Intermec PC4 Programmer's Reference Manual page 119

Remarks: In addition to the label gap sensor, the printers have a black mark
ESim for the PC4 and PF8 Printers Programmer's Reference Manual
sensor that determines the top of each form by sensing a preprinted
black mark on the back of the media. The sensor is located slightly to
the right of the center of the media path (as seen from the front of the
printer).
Refer to your printer user's manual for specifications of the size and
location of black marks.
Example 1:
On this tag, the black marks are printed on the perforation in a 203.2
dpi (8 dots/mm) printer:
p = 31 mm (248 dots)
1
p = 7.0 mm (56 dots)
2
p = 0.5 mm (4 dots)
3
p
1
Example 1: Printing on Perforations
The Q command would be:
Q248,B56+4
Example 2:
On the tag below, the black marks are printed between the
perforations. The printer has a 203.2 dpi (8 dots/mm) printhead.
Chapter 4 — ESim Commands
Perforation
p
2
p
3
105