Outputs the root navigation category com.arsdigita.london.navigation.ui.category.Root Outputs the first level navigation categories (ie immediate children of the root). com.arsdigita.london.navigation.ui.category.TopLevel Outputs siblings of the category category (ie, those categories at the same level as the current category. com.arsdigita.london.navigation.ui.category.Siblings Outputs immediate children of the current category com.arsdigita.london.navigation.ui.category.Children Outputs the categories on a path between the root navigation category (exclusive) and the current category (inclusive). com.arsdigita.london.navigation.ui.category.Path Outputs the immediate children of all categories between the root navigation category & the current category (both inclusive). This is intended for showing a contextually-expanded tree to the current category. com.arsdigita.london.navigation.ui.category.Menu Outputs all categories, starting from the root navigation category and recursing. com.arsdigita.london.navigation.ui.category.Hierarchy Represents the information for a single category. When generating links to the category page, the url attribute is the preferred method. The id attribute is merely present for informational purposes.