HTML The Definitive Guide (31 page)

tags, you can alter this alignment with the align attribute and one of the values left, center, right, or justify.
Figure 4.4
shows these alternative alignments as rendered from the following source: Right over here! Slide back left. Smack in the middle.
Figure 4.4: The headings align attribute in action
The justify value for align is not supported yet by any browser, and don't hold your breath. The align attribute is deprecated in HTML 4.0 in deference to style sheet-based controls.

4.2.1.2 The dir and lang attributes

The dir attribute lets you advise the browser as to which direction the text within that paragraph ought to be displayed, and lang lets you specify the language used within the heading.
[The dir

attribute, 3.5.1.1] [The lang attribute, 3.5.1.2]

4.2.1.3 The class, id, style, and title attributes
Use the id attribute to create a label for the heading that can later be to used to unambiguously reference that heading in a hyperlink target, for automated searches, as a stylesheet selector, and with a host of other applications.
[The id attribute, 4.1.1.4]

Use the optional title attribute and quote-enclosed string value to provide a descriptive phrase for the heading.
[The title attribute, 4.1.1.5]

Use the style attribute with the heading tags to create an inline style for the headings' contents. The class attribute lets you label the heading with a name that refers to a predefined class declared in
some document-level or externally defined style sheet. [Inline Styles: The style Attribute, 9.1.1]
[Style

Classes, 9.2.4]

4.2.1.4 Event attributes

User-initiated events that may happen in and around a heading each are recognized by the browser if it conforms to the HTML 4.0 specification (none do fully). With the respective "on" attribute and value, you may react to that event by displaying a user dialog box or activating some multimedia event.
[JavaScript Event Handlers, 13.3.3]

4.2.2 Appropriate Use of Headings

It's good form to repeat your document's title in the first heading tag, since the title you specify at the beginning of your HTML document doesn't appear in the user's main display window. The title should match the one in the document's . The following HTML segment is a good example of repeating the document's title in the header and in the body of the document:

Kumquat Farming in North America

Perhaps one of the most enticing of all fruits is the...

While the browser may place the title somewhere in the document window and may also use it to create bookmarks or hotlist entries, all of which vaguely are somewhere on the user's desktop, the level three title heading in the example will always appear at the very beginning of the document. It serves as a visible title to the document regardless of how the browser handles the