This question was posted in response to the following article: http://help.adobe.com/en_US/photoshop/cs/using/WSfd1234e1c4b69f30ea53e41001031ab64-778ea.h tml
My Photoshop Elements 9 does not have "duotone" as a choice, in the Image - Mode tab. (Just bitmap, grayscale, indexed color and RGB color) Help!
You're looking at the documentation for Photoshop, not Elements. Elements does not have all the features of Photoshop.