This is an old revision of the document!
aka 'Child Menus', 'Page Hierarchies', 'Nested Menus' and a lot of other things
In Page Options you can mark a page as the 'Child' of another. This has the effect of giving the page a url of parent\child but doesn't alter the navigation menu links. GS supports any number of levels of url hierarchy.
get_navigation() template tag creates a simple, single series of links to pages marked for inclusion in the menu arranged in order as
Will be a brief 'how-to' for sub-pages and hierarchical navigation