For example, use MathML to mark up mathematical equations, and style sheets to format text and control layout. Also, avoid using images to represent text -- use text and style sheets instead.

Mathematical and scientific equations and symbols and musical notations are often presented as bit-mapped images, like the one in this example. The image of the equation is inaccessible, and alt-text is usually insufficient to convey the meaning of the equation. Groups like the W3C are developing markup languages that will ease the creation of and permit the accessible interpretation of special notations.

One particular language being developed is called MathML.

Select this link to see the MathML markup that might generate the following equation,

To Checkpoints for Guideline 3.Next slide: Example for Checkpoint 3.2