Dell S3221QS User Manual page 52

Service Tag Display the service tag number of the display. The Service
Reset Others Reset all settings under the others setting menu to the
Factory
Reset
NOTE: Your monitor has a built-in feature to automatically calibrate
the brightness to compensate for LED aging.
52 │ Operating your monitor
Tag is a unique alphanumeric identifier that allows Dell to
identify the product specifications and access warranty
information.
NOTE: The Service Tag is also printed on a label
located at the back of the cover.
factory preset values.
Restore all preset values to the factory default settings.