Template:Collapsible sections option

How to manage this template's collapsible groups/sections option
 * This template uses Navbox with collapsible groups. When a page that transcludes it is displayed, one of its groups/sections may be set to be expanded (visible) while the others remain collapsed (hidden apart from their titles). To achieve this, use, where group/section is one of the following names identifying the groups/sections (omit any speech or quote marks):