As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) PORTER FLIGHT PD632, DURING CLIMB THE DOOR WARNING CAUTION LIGHT ILLUMINATED. PAN PAN WAS CALLED BY THE CREW THE ACFT RETURNED TO DEPARTURE. UPON FURTHER INVESTIGATION AT THE GATE IT WAS FOUND THAT THE AFT BAGGAGE DOOR HANDLE WAS NOT ENGAGED. DOOR OPERATION CARRIED OUT WITHOUT FAULT. HANDLE LOCKED AND THE CAUTION LIGHT WAS CLEARED. ACFT DEPARTED WITHOUT FURTHER INCIDENT.