+- $out: HTMLOutputter used to output (usually an Action, but not always!)
+- $items: array of menu items
+
+StartSubMenu: Before outputting a submenu (including enclosing tags) to HTML
+- $out: HTMLOutputter used to output (usually an Action, but not always!)
+- $menu: The Menu object outputted as a submenu.
+- $label: Localized text which represents the menu item.
+
+EndSubMenu: After outputting a submenu (including enclosing tags) to HTML
+- $out: HTMLOutputter used to output (usually an Action, but not always!)
+- $menu: The Menu object outputted as a submenu.
+- $label: Localized text which represents the menu item.
+
+StartDocNav: Before outputting the docs Nav
+- $nav: The DoclNav widget