As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LAVATORY SMOKE INDICATION CAME ON AT APPROX 30,000''. NO SMOKE, APPEARED IN EITHER, AFT LAVATORY INDICATION WENT AWAY AT 10,000". NO SMOKE EVER APPEARED. QRH PROCEDURE WAS PILOT AWARENESS ONLY. IAW FIM 26-14-00-815 AFT LAVATORY SMOKE DETECTOR SYS TESTED NORMAL.