Abstract: A connecting arrangement for box-shaped support structures connects the upright walls constituting the support structure to one another at upright marginal portions thereof. The connecting arrangement includes upper and lower connecting projections which are rigid with the marginal portions of one of the walls, and upper and lower slots which are provided in the marginal portions of another wall constituting the support structure. Each of the upper slots has an L-shaped configuration, commences at the upper end face of the marginal portion and extends first downwardly therefrom and then toward the side face of the marginal portion. Each of the lower slots has a substantially inverted V-shaped configuration and extends inwardly from the above-mentioned side face of the marginal portion, first upwardly and then downwardly. The respective end zones of the slots are vertically aligned with one another and receive the connecting projections of the first-mentioned marginal portion.