Unassigned alarm
The reason why you hear the term "Unassigned Class 3" is because the private fire alarm (PFA)might have an application pending, or has not filed an application for that alarm system to be registered with FDNY. The PFA charges the customers for the alarm system & an additional fee to monitor the system 24 hours a day. A small percentage of the charge was to go to NYC, but if the PFA fails to register the alarm, then there profits increase. Once the application is approved, that alarm system is assigned a terminal number for the associated fire alarm box number. Some Manhattan fire boxes use to have several hundred terminals assigned, but in recent years with master alarm systems systems in each building, the number of class 3 terminals have been greatly decreased.