As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ATB RETURN TO BOS DUE TO CABIN ALTITUDE WARNING. CORRECTED LANDING ALTITUDE SETTING ON CABIN PRESSURE CONTROL PANEL. BIT CBN AUTO PRESS CONTROLLERS 1 AND 2. NO FAULTS NOTED. PRESSURIZED A/C TO ENSURE NO MAJOR LEAKS. A/C RETURNED TO SERVICE.