Because the large number of containers makes it impossible to keep track of them by simple observation, means must be provided for identifying each container, so that it can be found when it is needed, and also to ensure that it is moved to the place where it is wanted.
Kuba izikhongozeli ezininzi ezinkulu zenza kube nzima ukuba ziqwalaseleke zizonke uncedo malunikwe kuzo ukukwazeka ukuyikhomba enye, ukuze ifunyanwe xana ifunwa nokuqinisekisa iye kanye kule ndawo bekufuneka iye kuyo.