HTML & XHTML: The Definitive Guide, 5th Edition

Advanced Table Tags

While it is possible to build a simple table quickly, complex tables with varying border styles, running headers and footers, and column-based layout were not easily constructed from the old HTML 3.2 table model. Microsoft rectified this inadequacy somewhat by adding a number of table-layout controls to Internet Explorer Version 3.0. These very useful extensions found their way into the HTML 4 standard and subsequently into XHTML. They provide row-based grouping and running headers and footers, along with column-based layout features.

There is good news and bad news about these table features, of course. They provide a nice way to make your tables more attractive and presentable, but they currently work only within Internet Explorer and Netscape 6. If you choose to use them, make sure your tables stand up with the older browsers, too.

Defining Table Sections

Within tables, all rows are created equal. In real tables, some rows are more equal than others. And most tables have header and footer rows that repeat from page to page. In large tables, adjacent rows are grouped and delineated with different rule lines to make the tables easier to read and understand. HTML 4 and XHTML support all of these features with the <thead>, <tfoot>, and <tbody> tags.

The <thead> Tag

Use the <thead> tag to define a set of table header rows. The <thead> tag may appear only once per table and is placed at the beginning, just after the <table> tag. Within the <thead> tag, you may ...