events
- Events that may occur to a document or part of a document that cause
the browser to behave in a certain way. For instance, an event occurs
when a document is loaded into the browser or unloaded, and an event
occurs when a mouse button is depressed and another when released (when
released, the browser performs the action specified by the button), an
event occurs when a link is activated (it is generally followed), etc.
Events can occur with or without user action, especially with documents
using DTML and scripting programs.
The user should be able to customize the presentation of the selection
and the focus (e.g., through style sheets).
A browser may offer several views of
the same document. For instance, one view may show a table of contents and
a second the actual contents. Each view may have its own selection, but
only one should have the focus at a given moment.
- [PRIORITY 1]
Allow the user to override default
values for the following properties:
font face,
font size, and
foreground and background colors.
- [PRIORITY 1]
Allow the user to override author
styles for the following properties:
font face,
font size, and
foreground and background colors.
- [PRIORITY 1]
Allow the user to turn off author
CSS Style Sheets
- [PRIORITY 1]
Allow the user to turn off background
images
- [PRIORITY 1]
Allow the user to adjust the highlight
foreground and background colors used by the browser to
indicate the selection.
- [PRIORITY 1]
Allow the user, through a keyboard command, to switch between
browser default values and
current values.
- [PRIORITY 3]
Allow the user to specify browser default
values from an external file (e.g., initialization file or style
sheet). This is very useful in public access computer environments where
several people use the same computer. User profiles allow for convenient
customization and allow users to share effective profiles with each
other.
- [PRIORITY 1]
Allow the user to turn off the display of
images inserted by
HTML's IMG element (see [HTML40]) and display
descriptive text in place of the image. There are potentially two
sources of descriptive text information (in order): the "alt"
and "title". If both "alt" and "title" are
specified, "alt" should be used as a description of the image,
and "title" as a tool tip. If only "title" is
available it should be used as the description of the image. If both
these sources are omitted the browser should display "No alt text
available".
The entire text should be rendered no matter what the source of the
text or the dimensions specified for the original image. Text should
be wrapped so the user doesn't need to do a horizontal scroll to read
the description.
- [PRIORITY 1]
Allow the user to turn off the display of
images inserted by
HTML's OBJECT element (see [HTML40]) and
display descriptive text in place of the image. The innermost text of
the OBJECT is considered its alternative text. If the author has not
supplied alternative content the browser should display "No
description available".
The entire description text should be rendered no matter what the
source of the text or the dimensions specified for the original image.
Text should be wrapped so the user doesn't need to do a horizontal
scroll to read the description.
- [PRIORITY 1]
When an IMG element has a value for the "longdesc"
attribute and the user has turned off the display of images, render a
"description link" (D-link) inline to give access
to the long description. Provide keyboard access to locate and select
the long description (in addition to pointer access for able-bodied
users). The D-Link should function the same as a standard ANCHOR
element.
- [PRIORITY 3]
When an IMG element has a value for the "longdesc"
attribute and the author has already defined a "description
link" (D-link) for the image, the "longdesc"
D-Link should be suppressed. Therefore if an IMG element has both a
value for "longdesc" and a
hard coded D-Link only one D-Link should be presented to the user.
- [PRIORITY 3]
A user selectable option is available to turn off the display
of hard coded "description link" (D-link) in a
document.
- [PRIORITY 1]
Allow the user to turn on audio descriptions of videos, movies,
and animations. This would set a flag in the browser that can be used to
notify multi-media players to display audio descriptions. Multi-media
players need to recognize the flag to render the audio description
information.
- [PRIORITY 1]
Allow the user to turn on closed
captioning of video, movies, and animations. This would set a flag
in the browser that can be used to notify multi-media players to display
captioning information for the hearing impaired. Multi-media players
need to recognize the flag to render the captioning information. If a
system level flag is available in the operating system to indicate the
users need for closed captioning the browser flag should default to the
system value (i.e. show sounds in Windows 95/NT).
- [PRIORITY 1]
Allow the user to turn off the presentation of applications
embedded with the OBJECT element and
cause alternative text to be rendered instead. Users with some
disabilities may not be able to use an application, but need to know
about its existence, purpose, and function.
The entire text should be rendered no matter what the source of the
text or the dimensions specified for the original object. Text should
be wrapped so the user doesn't need to do a horizontal scroll to read
the description.
If an OBJECT element could not be loaded, the browser should tell
the user why it could not be loaded (e.g., missing object, server not
ready, etc.).
- [PRIORITY 1]
Allow the user to turn off the presentation of applications
embedded with the APPLET element and
cause alternative text to be rendered instead. Note.
the APPLET element is deprecated in HTML 4.0 (see [HTML40])
and authors should use the OBJECT element instead.
Alternate text for the APPLET element is specified with its "alt"
attribute.
If an APPLET element could not be loaded, the browser should tell
the user why it could not be loaded.
- [PRIORITY 2]
Allow the user to identify quickly the important
elements of a page. For example, when used
properly, header elements (H1-H6) may be used to create an outline of
major topics. The user should be able to select headers in the outline
view, causing the corresponding locations in the main view to be
displayed.
If the browser provides more than one view, the user should be able
to toggle between the full and outline view of the document.
Selections between views should be synchronized.
- [PRIORITY 2]
Provide a text-only view of page (cf. Lynx in Unix). All
non-textual information is hidden and alternative text is used for
images and other objects.
- [PRIORITY 2]
Provide a "serialized" view of tables. The first line
of the table provides the size and name of a table. Then, for each cell,
render the row and column coordinates of the cell followed by the cell's
contents. If row and column heading information has been specified in
the table (TH element) it should be used in the row and column
coordinate information. If no heading information is defined in the
table the user should have the option of requesting that the first
column and row be used as header information. This is useful for simple
tables, where authors have not specified the table header information.
- [PRIORITY 1]
Maintain the document view and
focus as a user moves between documents. As a
user activates links and returns to previously visited documents that
their last view and focus
in the document remain the same.
- [PRIORITY 1]
When the user changes the view of a document and the current
link or control that has thefocus is no longer
in view, the focus is shifted to a location in
the current view. Thus, after changing the view, if the user uses
keyboard commands to move or select the focused element, the view does
not abruptly change to another portion of the document with the focused
element.
- [PRIORITY 1]
When the user selects a link in one frame that causes a new
document to be loaded into a different, currently visible frame, move
the focus to a location in the new document. If the new document was
previously viewed, the view and the location of the focus should be on
the last element that was in focus.
- [PRIORITY 2]
When a page is loaded, display short document summary
information: the size of the document, the number of structural elements
related to the document. The information could be displayed on a status
line.
- [PRIORITY 2]
Display short document summary information when requested by
the user. A user command would update a status line or open a standard
window or dialog box with the document summary information.
- [PRIORITY 1]
Display information about elements
and dynamic HTML events when certain events
occur (e.g., focus, hover, etc.). Element
information should be displayed on the status line of the browser when
an element receives the focus or an event occurs.
- [PRIORITY 2]
Render the content of the TITLE element. The operating system
may impose conventions about where and how title information is
rendered.
To navigate a document may involve displaying different parts of it
(e.g., by scrolling) or shifting focus to
elements of the document. One of the key
issues related to navigation and control is the ability to use the
keyboard to access all links, form controls and DHTML events. This
includes the emulation of DHTML based mouse events.
- [PRIORITY 1]
Allow the user to use key board commands to sequentially move
between every frame, link, IMG elements with the "longdesc"
attribute set (if it is a link or has a LONGDESC attribute), and form
controls.
- [PRIORITY 2]
or [PRIORITY 3]
Allow the user to use the keyboard to navigate a
hierarchical or outline representation of the document. Highlight the
focus within the hierarchy in a way that is compatible with third-party
assistive technology (see section on compatibility).
The user should be able to use keyboard commands to navigate, expand or
contract the hierarchy. The hierarchy should be based on structural
block level elements like H1-H6, UL, OL and etc...
- [PRIORITY 1]
Allow the user to use the keyboard to move the
focus directly to links and controls on a
page. Users should be able to search for (and shift the focus to) a link
or control by its numerical position (a list of numbered links) or by
its name (search for search text matches only in links).
- [PRIORITY 2]
Allow the user to use the keyboard to move the
selection directly to
elements that are not links or form
controls. The selection typically can be
tracked by third party assistive technology to provide alternative
presentation of the selection through speech, enlargement or dynamic
Braille display.
- [PRIORITY 2]
Allow the user to use the keyboard to move the
selection between cells in a table. The
selection typically can be tracked by
third party assistive technology to provide alternative presentation of
the selection through speech, enlargement or dynamic Braille display.
- [PRIORITY 1]
Allow the user to use the keyboard to move the
focus between frames.
- [PRIORITY 1]
Highlight the focus in an obvious
manner so that users with low vision may identify it.
- [PRIORITY 1]
Provide a means for third-party assistive technologies to
identify the focus (see
compatibility section for more
information.)
- [PRIORITY 1]
Provide a means for third-party assistive technologies to
identify which elements have associated dynamic HTML
events. This maybe done by exposing DHTML
events through accessibility APIs.
- [PRIORITY 1]
Allow the user to use keyboard commands to create a list of
elements and their associated dynamic HTML events,
and to select and execute an event on the list.
- [PRIORITY 2]
Allow the user to use the keyboard to create a history of
visited documents, and to select and visit a document on the list.
- [PRIORITY 1]
Display keyboard shortcut navigation commands in menus if the
user interface or the operating system supports this.
- [PRIORITY 2]
If menu options exist for element navigation, these menus
should also be used to display summary information for elements reached
through that menu.
For example, if a browser has a menu item labeled "Headers",
that menu should allow navigation among header elements. The display
of the "Headers" menu could read "N Headers" where
"N" is the number of headers in the current document. The
sub-menu items might include "Next Header", "Previous
Header", "All Headers", and a dynamically created list
of the first 10 headers in the document.
- [PRIORITY 1]
Description of accessibility features are available in on-line
documentation. The on-line documentation needs to include information on
features that can be used to improve the usability of the browser by
persons with disabilities and provide a list of all keyboard commands.
The search index should include references to key words like "disability",
"handicapped", "accessibility", "impairment",
"keyboard" and "shortcut".
- [PRIORITY 1]
Description of accessibility is available in print
documentation. If print manuals are distributed with the browser, there
should be information about accessibility information in the print
manuals. The table of contents and the index should have entries that
clearly identify disability access features. The table of contents and
index should include references to key words like "disability",
"handicapped", "accessibility", "impairment",
"keyboard" and "shortcut".
- [PRIORITY 1]
Print and on-line information should be available in
alternative formats for people with print impairments. This includes
large print, audio tape and Braille. Information on how to obtain
information in alternative formats should be available in both on-line
and print materials.
The following guidelines apply to browsers that implement Cascading
Style Sheets (see CSS, level 1 and
CSS, level 2. Cascading style sheets may be part
of a document or may stand alone and be linked to a source document.
Overlapping rules from author, user, and browser style sheets cascade
(i.e., combine) to produce a single rule that assigns a
current value to a property.
- [PRIORITY 1]
Support the :before and
:after pseudo-elements as defined in CSS2 ([CSS2],
section 12.1) to allow users to label structural elements of a document.
The labels can be used to help orient the user to the element that is
being spoken or presented in Braille by third party assistive
technology.
- [PRIORITY 1]
Support the outline
property as defined in CSS2 ([CSS2], section
18.4) to users to customize the visual indication of the focus element.
A personal style sheet or the browser's default style can be used to
adjust the focus indication to the preferences of the user.
- [PRIORITY 1]
Implement the !important
rule as defined in CSS2 ([CSS2],
section 6.4.2) to allow users to override author
styles and browser defaults.
- [PRIORITY 1]
Allow the user to turn off author
styles represented by author style sheets.
- [PRIORITY 1]
Allow the user to adjust default
values represented by browser style sheets.
- [PRIORITY 1]
Implement CSS element focus outlines (see [CSS2],
section 18.4).
- [PRIORITY 2]
Support aural cascading style
sheets (see [CSS2], chapter 19)
for the auditory presentation of documents.
- [PRIORITY 2]
Allow the user to specify user
styles through style sheets
(see [CSS2], section 6.4).
[PRIORITY 1]
Use standard rather than custom controls when designing browsers
to increase their accessibility. Third-party assistive technology
developers are more likely able to access standard controls than custom
controls. If you must use custom controls, review them for accessibility
and compatibility with third-part assistive technology.
[PRIORITY 1]
Most popular operating systems have built-in accessibility
features. Developers should make sure that their products are compatible
with operating system built-in accessibility features. Built-in features
typically found on operating systems include: sticky keys, filter keys,
toggle keys, high contrast screen colors, system font size and face, and
mouse keys. Developers should test there programs with the various
features to insure that their technology is compatible with the features
available in the operating system. See Appendix A
for a list of features available in current operating systems.
[PRIORITY 1]
Some operating systems have developed accessibility application
programming interfaces (APIs). The accessibility APIs are designed to
provide a bridge between the standard user interface supported by the
operating system and alternative user interfaces developed by third party
assistive technology vendors to provide access to persons with
disabilities. Applications supporting these APIs are therefore more
compatible with third party assistive technology. A list of currently
available accessibility APIs can be found in Appendix
B. There
Many major operating systems have built-in accessibility features for
improving the usability of the standard operating system by persons with
disabilities. When designing an application program, developers should
test to see if their product is compatible with the features in the target
operating system. This should not be a problem if developers using
standard development tools and standard software design practices.
The accessibility options are found in the control panel of Windows 95.
All of the following options can be adjusted from the control panel.
- Sticky Keys: Allows user to temporarily hold down shift, alt and
control keys to allow one finger typing.
- Filter Keys: Allows user to change keyboard timing for accepting a
keypress and repeat rate.
- Toggle Keys: Provides auditory feedback when modifier or lock keys
are pressed.
- Mouse Keys: Allows the user to emulate pointer movement and button
press operations using the numeric keypad keys.
- High Contrast Display Mode: Changes the colors used on the display to
a high contrast color combination.
- Sound Sentry: Monitors the system sounds and flashes the menu bar
when sound output is detected. Used by the hearing impaired to know when
sound is being generated by the system.
- Show Sounds: A flag that is available to applications (including
browsers) to notify them to present audio information in a visual form
for the hearing impaired. This requires the application program to
provide the alternative format of information. This can include closed
captioning information on animations and video clips.
The accessibility options are found in the control panel of Windows NT
4.0. All of the following options can be adjusted from the control panel.
- Sticky Keys: Allows user to temporarily hold down shift, alt and
control keys to allow one finger typing.
- Filter Keys: Allows user to change keyboard timing for accepting a
keypress and repeat rate.
- Toggle Keys: Provides auditory feedback when modifier or lock keys
are pressed.
- Mouse Keys: Allows the user to emulate pointer movement and button
press operations using the numeric keypad keys.
- High Contrast Display Mode: Changes the colors used on the display to
a high contrast color combination.
- Sound Sentry: Monitors the system sounds and flashes the menu bar
when sound output is detected. Used by the hearing impaired to know when
sound is being generated by the system.
- Show Sounds: A flag that is available to applications (including
browsers) to notify them to present audio information in a visual form
for the hearing impaired. This requires the application program to
provide the alternative format of information. This can include closed
captioning information on animations and video clips.
The accessibility options can be adjusted from the control panels
through the Easy Access option and the Closeview option.
- Sticky Keys: Allows user to temporarily hold down shift, open apple
and control keys to allow one finger typing.
- Slow Keys: Allows user to change keyboard timing for accepting a
keypress and repeat rate.
- Mouse Keys: Allows the user to emulate pointer movement and button
press operations using the numeric keypad keys.
- Closeview: Closeview is a screen enlargement and enhancement program
used by persons with low vision to magnify the information on the visual
display and change the colors used by the system.
Disability access server features, known as
AccessX,
provide basic workstation accessibility, typically used by people with
mobility impairments. AccessX became a supported part of the X Windows
server in version X11/R6. The built-in server level access features
include:
- StickyKeys: Provides locking or latching of modifier keys (eg, Shift,
Control) so that they can be used without simultaneously pressing the
keys being modified. This allows single finger operation of multiple key
combinations.
- RepeatKeys: Delays the onset of key repeat, allowing users with
limited coordination time to release keys before multiple characters are
sent.
- SlowKeys: Requires a key to be held down for a set period before
keypress acceptance. This allows users with limited coordination to
accidentally press keys without sending keypress events.
- MouseKeys: An alternative to the mouse which provides keyboard based
explicit control of cursor movement and all mouse button press/release
events
- ToggleKeys: Indicates locking key state with a tone when pressed,
e.g., Caps Lock.
- BounceKeys: Requires a delay between keystrokes before accepting the
next keypress so users with tremors can prevent the system from
accepting inadvertent keypresses.
The following is a list of currently public accessibility APIs that are
available for various operating systems. The inclusion of this list is not
an endorsement of any particular accessibility API by the W3C in general
or WAI in particular. The information is purely for reference to browser
developers. The use of accessibility APIs is strongly recommended by WAI
for compatibility with 3rd party assistive technology. Third party
assistive technology can use the accessibility information provided by the
APIs to provide an alternative user interface for various disabilities.
When developing new applications for Windows 95/NT, build active
accessibility compatibility into the specifications and design. This
provides third-party assistive technology developers with important
information about your program. More information on active accessibility
can be found at the
Microsoft WWW
site on Active Accessibility.
When developing new applications using SunSoft Java
technology, build into the specifications and design the use of the
Java Accessibility API. This provides third-party assistive technology
with important information for accessibility, so persons with disabilities
can use assistive technology to more efficiently access your programs.
More information on Java Accessibility API can be found at
Java
Accessibility Utilities.
- WAI Markup Guidelines Working Group Chair:
- Jon Gunderson, University of
Illinois at Urbana/Champaign
- W3C Team contacts:
- Judy Brewer and
Daniel Dardailler
In addition, we would like to thank the following people who have
contributed through review and comment: James Allen, Irene Au, Kitch
Barnicle, Kevin Carey, Wendy Chilstrom, Chetz Colwell, Neal Ewers, Geoff
Freed, Larry Goldberg, Jon Gunderson, Chris Hasser, Phill Jenkins, Leonard
Kasday, George Kerscher, Josh Krieger, Greg Lowney, Scott Luebking,
William Loughborough, Charles McCathieNevile, Masafumi Nakane, Charles
Opperman, Mike Paciello, David Pawson, Helen Petrie, David Poehlman,
Michael Pieper, Jan Richards, Greg Rosmaita, Liam Quinn, T.V. Raman,
Robert Savellis, Constantine Stephanidis, Jim Thatcher, Jutta Treviranus,
Steve Tyler, Gregg Vanderheiden, Jaap van Lelieveld, Jon S. von Tetzchner,
Ben Weiss, Evan Wies, Chris Wilson, Henk Wittingen, and Tom Wlodkowski.
If you have contributed to the UA guidelines and your name
does not appear please contact the editor to add your name to the list.
- [HTML40]
- "HTML 4.0 Recommendation", D. Raggett, A. Le Hors, and I.
Jacobs, eds. The HTML 4.0 Recommendation is available at:
http://www.w3.org/TR/REC-html40/.
- [CSS1]
- "CSS, level 1 Recommendation", B. Bos, H. Wium Lie, eds.
The CSS1 Recommendation is available at:
http://www.w3.org/TR/REC-CSS1-961217/.
- [CSS2]
- "CSS, level 2 Recommendation", B. Bos, H. Wium Lie, C.
Lilley, and I. Jacobs, eds. The CSS2 Recommendation is available at:
http://www.w3.org/TR/REC-CSS2/.
- [WAI-PAGEAUTH]
- "WAI Accessibility Guidelines: Page Authoring" for
designing accessible documents are available at:
http://www.w3.org/TR/WD-WAI-PAGEAUTH.