A-Z Indexes to Enhance Site Searching
http://www.digital-web.com/articles/a_z_indexes_site_searching/

Digital Web Magazine
2005

Abstract:

On a Web site or intranet each of the alphabetically arranged entries or subentries is hyperlinked to the page or to an anchor within a page to where the topic is discussed. Since an alphabetical index can be quite long, it is often divided into pages for each letter of the alphabet. Typically, each letter is linked at the top of the page allow a jump to the start of that letter’s section of the index.