Ricoh Aficio 551 Copy Reference Manual page 157

If the calculated ratio is under the available minimum ratio, it will be adjusted
to the minimum ratio. However, with some ratios, parts of the image might
not be copied.
Even if the direction of originals is different from that of the copy paper, the
machine will automatically rotate the image by 90 to make copies properly.
Book 2 Sided
Copies a two-page spread original onto both sides of a sheet.
1
Note
See the following table when you select original and copy paper sizes with
100% ratio:
Metric version
Original
A3L
B4L
A4L
Inch version
Original
11" 17"L
1
8 / " 11"L
2
2 1
2
Copy paper
A4 (2-sided)
B5 (2-sided)
A5 (2-sided)
Copy paper
1
8 / " 11" (2-sided)
2
1 1
5 / " 8 / " (2-sided)
2 2
Series/Book
2
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