See Understanding Techniques for WCAG Success Criteria for important information about the usage of these informative techniques and how they relate to the normative WCAG 2.0 success criteria. The Applicability section explains the scope of the technique, and the presence of techniques for a specific technology does not imply that the technology can be used in all situations to create content that meets WCAG 2.0.
Any technology that can use CSS to include images.
This technique relates to:
The objective of this technique is to provide a mechanism to add purely decorative images and images used for visual formatting to Web content without requiring additional markup within the content. This makes it possible for assistive technologies to ignore the non-text content. Some user agents can ignore or turn off CSS at the user's request, so that background images included with CSS simply "disappear" and do not interfere with display settings such as enlarged fonts or high contrast settings.
Background images can be included with the following CSS properties:
background
,
background-image
,
content
, combined with the :before
and
:after
pseudo-elements,
list-style-image
.
Note: This technique is not appropriate for any image that conveys information or provides functionality, or for any image primarily intended to create a specific sensory experience.
The stylesheet for a Web page specifies a background image for the whole page.
Example Code:
…
<style type="text/css">
body { background: #ffe url('/images/home-bg.jpg') repeat; }
</style>
</head>
<body>
...
The stylesheet for a Web page uses the CSS background
property to create a decorative rollover effects when a user hovers
the mouse pointer over a link.
Example Code:
a:hover { background: #ffe url('/images/hover.gif') repeat; color: #000;
text-decoration: none;
}
The styleseet for a Web page uses the CSS background
property to create rounded corners on elements.
Example Code:
…
<style type="text/css">
div#theComments { width:600px; }
div.aComment { background: url('images/middle.gif') repeat-y left top;
margin:0 0 30px 0; }
div.aComment blockquote { background: url('images/top.gif') no-repeat left top;
margin:0; padding:8px 16px; }
div.aComment div.submitter { background:#fff url('images/bottom.gif') no-repeat left top;
margin:0; padding-top:30px; }
</style>
</head>
<body>
<div id="theComments">
<div class="aComment">
<blockquote>
<p>Hi John, I really like this technique and I'm gonna use it on my own Website!</p>
</blockquote>
<div class="submitter">
<cite><a href="http://example.com/">anonymous coward</a> from Elbonia</cite>
</div>
</div>
<div class="aComment">
…
</div>
</div>
…
Resources are for information purposes only, no endorsement implied.
The HTML 4.01 specification states that the
background
attribute of the body
element is deprecated
Check for the presence of decorative images
Check that they are included with CSS
If #1 is true, then #2 is true.
If this is a sufficient technique for a success criterion, failing this test procedure does not necessarily mean that the success criterion has not been satisfied in some other way, only that this technique has not been successfully implemented and can not be used to claim conformance.