On the Keyboard node in the Policy Properties dialog, select how you want to apply key combinations (e.g. Alt+Tab) that you press on the keyboard:
On the local computer. Key combinations will be applied to Windows running on the local computer.
On the remote computer. Key combinations will be applied to Windows running on the remote computer.
In full screen mode only. Key combinations will be applied to the remote computer only when in the full-screen mode.
Select or clear the Send unicode characters as needed.