If you mean when the print preview is open, I don't there is one or I am not aware of it. Help only contains these:

Print Preview Window
Shortcut Actions
Z           Zooms in and out of the page. 
L           Toggles between various zoom levels. 
G           Opens Goto page dialog box. 
ESC Closes  Print Preview window. 
LEFTARROW   Scrolls to the left of the page in the Print Preview window. 
RIGHTARROW  Scrolls to the right of the page in the Print Preview window. 
UPARROW     Scrolls towards the top of the page in the Print Preview window. 
DOWNARROW   Scrolls towards the bottom of the page in the Print Preview window. 
PAGEDOWN    Moves to the next page in the Print Preview window. 
PAGEUP      Moves to the previous page in the Print Preview window.