Explanatory notes
… 25.14 when in the mass, or in the form of blocks, slabs or sheets obtained by splitting, rough cutting or squaring or … cut otherwise than rectangular (including square), ground, polished, chamfered, drilled, varnished, enamelled, moulded … roofing, facing and damp course slates, not only of special shapes (polygonal, rounded, etc.), but also in rectangular …