NCR 7870 manual Decoding was difficult. May be due to

Chapter 7: Programming 7-63

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).