Dell Users Guide
Page 167
... a six page document, rear sides are printed in the order page 1 (rear of page 2), page 3 (rear of page 4), then page 5 (rear of page 6). The orange LED lights and the message appears on both sides of the paper is not possible if the document consists of various sizes of page 6, page 4, then... before setting them as they are printed, remove the paper stack from the output tray and set them . When Using the Priority Sheet Inserter (PSI) (Dell C1760nw Color Printer only) 1 First print the even pages (rear sides).
... a six page document, rear sides are printed in the order page 1 (rear of page 2), page 3 (rear of page 4), then page 5 (rear of page 6). The orange LED lights and the message appears on both sides of the paper is not possible if the document consists of various sizes of page 6, page 4, then... before setting them as they are printed, remove the paper stack from the output tray and set them . When Using the Priority Sheet Inserter (PSI) (Dell C1760nw Color Printer only) 1 First print the even pages (rear sides).