Coded data for disposal on or in an interface surface associated with a product item, the coded data being indicative of an identity of the product item, such that the coded data distinguishes the product item from every other product item. The coded data is arranged in accordance with at least one layout having n-fold rotational symmetry about a center of rotation, where n is at least two. The layout also includes n identical sub-layouts rotated 1/n revolutions apart about the center of rotation, at least one sub-layout including rotation-indicating data that distinguishes that sub-layout from each other sub-layout.