This objective of this technique is to avoid unnecessary duplication that occurs when adjacent text and iconic versions of a link are contained in a document.

Many kinds of links have both a text and iconic link adjacent to each other. Often the text and the icon link are rendered in separate links, in part to create a slight visual separation from each other. Visually they appear to be the same link, but they are experienced by many people as two identical links and this can be confusing. To avoid this, some authors omit alternative text from the image, but this would fail Success Criterion 1.1.1 because the text alternative would not serve the same purpose as the graphical link. The preferred method to address this is to put the text and image together in one link, and provide null alternative text on the image to eliminate duplication of text.

Sometimes the text and the icon link are rendered in separate, adjacent table cells to facilitate page layout. Although WCAG 2 does not prohibit the use of layout tables, CSS-based layouts are recommended in order to retain the defined semantic meaning of the HTML table elements and to conform to the coding practice of separating presentation from content. If CSS is used, this technique can be applied to combine the links.

The objective of this technique is to provide a logical tab order when the default tab order does not suffice. Often, placing the interactive elements in an order that follows sequences and relationships within the content is sufficient and this technique is not necessary. It can be very easy to introduce usability bugs when setting the tab order explicitly.

In some cases, the author may want to specify a tab order that follows relationships in the content without following the order of the interactive elements in the code. In these cases, an alternative order can be specified using the tabindex attribute of the interactive element. The tabindex is given a value between 0 and 32767.

When the interactive elements are navigated using the tab key, the elements are given focus in increasing order of the value of their tabindex attribute. Elements that have a tabindex value higher than zero will receive focus before elements without a tabindex or a tabindex of 0. After all of the elements with a tabindex higher than 0 have received focus, the rest of the interactive elements are given focus in the order in which they appear in the Web page.

The objective of this technique is to provide text alternatives that serve the same purpose as the selectable regions of an image map. An image map is an image divided into selectable regions defined by area elements. Each area is a link to another Web page or another part of the current Web page. The alt attribute of each area element serves the same purpose as the selectable area of the image.

All HTML and XHTML documents, including those in individual frames in a frameset, have a title element in the head section that defines in a simple phrase the purpose of the document. This helps users to orient themselves within the site quickly without having to search for orientation information in the body of the page.

Note that the (mandatory) title element, which only appears once in a document, is different from the title attribute, which may be applied to almost every HTML and XHTML element.

If object is used, provide a text alternative in the content of the element:

The objective of this technique is to provide expansions or definitions for abbreviations by using the abbr and acronym elements.

It is always appropriate to use the abbr element for any abbreviation, including acronyms and initialisms. When using HTML and XHTML, initialisms and acronyms may be marked up using the acronym element. Versions of HTML after HTML 4 eliminate the acronym element in favor of the more general abbr element.

The objective of this technique is to describe the purpose of a link by providing descriptive text as the content of the a element. The description lets a user distinguish this link from other links in the Web page and helps the user determine whether to follow the link. The URI of the destination is generally not sufficiently descriptive.

When an image is the only content of a link, the text alternative for the image describes the unique function of the link.

When the content of a link contains both text and one or more images, if the text is sufficient to describe the purpose of the link, the images may have an empty text alternative. (See Using null alt text and no title attribute on img elements for images that assistive technology should ignore.) When the images convey information beyond the purpose of the link, they must also have appropriate alt text.

The objective of this technique is to provide a mechanism that allows users to explicitly request changes of context. The intended use of a submit button is to generate an HTTP request that submits data entered in a form, so it is an appropriate control to use for causing a change of context.

The objective of this technique is to demonstrate how to use a title attribute on an anchor element to provide additional text describing a link. The title attribute is used to provide additional information to help clarify or further describe the purpose of a link. If the supplementary information provided through the title attribute is something the user should know before following the link, such as a warning, then it should be provided in the link text rather than in the title attribute.

Because of the extensive user agent limitations in supporting access to the title attribute, authors should use caution in applying this technique. For this reason, it is preferred that the author use technique C7: Using CSS to hide a portion of the link text or H30: Providing link text that describes the purpose of a link for anchor elements.

The objective of this technique is to use Unicode right-to-left marks and left-to-right marks to override the HTML bidirectional algorithm when it produces undesirable results. This may be necessary, for instance, when placing neutral characters such as spaces or punctuation between different directional text runs. The concepts used in this technique are described in What you need to know about the bidi algorithm and inline markup.

Unicode right-to-left marks and left-to-right marks can be entered directly or by means of character entities or numeric character references, as shown here.

Due to the bidi algorithm, a source code editor may not display character entities or numeric character references as expected.

Provide a text alternative for an applet by using the alt attribute to label an applet and providing the text alternative in the body of the applet element. In this technique, both mechanisms are required due to the varying support of the alt attribute and applet body text by user agents.

For input elements of type 'image', the alt attribute of the input element is used to provide a functional label. This label indicates the button's function, but does not attempt to describe the image. The label is especially important if there are multiple submit buttons on the page that each lead to different results.

The input element is used to create many kinds of form controls. Although the HTML and XHTML DTDs permits the alt attribute on all of these, it should be used only on image submit buttons. User agent support for this attribute on other types of form controls is not well defined, and other mechanisms are used to label these controls.

When using the img element, specify a short text alternative with the alt attribute. Note. The value of this attribute is referred to as "alt text".

When an image contains words that are important to understanding the content, the alt text should include those words. This will allow the alt text to play the same function on the page as the image. Note that it does not necessarily describe the visual characteristics of the image itself but must convey the same meaning as the image.

The objective of this technique is to programmatically associate captions for data tables where captions are provided in the presentation. The caption for a table is a table identifier and acts like a title or heading for the table.

The caption element is the appropriate markup for such text and it ensures that the table identifier remains associated with the table, including visually (by default). In addition, using the caption element allows screen reading software to navigate directly to the caption for a table if one is present.

The caption element may be used whether or not the table includes a summary attribute. The caption element identifies the table whereas the summary attribute gives an overview of the purpose or explains how to navigate the table. If both are used, the caption should not duplicate information in the summary.

Although WCAG 2.0 does not prohibit the use of layout tables, CSS-based layouts are recommended in order to retain the defined semantic meaning of the HTML and XHTML table elements and to conform to the coding practice of separating presentation from content. If a table is used for layout, the caption element is not used. The purpose of a layout table is simply to control the placement of content; the table itself is “transparent" to the user. A caption would "break" this transparency by calling attention to the table.

The objective of this technique is to provide the definitions of words or phrases by presenting them in a definition list. The list is marked up using the dl element. Within the list, each term is put in a separate dt element, and its definition goes in the dd element directly following it. The title attribute can be used to provide additional information about the definition list.

Using dl, dt, and dd ensures that relationships between terms and their definitions are preserved if the presentation format changes and that the list of terms and definitions is treated as a unit.

Definition lists are easiest to use when the definitions are put in alphabetical order. Definition lists are typically used in a glossary.

The objective of this technique is to use HTML and XHTML heading markup to provide semantic code for headings in the content. Heading markup will allow assistive technologies to present the heading status of text to a user. A screen reader can recognize the code and announce the text as a heading with its level, beep or provide some other auditory indicator. Screen readers are also able to navigate heading markup which can be an effective way for screen reader users to more quickly find the content of interest. Assistive technologies that alter the authored visual display will also be able to provide an appropriate alternate visual display for headings that can be identified by heading markup.

The objective of this technique is to associate each data cell (in a data table) with the appropriate headers. This technique adds a headers attribute to each data cell (td element). It also adds an id attribute to any cell used as a header for other cells. The headers attribute of a cell contains a list of the id attributes of the associated header cells. If there is more than one id, they are separated by spaces.

This technique is used when data cells are associated with more than one row and/or one column header. This allows screen readers to speak the headers associated with each data cell when the relationships are too complex to be identified using the th element alone or the th element with the scope attribute. Using this technique also makes these complex relationships perceivable when the presentation format changes.

This technique is not recommended for layout tables since its use implies a relationship between cells that is not meaningful when tables are used for layout.

The objective of this technique is to use the label element to explicitly associate a form control with a label. A label is attached to a specific form control through the use of the for attribute. The value of the for attribute must be the same as the value of the id attribute of the form control.

The id attribute may have the same value as the name attribute, but both must be provided, and the id must be unique in the Web page.

This technique is sufficient for Success Criteria 1.1.1, 1.3.1 and 4.1.2 whether or not the label element is visible. That is, it may be hidden using CSS. However, for Success Criterion 3.3.2, the label element must be visible since it provides assistance to all users who need help understanding the purpose of the field.

An additional benefit of this technique is a larger clickable area for the control, since clicking on the label or the control will activate the control. This can be helpful for users with impaired motor control.

Note that the label is positioned after input elements of type and type.

The objective of this technique is to provide information in a file designated by the longdesc attribute when a short text alternative does not adequately convey the function or information provided in the image. The longdesc attribute is a URI, the target of which contains a long description of the non-text content.

The objective of this technique is to provide alternative content for the embed element in a noembed element. The noembed is rendered only if the embed is not supported. While it can be positioned anywhere on the page, it is a good idea to include it as a child element of embed so that it is clear to assistive technologies that a text alternative is associated with the embed element it describes.

The objective of this technique is to create lists of related items using list elements appropriate for their purposes. The ol element is used when the list is ordered and the ul element is used when the list is unordered. Definition lists (dl) are used to group terms with their definitions. Although the use of this markup can make lists more readable, not all lists need markup. For instance, sentences that contain comma-separated lists may not need list markup.

When markup is used that visually formats items as a list but does not indicate the list relationship, users may have difficulty in navigating the information. An example of such visual formatting is including asterisks in the content at the beginning of each list item and using br]]> elements to separate the list items.

Some assistive technologies allow users to navigate from list to list or item to item. Style sheets can be used to change the presentation of the lists while preserving their integrity.

The list structure (ul/ol) is also useful to group hyperlinks. When this is done, it helps screen reader users to navigate from the first item in a list to the end of the list or jump to the next list. This helps them to bypass groups of links if they choose to.

The objective of this technique is to demonstrate how semantic markup can be used to mark emphasized or special text so that it can be programmatically determined. Using semantic markup to mark emphasized or special text also provides structure to the document. User agents can then make the structure perceivable to the user, for example using a different visual presentation for different types of structures or by using a different voice or pitch in an auditory presentation.

Most user agents will visually distinguish text that has been identified using semantic markup. Some assistive technologies provide a mechanism for determining the characteristics of content that has been created using proper semantic markup.

The objective of this technique is to demonstrate how to group links into logical sets using the element. When links are grouped into logical sets (for example, in a navigation bar or main menu that appears on every page in a site) they should be marked up as a unit. Navigation bars are usually the first thing someone encounters on a page. People who are sighted are often able to ignore navigation parts and start reading the content of the page. Someone using a screen reader must first listen to the text of each link in the navigation bar before reading the interesting content. This technique uses the element to mark up content so that a user with a screen reader can jump over the navigation bar and avoid reading all of the links.

The objective of this technique is to present tabular information in a way that preserves relationships within the information even when users cannot see the table or the presentation format is changed. Information is considered tabular when logical relationships among text, numbers, images, or other data exist in two dimensions (vertical and horizontal). These relationships are represented in columns and rows, and the columns and rows must be recognizable in order for the logical relationships to be perceived.

Using the table element with the child elements tr, th, and td makes these relationships perceivable. Techniques such as inserting tabs to create columns or using the pre element are purely visual, and visually implied logical relationships are lost if the user cannot see the table or the visual presentation is changed.

Simple tables generally have only one level of headers for columns and/or one level of headers on the rows.

Usually, for simple tables, row 1 column 1 is either blank or describes the contents of the entire column 1. Row 1 columns are not blank (i.e. they contain "column headings"), describe the contents of the entire column, and allow the reader to distinguish the difference in meaning between that column and other columns.

Column 1 rows are usually not blank, they often contain "row headings" which describe the contents of the entire row, and allow the reader to distinguish the difference in meaning between that row and the other rows. Otherwise, the Column 1 would contain simple data.

The objective of this technique is to provide a text alternative for content rendered using the object element. The body of the object element can be used to provide a complete text alternative for the object or may contain additional non-text content with text alternatives.

The objective of this technique is to use the dfn to mark the use of a word or phrase where it is defined. The dfn element is used to indicate the defining instance of the enclosed term. In other words, it marks the occurrence of the term where the term is defined. Note that it encloses the term, not the definition. This technique would be used in combination with Using inline definitions to provide the definition.

The objective of this technique is to identify changes in the text direction of text that includes nested directional runs by providing the dir attribute on inline elements. A nested directional run is a run of text that includes mixed directional text, for example, a paragraph in English containing a quoted Hebrew sentence which in turn includes an English phrase. Use of the dir attribute on an enclosing span or other inline element may be necessary because the Unicode bidirectional algorithm can produce undesirable results when mixed directional text contains spaces or punctuation. The concepts used in this technique are described in What you need to know about the bidi algorithm and inline markup.

The objective of this technique is to identify the default language of a document by providing the lang and/or xml:lang attribute on the html element.

Identifying the language of the document is important for a number of reasons:

HTML 4.01 uses the lang attribute of the html element. XHTML served as text/html uses the lang attribute and the xml:lang attribute of the html element, in order to meet the requirements of XHTML and provide backward compatibility with HTML. XHTML served as application/xhtml+xml uses the xml:lang attribute of the html element. Both the lang and the xml:lang attributes can take only one value.

The objective of this technique is to clearly identify any changes in language on a page by using the lang or xml:lang attribute, as appropriate for the HTML or XHTML version you use.

HTML 4.01 uses the lang attribute on elements. XHTML served as text/html uses the lang attribute and the xml:lang attribute on elements, in order to meet the requirements of XHTML and provide backward compatibility with HTML. XHTML served as application/xhtml+xml uses the xml:lang attribute on elements.

Allowed values for the lang and xml:lang attributes are indicated in the resources referenced below. Language tags use a primary code to indicate the language, and optional subcodes (separated by hyphen characters) to indicate variants of the language. For instance, English is indicated with the primary code "en"; British English and American English can be distinguished by using "en-GB" and "en-US", respectively. Use of the primary code is important for this technique. Use of subcodes is optional but may be helpful in certain circumstances.

The objective of this technique is to describe how the link element can provide metadata about the position of an HTML page within a set of Web pages or can assist in locating content with a set of Web pages. The value of the rel attributes indicates what type of relation is being described, and the href attribute provides a link to the document having that relation. Multiple link elements can provide multiple relationships. Several values of rel are useful:

The objective of this technique is to provide a mechanism for locating a glossary. When terms in the content are defined on a separate glossary page, the glossary is referenced using a link element in the head element of the document that uses the glossary. The rel attribute of the link element is set to "glossary", and the href attribute contains the URI of the glossary page. User agents can then assist users in accessing the glossary quickly and easily.

The objective of this technique is to use ruby annotation to provide information about the pronunciation and meaning of a run of text where meaning is determined by pronunciation.

There are many languages in which a run of text may mean different things depending on how the text is pronounced. This is common in East Asian languages as well as Hebrew, Arabic, and other languages; it also occurs in English and other Western European languages.

Ruby Annotation allows the author to annotate a "base text," providing a guide to pronunciation and, in some cases, a definition as well. Ruby is commonly used for text in Japanese and other East Asian languages. Ruby Annotation is defined as a module for XHTML 1.1.

There are two types of Ruby markup: simple and complex. Simple Ruby markup applies to a run of text such as a complete word or phrase. This is known as the "base" text (rb element). The Ruby annotation that indicates how to pronounce the term (the rt element, or Ruby text) is shown in a smaller font. (The term "Ruby" is derived from a small font used for this purpose in printed texts.) The Ruby text is usually rendered above or immediately before the base text, that is, immediately above horizontal text or immediately to the right of vertical text. Sometimes Japanese uses Ruby to provide the meaning of text on the other side of the base text (visually) from the phonetic annotation. Simple Ruby markup also provides a "fallback" option for user agents that do not support Ruby markup (that is, user agents that do not support XHTML 1.1).

Complex Ruby markup makes it possible to divide the base text into smaller units, each of which may be associated with a separate Ruby annotation. Complex Ruby markup does not support the fallback option.

Ruby annotation is uncommon in languages such as Hebrew, where Unicode fonts can include diacritical marks that convey pronunciation. It is also uncommon in English and European languages.

Note: The primary reason for indicating pronunciation through Ruby or any other means is to make the content accessible to people with disabilities who could read and understand the language of the content if information about pronunciation were provided. It is not necessary to provide information about pronunciation for use by people who are not familiar with the language of the content.

The objective of this technique is to associate header cells with data cells in complex tables using the scope attribute. The scope attribute may be used to clarify the scope of any cell used as a header. The scope identifies whether the cell is a header for a row, column, or group of rows or columns. The values , , , and identify these possible scopes respectively.

For simple data tables where the header is not in the first row or column, like the one in Example 1, this technique can be used. Based on screen reader support today, its use is suggested in two situations both relating to simple tables: :

The objective of this technique is to demonstrate the use of the title attribute of the frame or iframe element to describe the contents of each frame. This provides a label for the frame so users can determine which frame to enter and explore in detail. It does not label the individual page (frame) or inline frame (iframe) in the frameset.

Note that the title attribute labels frames, and is different from the title element which labels documents. Both should be provided, since the first facilitates navigation among frames and the second clarifies the user's current location.

The title attribute is not interchangeable with the name attribute. The title labels the frame for users; the name labels it for scripting and window targeting. The name is not presented to the user, only the title is.

The objective of this technique is to use the title attribute to label form controls when the visual design cannot accommodate the label (for example, if there is no text on the screen that can be identified as a label) or where it might be confusing to display a label. User agents, including assistive technology, can speak the title attribute.

The purpose of this technique is to show how images can be marked so that they can be ignored by Assistive Technology.

If no title attribute is used, and the alt text is set to null (i.e. alt) it indicates to assistive technology that the image can be safely ignored.

Note: Although alt is also valid, alt is recommended.

The objective of this technique is to use section headings to convey the structure of the content. Heading markup can be used:

In some technologies, Headings are designed to convey logical hierarchy. Skipping levels in the sequence of headings may create the impression that the structure of the document has not been properly thought through or that specific headings have been chosen for their visual rendering rather than their meaning. Authors are encouraged to nest headings hierarchically. When headings are nested hierarchically, the most important information is given the highest logical level, and subsections are given subsequent logical levels.(i.e., h2 is a subsection of h1).

Since headings indicate the start of important sections of content, it is possible for users with assistive technology to jump directly to the appropriate heading and begin reading the content. This significantly speeds interaction for users who would otherwise access the content slowly. Headings create chunks of information that can be found easily by people with disabilities, such as a blind person using a screen reader, or a person with a cognitive disability who uses assistive technology that delineates groups of information, or someone with a communication disability or illiteracy, who uses a screen reader to assist them in their reading.

The objective of this technique is to demonstrate how framesets can be used to group blocks of repeated material. Since most user agents and assistive technology provide a way to navigate from frame to frame, using frames to organize elements can provide a mechanism for easily bypassing blocks of repeated content. If the site uses framesets, organize the blocks of content into separate frames. Make certain that the repeated blocks of content appear in the same frame within the frameset of each Web page. In addition, each frame element must have a title attribute to describe the content of the frame. When frames are properly titled, users can use frame navigation to easily navigate between blocks of content.

This technique is appropriate when framesets are already used to organize the content of the page; other techniques are preferred for pages that are not already using framesets, because many people using assistive technology have trouble with frames . An advisory technique about using noframes is available in Success Criterion 1.1.1.

The objective of this technique is to provide a semantic grouping for related form controls. This allows users to understand the relationship of the controls and interact with the form more quickly and effectively.

Form controls can be grouped by enclosing them within the fieldset element. All controls within a given fieldset are then related. The first element inside the fieldset must be a legend element, which provides a label or description for the group. Authors should avoid nesting fieldsets unnecessarily, as this can lead to confusion.

Grouping controls is most important for related radio buttons and checkboxes. A set of radio buttons or checkboxes is related when they all submit values for a single named field. They work in the same way as selection lists, allowing the user to choose from a set of options, except selection lists are single controls while radio buttons and checkboxes are multiple controls. The individual label associated with each radio or checkbox control may not fully convey the group's descriptive context. In this situation, it is essential that they be grouped together semantically to facilitate being treated as a single control, as well as to provide an additional group level description. Often, user agents will present the value of the legend before the label of each control to provide this description, as well as to remind users that they are part of the same group.

It can also be useful to group other sets of controls less tightly related than radio buttons and checkboxes. For instance, several fields that collect a user's address might be grouped together with a legend of "Address", thus providing a group level description for these controls. As a rule of thumb, it can be said that where a group of controls within a larger form requires an additional heading to provide a description specific to that particular group, the use of fieldset and legend elements is appropriate.

However, when a group of related radio buttons or checkboxes (even having values for a single named field) includes clear instructions and distinct selections (i.e. where the individual label associated with each particular control provides a sufficient description), the use of the fieldset and legend elements is not required. is sufficient in this case.

Authors sometimes avoid using the fieldset element because of the default display in the browser, which draws a border around the grouped controls. This visual grouping is also useful and authors should seriously consider retaining it (or some form of visual grouping). The visual effect can be modified in CSS by overriding the "border" property of the fieldset and the "position" property of the legend.

When a small group of related radio buttons includes clear instructions and distinct selections it may not be necessary to use fieldsets and legends; , may also be sufficient.

The objective of this technique is to provide a brief overview of how data has been organized into a table or a brief explanation of how to navigate the table. The summary attribute of the table element makes this information available to people who use screen readers; the information is not displayed visually.

The summary is useful when the table has a complex structure (for example, when there are several sets of row or column headers, or when there are multiple groups of columns or rows). The summary may also be helpful for simple data tables that contain many columns or rows of data.

The summary attribute may be used whether or not the table includes a caption element. If both are used, the summary should not duplicate the caption.

Although WCAG 2 does not prohibit the use of layout tables, CSS-based layouts are recommended in order to retain the defined semantic meaning of the HTML table elements and to conform to the coding practice of separating presentation from content. However, if a layout table is used, then the summary attribute is not used or is null. The purpose of a layout table is simply to control the placement of content; the table itself is “transparent" to the user. A summary would “break" this transparency by calling attention to the table. A null summary ( summary) on layout tables is acceptable.

The objective of this technique is to avoid key errors that are known to cause problems for assistive technologies when they are trying to parse content which involve having opening and closing tags that are not used according to specification. These errors can be avoided by using the HTML or XHTML mechanism to specify the technology and technology version, and making sure the Web page does not have these types of errors in it. There are several validators that the developer can use: validation reports generally mention these types of errors. This technique deals only with errors related to incorrectly formed opening and closing tags. The document type declaration is not strictly necessary for this type of evaluation, but specifying the document type declaration makes it easier to use a validator.

The objective of this technique is to avoid key errors that are known to cause problems for assistive technologies when they are trying to parse contents. Well-formedness is checked by parsing the document with a conforming XML parser and checking if the validation report mentions well-formedness errors. Every conforming XML parser is required to check well-formedness and stop normal processing when a well-formedness error is found (a conforming XML parser does not need to support validation).

The objective of this technique is to enable redirects on the client side without confusing the user. Redirects are preferably implemented on the server side (see Implementing automatic redirects on the server side instead of on the client side), but authors do not always have control over server-side technologies.

In HTML and XHTML, one can use the meta element with the value of the http-equiv attribute set to "" and the value of the content attribute set to "0" (meaning zero seconds), followed by the URI that the browser should request. It is important that the time-out is set to zero, to avoid that content is displayed before the new page is loaded. The page containing the redirect code should only contain information related to the redirect.

The objective of this technique is to identify the purpose of a link from the link and its list item context. The list item enclosing the link provides context for an otherwise unclear link when the link item is the nearest enclosing block-level ancestor element. The description lets a user distinguish this link from links in the Web page that lead to other destinations and helps the user determine whether to follow the link. Note that simply providing the URI of the destination is generally not sufficiently descriptive.

The objective of this technique is to identify the purpose of a link from the link in its paragraph context. The paragraph enclosing the link provides context for an otherwise unclear link when the paragraph is the nearest enclosing block-level ancestor element. The description lets a user distinguish this link from links in the Web page that lead to other destinations and helps the user determine whether to follow the link. Note that simply providing the URI of the destination is generally not sufficiently descriptive.

The objective of this technique is to identify the purpose of a link from the link in its data table context. This context is the table cell enclosing the link and the cell's associated headings. The data table context provides the purpose for an otherwise unclear link when the table cell is the nearest enclosing block-level ancestor element. It lets a user distinguish this link from other links in the Web page that lead to other destinations and helps the user determine whether to follow the link. Note that simply providing the URI of the destination is not sufficiently descriptive for people with disabilities, especially those with cognitive disabilities.

The objective of this technique is to describe the purpose of a link from the context provided by its heading context. The preceding heading provides context for an otherwise unclear link. The description lets a user distinguish this link from links in the Web page that lead to other destinations and helps the user determine whether to follow the link.

The objective of this technique is to describe the purpose of a link in a nested list from the context provided by the list item under which the list is nested. This list item provides context for an otherwise unclear link. The description lets a user distinguish this link from links in the Web page that lead to other destinations and helps the user determine whether to follow the link.

Because current assistive technologies do not include commands to query contextual information provided by parent list items, use of this technique requires users to navigate the list one item at a time. Therefore, this technique may not be appropriate for very long or deeply nested lists.

The objective of this technique is to avoid confusion that may be caused by the appearance of new windows that were not requested by the user. Suddenly opening new windows can disorientate or be missed completely by some users. In HTML 4.01 Transitional and XHTML 1.0 Transitional, the target attribute can be used to open a new window, instead of automatic pop-ups. (The target attribute is deleted from HTML 4.01 Strict and XHTML 1.0 Strict.) Note that not using the target allows the user to decide whether a new window should be opened or not. Use of the target attribute provides an unambiguously machine-readable indication that a new window will open. User agents can inform the user, and can also be configured not to open the new window. For those not using assistive technology, the indication would also be available from the link text.

The objective of this technique is to allow the user to control when an action is performed, rather than having the action occur as a side effect of choosing a value for the select element. The user may inspect the different values of the select element, or may accidentally choose the wrong value, without causing the action to occur. When the user is satisfied with their choice, they select the button to perform the action.

This is particularly important for users who are choosing the value of the select element via the keyboard, since navigating through the options of the select element changes the value of the control.

The objective of this technique is to group items in a selection list. A selection list is a set of allowed values for a form control such as a multi-select list or a combo box. Often, selection lists have groups of related options. Those groups should be semantically identified, rather than simply delimiting the groups with "dummy" list entries. This allows user agents to collapse the options by group to support quicker skimming of the options, and to indicate in what group an option of interest is located. It also helps to visually break up long lists so that users can more easily locate the option(s) they are interested in.

In HTML, the select element is used to create both multi-select lists and combo boxes. The various allowed options are each indicated with option elements. To group options together, use the optgroup element, with the related option elements inside that element. Label the group with the "label" attribute so users will know what to expect inside the group.

The optgroup element should be directly inside the select element, and the option elements directly inside the optgroup. It is possible for a select element to contain both single option elements and optgroup groups, though authors should consider if this is in fact the desired intent when using this. It is not possible to nest the optgroup element, so only one level of grouping can be done within a select.

If grouping information is essential to understanding the list, authors may define option labels that can be understood even when the screen reader does not present the grouping information provided by optgroup.

Before graphics became widely used on the internet, ASCII characters were often arranged to form pictures or graphs. Although ASCII art is not used frequently on the Web anymore, it must be remembered that, when it is used, it is very confusing to people who are blind and accessing the internet using screen readers. If it is used it should also have a text explanation of what the picture is. It is also suggested that there be a link to skip over the ASCII art (although this is not required).

Emoticons are very popular. They include ASCII characters that form facial expressions and other ways to communicate an emotion. They can be confusing for screen reader users. When possible it is better simply to use a word like "smile" instead of an emoticon. But if emoticons are used they should have a text alternative. In some contexts, blog and forum software for example, plug-ins are available that automatically convert ASCII characters used as emoticons into HTML images with text alternatives.

Leetspeak uses various combinations of ASCII characters to replace Latinate letters. Leet has become a part of Internet culture and slang. Leet is frequently used to beat text and spam filters. It is often incomprehensible to blind people using screen readers, and therefore requires a text alternative in order to conform to Success Criteria 1.1.1.

This technique helps avoid situations where horizontal scrolling may occur. Many people with cognitive disabilities and low vision users who do not use assistive technology have a great deal of trouble with blocks of text that require horizontal scrolling. It involves not interfering with the reflow of text if the window is narrowed. One of the best ways to do this is to define widths of text block containers in percentages.

HTML and XHTML user agents automatically reflow text as the browser window is narrowed as long as the author does not specify widths using absolute measurements such as pixels or points.

The objective of this technique is to use HTML and XHTML according to their respective specifications. Technology specifications define the meaning and proper handling of features of the technology. Using those features in the manner described by the specification ensures that user agents, including assistive technologies, will be able to present representations of the feature that are accurate to the author's intent and interoperable with each other.

At the time this technique was published, the appropriate versions of these technologies is HTML 4.01 and XHTML 1.0. HTML 4.01 is the latest mature version of HTML, which provides specific accessibility features and is widely supported by user agents. XHTML 1.0 provides the same features as HTML 4.01, except that it uses an XML structure, and has a more strict syntax than the HTML structure. Later versions of these technologies are not mature and / or are not widely supported by user agents at this time.

There are a few broad aspects to using HTML and XHTML according to their specification.

The objective of this technique is to provide context sensitive help for users as they enter data in forms by providing the help information in a title attribute. The help may include format information or examples of input.

The objective of this technique is to provide a clear indication that a specific form control in a Web application or form is required for successful data submission. A symbol or text indicating that the control is required is programmatically associated with the field by using the label element, or the legend for groups of controls associated via fieldset. If a symbol is used, the user is advised of its meaning before the first use.