Nikon D6 - Page 704

652
Flash Modes
1
Y
icon flashes if flash unit does not support red-eye reduction.
2 Not available in modes S and M. Fill flash is selected instead.
3 Not available in modes S and M. Red-eye reduction is selected instead.
4In modes P and A, slow rear-curtain sync will be selected as
shown when the
W
(
M
) button is released.