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, the coded data being 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 including 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.