This accessible-for-notify object carries an entity index number, corresponding to a physical component such as a board or slot, that is included in forwarding-resource notifications to identify which hardware entity is affected. An admin correlates this value with the standard entPhysicalName data (also carried in the same trap) to pinpoint exactly which line card or slot triggered a forwarding-resource-lack alarm, rather than just knowing some board is affected. For example, a hwWholeFwdResLack trap carrying hwEntPhysicalindex value 67 lets the admin cross-reference the entity table to identify that a specific slot's forwarding engine is running out of resources.