Abstract: An attache case size, portable rack is fabricated from spaced, vertical supports and spaced shelves, for holding containers. A key entry system is provided which may be used to codify the material stored in the container. A multiple lock locking system of two-element locks, with one lock element of each two-element lock mounted on the rack and the second lock element of each two-element lock mounted on the container functions to define discrete container parking spaces on the rack. The same lock elements that define a container parking space combine with lock elements on the container for locking the container in the parking space defined by those lock elements.