CHAPTER 2 HTML DESIGN PATTERNS
Additional elements are included in the HTML5 specification, but I did not list them in the
preceding table because they have little semantic or structural meaning, are rarely used, or have quirky
implementations. The following elements style text: <i>, <b>, <big>, <small>. The <pre> element
preserves whitespace, but it cannot contain images, objects, subscripts, or superscripts. The <q> element
automatically inserts quotes differently depending on the browser. The <ins> and <del> elements mark
elements as inserted or deleted. Frames can cause problems for search engines and users: <iframe>,
<frameset>, <frame>, and <noframe>. Internet Explorer 7 will not remove built-in styles from <hr>,
<fieldset>, and <legend>, but later versions will. Also from an SEO perspective, traditional frames are
not indexed well when displayed since the content is typically indexed outside of the controls that reside
in a separate frame. At the same time, traditional framesets are fairly obsolete. Finally, <base> changes
the root of all links in your document—use it only if you fully understand it, or it may break all your links.
Similarly there are many other elements defined in the HTML5 draft spec that are either not yet
implemented in browsers or still undergoing significant revisions.