Based on its name and PositionIndex syntax, this value identifies the physical shelf or chassis position of the synchronous data circuit (SDC) interface this table row describes; the source MIB provides no description text for this object. Admins would use it, together with the port and circuit indexes, to locate exactly which physical slot a given SDC row's lead-state and speed data belongs to. As an illustrative example, a value of 3 would identify position 3 in the chassis as the location of that SDC interface.