The current level if this supply is a container; the remaining space if this supply is a receptacle. If this supply container/receptacle can reliably sense this value, the value is reported by the printer and is read-only; otherwise, the value may be written (by a Remote Control Panel or a Management Application). The value (-1) means other and specifically indicates that the sub-unit places no restrictions on this parameter. The value (-2) means unknown. A value of (-3) means that the printer knows that there is some supply/remaining space, respectively.