As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: LAVATORY SMOKE WARNING RECEIVED IN FLIGHT. DETERMINED TO BE AFT RIGHT LAVATORY, BUT WAS UNOCCUPIED AND NO EVIDENCE OF SMOKE. MAINTENANCE REMOVED DEBRIS FROM AFT RIGHT LAVATORY DETECTOR FILTER. PERFORMED A SATISFACTORY OPERATIONAL TEST OF LAVATORY SMOKE DETECTOR SYSTEM PER AMM 26-17-00 WITH NO FAULTS NOTED.