Landmark Roles

application: Avoid unless your app is app enough (i.e. Gmail, Google Docs, etc.)
banner: Page Header
complementary: Page Sidebar
contentinfo: Footer
form: Forms
main: Main page content; Stop using <div id="main">; Use <main role="main"> instead
navigation: Page or other navigation; Stop using <div id="nav">; Use <nav role="navigation"> instead
search: Search

Landmark Roles in Action