HTML & XHTML: The Definitive Guide, 6th Edition

Headings

Users have a hard enough time reading what's displayed on a screen. A long flow of text, unbroken by title, subtitles, and other headers, crosses the eyes and numbs the mind, not to mention the fact that it makes it nearly impossible to scan the text for a specific topic.

You should always break a flow of text into several smaller sections within one or more headings (like this book). There are six levels of HTML/XHTML headings that you can use to structure a text flow into a more readable, more manageable document. And, as we discuss in Chapters 5 and 8, there are a variety of graphical and text-style tricks that help divide your document and make its contents more accessible as well as more readable.

Heading Tags

The six heading tags—written as <h1>, <h2>, <h3>, <h4>, <h5>, and <h6>—indicate the highest (<h1>) to lowest (<h6>) precedence a heading may have in the document.

<h1>, <h2>, <h3>, <h4>, <h5>, <h6>

Function	Define one of six levels of headers
Attributes	align, class, dir, id, lang, onClick, onDblClick, onKeyDown, onKeyPress, onKeyUp, onMouseDown, onMouseMove, onMouseOut, onMouseOver, onMouseUp, style, title
End tag	</h1>, </h2>, </h3>, </h4>, </h5>, </h6>; never omitted
Contains	text
Used in	body_content

The text enclosed within a heading typically is rendered by the browser uniquely, depending upon the display technology available to it. The browser may choose to center, format in boldface, enlarge, italicize, underline, or change the color of headings to ...