DITA2Go can produce a functioning index for HTML, based on the <indexterm> elements in your DITA document. The settings described here are intended for non-Help HTML output. You can also use the settings described for Help systems; see §16.5 Configuring index entries for Help systems.
§14.7.3.1 Choosing the type of index to generate for HTML
§14.7.3.2 Specifying index file name and heading
§14.7.3.3 Specifying CSS classes for index components
§14.7.3.4 Including heading letters in the index