Avoid Hidden Text

There are two types of hidden text, intentional and unintentional. When search engines first became popular, webmasters and SEO consultants learned that they could hide text on pages by making the text color the same as the background or by using the <input type="hidden"> tag. They would load up the hidden text with keywords that would boost their search rankings. The search engines caught on to this quickly and now penalize sites that try to trick them with intentionally hidden text.

Unintentionally hidden text occurs most often as a result of graphics being used in replace of text. Search engine spiders don't recognize text in images. And if you're using images instead of heading tags, you're missing great opportunities for your search terms.