Brother MFC990CW Service Manual page 435

Reading Labels
An individual machine has a "serial number label" for the machine itself and "property labels"
for the head/carriage unit. A battery in the cordless handset also has a "manufacturing
information label."
This section lists the coding information for those serial number, head property data, and
manufacturing information.
(1) Serial number label for the machine itself
(app01a)
Location
Serial number label
(app01b_1)
Confidential
App. 1-1