Informative Image Rules

HTML Markup Details

alt attribute
The alt attribute should provide a short text equivalent to describe the purpose of the image on the web resource and orient the user to the content contained in the image.
longdesc attribute pointing to internal link
The longdesc attribute of an img element specifies a link to a long description of the image.
This HTML markup is not well supported in graphical browsers and therefore difficult for authors to test and users to access. As the result, using longdesc attribute to add text equivalent information beyond the alt attribute is not recommended.
The best way to use the longdesc attribute is to build an internal link as the content of the attribute. This internal link would direct to the content on the current resource that provides the text equivalent information (longdesc="#linktext").

Accessibility Evaluation Rules

no. Testing Description Implementation
FAE Firefox
1 Fail/Pass

Every img element must have alt attribute.

1.0 1.5
2 Warning/Pass

If the content of the alt attribute is not empty, it should contain at least 7 characters and less than 90 characters. The text should provide people who cannot see the image with an orientation to the content and the purpose of the image in the web resource.

Implementation Notes

  • No evaluation should be made when the alt attribute content is empty.
NI 1.5
3 Warning/Pass

The alt attribute content should not include file name of the image.

Implementation Notes

  • File names in the alt attribute will be checked by identifying common image file suffixes in the alt attribute content, including: .jpg, .jpeg, .jfif, .gif, .png, .tif and .tiff.
NI 1.5
4 Warning/Pass

The alt attribute content should not include information that is redundant with the img element.

Implementation Notes

  • For English the following words should not appear anywhere in the alt attribute content: "image", "picture", "graphic", "photo" and "photograph".
NI 1.5

FAE Rule Implemetation

Illinois Functional Accessibility Evaluator 1.0
The Illinois Functional Accessibility Evaluator is a web based tool to help developers evaluate web resources for the use of the iCITA HTML best practices.
Web interface cannot currently analyze content generated dynamically with javascript.
Illinois Firefox Accessibility Extension
The Illinois Firefox Accessibility Extension is a Firefox add-in that is designed to identify accessibility features for both static and dynamically generated html content.
Useful for identifying the location of specific accessibility problems for failures and warnings indentified in FAE reports.
Create FAE reports for a page that uses javascript to generate page content with the FAE DHTML Report feature.