User Agent Support Notes for HTML and XHTML Techniques

The HTML 4.01 specification explains that the text of the alt attribute is to be displayed when the element cannot be rendered normally. User Agents will display the alt attribute text when images are not displayed. However, currently, visual User Agents do not display the alt attribute text for area elements of image maps when accessed by keyboard or when images are not displayed, and may clip the area elements if the intrinsic size of the image is not used. In addition, the display of alt attribute text in response to mouse-hover does not display in the font size or color combination set in the User Agent.

The title attribute is meant to provide additional information. However, current implementation in User Agents is access to either the title or alt attribute, but not both. User Agents generally will display the title attribute text when the mouse is placed over the element containing the title attribute.

Therefore, when using image maps, successful implementation of this technique would require either:

• Ensuring the area element alt attribute value is displayed in response to attaining focus (including keyboard focus), and that this applies both to situations where images are loaded and not loaded. OR

• A redundant mechanism serving the same purpose as the area elements is present in the Web Page.

This technique is not supported well by assistive technologies and cross-browser support is irregular.

• Assistive technologies provide different levels of support for speaking abbreviations and acronyms, often dependent upon specific customization settings.

• This technique is only sufficient if the abbr or acronym element's title attribute is accessibility supported. The content of the title attribute needs to be available to all keyboard users (not only those with text-to-speech software) for this attribute to be accessibility supported.

• JAWS 6.2 and higher and WindowEyes 5.0 and higher support the abbr and acronym elements. They can all be set to speak the title attribute when these elements are encountered, but this is not the default setting and is often not turned on by users.

• Many graphical user agents render text enclosed within an abbr or acronym element with a dotted line below or surrounding it. In addition, when the mouse hovers over the element, the expansion is displayed as a tool tip.

• In Internet Explorer 7 and below, items marked using the abbr element are not displayed with any additional formatting. For IE 6 and below, the expanded version does not display as a tooltip when the mouse hovers over the item.

• Within a given user agent or assistive technology, abbr and acronym elements are presented to users in the same way.

• Current user agents and assistive technology provide no feedback to the user when links have title attribute content available.

• Some graphical user agents will display a tool tip when the mouse hovers above an anchor element containing a title attribute. However, current user agents do not provide access to title attribute content via the keyboard.

• The tool tip in some common user agents disappears after a short period of time (approximately 5 seconds). This can cause difficulty accessing title attribute content for those users who can use a mouse but have fine motor skill impairment, and may result in difficulties for users who need more time to read the tool tip.

• Current graphical user agents do not provide mechanisms to control the presentation of title attribute content. The user cannot resize the tool tip text or control the foreground and background colors. The placement and location of the tool tip cannot be controlled by users, causing some screen magnifier users to be unable to access meaningful portions of the title attribute content because the tool tip cannot be fully displayed within the viewport.

• Some user agents allow access to supplementary information through the context menu. For example, the keystroke combination Shift+F10 followed by P will display the title attribute content, along with other supplementary information in Mozilla/Firefox.

• The HTML 4.01 specification explains that the text of the alt attribute is to be displayed when the element cannot be rendered normally. Thus, visual User Agents will display the alt attribute text when images are not displayed. The title attribute is meant to provide additional information. User Agents generally will display the title attribute text when the mouse is placed over the element containing the title attribute. Internet Explorer will display the alt text on mouse-over if there is no title text. The Firefox and Opera browsers only display the title text on mouse-over and do not use the alt attribute text for this purpose.

• Assistive technologies provide different levels of support for speaking title attributes. Some do not include features that allow users to access information provided via the title attribute.

• JAWS 7.0 and above will speak the value of title attributes depending upon a JAWS setting. This setting can be changed temporarily or permanently within JAWS.

• WindowEyes 5.5 and above has a hot key, ins-E, that will speak additional information, including the title attribute, for the item with focus.

• Implementing this technique with the title attribute is only sufficient if the title attribute is accessibility supported. If the value of the title is essential to understanding the purpose of the link for all users, then the content of this attribute needs to be available to all keyboard users (not only those with text-to-speech software) for this technique to be accessibility supported.

• This technique is not supported well by assistive technologies. The HTML specification explains that text alternatives for applets are to be displayed when the element cannot be rendered. Therefore, text alternatives that are included in the body of applet elements may not be available to users unless the user agent either does not support or has been configured not to render applets.

• IE 6 for Windows and Firefox 1.5 and Opera 9 on Windows treat alternative text for the applet element differently. IE will display the body text of the applet element and not the alt attribute. Firefox and Opera will display the alt attribute but not the body text.

The HTML and XHTML specifications allow both implicit and explicit labels. However, some assistive technologies do not correctly handle implicit labels (for example, <label>First name <input type="text" name="firstname"></label>).

• JAWS 7.10 was tested on Windows XP with Internet Explorer 6.0 and Firefox 1.5. It reads the label for explicit and implicit labels for text fields in both virtual PC cursor and forms reading mode. In forms mode it does not read the label for implicit labels on checkboxes and radio fields.

• Window-Eyes 5.5 was tested on Windows XP with Internet Explorer 6.0 and Firefox 1.5. It will always speak the label for an explicitly labelled form field. It does not speak the label for the implicitly labelled form control in browse on mode but will speak the implicit label when navigating from control to control in browse off mode.

User agents will display a tool tip when the mouse hovers above an input element containing a title attribute. Title attributes are exposed to assistive technology and are displayed as tooltips in many graphical browsers. Tooltips can't be opened via the keyboard, so this information may not be available to sighted keyboard users.

If no label is available, JAWS and Window-Eyes speak the title attribute when the form control receives focus

• JAWS 6.0 and later can be set to speak both label and title when the two items are different; however, very few users are aware of this setting.

• WindowEyes 5.5 has a hot key, ins-E, that will display additional information, including the title attribute, for the item with focus.

User Agent support for longdesc varies, but overall support is improving. Screen readers such as JAWS, NVDA, and Window-Eyes support longdesc, but Voiceover 4.0, Orca 2.32.0, and screen magnifier Zoomtext 10.0 do not yet support the longdesc attribute. Browsers including Internet Explorer, Firefox, Opera, and Chrome all support longdesc.

Assistive technologies include inconsistent support for various uses of the type attribute used to indicate numbering and bullet styles.

• Some semantic elements are not supported well by assistive technologies. Elements and attributes that are known to have limited support include code, del, dfn, ins, kbd, s, sub, sup, tt, and q. For these elements, authors are encouraged to consider whether they are using them in a way that would require users to be able to access the semantic meaning of the markup in order to understand the content and, where understanding the semantics is required, to provide this information in text.

• Most screen readers do not provide automatic notification about em, strong, b, or i.

• JAWS contains support for blockquote and cite. WindowEyes contains support for blockquote, q and cite.

• Firefox 1.0 (Windows) and higher, Opera 7.54 (Windows) and higher, Mozilla 1.7.3 (Windows) and higher automatically generate quotes around q elements, but Internet Explorer 6 for Windows does not.

This technique is not supported well by assistive technologies and cross-browser support is irregular.

Additional subtags for region, script, variant or other aspects may lead to errors in language switching in older versions of some screenreaders.

JAWS 8.0 can be configured to change language automatically on the basis of the lang attribute. However, it only switches amongst major languages as indicated by the primary code. If a regional language variant is indicated with a language subcode, JAWS will use the default variant for which it is configured.

Additional subtags for region, script, variant or other aspects may lead to errors in language switching in older versions of some screenreaders.

JAWS 8.0 can be configured to change language automatically on the basis of the lang attribute. However, it only switches amongst major languages as indicated by the primary code. If a regional language variant is indicated with a language subcode, JAWS will use the default variant for which it is configured.

• The link element has inconsistent user agent and assistive technology support.

• Some user agents provide an optional navigation bar which will display the information specified in the link element. Current versions of the Mozilla and Opera browsers provide this functionality. IE 6.0 and Firefox 1.5 do not offer this feature but it may be available through extensions or add-ons.

  See The 'link'-Element in (X)HTML for more information on browser support for link.

Some user agents provide an optional navigation bar which will display the information specified in the link element. Current versions of the Mozilla and Opera browsers provide this functionality. IE 6.0 and Firefox 1.5 do not offer this feature but it may be available through extensions or add-ons. See The 'link'-Element in (X)HTML for more information on browser support for the link element.

Ruby markup includes the rp element as a fallback mechanism for user agents that do not support XHTML 1.1. Although ruby markup is only defined in XHTML 1.1, IE 5.0 and later supports the ruby, rt, and rp elements even if they are used in HTML 4.01 or XHTML 1.0.

The row and col values of the scope attribute are currently supported to a large extent by most current versions of JAWS. However, there are still some problems and WindowEyes support for scope is inconsistent. The same is true for Japanese versions of these screen readers. Versions of JAWS prior to version 5 and older versions of Window-Eyes have inconsistent support for scope.

At the current time, those who want to ensure consistent support across Assistive Technologies for tables where the headers are not in the first row/column may want to use the technique for complex tables H43: Using id and headers attributes to associate data cells with header cells in data tables. For simple tables that have headers in the first column or row we recommend the use of the th and td elements.

The use of the longdesc attribute in HTML 4 on frame and iframe elements to specify a link to a long description of a frame is not supported well by assistive technologies. The use of title as described in this technique is recommended instead.

• User agents will display a tool tip when the mouse hovers above an input element containing a title attribute.

• If no label is available, JAWS and Window-Eyes speak the title attribute when the form control receives focus

  • JAWS 6.0 and later can be set to speak both label and title when the two items are different; however, very few users are aware of this setting.

  • WindowEyes 5.5 has a hot key, ins-E, that will display additional information, including the title attribute, for the item with focus.

Most screen readers provide navigation via headings and provide information about the level of the heading. The Opera browser provides a mechanism to navigate by headings. Additional plugins support navigation by headings in other user agents. See the Resources section for references to some of these plugins.

JAWS 5.0 and later includes the following keystrokes:

• alt+leftArrow: read previous sentence

• alt+rightArrow: read next sentence

• alt+NumPad 5: read current sentence

• Ctrl+NumPad5: read current paragraph

If alt+numPad5 is pressed when a link has focus, the sentence is read without changing the focus.

If Ctrl+NumPad 5 is pressed when the link has focus, the entire paragraph is read without changing the focus.

Window-Eyes 5.5 has hotkeys to read the current sentence and current paragraph.

To surf the internet with WindowEyes you must be in browse mode. Current sentence and current paragraph hot keys do not work in browse mode in version 6.1.

The factory default settings for reading surrounding link context are as follows:

Desktop settings:

• Character = CTRL-NUMPAD-LEFT ARROW

• Word = CTRL-NUMPAD-RIGHT ARROW

• Line = CTRL-NUMPAD-CENTER

• Sentence = Not available in Browse mode

• (Next Sentence command is undefined by default on Desktop mode but the next line is the DOWN Arrow.)

• Next Paragraph = P

• Prior Paragraph = Shift P

• Current Paragraph = Not Available in Browse mode

Laptop

• Character = ALT-SHIFT-LESS THAN

• Word Prior = ALT-SHIFT-J

• Word = ALT-SHIFT-K

• Word Next = ALT-SHIFT-L

• Sentence Prior = ALT-SHIFT-7

• Sentence = unavailable in browse mode

• Sentence Next = unavailable in browse mode

• Paragraph = Undefined on Laptop by default

• Line Prior = ALT-SHIFT-U

• Line = ALT-SHIFT-I

• Line Next = ALT-SHIFT-O

The "speak parent element" command in Fire Vox (Ctrl+Shift+u) works without changing the focus. Fire Vox is a free screen reader designed specifically for Firefox 1.0 and later. It supports Windows, Macintosh, and Linux.

The command to take advantage of this technique in JAWS is "JAWS KEY + T".

Although the context information is programmatically associated with the link, assistive technology lacks commands for reading the parent list item without moving focus away from the link.

The optgroup element is not widely supported by many screen readers including JAWS 11 and below or Window-Eyes 6 and below.

The label attribute for option and optgroup is supported inconsistently across user agents and is not widely supported by screen readers including JAWS 11 and below and Window-Eyes 6 and below.

• Assistive technologies provide different levels of support for speaking title attributes. Some do not include features that allow users to access information provided via the title attribute.

• Implementing this technique with the title attribute is only sufficient if the title attribute is accessibility supported. The content of the title attribute needs to be available to all keyboard users (not only those with text-to-speech software) for this attribute to be accessibility supported.

• JAWS 6.2 and higher and WindowEyes 5.0 and higher support the abbr and acronym elements. They can all be set to speak the title attribute when these elements are encountered, but this is not the default setting and is often not turned on by users.

• Many graphical user agents render text enclosed within an abbr or acronym element with a dotted line below or surrounding it. In addition, when the mouse hovers over the element, the expansion is displayed as a tool tip.

• In Internet Explorer 7 and below, items marked using the abbr element are not displayed with any additional formatting. For IE 6 and below, the expanded version does not display as a tooltip when the mouse hovers over the item.

• Within a given user agent or assistive technology, abbr and acronym elements are presented to users in the same way.

• Some current assistive technology provide feedback to the user when form fields have title attribute content available.

• Some graphical user agents will display a tool tip when the mouse hovers above a form field containing a title attribute. However, current user agents do not provide access to the title attribute content via the keyboard.

• The tool tip in some common user agents disappears after a short period of time (approximately 5 seconds). This can cause difficulty accessing title attribute content for those users who can use a mouse but have fine motor skill impairment, and may result in difficulties for users who need more time to read the tool tip.

• It is difficult for most users to resize, adjust background colors, reposition or otherwise control the presentation of title attribute content in many current user agents.

• This technique can only be used when the element has an explicitly associated label. In the absence of a label, the title will be used as the Name in the accessibility API of current user agents that support one. The help text described below makes a poor name.

The HTML and XHTML specifications allow both implicit and explicit labels. However, some assistive technologies do not correctly handle implicit labels (for example, <label>First name <input type="text" name="firstname"></label>).

• JAWS 7.10 was tested on Windows XP with Internet Explorer 6.0 and Firefox 1.5. It reads the label for explicit and implicit labels for text fields in both virtual PC cursor and forms reading mode. In forms mode it does not read the label for implicit labels on checkboxes and radio fields.

• Window-Eyes 5.5 was tested on Windows XP with Internet Explorer 6.0 and Firefox 1.5. It will always speak the label for an explicitly labelled form field. It does not speak the label for the implicitly labelled form control in browse on mode but will speak the implicit label when navigating from control to control in browse off mode.

User agents will display a tool tip when the mouse hovers above an input element containing a title attribute. Title attributes are exposed to assistive technology and are displayed as tooltips in many graphical browsers. Tooltips can't be opened via the keyboard, so this information may not be available to sighted keyboard users.

If no label is available, JAWS and Window-Eyes speak the title attribute when the form control receives focus

• JAWS 6.0 and later can be set to speak both label and title when the two items are different; however, very few users are aware of this setting.

• WindowEyes 5.5 has a hot key, ins-E, that will display additional information, including the title attribute, for the item with focus.

Some user agents (specifically the Window-Eyes screen reader) do not by default voice the asterisk character in form labels. There is a preference that Window-Eyes users can modify to adjust this behavior but many users should be expected not to have made this change.

JAWS does not insert a space between an image's alt text and any adjacent text.