Brother MFC990CW Service Manual page 258

(21) A head/carriage unit is assigned a property code that represents the properties unique to
that head/carriage unit. The property code is printed on head property labels--bar code label
and QR code label, each of which is attached to the lower cover and carriage-head flat
cable, respectively.
When you remove the head/carriage unit and store it separately from the machine, remove
the property label (bar code label) from the lower cover and store it together with the head/
carriage unit.
If you replace the head/carriage unit, attach the property label (bar code label) that comes
with the new head/carriage unit to the lower cover as shown below.
Carriage-head flat cable
Head/carriage unit
Lower cover
Head property label (Bar code)
ALR7765501200000
HEDA8999999 999Z
Head property label (QR code)
6-74
Property code
(16-digit)
(6_63)
Confidential