Be sure you get the graphic details right: the selected tab should be graphically unambiguous, and the remaining tabs should clearly be behind the selected tab. This type of “you are here” marker is essential in orienting users within the site. Tabs can also be used to implement a two-tiered navigation scheme, in which a secondary horizontal list of links appears under the selected tab, again as a simple html list with css styling, to keep things semantic, accessible, and search visible (fig. 6.2).