Some podiums and "half racks" in classrooms come equipped with a slim-line power distribution unit (PDU) to regulate electrical current and protect the integrity of electronic components. Across the front of the power supply, a row of green lights indicates power status for each internal outlet. The red flashing alert light on those power supplies simply means "I'm a network controlled power supply but I'm not connected to network, and I think it's very important that you know that, so I flash red". In order for the AV system in the room to function properly, it is essential that the rack or podium have power. Even if you see the flashing red light, please do not power down the equipment.