Machine-readable coded data for use in the identity-coding and position-coding of surfaces. The machine-readable coded data being disposed on or in a substrate in accordance with a layout having mirror symmetry and n-fold rotational symmetry, where n is at least two, the layout including n identical first sub-layouts rotated 1/n revolutions apart about a center of rotational symmetry of the layout, the layout further including n identical second sub-layouts rotated 1/n revolutions apart about a center of rotational symmetry of the layout, each second sub-layout being a reflection of a corresponding one of the first sub-layouts, the coded data disposed in accordance with each sub-layout including rotation-indicating data that distinguishes the rotation of that sub-layout from the rotation of at least one other sub-layout within the layout, the coded data disposed in accordance with each sub-layout further including reflection-indicating data that distinguishes the reflection of that sub-layout from the reflection of its corresponding reflected sub-layout.