As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 7764 ORF TO IAD - ON TAXI INTO GATE FWD LAV SMOKE DETECTOR WENT OFF. CREW REPORTS STRONG SMELL IN COCKPIT AND REAR OF AIRPLANE. MAINTENANCE RAN ENGINES, NO TRACE OF SMOKE DETECTED. THIS IS A FIRST OCCURRENCE ON THIS AIRCRAFT AND HAS NOT REPEATED. SUSPECT SMOKE CAUSED BY STARTING OF APU.