Page Comparison

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Please see more detailed information on how to comply with this guideline.

PROVIDE CONTENT IN A MEANINGFUL SEQUENCE

Enable a user agent to provide an alternative presentation of content while preserving the reading order needed to understand the meaning.

It is important that it be possible to programmatically determine at least one sequence of the content that makes sense.

A sequence is meaningful if the order of content in the sequence cannot be changed without affecting its meaning. For example, if a page contains two independent articles, the relative order of the articles may not affect their meaning, as long as they are not interleaved. In such a situation, the articles themselves may have meaningful sequence, but the container that contains the articles may not have a meaningful sequence.

The semantics of some elements define whether or not their content is a meaningful sequence. For instance, in HTML, text is always a meaningful sequence. Tables and ordered lists are meaningful sequences, but unordered lists are not.

This helps people who rely on assistive technologies that read content aloud. The meaning evident in the sequencing of the information in the default presentation will be the same when the content is presented in spoken form.

Example 1:

In a multi-column document, the linear presentation of the content flows from the top of a column to the bottom of the column, then to the top of the next column.

Example 2:

CSS is used to position a navigation bar, the main story on a page, and a side story. The visual presentation of the sections does not match the programmatically determined order, but the meaning of the page does not depend on the order of the sections.

Example 3:

In this example structural markup (definition lists) have been applied to the content. CSS has been used to style the content into columnar form. Each class absolutely positions the content into columns and the margins have been set to 0 to override the default behavior of user agents to display HTML definition lists with the DD element indented.

Here is the content to be displayed:

 <div class="box">
  <dl>
    <dt class="menu1">Products</dt>
    <dd class="item1">Telephones</dd>
    <dd class="item2">Computers</dd>
    <dd class="item3">Portable MP3 Players</dd>
    <dt class="menu2">Locations</dt>
    <dd class="item4">Idaho</dd>
    <dd class="item5">Wisconsin</dd>
    </dt>
  </dl>
 </div>

Here is the CSS which positions and styles the above elements:

 .item1 {
   left: 0;
   margin: 0;
   position: absolute;
   top: 7em;
 }
 .item2 {
   left: 0;
   margin: 0;
   position: absolute;
   top: 8em;
 }
 .item3 {
   left: 0;
   margin: 0;
   position: absolute;
   top: 9em;
 }
 .item4 {
   left: 14em;
   margin: 0;
   position: absolute;
   top: 7em;
 }
 .item5 {
   left: 14em;
   margin: 0;
   position: absolute;
   top: 8em;
 }
 .menu1 {
   background-color: #FFFFFF;
   color: #FF0000;
   font-family: sans-serif;
   font-size: 120%;
   left: 0;
   margin: 0;
   position: absolute;
   top: 3em;
 }
 .menu2 {
   background-color: #FFFFFF;
   color: #FF0000;
   font-family: sans-serif;
   font-size: 120%;
   left: 10em;
   margin: 0;
   position: absolute;
   top: 3em;
 }
 #box {
   left: 5em;
   position: absolute;
   top: 5em;
 }

When style sheets are applied, the data are displayed in two columns of "Products" and "Locations." When the style sheets are not applied, the text appears in a definition list which maintains the structure and reading order.

WCAG Related References

1.3.2 Meaningful Sequence (Level A)

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