If checked this view's menu entry will be provided as a tab, and will be the default tab for that URL path. For example, if the URL is 'tracker/all' and it is set as the default menu tab, it will be put into the menu as 'tracker' and 'tracker/all' will be the default tab. The following settings allow you to customize the parent item, for example 'tracker'. For tabs to work properly, one tab in the group must be set as the default.