HTML and CSS Reference
4.3.2. Physical Styles
We use the word intent a lot when we talk about content-based style
tags. That's because the meaning conveyed by the tag is more import-
ant than the way a browser displays the text. In some cases, however,
you might want the text to appear explicitly in some special wayitalic or
bold, for exampleperhaps for legal or copyright reasons. In those cases,
use a physical style for the text.
While the tendency with other text-processing systems is to control style
and appearance explicitly, with HTML or XHTML you should avoid phys-
ical tags except on rare occasions. Provide the browser with as much
contextual information as possible. Use the content-based styles. Even
though current browsers may do nothing more than display their text
in italic or bold, future browsers and various document-generation tools
may use the content-based styles in any number of creative ways.