NCR 7870 User Manual page 179

The EOM bit, if applicable, is in the last byte sent, not the last byte of
the label data. The Decoding Codes are specified in the following
table.
Decoding Codes Description
Y Z
1 z Decoding was difficult. May be due to
inconsistent printing.
2 z Fragmented or folded label or inconsistent
printing.
3 z Decoding was difficult due to fragmented,
folded, or inconsistently printed label.
y 1 Label appears to be highly underprinted.
y 2 Label appears to be highly overprinted.
y 4 Label appears to have missing bars or margins.
y 5 Label appears to be highly underprinted and to
have missing bars or margins.
y 6 Label appears to be highly overprinted and to
have missing bars or margins.
0 0 Label was decoded without major problems.
9 9 If a particular label intermittently shows this
code, the label should be analyzed more closely
for out-of-specification conditions, even though
the label may show a Code 00 when it does scan
(printing may be inconsistent).
Chapter 7: Programming 7-63