By default, DITA2Go navigation macros <$_prev> and <$_next> produce simple text links. However, you can specify buttons instead:
[NavigationMacros] ; UseNavButtons = No (default, use links for <$_prev> and <$_next>) ; or Yes (change the set of defaults to those for buttons instead) UseNavButtons = Yes
When UseNavButtons=Yes, DITA2Go navigation macros produce JavaScript code such as the following:
<button type="button" onclick="javascript:location.href='Destination'">Label</button>
When UseNavButtons=No, DITA2Go navigation macros produce HTML code such as this:
<a href="Destination">Label</a>
Both button and text-link navigation macros use predefined macro variables to provide appropriate values for Destination and Label; see Table 29-1.