1. LAYOUT AND PLACEMENT
Don't design app bars on the left and right sides of the screen.
Do place the app bars on the top and bottom of the screen.
2. INVOKING THE APP BAR
Don’t design the top and bottom app bars to be invoked using separate gestures.
Do design the top and bottom app bars to appear simultaneously with a single swipe or right-click.
3. CLOSING THE APP BAR
Don't put a close button in the app bar
Do close the app bar by tapping or clicking outside of it.
4. CONTENT AND ADVERTISEMENTS
Don't place any content in the app bars.
Do reserve the top app bar for navigation and the lower app bar for actions.
5. NAVIGATION
Don't use the bottom app bar for navigating to content sections.
Do use the top app bar for navigating to sections.
6. ACTIONS
Don't place actions in the top app bar.
Do place actions in the bottom app bar.
7. OMITTING CHARM FUNCTIONS
Don't place charm functionality such as search in the app bar.
Do reserve the top app bar for navigation and the lower app bar for actions.
8. GLOBAL AND LOCAL ACTIONS
Don't mix global and local actions together
Do keep local actions to the left and global actions to the right.
9. NESTING APP BARS
Don't allow for app bars to expand or collapse for nesting actions.
Do use fly-outs to support nested actions.
10. LOGOS
Don't show your logo on the app bar.
Do keep the app bar free of the logo.
12. CREATIVE SHAPES AND SIZES
Don't be restrained to using standard app bar dimensions.
Do explore creative ways of using the app bars.