Printronix P8000 Plus Series Administrator's Manual page 193

Any form elements (text, graphics, or dots) immediately to the right of the original barcode can force this
first attempted placement to be modified. The replacement barcode will shift left to avoid obstacles on the
right provided that there are also no obstacles on the left.
•
Center (factory default). The first attempted position of the center bar of the replacement barcode will
be the same position as the center bar of the original barcode.
If the replacement barcode is smaller than the original barcode, it will be replaced as follows:
If the replacement barcode is longer than the original barcode, it will still be centered, but it will extend
beyond the end of the original barcode on both the left and the right.
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