Contents
This section is normative.
This module defines the Core attribute collection.
The class attribute can be used for different purposes in XHTML, for instance as a style sheet selector (when an author wishes to assign style information to a set of elements), and for general purpose processing by user agents.
For instance in the following example, the p element is used in conjunction with the class attribute to identify a particular type of paragraph.
<p class="note"> These programs are only available if you have purchased the advanced professional suite. </p>
Style sheet rules can then be used to render the paragraph appropriately, for instance by putting a border around it, giving it a different background colour, or where necessary by not displaying it at all.
The id attribute has several roles in XHTML:
As an example, the following headings are distinguished by their id values:
<h id="introduction">Introduction</h> <p>...</p> <h id="events">The Events Module</h> <p>...</p>
Values of the title attribute may be used by user agents in a variety of ways. For instance, visual browsers should display the title as a "tool tip" (a short message that appears when the pointing device pauses over an object). Audio user agents may speak the title information in a similar context.
Example of the use of title:
<a href="Jakob.html" title="Author biography">Jakob Nielsen</a>'s Alertbox for January 11, 1998
Implementation: RELAX NG