# Header - `header-option-simple.html` renders menus without nested items - `header-option-nested.html` renders menus with nested items - `header-option.html` decides which template to render given the menu - `js/header.js` exposes a method to toggle visibility of nested menus - Nesting is configured using the `parent` and `identifier` properties in `menus.en.yml`. Example ```yml main: - name: Product identifier: product weight: 1 - name: Analytics pageRef: analytics weight: 1 parent: product - name: Engagement pageRef: engagement weight: 2 parent: product secondary: - name: Engineering identifier: engineering weight: 1 - name: Computers pageRef: computers weight: 1 parent: engineering - name: Rockets pageRef: rockets weight: 2 parent: engineering ```