Okura Yusoki A Series Manual page 209

Products are also laid evenly by blue doublet. [On-line] or [Both side] for blue
doublet can be chosen.
Blue Doublet
Blue Doublet can specify products and gaps to be laid evenly.
The horizontal doublet can be moved by [Up] or [Down] and the vertical one
by [Left] or [Right].
The below example shows you a pattern to have (18)-products laid centered and
evenly spaced out.
Laid evenly
13-19