Function key reference - Ctrl + Function key

 Expand or collapse the ribbon (Ctrl + F1 )

Choose the print preview command (Ctrl + F2 )

Cut to the spike (Ctrl + F3 )

Close the window (Ctrl + F4 )

Co to the next window (Ctrl + F6 )

Insert an empty field  (Ctrl + F9 )

Maximize the document window  (Ctrl + F10 )

Lock a field  (Ctrl + F11 )

Choose the open command  (Ctrl + F12 )