This read-write PortList is an action object: writing a bitmask of ports to it clears the POE power-consumption history recorded for those specific ports. An admin would use this after resolving a power issue or before a baseline measurement, so old consumption data does not skew a fresh energy audit of PoE-powered devices like cameras or phones. For example, after swapping a power-hungry PoE camera on port 5 for a lower-draw model, the admin writes this PortList to include port 5 to reset its consumption history and get clean data going forward.