By clicking any of these options Duplexing is turn on - borders of the sheet will be witched on even sheets. Left-Right and Top-Bottom Duplexing can be set separately.
When choosing imposition type Duplexing is set as follows:
Top-Bottom is never turned on.
Left-Right is turned on when "Booklet" or duplex "Cut Stacks" is chosen. In other cases Left-Right Duplexing is turned off.
After choosing the imposition type Duplexing can be changed arbitrarily.