Brother GTX600NB Instruction Manual page 218

(3) Wipe the area between the print head's nozzle surface and nozzle guard.
<IMPORTANT>

Be sure not to touch the red-frame zone of the nozzle surface.

For cleaning, be sure not to use any tool other than clean stick R.

Do not rub the nozzle strongly.
Clean this part
Nozzle guard
Cleaning conditions
Cleaning location
Between the nozzle surface
and nozzle guard
<IMPORTANT>

Be sure to use the clean stick R separately for white ink and color ink.
Precautions to keep good printing quality/use printer over the long term
Cleaning location
Between the nozzle surface and nozzle guard
Nozzle guard rearward
Pre-cleaning state
Cleaning location
Nozzle guard frontward
Cleaning location
Nozzle guard
rearward
Nozzle guard frontward
Nozzle surface
6-50
Post-cleaning state
X1018
X1046