As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE CREW REPORTED A LAV SMOKE INDICATION AFTER TAKE OFF. THE ACFT RETURNED TO WHERE IT LANDED WITHOUT INCIDENT. MX INSPECTED THE ACFT, R & R THE LAVATORY SMOKE DETECTOR, OPS TESTED WITH NO DEFECTS, AND THE ACFT WAS APPROVED FOR RETURN TO SERVICE.