a polygonal section comprising lateral walls surrounding an interior space;

an upper wall forming a top bound on the interior space, the upper wall being connected to at least two of the lateral walls by upper fold lines;

a lower wall forming a bottom bound on the interior space, the lower wall being connected to at least two of the lateral walls by lower fold lines;

an alignment tab that straddles a respective one of the upper fold lines, wherein a first end of the alignment tab is connected to the upper wall by a first join line and a second end of the alignment tab is connected to an adjacent one of the lateral walls by a second join line, wherein the alignment tab has two opposed lateral sides crossing the respective one of the upper fold lines, wherein the alignment tab also has an intermediate fold line between the first and second ends of the alignment tab that is closer to the first end than to the second end, such that the alignment tab projects upward from the upper wall and separates two vertical, inward facing alignment edges at an upper end of the adjacent one of the lateral walls, and

a retention tab extending downward from the adjacent one of the lateral walls past a fold line connecting the adjacent one of the lateral walls to the lower wall, wherein the retention tab is configured to engage two vertical, inward facing alignment edges of a similar container for alignment in a stack.